Tag Archives: lead

NCHR Written Statement for North Salem Central School District Board of Education

May 12, 2021


Dear Dr. Freeston and the North Salem Central School District Board of Education:

As president of the National Center for Health Research, I want to share the information we have provided to Members of Congress, state and federal agencies, state and local legislators, parents, and others who want to ensure that our children are not exposed to dangerous chemicals or other substances when they play on artificial turf or playgrounds. Our nonprofit think tank is located in Washington, D.C. Our scientists, physicians, and health experts conduct studies and scrutinize research conducted by other experts in the field. Our goal is to explain scientific and medical information that can be used to improve public health.

Our organization has been testifying and writing about the dangers of synthetic turf and playground surfaces for several years.  Our scientific staff has reviewed all publicly available scientific studies pertaining to the health impact of the lead and chemicals that are in artificial turf and playground surfaces, compared to natural surfaces such as grass and engineered wood fiber.

In the last year, scientists have reported finding potentially dangerous levels of lead in artificial turf fields and playground surfaces.  In addition, plastic grass and synthetic rubber are made with different types of hormone-disrupting chemicals, some of which are known to be particularly harmful to growing children.  Scientists at the National Institute of Environmental Health Sciences, which is an institute of NIH, have concluded that these chemicals can be threats to health even at low levels.

Manufacturers and advocates for synthetic turf often state that artificial turf has been declared safe by federal authorities.  That is completely untrue.  It is essential to understand that there are no federal requirements for safety testing of these synthetic turf products before they are sold. The EPA and the federal Consumer Product Safety Commission are jointly studying the chemicals used in these products, but they have not yet released any data on studies of children exposed to these fields and playgrounds day after day and week after week.

There is a dangerous trend of replacing natural fields and playground surfaces with materials that are dangerous to our children’s health, potentially dangerous to adult fertility and health, and bad for our environment.  In the last year, we’ve learned new information about lead and PFAS in artificial turf, as well as the risks of some of the newer infill materials that turf companies are using to replace tire crumb.

The “plastic grass” itself has dangerous levels of lead, PFAS, and other toxic chemicals.  PFAS are of particular concern because they are “forever chemicals” that get into the human body and are not metabolized, accumulating over the years. As I mentioned in an NPR interview this week1, new research published in the prestigious Journal of the National Cancer Institute found that people with greater exposure to PFAS are significantly more likely to be diagnosed with kidney cancer.2  Previous research suggests that testicular cancer is also associated with PFAS.

Lead

The American Academy of Pediatrics states that no level of lead exposure is safe for children, because lead can cause cognitive damage even at low levels.  Some children are even more vulnerable than others, and that can be difficult or even impossible to predict. You may have been told that lead is only a problem for artificial turf made with tire crumb infill, but that’s not correct. The Centers for Disease Control and Prevention (CDC) warns that the “plastic grass” made with nylon or some other materials also contain lead.  The lead doesn’t just stay on the surface.  With wear, the turf materials turn to dust that is invisible to the eye but that children are inhaling when they play.

Why are Chemicals that are Banned from Children’s Toys Allowed in Artificial Turf and Rubber Playground Surfaces?

There are numerous studies indicating that endocrine-disrupting chemicals found in plastic cause serious health problems. As noted above, scientists at the National Institute of Environmental Health Sciences have concluded that unlike most other chemicals, these hormone-disrupting chemicals can be dangerous at very low levels, and the exposures can also be dangerous when they combine with other exposures in our environment.

That is why the U.S. Consumer Product Safety Commission has banned numerous endocrine-disrupting chemicals from toys and products used by children. The products involved, such as pacifiers and rubber duckies, are banned even though they would result in very short-term exposures compared to artificial turf or playground surfaces.

A report warning about possible harm to people who are exposed to hormone disrupting chemicals at work explains that these chemicals “can mimic or block hormones and disrupt the body’s normal function, resulting in the potential for numerous health effects… Similar to hormones, EDC [endocrine disrupting chemicals] can function at very low doses in a tissue-specific manner and may exert non-traditional dose–response because of the complicated dynamics of hormone receptor occupancy and saturation.”3

Studies are beginning to demonstrate the contribution of skin exposure to the development of respiratory sensitization and altered pulmonary function. Not only does skin exposure have the potential to contribute to total body burden of a chemical, but also the skin is a highly biologically active organ capable of chemical metabolism and the initiation of a cascade of immunological events, potentially leading to adverse outcomes in other organ systems.

Envirofill and Other Alternative Infills

Replacing tire waste with silica, zeolite, and other materials also has substantial risks because the dust from these materials can be inhaled.

Summers in New York can get hot.  Even when the temperature is a pleasant 80 degrees Fahrenheit, artificial turf and playground surfaces can reach 150 degrees or higher.  Obviously, turf and playground surfaces are likely to be even hotter than 150 degrees on a sunny 90 degree day.  That can cause “heat poisoning” as well as burns.

Envirofill artificial turf fields are advertised as “cooler” and “safer,” but our research indicates that these fields are still at least 30-50 degrees hotter than natural grass. Envirofill is composed of materials resembling plastic polymer pellets (similar in appearance to tic tacs) with silica inside. Silica is classified as a hazardous material according to OSHA regulations, and the American Academy of Pediatrics specifically recommends avoiding it on playgrounds. The manufacturers and vendors of these products claim that the silica stays inside the plastic coating.  However, sunlight and the grinding force from playing on the field breaks down the plastic coating. For that reason, even the product warranty admits that only 70% of the silica will remain encapsulated. The other 30% can be very harmful as children are exposed to it in the air.

In addition, the Envirofill pellets have been coated with an antibacterial called triclosan.  Triclosan is registered as a pesticide with the EPA and the FDA has banned triclosan from soaps because manufacturers were not able to prove that it is safe for long-term use.  Research shows a link to liver and inhalation toxicity and hormone disruption.  The manufacturer of Envirofill says that the company no longer uses triclosan, but they provide no scientific evidence that the antibacterial they are now using is any safer than triclosan.  Microscopic particles of this synthetic turf infill will be inhaled by children, and visible and invisible particles come off of the field, ending up in shoes, socks, pockets, and hair.

In response to the concerns of educated parents and government officials, other new materials are now being used instead of tire crumb and other very controversial materials.  However, all the materials being used (such as volcanic ash, corn husks, and Corkonut) have raised concerns and none are proven to be as safe or effective as well-designed grass fields.

Despite claims to the contrary, no independent studies have demonstrated that artificial turf is safe.  Although the Trump Administration’s EPA stated that there was no conclusive evidence that the levels of chemicals in artificial turf was harmful to children, they made it clear that their research was based on assumptions about likely exposures rather than scientific research on children.

Scientific Evidence of Cancer and Other Serious Harm

It is essential to distinguish between evidence of harm and evidence of safety. Like the Trump Administration’s EPA, companies that sell and install artificial turf often claim there is “no evidence children are harmed” or “no evidence that the fields cause cancer.” This is often misunderstood as meaning the products are safe or are proven to not cause harm. Neither is true.

It is true that there is no clear evidence that an artificial turf field has caused specific children to develop cancer. However, that statement is misleading because it is virtually impossible to prove any chemical exposure causes one specific individual to develop cancer. As an epidemiologist, I can also tell you that for decades there was no evidence that smoking or Agent Orange caused cancer.  It took many years to develop that evidence, and the same will be true for artificial turf.

I have testified about the risks of these materials at hearings of the U.S. Consumer Product Safety Commission and state and local agencies.  At these hearings, I am sorry to say that I have repeatedly seen and heard scientists paid by the turf industry and other turf industry lobbyists say things that are absolutely false, most recently at a hearing in a Connecticut community. They claim that these products are proven safe (not true) and that federal agencies have stated there are no health risks (also not true).

On the contrary, we know that the materials being used in artificial turf contain carcinogens, and when children are exposed to those carcinogens day after day, week after week, and year after year, they increase the chances of our children developing cancer, either in the next few years or later as adults.  That should be adequate reason not to install them in your community.  That’s why I have spoken out about the risks of artificial turf in my community and on a national level.  The question must be asked: if they had all the facts, would families choose to spend millions of taxpayer dollars on fields that are unhealthy and unsafe rather than well-designed natural grass fields?

Dangerously Hard Fields and Injuries From Turf

Artificial turf fields get hard over time, and this can cause brain injuries and other injuries.  Turf companies recommend annual tests at 10 locations on each turf field, using something called a Gmax scores.  A Gmax score over 200 is considered extremely dangerous and is considered by industry to pose a death risk.  However, the synthetic turf industry and ASTM (American Society for Testing and Materials), suggest scores should be even lower — below 165 to ensure safety comparable to a grass field.  Do you want to pay to have those tests conducted annually on artificial turf fields, and replace a relatively new field that fails the test?

The hardness of natural grass fields is substantially influenced by maintenance, rain and other weather; if the field gets hard, aeration water will make it safe again.  In contrast, once an artificial turf field has a Gmax score above 165, it needs to be replaced because while the scores can vary somewhat due to weather, the scores will inevitably get higher because the turf will get harder.  Gmax testing involves testing 10 different areas of a playing fields, to make sure all are considered safe.  Some officials average those 10 scores to determine safety; however, experts explain that is not appropriate.  If a child (or adult) falls, it can be at the hardest part of the field, which is why safety is determined based on each area tested.

