Category Archives: Environmental Exposures

Home sweet home? Flame retardants in your home can harm you

By Abigail Fredenburg, PhD, Caitlin Kennedy, PhD, Anna Mazzucco, PhD
Updated 2016

Could your couch increase your chances of getting cancer? Possibly. Studies show that every day we are exposed to chemicals that were intended to protect us from household fires but are hazardous to our health.1 2 Toxic flame retardants are used in upholstered furniture such as couches, chairs, and mattresses, as well as in drapery and carpets. They are even in our televisions and plastic-cased electronics. Flame retardants have also been found in foam in baby products such as baby carriers, high chairs, strollers, and nursing pillows.3

Who invited cancer-causing chemicals into our homes?

At one time, It made sense to require flame retardants that would prevent or slow the spread of fire, but we now know those same chemicals can cause cancer. They also can affect children’s growth and brain development.

Dr. Linda Birnbaum, the director of the National Institute of Environmental Health Services, explains that new research used 3-D imaging to demonstrate how synthetic flame retardants “interfere with the body’s natural hormones.”4 When chemicals affect adult hormone levels, they can be very harmful, such as reducing fertility or harming a developing fetus.

Other research shows how this can affect children’s learning. University of Cincinnati’s Dr. Aimin Chen and colleagues studied pregnant women and their children to determine the effect of prenatal exposure on learning and behavior. The researchers measured the amount of common flame retardants in 301 pregnant women at 16 weeks of pregnancy and tested their children during their first 5 years of life. Pregnant women with higher levels of flame retardants had children who tended to have more learning problems at ages 2, 3, 4, and 5 years, and the children also were more likely to be hyperactive.5

Another important way that young children are exposed to flame retardant chemicals is through their crib mattresses. The volatile organic compounds (VOCs) in crib mattresses come from the foam stuffing, usually made of polyurethane or polyester. Studies from the last ten years suggest that exposure to these chemicals increases the risk of asthma and lung infections in young children.6 7 A study from 2014 revealed that infants may be at greater risk from the chemicals in crib mattresses than adults for several reasons: their small size means there is less distance between a baby’s body and the mattress, and babies generate more body heat while sleeping which causes more chemicals to be released into the air that they breathe. Also, babies sleep more hours a day than adults do, lengthening the time they are exposed to the mattress chemicals.8

These findings have important implications for children’s health and are why previous flame retardants, such as brominated “Tris,”were banned from use in children’s pajamas in the late 1970s and chemicals called PentaBDE and OctaBDE were phased out of commercial products, beginning in 2004.9 10 Despite these laws, we are still exposed to these and even more harmful chemicals. Why? Because banned chemicals are replaced by new chemicals that we don’t yet know much about. As shown in recent studies, these new chemicals can also be dangerous, and in some cases may be more dangerous. Researchers found higher-than-expected levels of one such chemical, organophosphate esters, in the outdoor air in 5 sites around the U.S. Great Lakes. This new chemical was found in amounts 100 to 1,000 times higher than older PBDE’s.11

Even after flame retardants are phased out, we keep getting exposed when we use old furniture passed on to family members, or sold at garage sales. Because there is no standard process to safely dispose of furniture containing flame retardants, these chemicals remain in our environment via discarded furniture, dust, and air.2 Flame retardant chemicals can even be measured in tree bark. Research shows the highest levels are in densely populated areas, such as Toronto, Canada, but high levels are also found in remote regions of Indonesia and Nepal.12

Researchers at Duke University led a national study to identify flame retardant chemicals in the polyurethane foam used in couches. TDCPP was the most commonly detected flame retardant, often used to replace PentaBDE and OctaBDE in couches manufactured after their 2004 phase out. TDCPPcan cause cancer and is very similar to the Tris that was banned decades ago. Of the 102 couches tested, researchers detected toxic flame retardants in 85% of them.13

In a second study conducted by the Silent Spring Institute, dust samples were collected from 16 homes in California. House dust is the primary way Americans are exposed to toxic flame retardants, by inhaling and ingesting them.1 Researchers found Tris in 75% of the homes despite its ban from children’s pajamas more than 30 years ago and its listing in California as a chemical known to cause cancer.

