By Diana Zuckerman, PhD, Brandel France de Bravo, MPH, Dana Casciotti, PhD, Megan Cole, MPH, Krista Brooks, BS, Hannah Kalvin
You’ve probably heard about news stories claiming that “cell phones are dangerous” and others claiming that “cell phones have been proven safe.” It’s hard to know what to believe-especially when we’ve grown so dependent upon these convenient communication devices.
Should We Be Worried?
Have you ever read the fine print in your cell phone manual? All manuals say not to hold the phone next to your ear, but how many of us actually talk on cell phones while holding them an inch away?
There have been concerns, from both scientists and the media, that cell phone usage is linked to tumor development. The extensive use of cell phones is a relatively recent phenomenon, and since cancers usually take at least 10-20 years to develop, it will be years before research is likely to conclude whether cell phones cause cancer or not. In addition, the long-term risks of cell phone use may be much higher for children than adults.
International organizations have been researching this issue. The International Agency for Research on Cancer (IARC), which is part of the World Health Organization (WHO), brought together scientists, including those with financial ties to cell phone companies, to review all relevant data on radiation from wireless handheld devices such as cell phones. This type of radiation is known as Radio Frequency-Electromagnetic Radiation (RF-EMR), also referred to as microwave radiation. The IARC concluded that the evidence suggests this radiation is “possibly carcinogenic to humans,” and that there wasn’t enough research evidence to conclude that cell phones are dangerous or that they are safe.1
This resulted in the IARC creating the Interphone Project, an international effort (that did not include the United States) to investigate the risk of tumors from cell phones. After the 10-year project was finished in February 2012, scientists found that due to biases present in the study, no strong conclusions could be made.2
The Centers for Disease Control and Prevention, or CDC, called for caution in cell phone use because of “the unresolved cancer question” in 2014. However, the CDC removed this statement from their website soon after.3 Critics assume it was removed because of political pressure from cell phone companies. Currently, the CDC says that more research is needed on this topic since “there is no scientific evidence that provides a definite answer.”4
What Does Research Tell Us About Cell Phones, Tumors And Other Health Issues?
In 2007, a published review of 18 studies of cell phones and brain tumors, concluded that studies of individuals using cell phones for more than 10 years “give a consistent pattern of an increased risk for acoustic neuroma and glioma,” with the risk being highest for a tumor on the same side of the head that the phone is used.5 Gliomas are the most common cancerous brain tumor, and most gliomas are malignant (and usually fatal). Acoustic neuromas are benign tumors of the acoustic nerve that can cause deafness. In 2012, the same authors reviewed even more studies and also conducted a meta-analysis that combined the results of all the studies. These analyses confirmed the 2007 conclusions about the increase in acoustic neuromas and gliomas.6 However, a study conducted in 2013 found that while long-term cell phone use was associated with acoustic neuromas, it did not predict gliomas.7 In contrast, a study of 1,339 cell phone users, published in 2014, found that the heaviest cell phone users had an increased chance of developing gliomas. These heaviest users, who had a total of over 900 hours of cell phone usage, were found to have spent an average of 54 minutes on the phone per day.8 Although the results of studies on the effects of cell phones are inconsistent, probably related to how the time spent on cell phones is increasing over time, there is a trend toward showing that cell phone usage is associated with brain tumors.
A 2015 study in Germany also identified a connection between cell phone radiation and tumor growth. Researchers found that in comparison to a known cancer-causing agent, weak cell phone signals were more likely to promote tumor growth. Although this study was carried out in mice, it implies that cell phone radiation may negatively affect human health more than previously thought and that limits for cell phone radiation need to be lower.9
Scientists in countries around the world have published their own results on other health problems that appear to be a result of increasing cell phone usage. the following health problems connected to cell phone radiation:
skin irritation, especially on the face (this is a condition known as electrohypersensitivity)18,19
behavioral problems and increased chance of cancer tumor development in children. You can read more about this here.
Meanwhile, cell phone companies continue to insist that the evidence shows that their cell phones are safe. Cell phone companies tend to draw conclusions based on the studies they funded themselves, and those studies have always found cell phones are safe. In addition, many of those studies were conducted years ago, when cell phone usage was much lower for the average person than it is today.
Controversies On Cell Phone Research Results
Underlying the controversy about cell phone radiation is the belief by most physicists that cell phone radiation could not possibly cause cancer. Although epidemiological research seems to suggest otherwise, that is undermined by other factors: cancer takes a very long time to develop, cell phone technology and frequency of usage has changed dramatically, and any link between cancer and cell phones could possibly be caused by unknown exposures or traits. Additionally, there is potential for biases and errors in the collection of data in these studies, which could result in inaccurate conclusions. For example, many researchers questioned the Interphone study because they thought that risk was underestimated. Research is needed to determine the true effect of cell phones on different cancers.
Different Types Of Studies: How Can Researchers Get To The Bottom Of This?
There is a consensus among researchers that retrospective studies present problems and that prospective studies are needed. Retrospective studies are ones that look back in time to study or measure risk, such as whether past cell phone use makes a person more likely to develop cancer or other health problems. But people may not remember their past behaviors accurately and researchers have no way to verify the information. Unless they use phone records, retrospective studies are also subject to “recall bias,” which means people with a disease might remember the past differently than people without a disease. In the case of cell phones, people with brain tumors may exaggerate their past cell phone use in an attempt to find an explanation for the inexplicable. An analysis published in 2015 shows that information used for many retrospective studies may not be reliable because numerous brain tumor cases are not reported to the Swedish Cancer Register, the database that has commonly been used to try to disprove any connection between cell phones and tumors.20
Prospective studies are ones that follow people over time and monitor the health problems that arise in the different groups during the study period. A prospective study of cell phone users would have to compare the health of infrequent users (controls) to heavy users (cases) but it is becoming increasingly difficult to find people who never use cell phones. In addition, any study started now would take at least 10 years to have useful information about the development of cancer; by that time, millions of people would have been harmed if cell phone radiation is dangerous.
Wireless technologies are proliferating daily, and different countries have different limits on radiation from wireless devices, which is why more and better designed research is urgently needed to determine safe levels of exposure. And yet, as noted above, it is increasingly difficult to design and conduct studies that will answer key questions anytime soon.
Precautions You Can Take
Scientists recognize that most people are not going to stop using cell phones. Since many studies suggest that there may be risks, experts recommend that cell phone users take some precautions:
Limit the number of calls you make.
Limit the length of your calls.
Use hands-free devices (wired cell phone headsets or wireless ones like Bluetooth).
If you are not using a hands-free device, put the cell on “speaker phone” or hold the phone away from your ear.
When speaking on your cell phone, alternate sides.
Avoid carrying your phone in your pocket, on your belt, or anywhere close to your body since cell phones emit radiation even when they are not in use
Limit your cell phone use in rural areas or in any place where reception is poor. More radiation is emitted when you are farther from a cell phone tower.
Text message instead of talking (never while driving!).
Check out how much radiation your phone emits by looking at its SAR (specific absorption rate), which is a measure of the amount of radiation absorbed by your body. When buying a new phone, try to select one with a lower SAR. A list of cell phones with the lowest SARs can be found here. But remember, these SARs are based on a six foot tall, 200 pound man with an 11 pound head, and the levels are higher for smaller people.
In summary, although not enough time has passed for research to agree on the exact impact of cell phones on brain tumors and other health risks, the evidence so far suggests that we should be cautious. While hands-free driving laws are resulting in greater use of ear pieces in cars, more and more people are opting not to pay for land lines and are relying exclusively on their cell phone. As a result, adults and children are holding cell phones to theirs ears for hours each day.
Should we be concerned? Remember that most published studies evaluated relatively infrequent cell phone usage and that research is inadequate to draw conclusions regarding safety. The health impact of the long-term and frequent use of cell phones that is typical today could be substantially worse. And, if there is a cancer risk, we won’t see the effects of cell phone use on cancer rates for another 10-20 years. That is why it is important that researchers who do not have financial ties to cell phone companies continue long-term studies with more appropriate measures of high, medium, and low cell phone usage. In the meantime, you can play it safe and limit your cell phone use.
By Diana Zuckerman, PhD, Paul Brown, Laura Walls, and Anna E. Mazzucco, PhD
Bisphenol A (BPA) is a chemical used to make plastics. It is widely used in sports equipment, water bottles, medical devices, and as a coating in food and beverage cans. The Centers for Disease Control and Prevention found measurable amounts of BPA in the bodies of more than 90 percent of the U.S. population studied.21 The highest estimated daily intakes of BPA occur in infants and children.22
BPA is more likely to leach out of plastic when its temperature is increased, as when one warms up food in the microwave or warms up a baby bottle.2 In 2012, the Food and Drug Administration (FDA) banned the use of BPA in baby bottles—after several large manufacturers had already voluntarily removed it. Before the ban, most plastic baby bottles contained BPA.
How BPA affects our bodies
BPA mimics and interferes with the action of estrogen–a hormone that helps us develop when we’re young and eventually reproduce.23 BPA has been widely detected in blood, urine, amniotic fluid and breast milk, and has been found in nearly all adults and children who have been tested 24 For that reason, scientists are concerned about BPA’s effects on fetuses, infants, and children at current exposure levels, and whether it can affect the prostate, brain, testicles, breasts, and behavior.2 Studies suggest that the more a baby is exposed to estrogen while in the womb, the greater the risk of breast, testicular and prostate cancer later in life.25,26,27
BPA’s effects on Animals and Human Cells
A study published in October 2008 also found that cancer cells exposed to low levels of BPA were more resistant to chemotherapy.28 Studies have also linked the hormonal effects of BPA from canned cat food to the epidemic of hyperthyroidism in cats, especially females.29 After studies of rats and mice linked BPA to hyperactivity and brain activity, the first study of nonhuman primates found that BPA levels were associated with cognitive problems that could affect learning and memory.30 BPA experiments on rats linked the chemical to precancerous lesions in the prostate and mammary glands, and to early puberty in females at BPA dosages similar to human exposures, according to a 2008 report on BPA by the National Institutes of Health’s National Toxicology Program.2 A 2014 study that used mice to model prostate cancer in humans showed that a baby’s BPA exposure in the womb may increase risk of prostate cancer later in life 31 Another similar study in mice is creating concern about liver cancer risks as well.32 While early concerns were based primarily on animal studies and research on cells, there is increasing evidence from human studies that BPA causes serious harm. For instance, researchers have discovered possible links between BPA exposure and insulin resistance (a risk factor for Type II diabetes), increased formation and growth of fat cells (which can lead to obesity), and reproductive health problems for both men and women.4
The evidence so far is based on links scientists have observed between high levels in the body and health problems. Studies in which some people are intentionally exposed to BPA and others aren’t (randomized, controlled trials) have never been done because it could be dangerous and therefore is unethical.