Any child who plays on artificial turf knows about “turf burns” that can be very painful and can get infected, but other injuries are even more serious. A study of more than 2,000 young female soccer players from 109 teams over the course of a season found that ankle sprains were almost twice as likely on turf compared to natural grass.4 Knee injuries are also much more likely on artificial turf.  A 10-year study of 5 different types of knee injuries on grass compared to artificial turf was conducted across all 3 divisions of NCAA football. They found that posterior cruciate ligament (PCL) tears occurred almost 3 times as often on turf than on grass.5 Athletes playing at lower levels experienced anterior cruciate ligament (ACL) tears 1.6 times more often on turf than they did on the grass.  This issue persists at the professional level as well, which is why the National Football League’s Player Association demanded artificial turf fields be replaced with natural grass, citing the league’s official report regarding increases in injuries on artificial turf surfaces. The report showed non-contact knee injuries happened 32% more often on turf.6

Environmental Issues

In addition to the health risks to school children and athletes, approximately three tons of infill materials migrate off of each synthetic turf field into the community environment each year.  About 2-5 metric tons of infill must be replaced every year for each field, meaning that tons of the infill have migrated off the field into grass, water, and our homes.  The fields also continuously shed microplastics as the plastic blades break down.7,8 These materials may contain additives such as PAHs, flame retardants, UV inhibitors, etc., which can be toxic to marine and aquatic life; and microplastics are known to migrate into the oceans, food chain, and drinking water and can absorb and concentrate other toxins from the environment.9,10,11

Synthetic surfaces also create heat islands.12,13  In contrast, organically managed natural grass saves energy by dissipating heat, cooling the air, and reducing energy to cool nearby buildings.  Natural grass and soil protect groundwater quality, biodegrade polluting chemicals and bacteria, reduce surface water runoff, and abate noise and reduce glare.14

Conclusions

There have never been any safety tests required prior to sale that prove that any artificial turf products are safe for children who play on them regularly.  In many cases, the materials used are not publicly disclosed, making independent research difficult to conduct.  None of these products are proven to be as safe as natural grass in well-constructed fields.

I have cited several relevant scientific articles on artificial turf in this letter, and there are numerous studies and growing evidence of the harm caused by these synthetic materials.  I would be happy to provide additional information upon request (dz@center4research.org).

I am not paid to write this statement.  I am one of the many parents and scientists who are very concerned about the impact of artificial fields on our children.  I’m sure you agree that it is important that decisions are based on scientific evidence, not on sales pitches by individuals with conflicts of interest.

Officials in communities all over the country have been misled by artificial turf salespeople. They were erroneously told that these products are safe.  But on the contrary, there is clear scientific evidence that these materials are harmful.  The only question is how much exposure is likely to be harmful to which children?  We should not be willing to take such a risk.  Our children deserve better.

 

Sincerely,

Diana Zuckerman, Ph.D.

President

 

References

  1. Vega, T., & Zuckerman, D. (May 10, 2021). The Role of Environmental Regulations in the Fight Against Cancer. The Takeaway. New York City, New York; WNYC.
  2. Shearer, JJ et al, Serum Concentrations of Per- and Polyfluoroalkyl Substances and Risk of Renal Cell Carcinoma. 2021; JNCI: Journal of the National Cancer Institute, Volume 113, Issue 5, , Pages 580-587, https://doi.org/10.1093/jnci/djaa143
  3. Anderson SE and Meade BJ. Potential Health Effects Associated with Dermal Exposure to Occupational Chemicals. Environmental Health Insights. 2014; 8(Suppl 1):51–62. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4270264/
  4. Steffen, K., Andersen, T. E., & Bahr, R. Risk of injury on artificial turf and natural grass in young female football players. British Journal of Sports Medicine. 2007; 41 Suppl 1(Suppl 1), i33–i37. https://doi.org/10.1136/bjsm.2007.036665
  5. Loughran, G. J., Vulpis, C. T., Murphy, J. P., Weiner, D. A., Svoboda, S. J., Hinton, R. Y., & Milzman, D. P. Incidence of Knee Injuries on Artificial Turf Versus Natural Grass in National Collegiate Athletic Association American Football: 2004-2005 Through 2013-2014 Seasons. The American journal of sports medicine.2019;47(6), 1294–1301. https://doi.org/10.1177/0363546519833925
  6. Dulik, Brian. NFLPA asking teams to change all fields to natural grass. AP News. September 20, 2020. https://apnews.com/article/nfl-football-archive-9b34d4402f2f82ae60708605f65aa560
  7. Magnusson K, Eliasson K, Fråne A, et al. Swedish sources and pathways for microplastics to the marine environment, a review of existing data. Stockholm: IVL- Swedish Environmental Research Institute. 2016. https://www.naturvardsverket.se/upload/miljoarbete-i-samhallet/miljoarbete-i-sverige/regeringsuppdrag/utslapp-mikroplaster-havet/RU-mikroplaster-english-5-april-2017.pdf
  8. Kole PJ, Löhr AJ, Van Belleghem FGAJ, Ragas AMJ. Wear and tear of tyres: A stealthy source of microplastics in the environment. International Journal of Environmental Research Public Health. 2017;14(10):pii: E1265. https://www.ncbi.nlm.nih.gov/pubmed/29053641/
  9. Kosuth M, Mason SA, Wattenberg EV. Anthropogenic contamination of tap water, beer, and sea salt. PLoS One. 2018,13(4): e0194970. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5895013/
  10. Oehlmann J, Schulte-Oehlmann U, Kloas W et al. A critical analysis of the biological impacts of plasticizers on wildlife. Philosophical Transactions of the Royal Society B. 2009;364:2047–2062. http://rstb.royalsocietypublishing.org/content/364/1526/2047
  11. Thompson RC, Moore CJ, vom Saal FS, Swan SH. Plastics, the environment and human health: Current consensus and future trends. Philosophical Transactions of the Royal Society B. 2009;364:2153–2166. https://royalsocietypublishing.org/doi/full/10.1098/rstb.2009.0053
  12. Thoms AW, Brosnana JT, Zidekb JM, Sorochana JC. Models for predicting surface temperatures on synthetic turf playing surfaces. Procedia Engineering. 2014;72:895-900. http://www.sciencedirect.com/science/article/pii/S1877705814006699
  13. Penn State’s Center for Sports Surface Research. Synthetic turf heat evaluation- progress report. 012. http://plantscience.psu.edu/research/centers/ssrc/documents/heat-progress-report.pdf
  14. Stier JC, Steinke K, Ervin EH, Higginson FR, McMaugh PE. Turfgrass benefits and issues. Turfgrass: Biology, Use, and Management, Agronomy Monograph 56. American Society of Agronomy, Crop Science Society of America, Soil Science Society of America. 2013;105–145. https://dl.sciencesocieties.org/publications/books/tocs/agronomymonogra/turfgrassbiolog

Written Statement Regarding Artificial Turf to Woodbridge Ordinance Committee

March 16, 2021


Dear Members of the Ordinance Committee:

I am writing to share scientific information about artificial turf and playground surfaces, which I am confident will help you determine the best decisions to make for the children and adults in your community.

As President of the National Center for Health Research, I am writing at the request of many of your constituents to share the information we have provided to Members of Congress, state and federal agencies, state and local legislators, parents, and others who want to ensure that our children are not exposed to dangerous chemicals or metals when they play on artificial turf or playgrounds. Our nonprofit think tank is located in Washington, D.C. Our scientists, physicians, and health experts conduct studies and scrutinize research. Our goal is to explain scientific and medical information that can be used to improve policies, programs, services, and products.

We commend you for considering the possible risks of replacing grass fields and natural playgrounds with artificial turf. In the last two years, we’ve learned new information about lead and PFAS in artificial turf, as well as the risks of some of the newer infill materials that turf companies are using to replace tire crumb. Tire crumb has well-known risks, containing chemicals that have the potential to increase obesity; contribute to early puberty; cause attention problems such as ADHD; exacerbate asthma; and eventually cause cancer. However, the plastic grass itself has dangerous levels of lead, PFAS, and other toxic chemicals as well.  PFAS are of particular concern because they enter the body and the environment as “forever chemicals,” which means that they are not metabolized and do not deteriorate, accumulating over the years. Replacing tire waste with silica, zeolite, and other materials also has substantial risks.

Federal agencies such as the EPA and the U.S. Consumer Product Safety Commission have been investigating the safety of these products. Despite claims to the contrary, none have concluded that artificial turf is safe. Although the Trump Administration’s EPA stated that there was no conclusive evidence that the levels of chemicals in artificial turf was harmful to children, they made it clear that their research was based on assumptions rather than scientific research on children.

Lead

As you probably know, the American Academy of Pediatrics states that no level of lead exposure should be considered safe for children, because lead can cause cognitive damage even at low levels. Some children are more vulnerable than others, and that can be difficult or even impossible to predict. Since lead has been found in tire crumb as well as in new synthetic rubber, it is not surprising that numerous artificial turf fields and playground surfaces made with either tire crumb or “virgin” rubber have been found to contain lead. However, the Centers for Disease Control and Prevention (CDC) also warns that the “plastic grass” made with nylon or some other materials also contains lead. Whether from infill, plastic grass, or rubber playground surfaces, the lead doesn’t just stay on the surface. With wear, the materials turn to dust containing lead and other chemicals that is invisible to the eye and is inhaled by children when they play.

Why are chemicals that are banned from children’s toys allowed in artificial turf and rubber playground surfaces?