California has a higher furniture flammability standard than other states, known as Technical Bulletin 117 (TB117). Because of its large size, it is often easier for companies to follow California’s standards for all their products, not just those sold in California. Manufacturers also make their products comply with TB117 to protect themselves against law suits.14 But, as a result, they are risking consumers’ health by exposing Americans to higher levels of flame retardants in their homes than they would otherwise be.15

In general, California’s stricter standards (on organic foods and on air quality, for instance) have paved the way for protections across the country, but in the case of flame retardants, their standards have been harmful.

We all depend on government regulators to keep us as safe as possible, by making our homes, cars, airplanes, foods, and medicines as safe as possible. Unfortunately, current standards for flame retardant furniture are not based on solid research.16 Fortunately, California has responded to criticisms of their standards by adopting new guidelines in November 2013 based on the latest research. The new guidelines require upholstery and fabric covers to be smolder proof, a new test that simulates fires from a lit cigarette. The changes are meant to more accurately reflect the situations that usually lead to fires in homes, and make it possible for manufacturers to use lower amounts of less toxic chemicals. As a consequence, manufacturers will use different, and presumably safer, flame retardants for products sold in California and across the country. The changes went into effect in January 2015.17 18

Since many of us can’t buy all new furniture to help reduce exposure to these toxic chemicals, we need to try to keep our homes as dust free as possible. Remember, as these flame retardants are released or shed from upholstered furniture and other household products, they accumulate in house dust. Vacuum regularly, use a wet-mop, and wash your hands frequently. Have young children who spend a lot of time on the floor wash their hands regularly, too.

If you are thinking of buying a new mattress or furniture, the Green Science Policy Institute provides a reference guide for furniture made without added flame retardants.19 There are now also many “green” furniture companies that use all natural and non-toxic materials like wool and organic cotton that are not only better for you and your family, but also for the environment. In 2015, Ikea, Wal-Mart Stores Inc., Ashley Furniture industries Inc. and Macy’s Inc. stated they would ban flame retardants from all their furniture, although it is not clear when the bans would be in place.20 21 Keep in mind that not all furniture comes with a tag outlining what it is made from. You may want to check online to find out more before you buy furniture that could expose yourself and your loved one to chemicals for years to come.

The bottom line is that reducing dust in your home, maintaining or replacing old furniture and making careful decisions about new purchases are important steps for keeping a healthy home!

Children and Cell Phones: Is Phone Radiation Risky for Kids?

Hannah Kalvin

Children use cell phones to watch TV, play games, make phone calls, and send text
messages.  Many older kids and teens have their own cell phones, which they are attached to kid texting24/7. But are there risks to such frequent use by children, and if so is that different than the risks for adults?

Cell phones emit a type of radiation that is known as Radio Frequency-Electromagnetic Radiation (RF-EMR), also referred to as microwave radiation. There have been concerns from the scientific community about whether or not cell phones are safe. Cancer is a particular concern, but since cancers take 10-20 years to develop and children’s frequent cell phone use is a relatively recent development, there are more questions than answers.  To read more about whether we should be worried about cell phone radiation in general, read our article here.

There are several studies of the impact of cell phone radiation on children. Here are some of the conclusions so far:

  • A 2010 study of cell phone radiation noted that, “in general and on average, children suffer a higher exposure of their brain regions than adults.”  This is because children have proportionally smaller heads and brains, yet receive the same levels of cell phone radiation as adults.22 The American Academy of Pediatrics agrees, saying that “when used by children, the average RF energy deposition is two times higher in the brain and 10 times higher in the bone marrow of the skull, compared with mobile phone use by adults.”23
  • Another study found that people who begin using cell phones (and cordless landline phones) before the age of 20 are at an even higher risk of developing brain tumors than people who begin using these wireless phones as adults.24,25 This is because of the closer proximity of the source of radiation to the brain of kids (they have thinner tissues and bones than adults).
  • Research also suggests that cell phone exposure could affect children’s behavior.26 The children in the study who were hyperactive or had emotional or behavioral problems, including trouble getting along with other kids, were much more likely to have mothers who used cell phones during pregnancy. After accounting for other factors that could affect behavior, the children of these mothers were 80% more likely to have behavioral problems than children whose mothers rarely or didn’t use cell phones. However, this is difficult to study because mothers who use cell phones frequently during pregnancy or after the baby is born, may pay less attention to their children, resulting in the children’s bad behavior. More research is needed to understand the link between mother’s cell phone use and children’s behavior.
  • Children that used cell phones more were more likely to have ADHD. Although the link to ADHD was only for children who also had high levels of lead in their blood, when researchers adjusted for blood lead level, they still found that ADHD was more likely for children who made more phone calls and spent a longer amount of time on the phone.27 This study was conducted in Korea, so it would be important to do similar research on children living in other countries.
  • A 2014 article reviewing studies on children and their cell phone use found that the younger the child, the greater the risk of brain cancer and brain tumors. The same article also points to studies concluding that cell phones are associated with an increased risk of breast cancer (due to adolescents putting cell phones in their bras), parotid (salivary) gland tumors, and sperm damage for adolescents and adults.28