Health Effects in Girls and Women
There is concern about the impact of BPA on early puberty in girls. Studies have also linked BPA to frequent miscarriages.4
In addition, several studies have found a connection between high levels of BPA and decreased fertility in women, including less success with in vitro fertilization treatments.33
Health Effects in Boys and Men
A 2009 research article reported that men who were exposed to very high levels of BPA at work had less sexual desire and were four times as likely to have problems getting and maintaining an erection than men who did not work with BPA.34 BPA-exposed workers were also seven times as likely to have problems with ejaculation. Although the men in this study had much higher levels of BPA exposure than the average man, this study demonstrates that BPA can harm men’s sexual health and that workers need to be protected. Research is needed to study the effects of more typical BPA exposures on men’s sexual health. Unfortunately, several other studies have also linked high BPA levels to poorer sperm quality in men as well.35
Earlier Responses to BPA Concerns
The National Toxicology Program 2008 report recommended that more studies be conducted on BPA’s health effects on humans, and the report stated: “The possibility that bisphenol A may alter human development cannot be dismissed.”2
Also in 2008, based primarily on two chemical industry-funded studies, the Food and Drug Administration (FDA) claimed that BPA is safe.3 However, according to a publication of the American Chemical Society, the national professional association for chemists, 153 government-funded BPA experiments on lab animals and tissues found adverse effects while only 14 did not.1
After the 2008 National Toxicology report and FDA report, new studies of humans added greatly to concerns about the health risks of BPA.
In the fall of 2008, a major study was published in the Journal of the American Medical Association indicating that adults with higher levels of BPA in their bodies were more likely to be diagnosed with diabetes or heart disease.36 Adults with higher BPA were also more likely to be obese, but diabetes and heart disease were correlated with BPA levels even when obesity was statistically controlled.
Is it possible that BPA is contributing to the obesity epidemic and diabetes epidemic among children and adults? Wouldn’t it be ironic if the most popular water bottles for athletes contributed to obesity and diabetes?
Even before these more recent studies, the FDA Science Board, which consists of independent scientists who do not work for the FDA, disagreed with the FDA’s safety claims. The Science Board recommended in October 2008 that the FDA analyze the research literature again, relying less on the two industry-funded studies and taking into account the best independent studies. It also recommended that new research be conducted to examine BPA safety concerns. Government funding for that research was announced in late 2009.
What has actually been done to limit the potentially harmful effects of BPA?
In July 2013, the FDA responded to a petition from Representative Markey and comments from consumer groups by banning the use of BPA in packaging for infant formula, following on their 2012 ban of BPA from baby bottles. But further action from FDA to eliminate BPA from cans and other food containers still has not happened. Prior to the FDA ban, bills had been introduced in several states, cities, and in the U.S. Senate and House of Representatives (S. 593/H.R. 1523) to ban BPA in children’s products. Suffolk County in New York became the first in the U.S. to ban BPA in baby bottles and sippy cups, in March, 2009. In March 2009, the six major manufacturers of baby bottles in the United States announced that they would no longer sell baby bottles made with BPA in the U.S.37 A few days later, SUNOCO, a BPA manufacturer, announced that it would require customers to confirm that no BPA would be used in food or water containers for children under 3 years of age.38 In 2008, manufacturers such as Playtex and Nalgene and retailers such as Wal-Mart pledged to remove BPA from their products and stores by the end of the year.39
Despite these efforts, BPA still remains in many canned food and beverages sold to people and pets in the U.S. and other countries. But at least two producers of canned foods in the U.S. have BPA-free cans: Eden Foods began using BPA-free cans in 1999 and now uses BFA-free cans for everything except highly acidic tomato products, and Vital Choice introduced new cans and pouches for its fish products at the end of 2008.40,41 According to Eden, it costs the company $300,000 more a year to produce BPA-free cans, which are 14% more expensive than industry standard cans; this translates into about 2 cents more per can.42 In 2012, Campbell’s also announced that it would phase out BPA from its canned foods, although this has not yet happened.
What you can do to lower your family’s exposure to BPA
While we wait for more research to be conducted, you may want to avoid BPA. Is that possible? A 2011 study from the Silent Spring Institute showed that you can lower your BPA levels significantly by avoiding pre-packaged food and keeping your food from coming into contact with plastic containers, plastic utensils, and non-stick pans during preparation, eating and storage.43
BPA is found in polycarbonate (PC) plastics, which are typically clear and hard, marked with the recycle symbol “7″ or may contain the letters “PC” near the recycle symbol.
To avoid warming up food in plastic containers with these or other chemicals, use stoneware, china, or glass dishes and containers in your microwave. In 2012, the FDA banned BPA in baby bottles and children’s drinking cups, after several large manufacturers had already voluntarily removed it. However, bottles from before 2012 may still contain BPA. Another problem is that manufacturers are replacing BPA in plastic bottles with other chemicals that experts believe have many of the same effects as BPA but that we know even less about. For that reason, parents may want to include safer alternatives such as glass baby bottles, particularly for use at home.
When most people think of radiation, they think of manufactured devices such as the nuclear bomb or cancer treatments, which emit high doses of radiation. In reality, however, radiation takes many forms and is always around us. Some types are much more dangerous than others.44,45
Most researchers agree that there is no such thing as a dose of ionizing radiation that is so low that it will not have some effect on our body, such as damaging cells. Usually, the damage is small enough that one dose does not lead to any health problems. It is likely that the increased risk of cancer from low doses of radiation is so low that studies in the general population can’t detect it.46,47
It is important to note that each exposure to radiation builds up in our body and the risk of cancer increases with each radiation exposure. So even though a single source of exposure to radiation is unlikely to cause cancer by itself, the combined exposures add up throughout our lifetime and increase our risk of cancer over time.48 This is why it is important to limit unnecessary exposures to radiation. Radiation exposure during certain sensitive times of development, such as during childhood and puberty, also has more health risks than the same exposures in adults.49,50
Since radiation is always around us, we cannot avoid all radiation, but we can try to limit our exposures. This article will explain the various risks associated with different sources of radiation and how you can avoid getting too much exposure to radiation.
Background radiation refers to radiation that naturally occurs in our environment and does not come from any manufactured devices. Radiation is emitted from the earth, sun, our galaxy, and other galaxies. Even the human body naturally contains some radioactive elements.51People who receive few or no high-dose radiation medical tests usually get more exposure to radiation from the natural environment than from any manufactured device.52
This is because we are constantly exposed to a very low dose radiation for our whole lives, while devices such as x-ray tests expose you to radiation for a very short period of time. On the other hand, one CT scan can be equal to several years of background radiation exposures, so many people receive much higher doses of radiation from medical devices than they do from the natural environment.
The risk of developing cancer from a lifetime exposure of background radiation is about 1 in 100, or 1% of the population.53It is impossible to avoid all background radiation, but the best ways to limit unnecessary exposure to radiation from the environment is to prevent your exposure to radon and repeated unprotected sun exposure.
Radon is a color
less, odorless gas that comes from decaying rocks and soil. For the average person, radon accounts for over half their annual exposure to radiation. Radon comes up from the ground and gets trapped in houses and buildings.
Exposure to a small amount of radon inside is normal, but high levels can cause lung cancer. Radon is the second leading cause of lung cancer (smoking is the leading cause), and approximately 1 in every 15 houses have too much radon. The only way to know if you have a safe level of radon in your house is to get it tested.54
Cosmic and terrestrial radiation
Cosmic and terrestrial radiation is radiation that comes from the galaxy and from the earth. It makes up about 8% of our average yearly exposure to radiation.55 Cosmic radiation includes ultraviolet (UV) rays from the sun that cause tans and sunburns. UV rays can also damage the DNA in our skin cells and lead to skin cancer.56 Although we cannot avoid UV rays all the time, limiting exposure to direct sun light can reduce your risk of skin cancer. Tanning beds are also a common source of UV radiation and are just as dangerous as radiation from the sun. For more information on tanning beds, please read: Tanning Beds: Safe Alternative to Sun?
Being at higher altitudes, such as flying on a plane or living in a “mile high” location, will exposure you to higher levels of cosmic radiation than being at sea level. While there is technically no “safe” dose of ionizing radiation, the chances of getting cancer from frequent plane trips is very slim. Studies of airline crew members have not found a significant increase in risk of cancer after many years of working on airplane.57
In addition, living in Denver or other high altitude locations that receive higher doses of cosmic radiation has not been shown to increase the risk of cancer.58
How to Reduce Radiation Exposure from the Environment
Radon: Test the level of radon inside your house to make sure it is not too high. You can hire a professional to do this or you can purchase a “do-it-yourself” radon testing kit. It generally takes only a few minutes and is easy to do. If there is too high a level of radon in your house, people usually install an active soil depressurization (ASD) system, which is basically a ventilation system.2
UV Radiation: Some of the best ways to reduce your exposure to harmful UV rays are to:
Wear sunscreen (at least SPF 15) year-round in all areas of your body that are exposed to the sun. (However, it is good to get vitamin D from the sun for 15 minutes each day.)
Stay in the shade, especially when the sun is at it’s strongest (between 10am and 4pm)
Wear protective clothing, such as broad-brimmed hats and tightly-woven clothes that cover your hands and legs.
X-rays use ionizing radiation and are used for many types of diagnostic tests such as CT scans, mammograms, fluoroscopy, and simple x-rays. These tests allow your doctor to see potential problems inside your body and choose an appropriate treatment. They can help doctors make life-saving decisions, but some doctors are performing unnecessary scans or are using doses of radiation that are too high.59 Since x-rays use ionizing radiation, they can cause damage to our cells and DNA. X-ray tests can lead to cancer, but several common tests (such as mammograms and bone x-rays) use very low doses that have not been shown to cause a significant increased risk of cancer when administered properly.