Synthetic rubber and plastic are made with different types of endocrine (hormone) disrupting chemicals (also called EDCs). There is very good evidence regarding these chemicals in tire crumb, based on studies done at Yale and by the California Office of Environmental Health Hazard Assessment (OEHHA).1

A 2018 report by Yale scientists detected 92 chemicals in samples from 6 different artificial turf companies, including unused bags of tire crumb. Unfortunately, the health risks of most of these chemicals had never been studied. However, 20% of the chemicals that had been tested are classified as probable carcinogens and 40% are irritants that can cause asthma or other breathing problems, or can irritate skin or eyes.2

There are numerous studies indicating that endocrine-disrupting chemicals (also called hormone-disrupting chemicals) found in rubber and plastic cause serious health problems. Scientists at the National Institute of Environmental Health Sciences (which is part of NIH) have concluded that unlike most other chemicals, hormone-disrupting chemicals can be dangerous at very low levels, and the exposures can also be dangerous when they combine with other exposures in our environment.

That is why the Consumer Product Safety Commission has banned numerous endocrine-disrupting chemicals from toys and products used by children. The products involved, such as pacifiers and teething toys, are banned even though they would result in very short-term exposures compared to artificial turf or playground surfaces.

A report warning about possible harm to people who are exposed to rubber and other hormone disrupting chemicals at work explains that these chemicals “can mimic or block hormones and disrupt the body’s normal function, resulting in the potential for numerous health effects. Similar to hormones, endocrine-disrupting chemicals can function at very low doses in a tissue-specific manner and may exert non-traditional dose–response because of the complicated dynamics of hormone receptor occupancy and saturation.”3

Studies are beginning to demonstrate the contribution of skin exposure to the development of respiratory sensitization and altered pulmonary function. Not only does skin exposure have the potential to contribute to total body burden of a chemical, but also the skin is a highly biologically active organ capable of chemical metabolism and the initiation of a cascade of immunological events, potentially leading to adverse outcomes in other organ systems.

Scientific Evidence of Cancer and Other Systemic Harm

It is essential to distinguish between evidence of harm and evidence of safety. Companies that sell and install artificial turf often claim there is “no evidence children are harmed” or “no evidence that the fields cause cancer.” This is often misunderstood as meaning the products are safe or are proven to not cause harm. Neither is true.

It is true that there no clear evidence that an artificial turf field has caused specific children to develop cancer. However, the statement is misleading because it is virtually impossible to prove any chemical exposure causes one specific individual to develop cancer.

As an epidemiologist, I can also tell you that for decades there was no evidence that smoking or Agent Orange caused cancer. It took many years to develop that evidence, and the same will be true for artificial turf.

I have testified about the risks of these materials at the U.S. Consumer Product Safety Commission as well as state legislatures and city councils. I am sorry to say that I have repeatedly seen and heard scientists paid by the turf industry and other turf industry lobbyists say things that are absolutely false. They claim that these products are proven safe (not true) and that federal agencies have stated there are no health risks (also not true).

However, we know that the materials being used in artificial turf and rubber playground surfaces contain carcinogens, and when children are exposed to those carcinogens day after day, week after week, and year after year, they increase the chances of our children developing cancer, either in the next few years or later as adults. That should be adequate reason not to install them in your community. That’s why I have spoken out about the risks of artificial turf in my community and on a national level. The question must be asked: if they had all the facts, would Woodbridge or any other community choose to spend millions of dollars on fields that are less safe than well-designed natural grass fields?

Dangerously Hot and Hard Fields

I lived in Connecticut for several years while on the faculty at Yale and Vassar, and I know the climate well. When the weather is warm and/or sunny, it is usually quite pleasant to be outside – as long as you aren’t on artificial turf or an outdoor rubber surface. Even when the temperature above the grass is 80 degrees Fahrenheit, artificial turf can reach 150 degrees or higher. Obviously, a 90 degree day is likely to be even hotter than 150 degrees on turf. That can cause “heat poisoning” as well as burns.

Artificial turf fields get hard as well. Turf companies recommend annual tests at 10 locations on each turf field, using something called a Gmax score. A Gmax score over 200 is considered extremely dangerous, and it is considered by industry to pose a death risk. However, the synthetic turf industry and American Society for Testing and Materials (ASTM), suggest scores should be even lower — below 165 to ensure safety comparable to a grass field. Will Woodbridge pay to have these tests conducted annually on all your public artificial turf fields?

The hardness of natural grass fields is substantially influenced by rain and other weather; if the field gets hard, rain or watering will make it safe again. In contrast, once an artificial turf field has a Gmax score above 165, it needs to be replaced because while the scores can vary somewhat due to weather, the scores will inevitably get higher because the turf will get harder. Gmax testing involves testing 10 different areas of a playing fields, to make sure all are considered safe.  Some officials average those 10 scores to determine safety; however, experts explain that is not appropriate. If a child (or adult) falls, it can be at the hardest part of the field, which is why safety is supposed to be determined by the score of the hardest part of the field.

Environmental Issues

In addition to the health risks to school children and athletes, approximately three tons of infill materials migrate off of each synthetic turf field into the greater environment each year. About 2-5 metric tons of infill must be replaced every year for each field, meaning that tons of the infill have migrated off the field into grass, water, and our homes.4 The fields also continuously shed microplastics as the plastic blades break down.5,6 These materials may contain additives such as PAHs, flame retardants, and UV inhibitors, which can be toxic to marine and aquatic life. Microplastics are known to migrate into the oceans, the food chain, and drinking water, and they can absorb and concentrate other toxins from the environment.7,8,9

Synthetic surfaces also create heat islands.10,11 In contrast, organically managed natural grass saves energy by dissipating heat, cooling the air, and reducing energy to cool nearby buildings. Natural grass and soil protect groundwater quality; biodegrade polluting chemicals and bacteria; reduce surface water runoff; abate noise; and reduce glare.12

Envirofill and Alternative Infills

Envirofill artificial turf fields are advertised as “cooler” and “safer,” but our research indicates that these fields are still at least 30-50 degrees hotter than natural grass. Envirofill is composed of materials resembling plastic polymer pellets (similar in appearance to tic tacs) with silica inside. Silica is classified as a hazardous material according to OSHA regulations, and the American Academy of Pediatrics specifically recommends avoiding it on playgrounds. The manufacturers and vendors of these products claim that the silica stays inside the plastic coating. However, sunlight and the grinding force from playing on the field breaks down the plastic coating. For that reason, even the product warranty admits that only 70% of the silica will remain encapsulated. The other 30% can be very harmful as children are exposed to it in the air.

In addition, the Envirofill pellets have been coated with an antibacterial called triclosan. Triclosan is registered as a pesticide with the EPA, and the FDA has banned triclosan from soaps because manufacturers were not able to prove that it is safe for long-term use. Research shows a link to liver and inhalation toxicity and hormone disruption. The manufacturer of Envirofill says that the company no longer uses triclosan, but they provide no scientific evidence that the antibacterial they are now using is any safer than triclosan. Microscopic particles of this synthetic turf infill will be inhaled by children, and visible and invisible particles come off of the field, ending up in shoes, socks, pockets, and hair.

In response to the concerns of educated parents and government officials, other new materials are now being used instead of tire crumb and other very controversial materials. However, all the materials being used (such as volcanic ash, corn husks, and Corkonut) have raised concerns, and none are proven to be as safe or effective as well-designed grass fields.

Conclusions

There have never been any safety tests required prior to sale that prove that any artificial turf products are safe for children who play on them regularly. In many cases, the materials used are not publicly disclosed, making independent research difficult to conduct. None of these products are proven to be as safe as natural grass in well-constructed fields.

I have cited several relevant scientific articles on artificial turf in this letter, and there are numerous studies and growing evidence of the harm caused by these synthetic materials. I would be happy to provide additional information upon request (dz@center4research.org).

I am not paid to write this statement. I am one of the many parents and scientists who are very concerned about the impact of artificial fields on our children. Your decision about artificial turf and playground surfaces can save lives and improve the health of children in your community.  You owe it to your community to make sure that you know the risks of artificial turf and do all you can to protect your children from both the known risks and the suspected risks. Your decisions about artificial turf will be cited by other communities, making it even more important that your decision is based on scientific evidence, not on sales pitches by individuals with conflicts of interest.

Officials in communities all over the country have been misled by artificial turf salespeople. They were erroneously told that these products are safe. On the contrary, there is clear scientific evidence that these materials are harmful. The only question is how much exposure is likely to be harmful to which children? We should not be willing to take such a risk. Our children deserve better.

Sincerely,

Diana Zuckerman, Ph.D.