Reactions To Research About Cell Phone Radiation

In 2012, the American Academy of Pediatrics wrote a letter to the Federal Communications Commission, which sets the standards for cell phone radiation in the United States, and recommended that they reevaluate these standards since this had not been done since 1996. Their reasoning is that “children, however, are not little adults and are disproportionately impacted by all environmental exposures, including cell phone radiation.”2 But, as of 2015, the FCC still says that there is no evidence between wireless device use and health problems and continues to uphold the regulations from 1996.29 Other countries have taken a different approach. As of 2014, Turkey, Belgium, Australia, and France have warned about the dangers of children’s cell phone usage.7



Scientists disagree on whether cell phone radiation can cause cancer or other health problems.  Since so many children and adults use cell phones so frequently, that makes it difficult to do a study comparing high and low cell phone usage.  And since brain tumors and other cancers usually do not develop until several decades after the initial exposure, it could be years before we know how risky cell phones are and under what circumstances.7

By the time we find out, many people will have been harmed if cell phones are found to be dangerous. Here are some precautionary tips on how to protect your children from the health issues that could be connected to cell phone radiation.30

  1. Turn airplane mode on when giving a child a technology device or when a cell phone is near a pregnant abdomen, to prevent exposure to radiation.
  2. Turn off wireless networks and devices to decrease your family’s radiation exposure whenever you aren’t actively using them. As an easy first step, turn your Wi-Fi router off at bedtime.
  3. Decrease use of phones or wifi where wireless coverage is difficult, in order to avoid an increase in radiation exposure.
    The warning about RF exposure found on an iPhone 5s.
    The warning about RF exposure found on an iPhone 5s.
  4. Use the speaker phone or a plug in earpiece when you use a cell phone. To protect children from radiation, they should not use cell phones except in emergency and should use the speaker phone.
  5. Increase the distance between you and your cell phone whenever it is on, to reduce your exposure to radiation emitted. For example, do not use a cell phone while a child is on your lap, and do not carry your cell phone in your baby carrier, crib, or pockets. When the phone is on, tell your kids to put it in a backpack as far from their body as possible (such as an outside pocket) or on the desk or other furniture at home, instead of holding it or carrying it in a pocket.
  6. Read the fine print: All device manufacturers advise that cell phones should be at least 5 millimeters, or about ¼ of an inch away from your body or brain. With the iPhone 6 and the iPhone 6s, the company advises users to keep the cell phone at least 10 millimeters, or about half an inch, away from your body or brain. See the safe distance for your phone. For iPhone 5 and iPhone 6, this is located under: Settings -> General -> About -> Legal -> RF Exposure.
  7. Share this info with your friends, family, and schools so that they can make these simple changes as well.


All articles on our website have been approved by Dr. Diana Zuckerman and other senior staff.

Agent Orange and Serious Diseases including Multiple Myeloma

Nicholas J. Jury, PhD and Diana Zuckerman, PhD

It has taken many years to determine how Agent Orange exposure during the Vietnam War has harmed the health of those who were exposed. One of the reasons is that it can take decades for cancer to develop after a dangerous exposure.  Agent Orange was used extensively by the United States military during the Vietnam War to clear vegetation to make it easier to see enemy soldiers. Agent Orange was contaminated with dioxin, making it more dangerous to humans. Nearly 1.5 million veterans were exposed to Agent Orange during the war 31  when approximately, 20 million gallons of Agent Orange were sprayed over Vietnam during Operation Ranch Hand. 32,33

Although more research is still needed to learn more about the risks of Agent Orange, by 2012, the Institute of Medicine had concluded that individuals exposed to Agent Orange are more likely to develop these types of cancers and serious diseases 34:


  • Chronic B-cell leukemia
  • Chronic lymphocytic leukemia
  • Hodgkin disease
  • Non-Hodgkin lymphoma
  • Prostate cancer
  • Respiratory cancers (bronchus, larynx, lung, and trachea)
  • Soft tissue sarcoma

Serious diseases:

  • Early-onset peripheral neuropathy
  • High blood pressure
  • Ischemic heart disease
  • Parkinson disease
  • Stroke
  • Type 2 diabetes

The report also stated that some of the children being born to those exposed had spinal cord birth defects. 35

New research indicates Agent Orange also increases the chances of developing a type of cancer of the bone marrow called multiple myeloma.