Over the past few decades, the average level of radiation that Americans are exposed to has increased rapidly due to increased use of medical diagnostic tests such as x-rays (including dental x-rays and mammograms) and CT scans and cancer treatments. Diagnostic tests and treatments can help improve patients’ quality and length of life, but there are also risks. Usually, the benefit of receiving one of these tests outweighs the risk, but patients and doctors need to be wary of performing unnecessary tests, particularly if the test uses high doses of radiation.
Not all imaging tests use radiation that has been linked to cancer. Magnetic Resonance Imaging (MRIs) and ultrasounds do not use x-rays. Instead, they use non-ionizing radiation and have not been found to increase the risk of cancer or other health problems.60
MRIs and Ultrasounds are a safer alternative to diagnostics tests that use x-rays or other ionizing radiation.
Children, young adults, and fetuses of pregnant women should be particularly careful about getting any x-ray tests. Children, young adults, and fetuses are more sensitive to radiation, and their young age also allows a longer period of time for cancer to develop.61,62,63
Pregnant women should avoid any x-ray exposure, particularly when they are less than 20 weeks pregnant, since radiation exposure in the womb can lead to mental retardation, growth retardation, leukemia, and other cancers later in life.64 If it is necessary for a pregnant women to be x-rayed, the American College of Obstetricians and Gynecologists states a single x-ray test does not harm the fetus, but a protective lead apron should be used to cover the abdomen.65 However, high-dose, multiple-dose, or x-rays of the pelvic region should be avoided for pregnant women, whenever possible.
Many people get simple x-ray tests, such as an arm, leg, chest, or dental x-ray that look for broken bones or other problems. Simple x-ray tests use very low doses of radiation,66and studies have not found an increase risk of cancer among humans who have received a very low dose of radiation.67 Although the dose of radiation used to x-ray different parts of the body will vary, most simple x-rays use less radiation than other types of x-ray scans (such as a mammogram or CT scan).
While these doses of radiation could cause new cases of breast cancer, the appropriate use of mammograms has resulted in lives saved, and the benefits of getting regular mammograms are likely to be even greater than the risks when the frequency of mammograms is reduced to every other year.
Women who are carriers of the BRCA genetic mutation were previously recommended to begin yearly mammograms at age 25-30, since this mutation puts them at much higher risk of getting breast cancer. Newer studies have found that starting yearly mammograms before age 35 has no benefit to these women and may instead be harmful. They end up with higher exposure to radiation over their lifetime, which increases the chance of getting radiation-induced breast cancer that they may not have gotten otherwise.69
Fluoroscopyis an x-ray test that allows doctors to see a continuous x-ray image of your body (like a movie, rather than just a picture as with other x-ray tests). Fluoroscopy uses an x-ray absorbing dye that is either drunk or injected into the body, which allows doctors to see a better outline of the organ. This procedure is used to view the digestive system (such as stomach, kidneys, or colon), arteries, or joints.70
Since this test sends x-ray beams over an extended period of time (usually 20-60 minutes),71 it exposes people to much higher doses of radiation than a simple x-ray test, although the doses vary widely depending on the test.
Fluoroscopy and CT scans both use high doses of radiation and pose the greatest and most avoidable risk of radiation-induced cancer. Limiting the number of CT and fluoroscopy tests you receive is one of the best ways you can avoid getting cancer from radiation. In addition to increasing cancer risk, this test can damage the skin and cause burns.72
Computed Tomographic (CT) scans
CT Scans are a relatively new type of diagnostic imaging technology that allows doctors to view 3-dimentional pictures of various organs in your body. CT scans use higher doses of radiation than most other types of diagnostic test and are likely to cause new cancers in some patients, compared to their risk if they had not received a CT scan.
Today, an American’s average lifetime dose of radiation from diagnostic procedures is six times higher than it was in the 1980s.73 This is largely due to the increased use of CT scans. Everyday, 19,500 CT scans are performed in the U.S. and this number continues to climb. Each CT scan is equivalent to 30 – 442 chest x-rays, depending on the dose used for the CT scan.74 One study projected that CT scans performed in the U.S. in 2007 alone will result in 29,000 new cancer cases and roughly 15,000 deaths that would not have occurred if they had not received a CT scan.75 These risks would increase with each additional CT scan a person receives. Low-dose CT scans, which expose patients to less radiation, are now being used to screen for lung cancer, with concerns about whether the benefits outweigh the risks. For more information on low-dose CTs, click here.
Unfortunately, there is no established guideline for how much radiation should be used for each procedure. Different scans require different levels of radiation in order to get a clear image, but some doctors are using more radiation than is necessary. One study found that different medical facilities had huge variations in the dose of radiation used for the same procedure. On average, the highest dose given for a CT scan was 13 times higher than the lowest does given for the same type of scan.76 The researchers found no pattern in why this dose variation occurred, and no scientific justification.
Children’s exposure to radiation from CT scans is particularly worrisome because children have many more years to develop cancer than adults receiving CT scans and are more sensitive to the effects of radiation. A June 2012 study found that children receiving higher doses of radiation — through multiple CT scans– were more likely to develop brain tumors and leukemia than children who had only one CT scan.77 However, brain tumors and leukemia are very rare conditions and the increased risk due to CT scans was relatively small: for every 10,000 CT scans performed on children under 10 years-old, there will be one additional diagnosis of leukemia and one additional diagnosis of a brain tumor. The researchers concluded that the benefits of children having necessary CT scans outweighed the risks of later developing cancer.
A study published in May 2013 looked at children from infancy to 19 years of age in Australia and compared those who had undergone CT scans to those who had never had any.78 Ten years after getting scanned, there were 24% more cases of cancer among the 680,000 children and teenagers who had CT scans than among the 10 million children and teenagers who did not undergo CT scans. Young people who had CT scans during the 12-month period before being diagnosed with cancer were not counted because the decision to scan them may have had to do with cancer symptoms. Children 4 and under had the highest increased risk in cancer, and risk for all increased with the number of scans. The researchers concluded that for every 1,800 people under 20 who had a CT scan, there was 1 additional case of cancer that would not have occurred without the radiation from the CT scan. The CT scans in this study took place between 1985 and 2005 when radiation doses where generally higher than they are today.
Parents should make sure that CT scans ordered for their children are medically necessary and ask their doctors if lower-radiation alternatives exist. While parents should not stop their children from receiving a necessary CT scan because of radiation concerns, they should think about keeping the number of scans below age 20 to a minimum.
The FDA and investigative journalists have also released warnings about occurrence of extreme accidental overdoses of radiation from CT scans.79,80
In January 2010, the FDA reported that over 250 patients at 4 facilities had received as much as 8 times the amount of radiation that they were supposed to receive.81 Accidental radiation overdoses can result in skin redness, hair loss, increased risk of various cancers and cataracts in the future, and death. While extreme overdoses of radiation are rare, these avoidable mistakes have lead many health professionals to call for more standardized and comprehensive methods of overseeing medical radiation.82
PET scans differ from other types of diagnostic imaging in that they allow doctors to see how an organ or system is functioning rather than just seeing the structure. This test works in a very different way than other tests and does not use x-rays-rather, it uses gamma rays, which usually have a higher level of energy than x-rays.
PET scans work by injecting (or swallowing) small amounts of radioactive material, which then spreads throughout the body. The PET scanner is then used to detect the radiation that is emitting from the radioactive material in your body. Procedures that use radioactive material to diagnose and treat patients is referred to as “nuclear medicine.”83
The dose of radiation from a PET scan is similar to CT, and therefore exposes people to a relatively high dose of radiation in comparison to other types of scans.
Using Radiation to Treat Cancer:
Radiation therapy uses high doses of radiation to treat various types of cancers. Beams of radiation are directed at the cancer to kill off cancerous cells. This can save lives and prevent recurrence of cancer, but healthy cells that are exposed to radiation may develop into a new cancer. Fortunately, new cancers caused by radiation therapy are not thought to be very common since radiation technology can precisely irradiate a small part of the body that contains cancer, minimizing the amount of healthy cells that are exposed to radiation.84
Another concern about radiation therapy and diagnostic tests are errors in using this technology. Although relatively uncommon, some patients will accidently receive doses that are too high. In addition to being at increased risk of developing cancer in the future, the incorrect doses can cause serious wounds to the skin, bone, and other organs, as well as death.85,86
Between 1950 and 2006, the frequency of diagnostic radiation increased 10-fold.87 As health professionals continue to find new uses for medical devices that use radiation, people will be exposed to radiation more often. For example, many radiologists have recently started promoting the use of CT scans to screen for colon cancer (known as a virtual colonoscopy), although the FDA has not approved CT scans for this purpose.88
Although many patients would prefer this non-invasive procedure over the traditional direct examinations, it would expose people to high doses of radiation that is roughly equal to 100 chest x-rays (or 3 years of background radiation.89 This means more people are likely to be diagnosed with cancers that are caused by radiation than they would not have gotten otherwise.
Backscatter and millimeter scanners have begun replacing metal detectors and are designed to scan a person to determine what weapons or explosives they may have beneath their clothing. Currently, there are about 250 backscatter and 264 millimeter wave scanners in the United States. The TSA hopes to have 1,800 scanners of either type installed by the end of 2014 – which would mean that nearly every airport in the country will have one.
Backscatter scanners look like two large blue boxes:
People raise their arms and stand sideways between these two boxes when they are scanned.
In contrast, millimeter wave scanners look like circular glass phone booths, and the person being scanned stands with their arms raised while part of the scanner rotates around them:
If you are not sure which scanner is in use at your airport, ask a TSA official at the security checkpoint.
While metal detectors and millimeter scans both use non-ionizing radiation, which until recently was assumed to be safe (see our article Can Cell Phones Harm our Health?), backscatter scans use ionizing radiation, which is used in x-rays and known to potentially increase the risk of cancer. Backscatter scans work a little differently from x-rays. X-rays work by sending high-energy radiation to the body and recording the radiation that passes through the body. Dense parts of the body (like bones) block some of the radiation, resulting in lighter areas on the recorded image. Backscatter scanners also send radiation toward the body, but at much lower energy than an x-ray. Because it is not as strong as the radiation used in x-rays, the radiation does not pass through the body. Instead, the outer layers of the body “scatter” the radiation, which bounces off the body and back toward the machine. People receive most of the radiation that is absorbed by the body is deposited in the outer layers (like the skin and ribs), although a 2012 study showed that radiation from these scans may penetrate to other organs.90 Because the radiation is concentrated in the skin, there are concerns that this could cause skin cancer.