President

 

References

  1. State of California-Office of Environmental Health Hazard Assessment (OEHHA), Contractor’s Report to the Board. Evaluation of Health Effects of Recycled Waste Tires in Playground and Track Products. January 2007. http://www.calrecycle.ca.gov/publications/Documents/Tires%5C62206013.pdf
  2. Benoit G, Demars S. Evaluation of organic and inorganic compounds extractable by multiple methods from commercially available crumb rubber mulch. Water, Air, & Soil Pollution. 2018;229:64. https://doi.org/10.1007/s11270-018-3711-7
  3. Anderson SE and Meade BJ. Potential Health Effects Associated with Dermal Exposure to Occupational Chemicals. Environmental Health Insights. 2014; 8(Suppl 1):51–62. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4270264/
  4. York T. Greener grass awaits: Environmental & fiscal responsibility team up in synthetic turf. Recreation Management. February 2012. http://recmanagement.com/feature_print.php?fid=201202fe02
  5. Magnusson K, Eliasson K, Fråne A, et al. Swedish sources and pathways for microplastics to the marine environment, a review of existing data. Stockholm: IVL- Swedish Environmental Research Institute. 2016. https://www.naturvardsverket.se/upload/miljoarbete-i-samhallet/miljoarbete-i-sverige/regeringsuppdrag/utslapp-mikroplaster-havet/RU-mikroplaster-english-5-april-2017.pdf
  6. Kole PJ, Löhr AJ, Van Belleghem FGAJ, Ragas AMJ. Wear and tear of tyres: A stealthy source of microplastics in the environment. International Journal of Environmental Research Public Health. 2017;14(10):pii: E1265. https://www.ncbi.nlm.nih.gov/pubmed/29053641/
  7. Kosuth M, Mason SA, Wattenberg EV. Anthropogenic contamination of tap water, beer, and sea salt. PLoS One. 2018,13(4): e0194970. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5895013/
  8. Oehlmann J, Schulte-Oehlmann U, Kloas W et al.  A critical analysis of the biological impacts of plasticizers on wildlife. Philosophical Transactions of the Royal Society B. 2009;364:2047–2062. http://rstb.royalsocietypublishing.org/content/364/1526/2047
  9. Thompson RC, Moore CJ, vom Saal FS, Swan SH. Plastics, the environment and human health: Current consensus and future trends. Philosophical Transactions of the Royal Society B. 2009;364:2153–2166. https://royalsocietypublishing.org/doi/full/10.1098/rstb.2009.0053
  10. Thoms AW, Brosnana JT, Zidekb JM, Sorochana JC. Models for predicting surface temperatures on synthetic turf playing surfaces. Procedia Engineering. 2014;72:895-900. http://www.sciencedirect.com/science/article/pii/S1877705814006699
  11. Penn State’s Center for Sports Surface Research. Synthetic turf heat evaluation- progress report. 012. http://plantscience.psu.edu/research/centers/ssrc/documents/heat-progress-report.pdf
  12. Stier JC, Steinke K, Ervin EH, Higginson FR, McMaugh PE. Turfgrass benefits and issues. Turfgrass: Biology, Use, and Management, Agronomy Monograph 56. American Society of Agronomy, Crop Science Society of America, Soil Science Society of America. 2013;105–145. https://dl.sciencesocieties.org/publications/books/tocs/agronomymonogra/turfgrassbiolog

NCHR Comments on CPSC Priorities for FY2021/2022

National Center for Health Research, April 2020


Diana Zuckerman, Ph.D., President of the National Center for Health Research

Comments on the U.S. Consumer Product Safety Commission
Agenda and Priorities for FY2021/2022

April 2020

The National Center for Health Research is a nonprofit research center staffed by scientists, medical professionals, and public health experts who analyze and review research on a range of health issues. Thank you for the opportunity to share our views concerning the Consumer Product Safety Commission’s (CPSC) priorities for fiscal years 2021 and 2022. We greatly respect the essential role of the CPSC, as well as the challenges you face in selecting the most important priorities.

We want to start by emphasizing two issues involving chemicals in products that affect our and our children’s health, (1) artificial turf and playground surfaces and equipment, and (2) organohalogen flame retardants. We will also briefly discuss sport and recreational helmets, sleep-related products for infants, furniture stability, home elevators, and liquid nicotine packaging. All these issues should be CPSC priorities.

Artificial Turf and Playgrounds: Risky Chemicals and Lead

We expressed our concerns about artificial turf and playgrounds last year. Our concerns are even greater this year because of increasing evidence of lead exposure from these products, as well as from playground equipment.

Requiring testing for artificial turf, playground surfaces, and the paint used for playground equipment needs to be a priority, because children are exposed to these synthetic rubber and plastic fields and playground surfaces as well as playground equipment – and the lead and harmful chemicals they contain – day after day, year after year.

A new issue that arose in the last year is research indicating that the paint used on outdoor playground equipment contains lead. Professor Alexander Wooten from Morgan State conducted studies in Maryland that indicate that paint with lead is widely used on playground equipment, such as climbing structures, in some cases at very dangerous levels.1 We have learned that there are no federal restrictions on lead used in outdoor paint, even for products used exclusively by young children. CPSC should investigate this issue immediately.

The rubber and plastic that make up turf and playground surfaces contain chemicals with known health risks, which are released into the air and get onto skin and clothing. Crumb rubber – whether from recycled tires or “virgin rubber”– includes endocrine disruptors such as phthalates, heavy metals such as lead and zinc, as well as other carcinogens and skin irritants such as some polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs).2,3,4,5,6 Other plastic or rubber surfaces used in playgrounds also contain many of these chemicals.7 Moreover, the plastic grass in artificial turf also has dangerous levels of lead, PFAS, and other toxic chemicals as well. PFAS are of particular concern because they are “forever chemicals” that get into the human body and are not metabolized, accumulating over the years. Replacing tire waste with silica, zeolite, and other materials also has substantial risks.

Tire crumb is widely used as infill for artificial turf fields and also used for colorful rubber playground surfaces. In addition to the chemicals noted above, these playground surfaces contain lead and create lead dust on the surface that is invisible to the eye but that children are breathing in when they play.8

The CPSC is well aware that no level of lead exposure is safe for children, because lead can cause cognitive damage even at low levels. Some children are even more vulnerable than others, and this vulnerability can be difficult or even impossible to predict. Since lead has been found in tire crumb as well as new synthetic rubber, it is not surprising that numerous artificial turf fields and playgrounds made with either tire crumb or “virgin” rubber have been found to contain lead. However, the Centers for Disease Control and Prevention (CDC) also warns that the “plastic grass” made with nylon or other materials also contain lead. Whether from infill or from plastic grass, the lead doesn’t just stay on the surface – it can get into clothes, on the skin, or into the air that children breathe.

While one-time or sporadic exposures are unlikely to cause long-term harm, children’s repeated exposures, especially during critical developmental periods, raise the likelihood of serious harm. There are few activities that children engage in for as many hours in their early years as those on playgrounds and playing fields.

We appreciate the CPSC’s ongoing efforts to investigate the safety of crumb rubber on playgrounds and playing fields. As your study using focus groups to examine children’s use of playgrounds and exposure to playground surfaces has shown, children who use playgrounds with artificial surfaces could be exposed to the chemicals in these surfaces.9 It is unfortunate that the EPA report on artificial turf (which did not include playground surfaces or playground materials) did not provide the scientific evidence needed to support their assumptions that the likely levels of exposure to dangerous chemicals was low enough that it was not likely to harm children. The EPA did not study the actual impact of the exposure to endocrine disrupting chemicals on children and did not study lead exposure from synthetic playground surfaces, leaded paint used on playground equipment, or artificial turf.10

Meanwhile, we have repeatedly heard the companies that make these products and those that install them make erroneous claims at the state and local government levels, falsely stating that CPSC and other federal agencies have concluded that these materials are proven safe. As we all know, that is not correct.

We encourage you to closely evaluate the research that has been done, focusing on independently funded research of short-term and long-term safety issues. We need information that can protect our children from harm. In addition, we strongly urge you to convene a Chronic Hazard Advisory Panel (CHAP) to examine the short-term and long-term risks of different types of artificial turf used in playing fields and children’s playgrounds, including surfaces and lead paint used on climbing equipment and other materials.

In addition to the risks of lead and the long-term risks of cancer and other health problems caused by hormone disruption, these fields can cause short-term harms. Artificial turf generates dust which may exacerbate children’s asthma.11,12 Fields heat up to temperatures far higher than ambient temperature, reaching temperatures that are more than 70 degrees warmer than nearby grass; for example, 180 degrees when the temperature is in the high 90’s and 150-170 degrees on a sunny day when the air temperature is only in the 70’s.13,14 We have measured the temperatures ourselves and been shocked by the results. These temperatures can cause heat stress and burns.

Fields made of crumb rubber have been marketed as reducing injuries compared to grass. However, research has shown that this is not the case. We have spoken to students terribly harmed by turf burn, and studies have indicated increased risk for some types of injuries, including joint, foot, and brain injuries.15,16,17 That is the reason that only two Major League Baseball parks use artificial turf and why the men’s soccer World Cup is now always played on grass.  In response to the demands of women soccer players, the Women’s World Cup will require grass in 2023.

Organohalogen Flame Retardants

The National Academies of Sciences, Engineering, and Medicine issued their scoping plan to assess the hazards of organohalogen flame retardants (OFRs) last year.18 The report concluded that OFRs can be divided into subclasses on the basis of chemical structure, physicochemical properties, and predicted biologic activity. As noted in their summary of the report:

The committee identified 14 subclasses that can be used to conduct a class-based hazard assessment and concluded that the best approach is to define subclasses as broadly as is feasible for the analysis; defining subclasses too narrowly could defeat the purpose of a class approach to hazard assessment.

We encourage you to convene a CHAP to use this scoping plan to evaluate OFRs and to develop regulations to address OFRs in children’s products, upholstered residential furniture, mattresses/mattress pads, and the plastic casing of electronic devices. In addition, it is essential to consider current flammability standards to determine if there are changes that would improve their safety from chemical exposures as well as exposures during a fire.

OFRs are not bound to products to which they are added, so they migrate out of products and into dust. This allows them to get onto our skin and food and into the air. Because of their widespread use and the long-lasting nature of OFRs, consumers are continuously exposed to OFRs19 and many bioaccumulate in our food supply.20,21 As a result, OFRs are present in nearly all people in the U.S.22,23 For these reasons, CPSC should focus on the potential for hormone disruption, altered brain development, reduced ability to get and stay pregnant, and the timing of puberty.24,25 While not all OFRs have been adequately studied to determine whether all are unsafe, those that have been sufficiently studied have proved to be harmful to health.