Veterans who have been exposed to Agent Orange or other herbicides during military service are eligible to receive Veterans Administration health care benefits and compensation for respiratory cancers without having to prove the connection between their disease and exposure.  36

Does Agent Orange cause Multiple Myeloma?

Bone marrow is crucial for making new blood cells. Multiple myeloma causes blood cells to accumulate in the bone marrow and interfere with the process of making new blood cells. 37  Patients who develop multiple myeloma are usually diagnosed first with a condition called monoclonal gammopathy of undetermined significance (MGUS). 38, 39  Patients who have MGUS tend to develop multiple myeloma, and this risk increases over time. 40  More than 26,000 people are expected to be diagnosed with multiple myeloma this year, and less than half are predicted to survive. 41

In its 2012 report, the Institute of Medicine stated that there was insufficient evidence to conclude that exposure to Agent Orange can cause multiple myeloma. 42  However, a study published in a cancer journal in 2015 reported that veterans who were exposed to Agent Orange were 2.4 times more likely to develop MGUS than the veterans who were not exposed to it. 43  The study was based on 958 veterans who served in the United States Air Force during Operation Ranch Hand. This study provides compelling evidence that Agent Orange exposure can increase the risk of multiple myeloma.

Tanning beds: safe alternative to sun?

By Heidi Mallis, B.A and Diana Zuckerman, PhD
Updated 2015

For many years, tanning beds were advertised as a safe alternative to a natural suntan, but in fact, there was no evidence that was true.  No U.S. government agency evaluated sun lamps, tanning beds, or tanning booths to make sure they were safe.  As a result, nearly 30 million people in the U.S. were using tanning beds each year44, 2.3 million of whom were adolescents.45

Research evidence was growing about the risks of tanning beds.  According to the American Academy of Dermatology and the World Health Organization, indoor tanning increases a person’s chances of developing melanoma by 59 percent, and the risk goes up with each use.46

Finally, in 2014 the U.S. Food and Drug Administration (FDA) announced that all sun lamps and UV lamps intended for use in sun lamp products must come with warnings include the following:

  • This product is contraindicated for persons under the age of 18 years;
  • This product must not be used if skin lesions or open wounds are present;
  • This product should not be used on people who have had skin cancer or a family history of skin cancer
  • People repeatedly exposed to UV radiation should be regularly evaluated for skin cancer3

As evidence grew of the link between tanning beds and skin cancer, especially for men and women in their 20s, more than 60% of states passed some kind of legislation restricting the use of tanning salons by children under 18 and two states, California and Vermont, have passed complete bans of indoor tanning for minors.47

What does this mean for you?

Tanning beds expose the user to a lot of artificial UV radiation in a short period of time. Just one 8-20 minute session exposes a person to more UV radiation than an entire afternoon spent in natural sunlight. In fact, doses of UV radiation emitted by high pressure sunlamp products may be up to 10 to 15 times higher than that of the midday sun, which is more intense than UV radiation found in nature.

A study conducted by Dr. S. Elizabeth Whitmore and Dr. Warwick Morison of Johns Hopkins University School of Medicine found that ten tanning sessions in two weeks produced evidence of a suppressed immune system among participants. This means that the body is less capable of fighting off infectious agents.48 Tanning bed use is also associated with faster skin aging because the UV radiation destroys skin fibers and damages elasticity. Characteristics of skin aging include wrinkles, dark spots, and a leathery texture.49

The International Agency for Research on Cancer lists tanning beds in its highest cancer risk category, “carcinogenic to humans.” This means that there is enough evidence to conclude that tanning beds can cause cancer in humans. Prior to 2009, the agency, which is part of the World Health Organization (WHO), previously classified tanning beds as “probably carcinogenic.” The change came after an analysis of more than 20 epidemiological studies indicating that people who begin using tanning devices before age 30 are 75% more likely to develop cutaneous melanoma, the most serious type of skin cancer50