All data on backscatter scans are provided by TSA, a government agency that does not allow independent researchers to examine the machines they use.91 Researchers must therefore make educated guesses using data provided by the TSA, or they must make models of the scanners based on information that the agency releases.
The TSA states that backscatter scans use such low doses of radiation that estimating the potential effects of the scan is extremely difficult.92,93 A 2011 report using information from the TSA found that these backscatter scans expose people to the same amount of radiation that they receive from 3 to 9 minutes of normal daily life or from 1 to 3 minutes of flight.94 To put this into perspective, we would expect only 6 of the 100 million airline passengers each year to develop a cancer in their entire lives due to the backscatter scans.
Dr. David Brenner, a researcher at Columbia University, produced a different estimate based on the risk that the scanners are to the entire population, not just to an individual.95 Dr. Brenner multiplied the risk associated with one scan by the number of scans conducted each year to estimate the number of people who may develop cancer in one year because of the scanners. Because up to one billion scans may be performed each year, Brenner estimated that each year 100 people would develop cancer because of their exposure.
In April 2010, a group of scientists from the University of California, San Francisco wrote a letter of concern to Dr. John Holdren, the Assistant to President Obama for Science and Technology, about the backscatter scans. These researchers pointed out that because backscatter scans only penetrate outer layers of the body, it is possible that these layers receive a higher concentration of radiation than previously believed.
The scientists also expressed concern that sperm may mutate because the testicles are close to the surface of the skin and are exposed to radiation during these backscatter scans. In addition, they noted that the effects of radiation on the cornea (the outer surface of the eye) and the thymus (a part of the immune system located in the chest) have not been studied. While this letter only outlined concerns of the scientists and did not present new data, it called for further testing of backscatter scans. The scientists called for more rigorous and independent studies to ensure that the scans are safe for the entire population, as well as for all parts of the body.
In a joint reply with the TSA, the FDA stated that the radiation exposures from the backscatter scans were within established legal limits, even for frequent fliers.96 In reply to the scientists’ concerns that the radiation dose to the skin would be higher, the FDA wrote that their calculations showed that a person would have to pass through the scanner 1000 times in a year in order to begin to absorb the annual limit of what is considered safe.97
Not everyone agrees with the FDA, and some people have pointed out that TSA agents operating the scanners may improperly manage the devices or that mechanical errors may occur, either of which could cause the machines to emit more radiation than they are supposed to. From May 2010 to May 2011, there were 3,778 calls for mechanical problems on backscatter machines, but only 2% of those machines were evaluated for radiation safety.98
For a more in-depth look at airport security and radiation, read here.
Microwaves, Cell Phones, and Other Manufactured Devices
There is still much debate among scientists about whether non-ionizing (low-energy) radiation such as microwaves can increase your risk of cancer or other health problems. The concern is not about microwave ovens, but rather the long-term exposures to microwaves from other sources, such as communication towers and cell phones.99 Cell phones emit very low doses of microwave radiation, which was long assumed to be safe.
Although generally safer than ionizing radiation, the much longer-term exposure could make these products potentially dangerous. There are studies indicating that long-term exposures to low doses of non-ionizing radiation can damage DNA and may cause cancers and neurological and reproductive harm.100,101
Tobacco, fertilizer, welding rods, smoke detectors, and several other consumer products also contain some radiation, but radiation from these sources is generally very low (approximately 3% of our yearly radiation dose.
APPROXIMATE DOSE AND CANCER RISK OF VARIOUS RADIATION SOURCES: How does it compare to natural background radiation? What is the lifetime risk of cancer death from one exposure to this radiation source?
Type of Radiation (dose in mSv)†
Equivalent Period of Natural Background Radiation‡
Estimated Lifetime Risk of dying from cancer that results from a single exposure§
Airport Security x-ray scanner23(~0.0001mSv)
less than one hour
Almost (less than 1 in 100,000,000)
7 hour airplane flight9(~0.03 mSv)
a few days
Almost 0 (1 in 1,000,000 – 100,000)
Chest x-ray6(~0.1 mSv)
~ one week
Almost 0 (1 in 1,000,000 – 100,000)
Mammogram (~0.4 mSv)
a few months (~2 months)
1 in 100,000 to 10,000
CT of chest27(~7 mSv)
a few years (~2.3 years)
1 in 10,000 to 1,000
Fluoroscopy: colon (barium enema)27(~8 mSv)
a few years (~2.7 years)
1 in 10,000 to 1,000
CT of heart (angiography)27(~16 mSv)
a few years (~5.3 years)
1 in 10,000 to 1,000
PET scan, whole body5(~14 mSv)
a few years (~4.6 years)
1 in 10,000 to 1,000
Fluoroscopy: kidneys, ureters and bladder5(~15mSv)
a few years (~5 years)
1 in 10,000 to 1,000
Whole-body CT scan5(~22.5 mSv)
several years (~7.5 years)
1 in 1,000
Nuclear Medicine: Cardiac stress-rest test (thallium)27(~40.7mSv)
Lifetime risk of cancer death NOT caused by radiation§§
1 in 5
†Dose is based on a normal effective dose for that type of scan. Actual doses used for a specified scan vary widely depending on the medical institution, the individual, and other factors.102
‡Natural background radiation is equal to about 3mSv per year.103
§ Risk of developing cancer is based on EPA cancer risk estimates: “…health physicists currently estimate that overall, if each person in a group of 10,000 people exposed to 1 rem [10mSv] of ionizing radiation, in small doses over a life time, we would expect 5 or 6 more people to die of cancer than would otherwise.”
§§ “In this group of 10,000 people, we can expect about 2,000 to die of cancer from all non-radiation causes. The accumulated exposure to 1 rem [10 mSv] of radiation, would increase that number to about 2005 or 2006.”
All articles are reviewed and approved by Dr. Diana Zuckerman and other senior staff.
Fracking is in the news, but what is it exactly? Hydraulic fracturing or “fracking” has boomed in the last few years and is now producing most of the natural gas in the U.S. It is praised as helping the U.S. be more “energy independent” and has lowered the cost of natural gas. But, the controversy is whether it can harm our health, especially for people who live near the drilling sites, which are most common in Colorado, Texas, North Dakota, and Pennsylvania.
Fracking uses more than 750 chemicals, some of which are known to harm human health.104,105,106 But since fracking is a relatively new technology in the U.S., scientists are still trying to understand how fracking chemicals get into the air and drinking water in nearby areas.
Of the more than 750 chemicals used in fracking, more than 100 can affect our hormones. These chemicals are called endocrine-disrupting chemicals, and research published in 2011 shows that these chemicals can get into the water near fracking sites, where they could potentially cause infertility, diabetes, and cancer.107 This study in Colorado found higher levels of endocrine disrupting chemicals in water samples from areas with more drilling sites compared to areas with fewer sites. Many of the water samples were found to contain chemicals that either mimicked or blocked estrogen (a hormone that is high in females) or androgen (a hormone that is high in males). In fact, 89% of the samples taken near fracking sites had chemicals which increased estrogen, 41% had chemicals that blocked estrogen, 12% had chemicals that increased androgen, and 46% had chemicals that blocked androgens. In contrast, water from areas far from fracking rarely had chemicals that affect hormones. The researchers also found small increases in these chemicals in the Colorado River, probably from the fracking sites. This could spread the chemicals into a larger area.
What kind of impact could these chemicals have on human health? When children are exposed to high levels of hormones, this could cause early puberty in children, or abnormal sexual development in a fetus. Chemicals that block hormones could also affect sexual development or fertility. In adults, this exposure could increase the risk of infertility, obesity, diabetes, or certain types of cancer, such as breast cancer, testicular cancer, and vaginal cancer. Serious diseases, and especially cancer, can take years to develop, so it is important to study families in fracking areas carefully for many years to see what happens. Of course, meanwhile the families could be harmed if they are not protected from these chemicals in their water.
Two other reports have raised concern about fracking and the health of newborn babies. These reports provide evidence that mothers living near fracking sites are more likely to give birth to newborns who are underweight. One study found that babies were 25% more likely to have low birth weight if they were born to mothers living near fracking sites compared to babies born of mothers who didn’t live near one.108 A second study found that the chance of a low birth weight baby was more than 50% higher for babies born near fracking sites, compared to babies born to the same mothers in a location far from fracking.109 This study was presented at the annual meeting of the American Economic Association in January 2014. Neither of these two studies has been published yet.
To be more conclusive about the health risks of living near fracking sites, we need large public health studies that include information from medical records and residence history. Currently, most of the information we have is based on evidence of surface and ground water contamination from fracking sites.110,111
Meanwhile, several families and communities have already sued because of their concerns about health problems related to fracking, and the Environmental Protection Agency (EPA) and state agencies have investigated drinking water contamination in West Virginia, Pennsylvania, Wyoming and Texas. The EPA is currently working on a report on the potential impact of fracking on the U.S. water supply, with a draft expected late in 2014. Legislation to lower health risks due to fracking has been proposed in many states, including California and Illinois. In 2012, Vermont became the first and only state to ban fracking.
The U.S. Surgeon General just released an annual report on the negative health effects of smoking. But this one marks the 50th anniversary of the very first report on smoking in 1964. We’ve learned a lot about smoking in 50 years, and unfortunately most of the news is bad.
Many health problems in addition to Lung Cancer
While many people know that smoking comes with serious health risks, such as lung cancer and chronic obstructive pulmonary disease (COPD), the 50th anniversary report warns about less widely known risks. For example, smoking increases the risk of:
ectopic pregnancy (this type of pregnancy kills the fetus and the mother can also die or become infertile as a result)
difficulty getting or maintaining an erection (erectile dysfunction or ED).
Smoking also increases your chances of developing colorectal or liver cancer. If you have prostate cancer and smoke, the cancer is more likely to be aggressive and kill you.
Whether you’re a cancer patient, cancer survivor, or have no known health conditions, smoking puts you at greater risk of dying. Exposure to tobacco smoke while in the womb and smoking in the teenage years have both been shown to cause long-term problems regarding brain development.