We share the Commission’s concerns about fire hazards as well, but there is evidence that these flame retardants may not be effective at preventing deaths in real world situations.26,27 When the chemicals burn during a fire, the inhaled smoke is more toxic to humans, and exposures could result in serious harms, including death.

Helmets for Sport and Recreational Activities

There are up to 3.8 million concussions reported each year related to sport or recreational activities, with most reported for children and adolescents.28 This number is likely an underestimate.29 We urge the CPSC to focus greater attention on the need to ensure the effectiveness of helmets intended to protect against brain injuries during athletic activities. Currently, CPSC only provides guidelines for bicycle helmets, even though many organized sports and recreational activities use helmets to reduce the risk for severe head injuries, including baseball, football, snow sports, skiing/snowboarding, and climbing. Unfortunately, these helmets are not necessarily designed to prevent mild concussions.30 We encourage CPSC to consider how design changes could improve the ability of helmets to prevent severe head injuries as well as mild concussions, and to develop guidelines for helmets that reduce these risks without interfering with vision or hearing or other safety concerns.

Baby Products and Products Posing Risks to Young Children

The CPSC is the major safeguard to protect infants and young children from unsafe products that are widely sold and inadequately studied. Crib bumpers and infant sleepers are two examples that have received CPSC attention but CPSC has not adequately protected families from the tragedies of infant deaths caused by these products.

There is nothing more tragic than when an infant or young child dies due to a product in the home that families or loved ones purchased because they erroneously assumed they were tested and found to be safe. The standard for these products should not be based on the number of deaths per year, but rather the 1) risk to benefit ratio of the product and 2) whether regulations or restrictions would make the product safer. In the case of crib bumpers, they have no benefit. In the case of inclined infant sleepers, products were sold that were promoted as superior to other available products but in fact had no comparative benefits and were less safe.

Furniture that tips over and home elevators are two other examples of products that have resulted in deaths of young children. In both cases, CPSC should do more to prevent the sale of products that can be redesigned or modified to make them safe.

Liquid Nicotine Packaging

We agree with other public health and consumer organizations that have urged CPSC to immediately remove from the market dangerous liquid nicotine products lacking the child-resistant packaging and flow restrictors required under the Child Nicotine Poisoning Prevention Act of 2015. The law requires the CPSC to enforce a mandatory child-resistant packaging standard for liquid nicotine containers, including the use of flow restrictors.

Liquid nicotine is a highly toxic product that can seriously harm or kill children. Since liquid nicotine can be quickly absorbed through the skin, flow restrictors are an essential safeguard to reduce the risk of nicotine poisoning in children.

Effective CPSC enforcement measures to remove noncompliant products from the market are long overdue, and that enforcement should be an immediate priority.

Final Thoughts

CPSC is the only federal agency whose mission is to protect children and adults from harmful products used in their daily life. Flame retardants and lead and many different chemicals in artificial turf and playground surfaces and equipment get into the air and dust and thus into our bodies. These chemicals tend to have greater risks for fetuses and children. There are large gaps in our knowledge about the chemicals in the products on the market, because the companies do not provide that information to the public. Ideally, the potential health impact of all of these chemicals would be evaluated in the final product before it was sold. If that doesn’t happen, CPSC must do more to identify the health risks as soon as possible after children and adults have been exposed.

Too often, the lack of independently funded and publicly available research has been used to mislead the public. Claims that “there is no evidence of harm” are misunderstood to mean “there is no harm.”

While reducing exposures to dangerous products is key, there will always be some potential for harm. Whether those harms are from the intended use of a consumer product or an unintended but foreseeable use, CPSC has a very important role to play in reducing harm. Improving the timeliness and targeting of information campaigns to warn parents and children about harmful products is also a key task of the CPSC.

References

  1. Wooten, Alexander, Lead and Playgrounds, Presentation at the Takoma community forum in Washington, DC, July 29, 2019.
  2. California Office of Environmental Health Hazard Assessment (OEHHA). Evaluation of Health Effects of Recycled Waste Wires in Playground and Track Products. Prepared for the California Integrated Waste Management Board. 2007. https://www2.calrecycle.ca.gov/Publications/Details/1206
  3. Llompart M, Sanchez-Prado L, Lamas JP, et al. Hazardous organic chemicals in rubber recycled tire playgrounds and pavers. Chemosphere. 2013;90(2):423-431. https://www.ncbi.nlm.nih.gov/pubmed/22921644/
  4. Marsili L, Coppola D, Bianchi N, et al. Release of polycyclic aromatic hydrocarbons and heavy metals from rubber crumb in synthetic turf fields: Preliminary hazard assessment for athletes. Journal of Environmental and Analytical Toxicology. 2014;5(2):1133-1149. https://www.hilarispublisher.com/open-access/release-of-polycyclic-aromatic-hydrocarbons-and-heavy-metals-from-rubber-crumb-in-synthetic-turf-fields-2161-0525.1000265.pdf
  5. Benoit G, Demars S. Evaluation of organic and inorganic compounds extractable by multiple methods from commercially available crumb rubber mulch. Water, Air, & Soil Pollution. 2018;229:64. https://link.springer.com/article/10.1007/s11270-018-3711-7
  6. Perkins AN, Inayat-Hussain SH, Deziel NC, et al. Evaluation of potential carcinogenicity of organic chemicals in synthetic turf crumb rubber. Environmental Research. 2018;169:163–172. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6396308/
  7. KimS, Yang JY, Kim HH, et al. Health risk assessment of lead ingestion exposure by particle sizes in crumb rubber on artificial turf considering bioavailability. Environmental Health and Toxicology. 2012;27:e2012005. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3278598/
  8. Baca, N. Parents demand answers on playground lead in DC. wusa9.com. October 2, 2019. https://www.wusa9.com/article/news/local/dc/parent-forum-lead-playgrounds/65-45401b01-3371-436a-8f55-a364be0c07d3
  9. Consumer Product Safety Commission. Summary of Playground Surfacing Focus Groups. 2018. https://www.cpsc.gov/s3fs-public/Playground_Surfacing_Focus_Group_Report_2018.pdf
  10. National Center for Health Research. Children and Athletes at Play on Toxic Turf and Playgrounds. Center4research.org. http://www.center4research.org/children-athletes-play-toxic-turf-playgrounds/
  11. Shalat, SL. An Evaluation of Potential Exposures to Lead and Other Metals as the Result of Aerosolized Particulate Matter from Artificial Turf Playing Fields. Submitted to the New Jersey Department of Environmental Protection. 2011. http://www.nj.gov/dep/dsr/publications/artificial-turf-report.pdf
  12. Mount Sinai Children’s Environmental Health Center. Artificial Turf: A Health-Based Consumer Guide. 2017. http://icahn.mssm.edu/files/ISMMS/Assets/Departments/Environmental%20Medicine%20and%20Public%20Health/CEHC%20Consumer%20Guide%20to%20Artificial%20Turf%20May%202017.pdf
  13. Serensits TJ, McNitt AS, Petrunak DM. Human health issues on synthetic turf in the USA. Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology. 2011;225(3):139-146. https://plantscience.psu.edu/research/centers/ssrc/documents/human-health-issues-on-synthetic-turf-in-the-usa.pdf
  14. Penn State’s Center for Sports Surface Research. Synthetic Turf Heat Evaluation- Progress Report. 2012. http://plantscience.psu.edu/research/centers/ssrc/documents/heat-progress-report.pdf
  15. Theobald P, Whitelegg L, Nokes LD, et al. The predicted risk of head injury from fall-related impacts on to third-generation artificial turf and grass soccer surfaces: A comparative biomechanical analysis. Sports Biomechanics. 2010;9(1):29-37. https://www.ncbi.nlm.nih.gov/pubmed/20446637
  16. Balazs GC, Pavey GJ, Brelin AM, et al. Risk of anterior cruciate ligament injury in athletes on synthetic playing surfaces: A systematic review. American Journal of Sports Medicine. 2015;43(7):1798-804. https://www.ncbi.nlm.nih.gov/pubmed/25164575
  17. Mack CD, Hershman EB, Anderson RB, et al. Higher rates of lower extremity injury on synthetic turf compared with natural turf among national football league athletes: Epidemiologic confirmation of a biomechanical hypothesis. American Journal of Sports Medicine. 2019;47(1):189-196. https://www.ncbi.nlm.nih.gov/pubmed/30452873
  18. National Academies of Sciences, Engineering, and Medicine; Division on Earth and Life Studies; Board on Environmental Studies and Toxicology; Committee to Develop a Scoping Plan to Assess the Hazards of Organohalogen Flame Retardants. A Class Approach to Hazard Assessment of Organohalogen Flame Retardants. Washington (DC): National Academies Press (US). 2019. https://www.ncbi.nlm.nih.gov/books/NBK545458/
  19. Allgood JM, Vahid KS, Jeeva K, et al. Spatiotemporal analysis of human exposure to halogenated flame retardant chemicals. Science of the Total Environment. 2017;609:272-276. https://www.ncbi.nlm.nih.gov/pubmed/28750230
  20. Lupton SJ, Hakk H. Polybrominated diphenyl ethers (PBDEs) in US meat and poultry: 2012-13 levels, trends and estimated consumer exposures. Food Additives & Contaminants. Part A, Chemistry, Analysis, Control, Exposure & Risk Assessment. 2017;34(9):1584-1595. https://www.ncbi.nlm.nih.gov/pubmed/28604253
  21. Schecter A, Colacino J, Patel K, et al. Polybrominated diphenyl ether levels in foodstuffs collected from three locations from the United States. Toxicology and Applied Pharmacology. 2010;243(2):217-224. https://www.ncbi.nlm.nih.gov/pubmed/19835901
  22. Centers for Disease Control and Prevention. Fourth National Report on Human Exposure to Environmental Chemicals, Updated Tables. 2019. http://www.cdc.gov/exposurereport/
  23. Ospina M, Jayatilaka N, Wong LY, et al. Exposure to organophosphate flame retardant chemicals in the U.S. general population: Data from the 2013-2014 National Health and Nutrition Examination Survey. Environment International. 2017;110:32–41. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6261284/
  24. Dishaw L, Macaulay L, Roberts SC, et al. Exposures, mechanisms, and impacts of endocrine-active flame retardants. Current Opinion in Pharmacology. 2014;19:125-133. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4252719/
  25. Kim YR, Harden FA, Toms LM, et al. Health consequences of exposure to brominated flame retardants: A systematic review. Chemosphere. 2014;106:1-19. https://www.ncbi.nlm.nih.gov/pubmed/24529398
  26. Shaw SD, Blum A, Weber R, et al. Halogenated flame retardants: Do the fire safety benefits justify the risks? Reviews on Environmental Health. 2010;25:261-305. https://www.ncbi.nlm.nih.gov/pubmed/21268442
  27. McKenna S, Birtles R, Dickens K, et al. Flame retardants in UK furniture increase smoke toxicity more than they reduce fire growth rate. Chemosphere. 2018;196:429-439. https://www.ncbi.nlm.nih.gov/pubmed/29324384
  28. Halstead ME, Walter KD, Moffatt K, et al. Sport-related concussion in children and adolescents. Pediatrics. 2018;142(6):e20183074. https://pediatrics.aappublications.org/content/142/6/e20183074
  29. Baldwin GT, Breiding MJ, Dawn Comstock R. Epidemiology of sports concussion in the United States. Handbook of Clinical Neurology. 2018;158:163-74. https://www.ncbi.nlm.nih.gov/pubmed/30482376
  30. Consumer Product Safety Commission. Which helmet for which activity? https://www.cpsc.gov/safety-education/safety-guides/sports-fitness-and-recreation-bicycles/which-helmet-which-activity
  31. Perry, C. Why Inclined Baby Sleepers Are So Dangerous. Parents.com. November 8, 2019. https://www.parents.com/baby/sleep/basics/why-inclined-baby-sleepers-are-so-dangerous/