Skin cancer is the most common form of cancer, with more than one million cases diagnosed each year in the U.S. There are three types of skin cancer: squamous cell, basal cell, and melanoma. Squamous cell carcinomas typically occur on surfaces exposed to the most sunlight, such as the ears or face. This type of skin cancer can spread quickly to other organs in the body. Basal cell carcinomas account for 8 out of 10 skin cancers. They grow very slowly and rarely spread to other parts of the body (as a result, they are highly treatable). Melanomas are the third and most dangerous type of skin cancer. They are less common than basal and squamous cell carcinomas but much more serious.51 Melanomas usually present as a change to an existing mole or an entirely new mole that is black or has a blue-black area. Their diameter is typically larger than that of a pencil eraser. If caught early, melanomas are often completely curable. However, they are much more likely to spread to other parts of the body if not found early.52

Risk factors for all three types of skin cancer include:

  • Lifetime exposure to UV radiation (from natural or artificial sources)
  • Family history of skin cancer
  • Geographic location (people who live close to the equator as well as in the mountains are exposed to higher levels of UV radiation)
  • Fair skin that freckles or burns easily
  • Severe sunburns as a child
  • Radiation therapy

Here are a few ways to lower your risk and avoid wrinkles and other skin damage:

  • Avoid direct sun exposure during midday hours (from 10 am-4 pm),
  • Use sunscreen with a sun protection factor (SPF) of at least 15
  • Regularly check your skin for any new moles, sores, or scaly patches (and visit a dermatologist if you notice the lesion changing form or color), and
  • Avoid using a tanning bed or booth (especially if you are a child, teenager, or young adult).53

Keeping track of moles and other changes to your skin are an easy way to improve your skin health. However, the U.S. Preventive Services Task Force suggests that if you are not at an increased risk of developing skin cancer, there is no need for yearly skin checks by a dermatologist.54

Continue to monitor any existing or new moles and contact your doctor if you detect any significant changes in size, shape, or color.


Pesticides and cancer in children: is there a connection?

By Prianka Waghray


In murder mysteries, rat poison and pesticides intentionally added to food are sometimes used to kill.  Scientists have also warned they can cause birth defects.  However, more recent research shows that relatively low levels of pesticides and indoor bug sprays can cause cancer and other serious medical problems in children, and possibly adults.

A study published in September 2015 found that children exposed to indoor bug sprays and other insecticides are more likely to develop leukemia or lymphoma, and possibly brain cancer.  This was an important study because it combined data from 16 smaller studies in a type of statistics called a meta-analysis.55. Although it was already known that many chemicals used in pesticides, such as certain organophosphates, can cause cancer, the study aimed to find out how much exposure is needed to cause cancer in children.

The evidence about the risks of various chemicals has been growing. There is some evidence that high level of exposures to pesticides, especially among farm workers, may increase the chances of developing lung cancer, but more research is needed on which pesticides are most likely to cause harm 56. In March 2015, the well-respected International Agency for Research on Cancer announced that the widely used weed killer called Roundup probably causes cancer in humans, based on animal studies 57.  A study published in August 2015 found harmful effects in the liver and kidneys of rats exposed to low levels of Roundup in drinking water.58. Children are especially vulnerable to even small amounts of insecticides and pesticides that are meant to kill rodents or insects, even in tick and flea sprays used on pets, because children are smaller than adults and their bodies and brains are still developing.  Roundup, which was banned in Sri Lanka in 2014 due to health concerns, as well as other weed killers are currently being investigated by scientists to learn more about the risks for adults and children.

Even before the latest study, the American Academy of Pediatrics (AAP), which is the nonprofit organization for pediatricians, warned that children can be harmed by pesticides in their daily life.59. The AAP concludes that exposure to pesticides early in life can result in childhood cancers, behavioral problems, and lower scores on tests to measure thinking, reasoning, and remembering. They recommend that parents reduce their children’s exposure to pesticides as much as possible, by controlling bugs and other pests using non-chemical methods whenever possible, and by reducing the amount of pesticides in what children eat and drink.

Several studies have found, for instance, that children exposed to organophosphates, which are common in household insecticides, in their early years tend to have lower IQ and more likely to show the behaviors typical of autism and attention deficit and hyperactivity disorders.60 Environmental Protection Agency.61.