20 Million people have died from smoking since 1964
Although smoking has decreased over the 50 years—from 52% to 25% of adult men, and from 35% to 19% of adult women—the decline has slowed over the last two decades. However, among adults who never completed high school or who have a GED diploma, almost 1 in 2 are smokers.[end Centers for Disease Control and Prevention. Current Cigarette Smoking Among Adults—United States, 2011. Morbidity and Mortality Weekly Report. 2012; 61(44):889–94 [accessed 2014 Feb 10] The report estimates that half a million Americans die from smoking every year, and this number has not changed in a decade. Smoking costs the U.S. economy about $100 billion per year, including direct medical costs and the indirect cost of lost productivity from employee sick time due to smoking-related illness.
The Surgeon General cautions that current efforts to reduce smoking are not getting as much support as they need. While many states have received substantial funds from settlements with tobacco companies which were intended for tobacco control programs, this funding is frequently been spent elsewhere. In 2013, Alaska was the only state to fund their tobacco control programs at the level recommended by the Centers for Disease Control and Prevention (CDC).
What more should be done to reduce smoking?
In 2009, the FDA was given much more authority to regulate tobacco products, and in 2010, it made it illegal to sell tobacco products to anyone under 18, banned free samples of cigarettes, and prohibited cigarette brands from sponsoring music and other cultural events. While making public spaces smoke-free and increasing the price of cigarettes and other tobacco products has helped, we need to do more. Most experts agree that effective tobacco control programs require a combination approach: public health campaigns supplemented by laws that limit where you can smoke, make cigarettes harder to buy, and ensure that programs to help people quit smoking are covered by all health plans. Under the Affordable Care Act, Medicare, Medicaid and employer-sponsored insurance plans are required to cover medications to help with quitting. Unfortunately, it is still unclear exactly what will be covered through the state insurance exchanges, even though they are subsidized through the federal government.
Of course, the ideal strategy is to prevent a person from starting to smoke, since tobacco is very addictive. The Surgeon General’s report says more advertising campaigns targeting young people with anti-smoking messages are needed, since 87% of adult smokers had their first cigarette by age 18. A study published in 2014 revealed that the nicotine dose from cigarettes increased 15% between 1999 and 2011, making them more addictive without any warning to consumers.[end Land T et al. Recent Increases in Efficiency in Cigarette Nicotine Delivery: Implications for Tobacco Control. Nicotine and Tobacco Research. 2014.] That is only one example of a long history of misleading information from tobacco companies, which is why anti-tobacco ads are so important. For example, the Surgeon General’s report details how “low-tar” cigarettes, advertised by tobacco companies as safer, were later found to be just as harmful. In addition, other changes in cigarette design and content have also had unexpected health effects, such as increasing rates of one of the two most common types of smoking-related lung cancer, adenocarcinoma.
Once a person starts to smoke, all doctors and health experts agree: quitting smoking is one of the best things you can do for your health and the health of your loved ones, no matter how long you’ve been smoking. Studies show that the health benefits of quitting kick in soon after you stop. Twenty minutes after your last cigarette your high blood pressure will drop; within 3 months your lung function will improve; one year later your risk of heart disease will fall to half of what it was when you were smoking; and five years after your last cigarette your risk of several cancers will drop by half as well.[end S. A. Kenfield, M. J. Stampfer, B. A. Rosner, G. A. Colditz. Smoking and Smoking Cessation in Relation to Mortality in Women. JAMA: The Journal of the American Medical Association, 2008; 299 (17): 2037-2047.],[end Centers for Disease Control and Prevention. 2010 Surgeon General’s Report—How Tobacco Smoke Causes Disease: The Biology and Behavioral Basis for Smoking-Attributable Disease. 2010.] For information on how to quit, see this article. If you are considering taking medication to help with quitting, check out this article. And if you are thinking of using e-cigarettes to cut back on regular cigarettes, you should know that there are many unanswered questions about the risks of e-cigarettes and almost no research to support their use in smoking cessation. For more on e-cigarettes, read here. Many e-cigarette brands are owned by tobacco companies which have been caught lying to the American public about the risks of their products repeatedly.
The Honorable Edward J. Markey
Energy and Commerce Committee
U.S. House of Representatives
Washington, DC 20515
Dear Congressman Markey,
As members of the Patient, Consumer, and Public Health Coalition, we thank you for your commitment to the health of patients and consumers by introducing the Verifying Authority and Legality in Drug (VALID) Compounding Act of 2012. This bill would strengthen FDA oversight of compounding pharmacies in several essential ways, and is clearly needed to prevent tragedies such as the contaminated steroid injections that have already resulted in 356 cases of fungal meningitis and 28 deaths.
The current laws and regulations regarding compounding pharmacies have resulted in giant loopholes that allow medical products that are neither safe nor effective to be sold throughout the country, putting patients’ lives at risk. We are very grateful to you for your leadership on this very important, life-saving bill.
The VALID Act would protect the activities of traditional small compounding pharmacies while ensuring that compounding pharmacies that are essentially operating as drug manufacturers are regulated by the FDA the same way as other drug manufacturers. It would require pharmacies that engage in interstate commerce to register with the FDA and comply with minimum safety standards. The bill would require compounding pharmacies to report deaths and other serious adverse events to the FDA in a timely manner, so that other patients would not be harmed. It would authorize the FDA to inspect pharmacy facilities, which is absolutely essential. It would also require a warning to patients that compounded drugs have not been approved safe and effective by the FDA.
We look forward to working with you on the VALID Act, and share your desire to make sure that waivers are available when the public health is at stake, but are not used to undermine the integrity of the legislation.
The scandal around the lack of oversight of compounding pharmacies has alarmed lawmakers on both sides of the aisle. We will make every effort to secure bipartisan support for this bill.
Cancer Prevention and Treatment Fund
Jacobs Institute for Women’s Health
National Consumers League
National Research Center for Women & Families
Our Bodies Ourselves
Union of Concerned Scientists
VALID Compounding Act will give FDA authority it needs to ensure the safety of the compounding pharmacy sector nationwide
Today, Congressman Edward J. Markey (D-Mass.) announced legislation he plans to introduce tomorrow that will strengthen federal regulations for compounding pharmacies. The New England Compounding Center (NECC), a compounding pharmacy located in Rep. Markey’s Congressional District, has been found to be the source of contaminated injectable steroids that have led to 28 deaths and 377 illnesses in 19 states. The Verifying Authority and Legality in Drug (VALID) Compounding Act will give the Food and Drug Administration (FDA) clear, new authority to oversee compounding pharmacy practices throughout the country.
“Compounding pharmacies have been governed by fragmented regulations for too long, leading to the worst public health disaster in recent memory,” said Rep. Markey, senior member of the Energy and Commerce Committee. “The VALID Compounding Act ends this regulatory black hole by giving the FDA new, clear authority to protect patients and oversee these companies. I look forward to working with my colleagues in Congress on a bipartisan basis to move this legislation forward.”
A copy of the VALID Compounding Act can be found HERE. A one-page description of the legislation can be found HERE.
The VALID Compounding Act will:
Preserve state regulatory authority for traditional small compounding pharmacy activities;
Ensure that compounding pharmacies that are operating as drug manufacturers are regulated by the FDA as drug manufacturers;
Allow compounding pharmacies with a legitimate reason to compound drugs before the receipt of a valid prescription to request a waiver to enable them to do so;
Allow the FDA to waive the requirement to compound drugs solely for individual patients with valid prescriptions in the event of a drug shortage or to protect public health;
Allow the FDA to waive the requirement to compound drugs only if they are not copies of commercially-available drugs if doing so is necessary to protect public health or well- being; and
Increases transparency to the public by mandating that compounded drugs be labeled to ensure that recipients know that the drugs have not been tested for safety or effectiveness, publishing a “Do Not Compound” list of unsafe or ineffective drugs, and reporting of bad reactions to compounded drugs or any drug that poses a safety risk.
“This bill will save lives by ensuring that compounding pharmacies play by the rules that are essential to protect patients,” said Diana Zuckerman, PhD, president of the Cancer Prevention and Treatment Fund. “This month’s tragic meningitis outbreak from contaminated steroid injections was absolutely preventable. We call on Congress to work in a bipartisan manner to pass Congressman Markey’s legislation, which is necessary to protect our families from these predictable, preventable tragedies.”
The legislation has been endorsed by Cancer Prevention and Treatment Fund, Jacobs Institute for Women’s Health, National Consumers League, National Research Center for Women & Families, Our Bodies Ourselves, and Union of Concerned Scientists. A copy of the endorsement letter can be found HERE.
Earlier this week, Rep. Markey released the report “Compounding Pharmacies, Compounding Risk”, which revealed that even before the current outbreak, problems at compounding pharmacies led to at least 23 deaths and 86 illnesses in 34 states, and that state regulatory bodies typically focus on more non-safety related traditional pharmacy licensing activities. A timeline of Rep. Markey’s work on compounding pharmacies can be found HERE.
Laura Covarrubias, Cancer Prevention and Treatment Fund
Following the September 11th attacks in 2001, the Transportation Security Administration (TSA) was created and given responsibility for protecting the public from security threats in transportation systems, such as airports. Although metal detectors were once the main security devices used at American airports, the TSA introduced new technologies after terror attempts were made using hidden explosives (in shoes and underwear, for example). These backscatter and millimeter scanners have begun replacing metal detectors and are designed to scan a person to determine what weapons or explosives they may have beneath their clothing. Currently, there are about 250 backscatter and 264 millimeter wave scanners in the United States. The TSA hopes to have 1,800 scanners of either type installed by the end of 2014 – which would mean that nearly every airport in the country will have one.
Backscatter scanners look like two large blue boxes. People raise their arms and stand sideways between these two boxes when they are scanned.
In contrast, millimeter wave scanners look like circular glass phone booths, and the person being scanned stands with their arms raised while part of the scanner rotates around them:
If you are not sure which scanner is in use at your airport, ask a TSA official at the security checkpoint.
When a millimeter scan is used, the machine determines if the person has any potentially harmful items on his or her body. If so, only the outline of a standard human body is shown with potentially dangerous objects highlighted in yellow. If no dangerous objects are detected, the security officer will only see an empty green screen. The security official does not see an image of the actual individual when the millimeter scan is used.