National Center for Health Research Written Statement to Greenwich Board of Education

National Center for Health Research, February 19, 2020


Written Statement to Greenwich Board of Education

Diana Zuckerman, PhD, National Center for Health Research

February 19, 2020

Dear Chairman Bernstein and Members of the Greenwich Board of Education:

I am disappointed that I was unable to be there in person for your meeting on February 20, but I wanted to update you on the latest research about the health risks of artificial turf for children and adults.

As President of the National Center for Health Research, I want to share the information we have provided to Members of Congress, state and federal agencies, state and local legislators, parents, and others who want to ensure that our children are not exposed to dangerous chemicals or metals when they play on artificial turf or playgrounds. Our nonprofit think tank is located in Washington, D.C. Our scientists, physicians, and health experts conduct studies and scrutinize research. Our goal is to explain scientific and medical information that can be used to improve policies, programs, services, and products.

We commend you for considering the possible risks of replacing grass fields with artificial turf. In the last year, we’ve learned new information about lead and PFAS in artificial turf, as well as the risks of some of the newer infill materials that turf companies are using to replace tire crumb. Tire crumb has well-known risks, containing chemicals that have the potential to increase obesity; contribute to early puberty; cause attention problems such as ADHD; exacerbate asthma; and eventually cause cancer. However, the plastic grass itself has dangerous levels of lead, PFAS, and other toxic chemicals as well.  PFAS are of particular concern because they are “forever chemicals” that get into the human body and are not metabolized, accumulating over the years. Replacing tire waste with silica, zeolite, and other materials also has substantial risks.

Federal agencies such as the EPA and the U.S. Consumer Product Safety Commission have been investigating the safety of these products. Despite claims to the contrary, none have concluded that artificial turf is safe. Although the Trump Administration’s EPA stated that there was no conclusive evidence that the levels of chemicals in artificial turf was harmful to children, they made it clear that their research was based on assumptions rather than scientific research on children.

Lead

As you know, the American Academy of Pediatrics states that no level of lead exposure should be considered safe for children, because lead can cause cognitive damage even at low levels. Some children are more vulnerable than others, and that can be difficult or even impossible to predict. Since lead has been found in tire crumb as well as new synthetic rubber, it is not surprising that numerous artificial turf fields and playgrounds made with either tire crumb or “virgin” rubber have been found to contain lead. However, the Centers for Disease Control and Prevention (CDC) also warns that the “plastic grass” made with nylon or some other materials also contain lead. Whether from infill or from plastic grass, the lead doesn’t just stay on the surface. With wear, the turf materials turn to dust that is invisible to the eye but that children are breathing in when they play.

Why are chemicals that are banned from children’s toys allowed in artificial turf and rubber playground surfaces?

Synthetic rubber and plastic are made with different types of endocrine (hormone) disrupting chemicals (also called EDCs). There is very good evidence regarding these chemicals in tire crumb, based on studies done at Yale and by the California Office of Environmental Health Hazard Assessment (OEHHA).[1]

A 2018 report by Yale scientists detected 92 chemicals in samples from 6 different artificial turf companies, including unused bags of tire crumb. Unfortunately, the health risks of most of these chemicals had never been studied. However, 20% of the chemicals that had been tested are classified as probable carcinogens and 40% are irritants that can cause asthma or other breathing problems, or can irritate skin or eyes.[2]

There are numerous studies indicating that endocrine-disrupting chemicals found in rubber and plastic cause serious health problems. Scientists at the National Institute of Environmental Health Sciences (which is part of NIH) have concluded that unlike most other chemicals, hormone-disrupting chemicals can be dangerous at very low levels, and the exposures can also be dangerous when they combine with other exposures in our environment. 

That is why the Consumer Product Safety Commission has banned numerous endocrine-disrupting chemicals from toys and products used by children. The products involved, such as pacifiers and teething toys, are banned even though they would result in very short-term exposures compared to artificial turf or playground surfaces.

A report warning about possible harm to people who are exposed to rubber and other hormone disrupting chemicals at work explains that these chemicals “can mimic or block hormones and disrupt the body’s normal function, resulting in the potential for numerous health effects. Similar to hormones, EDC can function at very low doses in a tissue-specific manner and may exert non-traditional dose–response because of the complicated dynamics of hormone receptor occupancy and saturation.”[3]

Studies are beginning to demonstrate the contribution of skin exposure to the development of respiratory sensitization and altered pulmonary function. Not only does skin exposure have the potential to contribute to total body burden of a chemical, but also the skin is a highly biologically active organ capable of chemical metabolism and the initiation of a cascade of immunological events, potentially leading to adverse outcomes in other organ systems.

Scientific Evidence of Cancer and Other Systemic Harm

It is essential to distinguish between evidence of harm and evidence of safety. Like the Trump Administration’s EPA, companies that sell and install artificial turf often claim there is “no evidence children are harmed” or “no evidence that the fields cause cancer.” This is often misunderstood as meaning the products are safe or are proven to not cause harm. Neither is true.

It is true that there no clear evidence that an artificial turf field has caused specific children to develop cancer. However, the statement is misleading because it is virtually impossible to prove any chemical exposure causes one specific individual to develop cancer.

As an epidemiologist, I can also tell you that for decades there was no evidence that smoking or Agent Orange caused cancer. It took many years to develop that evidence, and the same will be true for artificial turf. 

I have testified about the risks of these materials at the U.S. Consumer Product Safety Commission as well as state legislatures and city councils. I am sorry to say that I have repeatedly seen and heard scientists paid by the turf industry and other turf industry lobbyists say things that are absolutely false. They claim that these products are proven safe (not true) and that federal agencies have stated there are no health risks (also not true). 

However, we know that the materials being used in artificial turf and rubber playground surfaces contain carcinogens, and when children are exposed to those carcinogens day after day, week after week, and year after year, they increase the chances of our children developing cancer, either in the next few years or later as adults. That should be adequate reason not to install them in your community. That’s why I have spoken out about the risks of artificial turf in my community and on a national level. The question must be asked: if they had all the facts, would Greenwich or any other community choose to spend millions of dollars on fields that are less safe than well-designed natural grass fields?

Dangerously Hot and Hard Fields

I lived in Connecticut for several years while on the faculty at Yale and Vassar, and I know the climate well. When the weather is warm and/or sunny, it is usually quite pleasant to be outside – as long as you aren’t on artificial turf or an outdoor rubber surface. Even when the temperature above the grass is 80 degrees Fahrenheit, artificial turf can reach 150 degrees or higher. Obviously, a 90 degree day is likely to be even hotter than 150 degrees on turf. That can cause “heat poisoning” as well as burns.