Several cancer-causing organophosphates have been banned from household pesticides. Unfortunately, they have been replaced with other organophosphates that have not yet been studied. Whether or not these chemicals cause cancer, they can be dangerous and children should not be exposed to them.62

Young children are more likely to be exposed to more pesticides and insecticides than adults because they are closer to the ground and often put whatever they find there, along with their own fingers, in their mouths. When bug spray or other pesticides are used in the home, chemical residues can linger in the air, on the floor or carpet where children crawl and play, and on toys.63 Children breathe in more pesticide than adults, too, because they are down low where the chemicals accumulate. Lawn and garden weed killers can be tracked in the house by pets or people, and left in carpets and rugs.

How can we reduce children’s exposure to pesticides?

The good news is that parents can reduce their children’s exposure to these chemicals. The easiest way is to stop using them in your home and garden. It is also safer to use roach motels, ant baits, and mouse traps instead of chemical sprays. You can weed the yard by hand instead of using weed killers (at least while your children are young).

What about the fruits and vegetables that you buy?  Be sure to wash, scrub, and peel fruits and vegetables if you don’t buy organic produce. Although washing and peeling fruits and vegetables doesn’t get rid of the pesticides that have been absorbed into the growing vegetable or fruit, it is still better than nothing. However, if you can afford to buy them, organic fruits and vegetables have the least amount of pesticide on and inside the fruit or vegetable.64

One way to reduce the use of bug sprays and other chemicals in the home is to not leave out food overnight that can attract bugs or rodents. Discourage rats by covering garbage cans.

If you must use pesticides, use the ones that are less toxic. If you aren’t sure how a product kills pests, look at the label. According to the EPA, pesticides with “warning” on the label are more dangerous to humans than the ones that say “caution.” Products with labels that say “danger” are the most harmful.65 66 Besides using the lowest risk products, be careful where you store pesticides, so that children can’t reach them and the chemicals won’t contaminate foods or medicines.

Is buying organic really better for you?

Researchers at Stanford University have concluded that organic fruits and vegetables are not more nutritious than other produce. However, they also found that children who eat organic produce have significantly lower levels of pesticides in their bodies than children who eat regular produce.67,68,69

Unfortunately, organic fruits and vegetables are not always available, and they are often more expensive. One way to eat organic less expensively is to limit your organic purchases to the fruits and vegetables on the Environmental Working Group’s (EWG) Dirty Dozen list.70 These are the 12 fruits and vegetables that tend to have the highest amount of pesticide residues. The list is constantly being updated based on recent test results so check it regularly ( There is also a Clean 15 list, which lists 15 foods that have the least amount of pesticides and, therefore, are safe even when they are not organic. By following these lists, you can feed your children more safely without breaking the bank.

As of January 2016, the Dirty Dozen consists of the following foods:

  1. Apples
  2. Dirty dozen; peachesPeaches
  3. Nectarines
  4. Strawberries
  5. Grapes
  6. Celery
  7. Spinach
  8. Sweet bell peppers
  9. Cucumbers
  10. Cherry tomatoes
  11. Snap peas – imported
  12. Potatoes

The Clean 15 list consists of the following foods, where it is not necessary to buy organic:

  1. Avocados
  2. Sweet Corn
  3. Pineapples
  4. Cabbageclean 15; red onions
  5. Sweet peas frozen
  6. Onions
  7. Asparagus
  8. Mangoes
  9. Papayas
  10. Kiwi
  11. Eggplant
  12. Grapefruit
  13. Cantaloupe
  14. Cauliflower
  15. Sweet potatoes


Even small amounts of pesticides are very harmful for children. They may cause behavior problems, harm children’s thinking and memory, and increase their risk of childhood cancers.  These chemicals can also harm adults, especially after years of exposure.  To help prevent these problems, limit your use of bug sprays, weed killers, and other pesticides and herbicides and buy organic fruits and vegetables that would otherwise have a lot of pesticide residue.

All articles on our website have been approved by Dr. Diana Zuckerman and other senior staff. 


Can cell phones harm our health?