In contrast, when a backscatter scan is used, a blurred, colorless image of the individual (without clothing) is produced. A security officer views the image and determines if further screening is necessary. In an effort to increase passenger privacy, the TSA updated the software on backscatter machines to make it harder to see details in the images. Still, some people argue that both types of machines violate their privacy.
While metal detectors and millimeter scans both use non-ionizing radiation, which until recently was assumed to be safe (see our article Can Cell Phones Harm our Health?), backscatter scans use ionizing radiation, which is used in x-rays and known to potentially increase the risk of cancer. Backscatter scans work a little differently from x-rays. X-rays work by sending high-energy radiation to the body and recording the radiation that passes through the body. Dense parts of the body (like bones) block some of the radiation, resulting in lighter areas on the recorded image. Backscatter scanners also send radiation toward the body, but at much lower energy than an x-ray. Because it is not as strong as the radiation used in x-rays, the radiation does not pass through the body. Instead, the outer layers of the body “scatter” the radiation, which bounces off the body and back toward the machine. Most of the radiation that is absorbed by the body is deposited in the outer layers (like the skin and ribs), although a 2012 study showed that radiation from these scans may penetrate to other organs. Because the radiation is concentrated in the skin, there are concerns that this could cause skin cancer.
All data on backscatter scans are provided by TSA, a government agency that does not allow independent researchers to examine the machines they use. Researchers must therefore make educated guesses using data provided by the TSA, or they must make models of the scanners based on information that the agency releases.
Scientists differ in their opinions regarding whether small doses of radiation increases the risk of cancer. Some scientists think that very small doses-like those received during backscatter scans-pose zero risk to the individual. Other scientists think that there isn’t enough research on the effects of such low doses of radiation to be able to say how it will affect a person’s cancer risk. However, radiation risk accumulates during a person’s lifetime. This means that even though a single exposure may be very small, it is “added” to every other exposure the person has ever encountered.
The TSA states that backscatter scans use such low doses of radiation that estimating the potential effects of the scan is extremely difficult. 2011 report using information from the TSA found that these backscatter scans expose people to the same amount of radiation that they receive from 3 to 9 minutes of normal daily life or from 1 to 3 minutes of flight. To put this into perspective, we would expect only 6 of the 100 million airline passengers each year to develop a cancer in their entire lives due to the backscatter scans.
Dr. David Brenner, a researcher at Columbia University, produced a different estimate based on the risk that the scanners are to the entire population, not just to an individual. Dr. Brenner multiplied the risk associated with one scan by the number of scans conducted each year to estimate the number of people who may develop cancer in one year because of the scanners. Because up to one billion scans may be performed each year, Brenner estimated that each year 100 people would develop cancer because of their exposure.
In April 2010, a group of scientists from the University of California, San Francisco wrote a letter of concern to Dr. John Holdren, the Assistant to President Obama for Science and Technology, about the backscatter scans. These researchers pointed out that because backscatter scans only penetrate outer layers of the body, it is possible that these layers receive a higher concentration of radiation than previously believed. Because of this, conventional estimates would be inaccurate. This higher concentration of radiation could pose particular risk to certain groups such as:
The elderly (due to their susceptibility to skin cancer)
Women who have the BRCA gene mutation
People with weakened immune systems (such as those with HIV or cancer)
Children and adolescents (who have smaller bodies but receive the same amount of radiation as adults with larger bodies)5
The scientists also expressed concern that sperm may mutate because the testicles are close to the surface of the skin and are exposed to radiation during these backscatter scans. In addition, they noted that the effects of radiation on the cornea (the outer surface of the eye) and the thymus (a part of the immune system located in the chest) have not been studied. While this letter only outlined concerns of the scientists and did not present new data, it called for further testing of backscatter scans. The scientists called for more rigorous and independent studies to ensure that the scans are safe for the entire population, as well as for all parts of the body. When Dr. Holdren received the letter, he sent it along to the Food and Drug Administration (FDA). The Food and Drug Administration does not have authority to regulate backscatter scanners because the devices are classified as electronic devices, not medical devices. However, the FDA has experience in regulating radiation-emitting devices used in medicine, such as mammography devices. In a joint reply with the TSA, the FDA stated that the radiation exposures from the backscatter scans were within established legal limits, even for frequent fliers. In reply to the scientists’ concerns that the radiation dose to the skin would be higher, the FDA wrote that their calculations showed that a person would have to pass through the scanner 1000 times in a year in order to begin to absorb the annual limit of what is considered safe.
Not everyone agrees with the FDA, and some people have pointed out that TSA agents operating the scanners may improperly manage the devices or that mechanical errors may occur, either of which could cause the machines to emit more radiation than they are supposed to. From May 2010 to May 2011, there were 3,778 calls for mechanical problems on backscatter machines, but only 2% of those machines were evaluated for radiation safety. Anyone who is concerned about the radiation from the scanners has the legal right to refuse to undergo a scan, as long as they agree to a full-body pat-down by a security officer.
Brenner DJ. Are x-ray backscatter scanners safe for airport passenger screening? For most individuals, probably yes, but a billion scans per year raises long-term public health concerns. Radiology. 2011;259(1):6-10. Available at: http://www.ncbi.nlm.nih.gov/pubmed/21436091
Have you ever wondered if where you work could be harming your health? Now you can find out. The National Library of Medicine’s Environmental Health and Toxicology division has an online database that lets you see what hazards, if any, you are being exposed to. It’s called “Haz-Map,” and it links jobs with illnesses and injuries that have been reported. Haz-Map is the product of occupational health science, which studies workplace safety and is “devoted to the anticipation, recognition, evaluation, and control” of workplace conditions which may cause illness or injury.[end Industrial Hygiene. Occupational Safety & Health Administration. United States Department of Labor. Available at: http://www.osha.gov/dte/library/industrial_hygiene/industrial_hygiene.html.]
Haz-Map began in 1991 with about 700 chemicals. Over time, chemical and biological agents known to cause health problems were added. Currently, it covers about 6000 chemical and biological agents and 235 occupational diseases.[end Fact Sheet: Haz-Map. U.S. National Library of Medicine. National Institutes of Health. May 2011. Available at: http://www.nlm.nih.gov/pubs/factsheets/hazmap.html.] Information on the website is regularly updated as new research is conducted. The new Haz-Map design allows you to search by job, disease, chemical or biological agent, or even by symptom or medical problem: click here to see it.
Interested in learning about the risks associated with your job? Simply click on “High Risk Jobs” or “Industries,” and search alphabetically or by the type of job. Are you a bartender? It turns out that working with the limes and celery often used for cocktails can cause rashes, and working continuously with wet hands may result in inflammation near your fingernails. Haz-Map shows that exposure to secondhand smoke increases the risk of lung cancer (smoking is banned in bars and restaurants in many states, but not all). Hairdresser? Working with dyes and bleach can cause asthma-and so can wearing latex gloves! Law enforcement officer? Policeman and detectives can both at risk of heat-related illnesses, and the firing ammunition can increase the risk of lead poisoning. Physicians and other types of health care providers are exposed to many different risky pathogens by handling needles and caring for sick patients, but can lower those risks by taking proper precautions.
You can also search Haz-Map by disease to see what jobs are associated with certain illnesses. Leukemia, for example, is more prevalent among workers exposed to radiation (such as health professionals working with X-rays and people who work at nuclear power plants) and workers who are regularly exposed to benzene, such as painters, printing press operators, and gas station attendants (since benzene is used in inks, rubber, paint removers, and gasoline). Mesothelioma, a rare cancer with a poor prognosis, is usually caused by exposure to asbestos, which is less likely today but is still in old insulation, textiles, cement and roof shingles.
Facts and Figures
How many people are harmed by their job? The most recent data from the Bureau of Labor Statistics (from 2010) show that fatal and nonfatal workplace injuries and illnesses have decreased since the 1990s.[end Injuries, Illnesses, and Fatalities. Bureau of Labor Statistics. United States Department of Labor. 2012. Available at: http://www.bls.gov/iif/home.htm.] The reason might be because there have been many safety measures implemented to limit exposure to chemical, biological and physical dangers and minimize health risks in case of an emergency. However, a trend away from industrial jobs and more toward service and other “desk” jobs that don’t pose the same kinds of dangers may be another factor.
Fatal occupational injuries in 2010: 4,690 total
Sex: 4,322 men and 368 women died on the job
Age: more deaths occurred in the 45-54 age range (1,189) than any other
Race: 3363 fatalities among white men and women occurred, while 412 black people and 707 Hispanics died.
Occupation: Most of the deaths (1,160) occurred in transportation-related occupations, 780 to construction workers, 545 in management, 363 to workers performing installation, maintenance and repair
Event: 1,857 deaths were attributed to transportation accidents. Many of these were among individuals working in the transportation industry, such as truck drivers, but some worked in other occupations that involve transporting, such as drilling workers driving diesel trucks to drilling sites. Assaults and violent acts resulted in 832 workplace fatalities. Contact with objects and equipment caused 738 deaths, and 646 people fell to their death. A smaller number (414) died from exposures to harmful substances.
We have a long way to go but times have changed
In 1995, 6,275 fatal occupational injuries occurred-almost 2,000 more than in 2010. Of these, 605 were due to exposure to harmful substances, as compared to 414 in 2011. The rate of fatal work injuries per 100,000 workers decreased from 5 in 1995 to 3.6 in 2010. Instances of nonfatal injuries and illnesses also decreased significantly, from 8.1% of workers in 1995 to 3.8% in 2010.
Organizations that study and regulate workplace health and safety
All of the organizations below are devoted to the study and regulation of workplace hazards:
The American Conference of Governmental Industrial Hygienists, or ACGIH, is an independent organization that formed in 1938.[end About: History. American Conference of Governmental Industrial Hygienists. May 2012. Available at: http://www.acgih.org/about/history.htm.] Originally, the organization offered membership to industrial hygiene (also known as occupational health) professionals in the U.S. and all governmental industrial hygiene professionals in other countries. Today, all occupational and environmental health professionals in the U.S. and other countries around the world can obtain a membership. Nine ACGIH committees focus on different aspects of the field such as agricultural safety and health, small businesses, and limits for chemical substances.
Several decades later, under the Nixon Administration, the OSH (Occupational Safety and Health) Act was passed in 1970.[end Occupational Safety and Health Act of 1970. Occupational Safety and Health Administration. December 1970. Available at: http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=OSHACT&p_id=2743.] With this act, Congress established OSHA, the Occupational Safety and Health Administration. OSHA creates and enforces standards to ensure safe working conditions for Americans.