Artificial turf fields get hard as well. Turf companies recommend annual tests at 10 locations on each turf field, using something called a Gmax scores. A Gmax score over 200 is considered extremely dangerous and is considered by industry to pose a death risk. However, the synthetic turf industry and ASTM (American Society for Testing and Materials), suggest scores should be even lower — below 165 to ensure safety comparable to a grass field. Is Greenwich paying to have these tests conducted on all your public artificial turf fields?

The hardness of natural grass fields is substantially influenced by rain and other weather; if the field gets hard, rain or watering will make it safe again. In contrast, once an artificial turf field has a Gmax score above 165, it needs to be replaced because while the scores can vary somewhat due to weather, the scores will inevitably get higher because the turf will get harder. Gmax testing involves testing 10 different areas of a playing fields, to make sure all are considered safe.  Some officials average those 10 scores to determine safety; however, experts explain that is not appropriate. If a child (or adult) falls, it can be at the hardest part of the field, which is why that is the way safety is determined.

Environmental Issues

In addition to the health risks to school children and athletes, approximately three tons of infill materials migrate off of each synthetic turf field into the greater environment each year. About 2-5 metric tons of infill must be replaced every year for each field, meaning that tons of the infill have migrated off the field into grass, water, and our homes.[4] The fields also continuously shed microplastics as the plastic blades break down.[5,6] These materials may contain additives such as PAHs, flame retardants, UV inhibitors, etc., which can be toxic to marine and aquatic life; and microplastics are known to migrate into the oceans, food chain, and drinking water and can absorb and concentrate other toxins from the environment.[7,8,9]

Synthetic surfaces also create heat islands.10,11 In contrast, organically managed natural grass saves energy by dissipating heat, cooling the air, and reducing energy to cool nearby buildings. Natural grass and soil protect groundwater quality, biodegrade polluting chemicals and bacteria, reduce surface water runoff, and abate noise and reduce glare.[12]

Envirofill and Alternative Infills

Envirofill artificial turf fields are advertised as “cooler” and safer, but our research indicates that these fields are still at least 30-50 degrees hotter than natural grass. Envirofill is composed of materials resembling plastic polymer pellets (similar in appearance to tic tacs) with silica inside. Silica is classified as a hazardous material according to OSHA regulations, and the American Academy of Pediatrics specifically recommends avoiding it on playgrounds. The manufacturers and vendors of these products claim that the silica stays inside the plastic coating. However, sunlight and the grinding force from playing on the field breaks down the plastic coating. For that reason, even the product warranty admits that only 70% of the silica will remain encapsulated. The other 30% can be very harmful as children are exposed to it in the air. 

In addition, the Envirofill pellets have been coated with an antibacterial called triclosan. Triclosan is registered as a pesticide with the EPA and the FDA has banned triclosan from soaps because manufacturers were not able to prove that it is safe for long-term use. Research shows a link to liver and inhalation toxicity and hormone disruption. The manufacturer of Envirofill says that the company no longer uses triclosan, but they provide no scientific evidence that the antibacterial they are now using is any safer than triclosan. Microscopic particles of this synthetic turf infill will be inhaled by children, and visible and invisible particles come off of the field, ending up in shoes, socks, pockets, and hair.

In response to the concerns of educated parents and government officials, other new materials are now being used instead of tire crumb and other very controversial materials. However, all the materials being used (such as volcanic ash, corn husks, and Corkonut) have raised concerns and none are proven to be as safe or effective as well-designed grass fields. 

Conclusions

There have never been any safety tests required prior to sale that prove that any artificial turf products are safe for children who play on them regularly. In many cases, the materials used are not publicly disclosed, making independent research difficult to conduct. None of these products are proven to be as safe as natural grass in well-constructed fields. 

I have cited several relevant scientific articles on artificial turf in this letter, and there are numerous studies and growing evidence of the harm caused by these synthetic materials. I would be happy to provide additional information upon request (dz@center4research.org).

I am not paid to write this statement. I am one of the many parents and scientists who are very concerned about the impact of artificial fields on our children. Last year, I told members of the BET that their decision about artificial turf can save lives and improve the health of children in Greenwich.  You owe it to your community to make sure you know the risks of artificial turf and do all you can to protect Greenwich children from the known risks and also the suspected risks.  Because of Greenwich’s reputation as a well-educated and affluent community, your decisions about artificial turf in Greenwich will be cited by other communities, making it even more important that your decision is based on scientific evidence, not on sales pitches by individuals with conflicts of interest.

Officials in communities all over the country have been misled by artificial turf salespeople. They were erroneously told that these products are safe. But on the contrary, there is clear scientific evidence that these materials are harmful. The only question is how much exposure is likely to be harmful to which children? We should not be willing to take such a risk. Our children deserve better.

Sincerely,

Diana Zuckerman, Ph.D.

President

The PDF of this letter can be found here.

References

  1. State of California-Office of Environmental Health Hazard Assessment (OEHHA), Contractor’s Report to the Board. Evaluation of Health Effects of Recycled Waste Tires in Playground and Track Products. January 2007. http://www.calrecycle.ca.gov/publications/Documents/Tires%5C62206013.pdf 
  2. Benoit G, Demars S. Evaluation of organic and inorganic compounds extractable by multiple methods from commercially available crumb rubber mulch. Water, Air, & Soil Pollution. 2018;229:64. https://doi.org/10.1007/s11270-018-3711-7 
  3. Anderson SE and Meade BJ. Potential Health Effects Associated with Dermal Exposure to Occupational Chemicals. Environmental Health Insights. 2014; 8(Suppl 1):51–62. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4270264/
  4. York T. Greener grass awaits: Environmental & fiscal responsibility team up in synthetic turf. Recreation Management. February 2012. http://recmanagement.com/feature_print.php?fid=201202fe02
  5. Magnusson K, Eliasson K, Fråne A, et al. Swedish sources and pathways for microplastics to the marine environment, a review of existing data. Stockholm: IVL- Swedish Environmental Research Institute. 2016. https://www.naturvardsverket.se/upload/miljoarbete-i-samhallet/miljoarbete-i-sverige/regeringsuppdrag/utslapp-mikroplaster-havet/RU-mikroplaster-english-5-april-2017.pdf
  6. Kole PJ, Löhr AJ, Van Belleghem FGAJ, Ragas AMJ. Wear and tear of tyres: A stealthy source of microplastics in the environment. International Journal of Environmental Research Public Health. 2017;14(10):pii: E1265. https://www.ncbi.nlm.nih.gov/pubmed/29053641/
  7. Kosuth M, Mason SA, Wattenberg EV. Anthropogenic contamination of tap water, beer, and sea salt. PLoS One. 2018,13(4): e0194970. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5895013/
  8. Oehlmann J, Schulte-Oehlmann U, Kloas W et al.  A critical analysis of the biological impacts of plasticizers on wildlife. Philosophical Transactions of the Royal Society B. 2009;364:2047–2062. http://rstb.royalsocietypublishing.org/content/364/1526/2047
  9. Thompson RC, Moore CJ, vom Saal FS, Swan SH. Plastics, the environment and human health: Current consensus and future trends. Philosophical Transactions of the Royal Society B. 2009;364:2153–2166. https://royalsocietypublishing.org/doi/full/10.1098/rstb.2009.0053
  10. Thoms AW, Brosnana JT, Zidekb JM, Sorochana JC. Models for predicting surface temperatures on synthetic turf playing surfaces. Procedia Engineering. 2014;72:895-900. http://www.sciencedirect.com/science/article/pii/S1877705814006699
  11. Penn State’s Center for Sports Surface Research. Synthetic turf heat evaluation- progress report. 012. http://plantscience.psu.edu/research/centers/ssrc/documents/heat-progress-report.pdf
  12. Stier JC, Steinke K, Ervin EH, Higginson FR, McMaugh PE. Turfgrass benefits and issues. Turfgrass: Biology, Use, and Management, Agronomy Monograph 56. American Society of Agronomy, Crop Science Society of America, Soil Science Society of America. 2013;105–145. https://dl.sciencesocieties.org/publications/books/tocs/agronomymonogra/turfgrassbiolog

NCHR Letter to Mayor Cohn and Members of the Rye City Council Concerning Artificial Turf and Playgrounds

National Center for Health Research, October 16th, 2019


Dear Mayor Cohn and Members of the Rye City Council:

I am writing on behalf of the National Center for Health Research.  Our nonprofit think tank is located in Washington, D.C. Our scientists, physicians, and health experts conduct studies and scrutinize research. Our goal is to explain scientific and medical information that can be used to improve policies, programs, services, and products.   We have been contacted by families in Rye who are concerned about the risks of artificial turf and playgrounds. We are impressed with their knowledge and agree with them that converting grass fields to artificial turf poses unnecessary dangers to children in your community.

As a scientist who has worked on health policy issues for more than 30 years, I don’t shock easily.  However, it is shocking and disturbing that artificial turf athletic fields and playgrounds are exposing children on a daily basis to chemicals and materials that are known to have the potential to increase obesity; contribute to early puberty; cause attention problems such as ADHD; harbor deadly bacteria; exacerbate asthma; and eventually cause cancer.

Federal agencies such as the EPA and the U.S. Consumer Product Safety Commission have been investigating the safety of these products. A recently released EPA report found toxic chemicals in artificial turf, but did not evaluate whether or not the level of exposure would harm children.  Despite claims to the contrary, no federal agency has concluded that artificial turf is safe.

Scientific Evidence of Cancer and Other Systemic Harm

First, it is important to distinguish between evidence of harm and evidence of safety.  Companies that sell and install artificial turf often claim there is “no evidence that children are harmed” or “no evidence that the fields cause cancer.”  This is often misunderstood as meaning the products are safe or are proven to not cause harm. Neither is true.