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 cellphonethe 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.71

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.72

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.73 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.”74

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.75 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.76 However, a study conducted in 2013 found that while long-term cell phone use was associated with acoustic neuromas, it did not predict gliomas.77 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.78 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.79

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:

  • salivary gland tumors80,81
  • dizziness and migraines82
  • less sleep and poor sleep quality83
  • increases and decreases in production of specific proteins in human cells84
  • decreased sperm count and quality85,86,87
  • skin irritation, especially on the face (this is a condition known as electrohypersensitivity)88,89
  • 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.90

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.


Are Bisphenol A (BPA) plastic products safe for infants and children?

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.91 The highest estimated daily intakes of BPA occur in infants and children.92

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.93   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 94  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.95,96,97

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.98  Studies have also linked the hormonal effects of BPA from canned cat food to the epidemic of hyperthyroidism in cats, especially females.99 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.100  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 101  Another similar study in mice is creating concern about liver cancer risks as well.102  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.103

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.104 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.105

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.106 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.107 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.108  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.109

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 2008.110,111  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.112  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.113

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.

Everything you ever wanted to know about radiation and cancer, but were afraid to ask

Julie Bromberg and Laura Covarrubias

Click link to jump to section:

Radiation from the Environment
Medical Devices that Use Radiation
Other Manufactured Devices that Use Radiation
Table: Approximate Dose and Cancer Risk of Various Radiation Sources

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.114,115

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.116,117

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.118 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.119,120

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.

Radiation from the Environment

Background 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.121  People 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.122

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.123It 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.124

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.125 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.126 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.127

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.128

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:

  1. 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.)
  2. Stay in the shade, especially when the sun is at it’s strongest (between 10am and 4pm)
  3. Wear protective clothing, such as broad-brimmed hats and tightly-woven clothes that cover your hands and legs.

Medical Devices that Use Radiation


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.129  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.130

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.131,132,133

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.134  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.135  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,136  and studies have not found an increase risk of cancer among humans who have received a very low dose of radiation.137 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).


Mammograms are an x-ray test that is used to detect breast cancer.  This test uses a higher dose of radiation than a simple x-ray, but less than a CT scan or Fluoroscopy.  According to the U.S. Preventative Services Task Force, a woman above age 50 who is at average risk of breast cancer should get a mammogram test once every two years until age 74.138 These new guidelines would expose women to less than half the amount of radiation from mammograms than following previous recommendations (which included annual mammograms starting at age 40 for women at average risk).

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.139


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.140

Since this test sends x-ray beams over an extended period of time (usually 20-60 minutes),141 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.142

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.143  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.144 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.145 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.146 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.147  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.148  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.149,150

 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.151 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.152

(Click here for more information on heart CT scans and cancer risk).

Positron Emission Tomography (PET) scans

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.”153

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

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.154

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.155,156

Between 1950 and 2006, the frequency of diagnostic radiation increased 10-fold.157 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.158

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.159 This means more people are likely to be diagnosed with cancers that are caused by radiation than they would not have gotten otherwise.

Other Manufactured Devices that Use Radiation

Airport and Building X-ray Scans

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:

(Source: Transportation Security Administration)
(Source: Transportation Security Administration)

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:

(Source: Transportation Security Administration, from
(Source: Transportation Security Administration, from

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.160  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.161 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.162,163 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.164 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.165 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.166 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.167

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.168

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.169 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.170,171

The rapid increase in use of cell phones and other wireless devices intensifies the need for further research on potential health effects of these non-ionizing radiation sources.  Click here to get more information on cell phones and health.

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.[10]

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) many years (~13.6 years) ~2 in 1,000
Transjugular intrahepatic portosystemic shunt placement27 (~70mSv) many years (~23.3 years) 1 in 100 – 1,000
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.172

‡Natural background radiation is equal to about 3mSv per year.173

§ 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.”[33]

§§ “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.”[33]

All articles are reviewed and approved by Dr. Diana Zuckerman and other senior staff.

Related Content:
Children and cell phones: is phone radiation risky for kids?
Airport security and radiation
Can cell phones harm our health?

Fracking and your health

By Anna E. Mazzucco, Ph.D.



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.174,175,176   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.177 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.178 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.179   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.180,181

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.


Letter to Representative Markey in Support of Legislation that would give FDA Authority to Oversee Compounding Pharmacies, October 31, 2012

October 31, 2012

The Honorable Edward J. Markey
Energy and Commerce Committee
U.S. House of Representatives
2108 Rayburn
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

The original letter can be found here.

Press release from Representative Markey.

November 1, 2012
Washington, D.C.

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.