The OSH Act also created the National Institute of Occupational Safety and Health, or NIOSH, which focuses on performing research and making recommendations to reduce the likelihood of workplace injury and illness.
How much exposure is too much?
Both OSHA and ACGIH have set standards or regulations for exposure to workplace health hazards. ACGIH created the term “threshold limit value” or TLV.[end Policy Statement on the Uses of TLVs and BEIs. American Conference of Governmental Industrial Hygienists. February 2008. Available at: http://www.acgih.org/TLV/PolicyStmt.htm.] This is the amount of a chemical substance a worker can be exposed to daily for his or her entire career without experiencing health problems related to the chemical. The TLV is just a guideline or recommendation, so it cannot be legally enforced.
The permissible exposure limit (PEL), on the other hand, is a legal limit set by OSHA. Unlike a TLV, PELs are not based on daily exposure over an entire working lifetime. Rather, they are typically given as a time-weighted average (TWA), which is measured over the course of an 8-hour workday.[end Permissible Exposure Limits (PELs). Occupational Safety and Health Administration. United States Department of Labor. October 2006. Available at: http://www.osha.gov/SLTC/pel/.] Sometimes, a PEL is measured as a ceiling limit, which is the amount of chemical that should never be exceeded at any time. A short-term exposure limit (STEL) is the amount of chemical in the air averaged over 15 minutes. Why are there so many different standards? In most jobs, chemical concentration fluctuates significantly throughout the day, so it is best to assess chemical presence and hazards in several different ways.
There are many safety efforts that have been designed and implemented to protect workers from various dangers. For instance, construction workers often use hard hats, shoes that will guard their feet from heavy objects, and earplugs if they will be around loud noises. Doctors and other health care professionals wear antibacterial gloves, and they must wear masks to protect themselves around contagious patients, and to protect immune-compromised patients from the germs doctors may be carrying. For workers who come into contact with dangerous chemicals, rubber gloves and air respirators are used to reduce risk. It is better to focus on minimizing exposure to harmful substances or other dangerous situations than to use protective equipment, but these safety measures can save lives when there is no viable alternative.
The Haz-Map can be a useful tool if you are curious about potential hazards at your workplace or a loved one’s, or if you just want to know more about different chemical and biological agents and how people can be exposed to them. Explore the Haz-Map using the search function, or just browse by job, disease, or hazardous agent.
Bisphenol A (BPA) is a chemical used to make plastics. It is frequently used in sports equipment, water bottles, medical devices, as a coating or lining in food and beverage cans, and in credit card receipts. It leaches out of plastic into liquids and foods, and the Centers for Disease Control and Prevention found measurable amounts of BPA in the bodies of 93% of the U.S.population studied.
Infants and children are estimated to have the highest daily intake of BPA because “they eat, drink, and breathe more than adults on a pound for pound basis,” according to the U.S. National Toxicology Program. Until a few years ago, most plastic baby bottles contained BPA. The chemical is especially likely to leach out of plastic when it is heated, such as when a baby bottle is warmed in the microwave, thereby allowing the BPA to be ingested and enter the bloodstream. On any given day, several times a day, a baby might drink liquid formula that was sold in a can lined with BPA and then warmed in a plastic baby bottle containing BPA.
If BPA is in so many different items that we use every day, it must have been proven safe, right? Unfortunately not. BPA was developed as a synthetic estrogen, and it mimics and interferes with the action of that hormone, which helps regulate development and reproduction. It is called an “endocrine disruptor” because it affects the body’s own hormones (its endocrine system) in ways that could be potentially harmful.
It is difficult to determine just how much BPA, or how much of any hormone-disrupting chemical, is unsafe. Toxicologists test chemicals at very high doses in animals to see if they die or if their health is harmed. After establishing the dangerous dose, much lower doses are then allowed in products used or consumed by humans. These products are labeled safe, despite the fact that the chemicals in them have rarely been tested at low doses in animals, and were never tested in humans at all. Furthermore, recent research shows a paradoxical phenomenon with BPA and other chemicals that affect the endocrine system: their impact on health is sometimes greater at low doses than at high doses.
While early concerns about BPA’s health effects were based primarily on animal studies and research on cells, there is increasing evidence from studies in humans that BPA can cause serious harm, such as increased risk of heart disease, diabetes, obesity, sexual dysfunction, and behavior problems in children.[5,6,7,8,9]
Before studies were conducted on humans, dozens of studies were conducted and are still being conducted in the lab. The American Chemical Society, the national professional association for chemists, reported that 153 government-funded BPA experiments on lab animals and tissues found harmful effects while only 14 did not.
BPA experiments on rats linked the chemical to precancerous lesions in the prostate and mammary glands, and to early puberty in females at BPA dosages similar to human exposures, according to a 2008 report on BPA by the National Institutes of Health’s National Toxicology Program. Another study on rats showed that exposure to BPA, as well as exposure to fungicides and pesticides, appears to cause ovarian cysts and fewer eggs in offspring—as many as three generations down the line (a rat’s great “grandchildren”).
Studies of mice exposed to BPA in the womb found that these mice tended to put on more body fat after birth.[11,12] However, as adults the BPA-exposed mice were the same size and weight as mice that were not exposed to BPA in the womb. A more recent study, published in 2012, found that adult mice given low doses of BPA twice a day for eight days did not gain weight, but they did develop problems with their metabolism that would lead to type 2 diabetes.
Studies have linked the hormonal effects of BPA from canned cat food to the epidemic of hyperthyroidism in cats, especially females. Studies of rats and mice have linked BPA to hyperactivity and various brain and behavioral changes, including increased anxiety and impaired cognition.[15,16,17,18] In 2008, the first study of nonhuman primates found that BPA levels were associated with cognitive problems that could affect learning and memory.
The National Toxicology Program’s 2008 report recommended that more studies be conducted on BPA’s health effects on humans, and the report stated: “The possibility that bisphenol A may alter human development cannot be dismissed.”
Since 2008, studies of humans have added greatly to concerns about the health risks of BPA. A major study published in January 2010, based on a major government data set (the NHANES), found that adults with higher levels of BPA in their urine were more likely to have heart disease, even when other variables were statistically controlled. The NHANES data also showed a separate link between levels of BPA in urine and high blood pressure, a major contributor to heart disease. These findings were similar to a study published in the Journal of the American Medical Association in 2008, which found a link between BPA levels and diabetes and heart disease, even when obesity was statistically controlled. A study published in Circulation in 2012 based on research in the UK supported these findings. At least two other articles published in 2012 conclude that BPA exposure puts humans at risk for metabolic disorders and obesity. One of the articles (a review) focused on in utero exposure to BPA, which Dr. Frederick vom Saal and his co-authors say appears to program the fetus to develop into an overweight adult.
As a weak estrogen, BPA has been shown to cause pre-cancerous growths in the mammary glands of rodents, so an important question is whether it could increase a woman’s chances of developing breast cancer, since breast cancer can feed on estrogen. Laboratory studies where scientists look at cells taken from the body suggest that BPA may cause breast cells to change and become cancerous. Not only does regular BPA exposure potentially increase a woman’s chances of developing breast cancer, but it appears to also interfere with chemotherapy for breast cancer patients, possibly reducing its efficacy.[24,25]
There is also evidence of harm to fertility and sexual activity. In one stucy, men who were exposed to very high levels of BPA at work were four times as likely to experience erectile dysfunction and reduced sexual desire compared to men who did not work with BPA. BPA-exposed workers were also seven times as likely to have problems with ejaculation. Although the men in that study had much higher levels of BPA exposure than the average man, this study demonstrates BPA’s potential to harm men’s sexual and reproductive health at high levels and it raises questions about lower levels of exposure. Research is needed to study the effects of more typical BPA exposures (non-occupational exposures) on men’s sexual health.
BPA can also affect a woman’s fertility and has been linked to miscarriages. Studies have shown that women undergoing in vitro fertilization (IVF) who have higher levels of BPA have more difficulty becoming pregnant due to the lower quality of their eggs, fewer fertilized eggs, and reduced levels of estrogen.[28,29,30]
Recent research links prenatal and early childhood BPA exposure to mildly increased anxiety, depression, hyperactivity, and aggression in children.[31,32,33,34,35] However, the extent to which BPA seems to affect behaviors varies in different studies, potentially due to differences in how long the child was exposed to BPA, age of the child when exposed or when behavior was examined, the child’s sex, and family factors such as parents’ education levels. Better studies are needed to clarify to what extent BPA exposure affects behavior.
After a Food and Drug Administration (FDA) analysis concluded that BPA was safe in 2008, the FDA Science Board, which consists of independent scientists who do not work for the FDA, recommended in October 2008 that the FDA analyze the research literature again, relying less on two industry-funded studies of rats and taking into account the best independent studies. It also recommended that new research be conducted to examine BPA safety concerns.
Meanwhile, Canada announced in 2008 that it intended to reduce infant and newborn exposure to BPA by banning its use in baby bottles, setting stringent standards for the amount of BPA allowed to migrate from the can into infant formula, and working with industry to develop alternative food packaging. In October 2010, Canada became the first government in the world to add BPA to its list of toxic substances, in preparation for regulating its use. France and Denmark joined Canada in banning BPA from baby bottles in 2010, and the European Commission voted that same year to ban European Union countries from making and selling baby bottles with BPA, beginning in 2011. In December 2012, the French parliament voted to ban BPA from all baby food packaging in 2013 and from all food containers in 2015.
In January 2010, the FDA announced that its National Center for Toxicological Research in cooperation with the National Toxicology Program is “carrying out in-depth studies to answer key questions and clarify uncertainties about the risks of BPA.” The FDA said that it “shares the perspective of the National Toxicology Program that recent studies provide reason for some concern about the potential effects of BPA on the brain, behavior, and prostate gland of fetuses, infants and children.” The FDA also recognized “substantial uncertainties” with the interpretation of BPA studies and how BPA may affect human health. Despite those uncertainties, the FDA said it supported “a more robust regulatory framework for oversight of BPA to be able to respond quickly, if necessary, to protect the public.” However, the agency said at that time that it was “not recommending that families change the use of infant formula for foods, as the benefit of a stable source of good nutrition outweighs the potential risk of BPA exposure.”
In March 2012, the FDA finally responded to a 2008 petition from the Natural Resources Defense Council (NRDC). The petition had asked the FDA to ban BPA’s use in food and beverage packaging, based on the studies at the time. After ignoring NRDC’s petition for years, the FDA—under pressure of a law suit—responded that there was insufficient evidence to remove the chemical from the products in which it is currently being used, and that the Agency would continue to review studies of BPA. It is important to note that the FDA’s rejection of the petition was based on the studies that the NRDC had submitted with the petition in 2008, not on the more recent studies.
In March 2009, Suffolk County in New York became the first county in the U.S. to ban BPA in baby bottles and “sippy” cups, and in May of 2009, Chicago and Minnesota followed.[42,43,44] Also in 2009, Connecticut passed a law banning BPA in children’s reusable bottles and cups as well as infant formula and baby food containers, which went into effect in October 2012. Between 2009 and 2013, 12 states and the District of Columbia have passed bans on BPA in either infant formula containers or other food-related products for children. By July 2013, the industry had stopped using BPA-based packaging for infant formula. It was not until the industry had voluntarily stopped using BPA that the FDA amended its rules to prevent BPA from use in these packages.
Members of the U.S. Congress have introduced BPA-related legislation since 2009 without success. In the Spring of 2015, Senator Dianne Feinstein (D-CA) introduced a bill in the Senate (S. 821) that would require any food packaging that contains BPA to state “This food packaging contains BPA, an endocrine-disrupting chemical, according to the National Institutes of Health.” 
BPA is found in polycarbonate (PC) plastics, which are typically clear and hard, marked with the recycle symbol “7” or may contain the letters “PC” near the recycle symbol. To avoid the risks of baby bottles with BPA or other questionable chemicals, look for packages that say “BPA-free” and also consider alternatives such as glass bottles. And to avoid warming up food in plastic containers with these chemicals, use only stoneware, china, or glass dishes and containers in your microwave.
In 2008, manufacturers such as Playtex and Nalgene and retailers such as Wal-Mart pledged to remove BPA from their products and stores by the end of the year. In March 2009, the six major manufacturers of baby bottles in the United States announced that they would no longer sell baby bottles made with BPA in the U.S. A few days later, SUNOCO, a BPA manufacturer, announced that it would require companies using BPA in their products to confirm that none of those products would be used to hold food or water for children under 3 years of age. These voluntary efforts were a result of negative publicity and consumer concerns about BPA.
BPA is still in most canned food and beverages sold to people and pets in the U.S. and other countries. Some companies are not waiting for a ban and are voluntarily removing BPA from their food packaging. Eden Foods began using BPA-free cans in 1999 and now uses BPA-free cans for everything except highly acidic tomato products. According to Eden, it costs the company $300,000 more a year to produce BPA-free cans, which are 14% more expensive than industry standard cans; this translates into about 2 cents more per can. Vital Choice introduced new cans and pouches for its fish products at the end of 2008. In 2015, the Environmental Working Group released a market survey of the company reported use of BPA in their cans for 252 food brands. Of the 143 brands from which they were able to obtain information, 31 stated that they used only BPA-free cans (e.g. Health Valley and Tysons) and 78 used cans containing BPA for all products (e.g. Chef Boyardee, Green Giant, Hormel, and Ocean Spray). The rest used BPA-lined cans for some products but not others (e.g.,StarKist, Libby’s, and 365 Everyday Value).
In response to new laws, regulations, and consumer concerns about BPA, many products are being made with two new chemicals, bisphenol S (BPS) and bisphenol F (BPF). These chemicals were not well studied prior to use, however in the past few years they have been shown to have endocrine disrupting similar effects to BPA in laboratory tests. BPA alternatives also enter the human body just as easily as BPA. This new research suggests that substituting BPA with new compounds that have not been adequately tested for safety is unlikely to provide any health benefits. What is needed is to test the safety of potential BPA substitutes before they can be sold.
While we wait for more research to be conducted, is it possible to avoid BPA and substitutes that may be just as worrisome? A recent study suggests that we can significantly lower our levels of BPA by strictly avoiding many packaged foods and beverages and also changing how we prepare and store food.
In 2012, Ruthann Rudel from the Silent Spring Institute and her co-authors published a study showing how BPA levels in the body are affected by consuming foods and beverages that have come into contact with BPA. Twenty participants in 5 families switched from their normal diet, including canned and packaged items, to a diet consisting of only fresh, unprocessed foods for 3 days. Their BPA levels were tested before the switch, during the 3 days of BPA-free eating and drinking, and again after they had returned to their normal diet. The researchers found that BPA levels went down significantly when people ate foods and drank beverages that had never spent time in cans, plastic bottles, or plastic food storage containers made with BPA and had never come into contact with plastic or nonstick pans during preparation or while eating.
“NTP-CEHR Monograph on the Potential Human Reproductive and Developmental Effects of Bisphenol A.” National Toxicology Program. U.S. Department of Health and Human Services (HHS). Sept. 2008. Web.3 Apr. 2009.
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Ishido M, Masuo Y, Kunimoto M, Oka S, Morita M (2004) Bisphenol A Causes Hyperactivity In The Rat Concomitantly With Impairment Of Tyrosine Hydroxylase Immunoreactivity.” Journal of Neuroscience Research,76:423-433
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Leranth, C., Hajszan, T., Szigeti-Buck, K., Bober, J., and Maclusky, N.J. “Bisphenol A prevents the synaptogenic response to estradiol in hippocampus and prefrontal cortex of ovariectomized nonhuman primates.” Proceedings of the National Academy of Sciences of the United States of America. <em>PNAS,</em> 2008; 105(37): 14187-14191.
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Mok-Lin E, Ehrlich S, Williams PL, Petrozza J, Wright DL, Calafat AM, Ye X, Hauser R. “Urinary bisphenol A concentrations and ovarian response among women undergoing IVF.” Int J Androl. 2010 Apr;33(2):385-93.
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Jacqueline Britz, Cancer Prevention and Treatment Fund
Why have allergies and asthma risen so dramatically in recent years? From 1980 to 1994, asthma rates in the United States increased 75% overall, with rates increasing among individuals of all races, all age groups, and both sexes. An especially disturbing increase in allergies, approximately 160%, was found for children under five. About 70% of individuals with asthma also have allergies. These statistics are very troubling, especially as asthma results in about 217,000 emergency room visits each year.
Research indicates that some of the products we use to avoid germs, such as antibacterial soaps, hand sanitizers, and laundry detergents, may contribute to the development of conditions like asthma and allergies. According to the FDA, the hygiene hypothesis “suggests that the critical post-natal period of immune response is derailed by the extremely clean household environments often found in the developed world.” In other words, an environment that is “too clean” including the current Western diet, may not allow enough exposure for germs to adequately “educate” the developing immune system of a young child. The resulting “inadequate” defenses can play a part in the development of asthma or allergies.
A recent study may shed light on the hygiene hypothesis and how chemicals may influence immune function.
Impact of Environmental Toxicants on Allergies and Immune Function
According to a new study by Dr. Erin Rees Clayton and her colleagues at the University of Michigan School of Public Health, young people with overexposure to antibacterial soaps containing triclosan may be at greater risk for suffering from allergies. Further, overexposure to Bisphenol A (BPA) may weaken the immune system of adults.
Both of these chemicals belong to a class of toxicants known as endocrine-disrupting compounds. Often found in personal care and other consumer products, food, pharmaceuticals, and the environment, these compounds mimic or disrupt hormones. What is particularly troubling about BPA and triclosan is that they are in many products that children and adults are exposed to regularly. Triclosan is contained in antibacterial soaps, diaper bags, laundry detergents, toothpaste, pens, children’s toys, and medical devices. Many plastics, including those that line food and soft drink cans, contain BPA, in addition to other products, like dental sealants.
While previous studies have researched the influence of BPA and triclosan on animals’ immune function, the Rees Clayton study was the first to investigate this relationship in humans. The study used data from the 2003-2006 National Health and Nutrition Examination Survey (NHANES) and looked at the relationship between urinary levels of BPA and triclosan and markers of how well the immune system functioned. The markers used were the diagnoses of allergies or hayfever, and overall levels of a particular antibody in the blood called cytomegalovirus antibody.
The study included two age groups: participants over the age of 18 and participants between 6 and 18. Participants in the younger age group that had higher levels of triclosan were more likely to have been diagnosed with hayfever or allergies, which seems to support the hygiene hypothesis. While this same relationship was not seen with BPA, high levels of BPA exposure were associated with high antibody levels for those over age 18 (a sign of improper functioning of an immune response called the cell-mediated immune system).
The findings are interesting, but more research is needed to understand the link between allergies, hayfever, and triclosan.
Flu Infection may help Prevent Asthma
With a similar interest in germs and asthma, Dr. Ya-Jen Chang and her colleagues, published in the Journal of Clinical Investigation, studied how the flu virus may later help prevent asthma. In this study, active infectious flu agents were found to give mice protection against asthma only if the mice were exposed when they were young (2 weeks old). If the mice were exposed to flu when they were older, the exposure did not provide any protection against asthma. Researchers emphasized that this “influenza-induced protection” does not mean that we should expose people to dangerous infections in an effort to prevent asthma, but instead how this information may be helpful in the development of a new therapeutic strategy for treating asthma. One of the authors, Dale Umetsu, MD, PhD, a Professor of Pediatrics at Harvard Medical School, explains “If we can understand how infections prevent asthma, we may be able to replicate the good parts and avoid the bad parts of infection and develop new treatments for children to prevent asthma.”
To be Clean or Not to be Clean…
These research results don’t mean that exposure to germs is always good. Germs spread disease, and regular hand-washing and other good hygiene habits will help prevent the spread of those germs. Nonetheless, the data suggest that using too many antibacterials may contribute to asthma and allergies, and that it can be beneficial to avoid over-exposure to products containing BPA and triclosan. There are many greener triclosan-free products, including sanitizers and disinfectants like Burt’s Bees Aloe & Witch Hazel Hand Sanitizer,CleanWell, For My Kids, and Clean George. Some companies that provide canned food with BPA-free cans include Eden Foods and Vital Choice. While it is not realistic to avoid exposure to all chemicals, mindful consumers can reduce exposure to those thought to be particularly harmful.
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