The artificial turf industry will tell you there is no clear evidence that their fields caused any child to develop cancer.  That is true, but the statement is misleading because it is virtually impossible to prove any chemical exposure causes one specific individual to develop cancer.

As an epidemiologist, I can also tell you that for decades there was no evidence that smoking or Agent Orange caused cancer. It took many years to develop that evidence, and the same will be true for artificial turf.

I have testified about the risks of these materials at the U.S. Consumer Product Safety Commission as well as state legislatures and city councils. I am sorry to say that I have repeatedly seen and heard scientists paid by the turf industry and other turf industry lobbyists say things that are absolutely false. They claim that these products are proven safe (not true) and that federal agencies have stated there are no health risks (also not true).

Most research has focused on the risks of infill made from recycled tire waste. However, recent research has indicated the presence of dangerous levels of chemicals in the plastic blades of grass as well as in the tire waste. So, even if the infill is replaced with a safer materials, the plastic grass carpet itself is dangerous.

We know that the materials being used contain carcinogens, and when children are exposed to those carcinogens day after day, week after week, and year after year, they increase the chances of our children developing cancer, either in the next few years or later as adults. That should be adequate reason not to install them in your community. That’s why I have spoken out about the risks of artificial turf in my community and on a national level. The question must be asked: if they had all the facts, would Rye or any other community choose to spend millions of dollars on fields that are less safe than well-designed natural grass fields?

Synthetic rubber and plastic are made with different types of endocrine (hormone) disrupting chemicals as well as carcinogens.  There is very good evidence regarding these chemicals in tire crumb, based on studies done at Yale and by the California Office of Environmental Health Hazard Assessment (OEHHA). [1]

A 2015 report by Yale scientists detected 96 chemicals in samples from 5 different artificial turf companies, including unused bags of tire crumb. Unfortunately, the health risks of most of these chemicals had never been studied.  However, 20% of the chemicals that had been tested are classified as probable carcinogens and 40% are irritants that can cause asthma or other breathing problems, or can irritate skin or eyes. [2]

There are numerous studies on the impact of hormone-disrupting chemicals (also called endocrine disrupting chemicals or EDCs), and the evidence is clear that these chemicals found in rubber and plastic cause serious health problems.  Scientists at the National Institute of Environmental Health Sciences (which is part of NIH) have concluded that unlike most other chemicals, hormone-disrupting chemicals can be dangerous at very low levels, and the exposures can also be dangerous when they combine with other exposures in our environment.

That is why the Consumer Product Safety Commission has banned numerous endocrine-disrupting chemicals from toys and products used by children. The products involved, such as pacifiers and teething toys, have been banned for more than a decade, even though they would result in very short-term exposures compared to artificial turf.

A report warning about possible harm to people who are exposed to rubber and other hormone disrupting chemicals at work explains that these chemicals “can mimic or block hormones and disrupt the body’s normal function, resulting in the potential for numerous health effects.  Similar to hormones, EDC can function at very low doses in a tissue-specific manner and may exert non-traditional dose–response because of the complicated dynamics of hormone receptor occupancy and saturation.”[3]

Studies are beginning to demonstrate the contribution of skin exposure to the development of respiratory sensitization and altered pulmonary function. Not only does skin exposure have the potential to contribute to total body burden of a chemical, but also the skin is a highly biologically active organ capable of chemical metabolism and the initiation of a cascade of immunological events, potentially leading to adverse outcomes in other organ systems.

Envirofill and Alternative Infills

Artificial turf fields are often 50-70 degrees hotter (or more) compared to grass fields, and this can be dangerous for children on a warm day.  Envirofill artificial turf fields is advertised as “cooler” and safer than tire crumb, but our research indicates that these fields are still at least 30-50 degrees hotter than natural grass.  Envirofill is composed of materials resembling plastic polymer pellets (similar in appearance to tic tacs) with silica inside.  Silica is classified as a hazardous material according to OSHA regulations, and the American Academy of Pediatrics specifically recommends avoiding it on playgrounds. The manufacturers and vendors of these products claim that the silica stays inside the plastic coating.  However, sunlight and the grinding force from playing on the field breaks down the plastic coating.   For that reason, even the product warranty admits that only 70% of the silica will remain encapsulated.  The other 30% can be very harmful as children are exposed to it in the air.

In addition, the Envirofill pellets have been coated with an antibacterial called triclosan.  Triclosan is registered as a pesticide with the EPA and the FDA has banned triclosan from soaps because manufacturers were not able to prove that it is safe for long-term use.  Research shows a link to liver and inhalation toxicity and hormone disruption.  The manufacturer of Envirofill says that the company no longer uses triclosan, but they provide no scientific evidence that the antibacterial they are now using is any safer than triclosan.  Microscopic particles of this synthetic turf infill will be inhaled by children, and visible and invisible particles come off of the field, ending up in shoes, socks, pockets, and hair.

In response to the concerns of educated parents and government officials, other new materials are now being used instead of tire crumb and other very controversial materials.  However, all the materials being used (such as volcanic rock, corn husks, and Corkonut) have raised concerns and none are proven to be as safe or effective as well-designed grass fields.  And as noted above, the plastic grass itself is made from dangerous chemicals.

Dangerously Hard Fields, Turf Burns, and Hot Fields

I want to briefly mention safety issues pertaining to Gmax scores.  A Gmax score measures how hard a field is, specifically regarding brain injuries.  A score over 200 is considered extremely dangerous and is considered by the synthetic turf industry to pose a death risk.  However, the synthetic turf industry and ASTM (American Society for Testing and Materials), suggest scores should be even lower — below 165 to ensure safety comparable to a grass field.

The hardness of natural grass fields is substantially influenced by rain and other weather; if the field gets hard, rain or watering will make it safe again.  In contrast, once an artificial turf field has a Gmax score above 165, it needs to be replaced because while the scores can vary somewhat due to weather, the scores will inevitably get higher because the turf will get harder.  Gmax testing involves testing 10 different areas of a playing fields, and some officials average those 10 scores to determine safety.  However, experts explain that is not appropriate.  If a child (or adult) falls, it can be at the hardest part of the field, which is why that is the way safety is determined.

In addition to hard fields, artificial turf is more likely to cause “turf burns” which can be very painful and can get infected.  There is a good reason why almost all professional baseball parks use grass rather than artificial turf, and why professional football and soccer teams also prefer natural grass.

In addition to the health risks to school children and athletes, approximately three tons of infill materials migrate off of each synthetic turf field into the greater environment each year.  About 2-5 metric tons of infill must be replaced every year for each field, meaning that tons of the infill have migrated off the field into grass, water, and our homes.[4] The fields also continuously shed microplastics as the plastic blades break down.[5,6] These materials may contain additives such as PAHs, flame retardants, UV inhibitors, etc., which can be toxic to marine and aquatic life; and microplastics are known to migrate into the oceans, food chain, and drinking water and can absorb and concentrate other toxins from the environment. [7,8,9]

As noted above, artificial turf gets much hotter than grass, and so does the air above it.  Synthetic surfaces create heat islands. [10,11] In contrast, organically managed natural grass saves energy by dissipating heat, cooling the air, and reducing energy to cool nearby buildings.  Natural grass and soil protect groundwater quality, biodegrade polluting chemicals and bacteria, reduce surface water runoff, and abate noise and reduce glare. [12]

Conclusions

There are currently no safety tests required prior to sale that prove that any artificial turf products are safe.  In many cases, the materials used are not made public, making independent research difficult to conduct. None of these products are proven to be as safe as natural grass in well-constructed fields.

I have cited several relevant scientific articles on artificial turf in this letter, and I can attest to the fact there are numerous studies and growing evidence of the harm caused by these synthetic materials. I would be happy to provide additional information upon request (dz@center4research.org or 202 223-4000).

I am not paid to write this statement. I am one of the many parents and scientists who are very concerned about the impact of artificial fields on our children.  Your decision about artificial turf can save lives and improve the health of children in Rye and will serve as a model to other communities.

Officials in communities all over the country have been misled by artificial turf salespeople. They were erroneously told that these products are safe.  But on the contrary, there is clear scientific evidence that these materials are potentially harmful. The only question is how harmful and how much exposure is likely to be harmful?  We should not be willing to take such a risk. Our children deserve better.

Sincerely,

Diana Zuckerman, PhD
President

 

References

  1. State of California-Office of Environmental Health Hazard Assessment (OEHHA), Contractor’s Report to the Board. Evaluation of Health Effects of Recycled Waste Tires in Playground and Track Products. January 2007. http://www.calrecycle.ca.gov/publications/Documents/Tires%5C62206013.pdf
  2. Yale Study Reveals Carcinogens and Skin Irritants in Synthetic Turf. http://wtnh.com/2015/09/03/new-yale-study-reveals-carcinogens-and-skin-irritants-in-synthetic-turf/
  3. Anderson SE and Meade BJ, Potential Health Effects Associated with Dermal Exposure to Occupational Chemicals, Environ Health Insights. 2014; 8(Suppl 1): pgs 51–62. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4270264/
  4. York T. Greener grass awaits: Environmental & fiscal responsibility team up in synthetic turf. Recreation Management. February 2012. http://recmanagement.com/feature_print.php?fid=201202fe02.
  5. Magnusson K, Eliasson K, Fråne A, et al. Swedish sources and pathways for microplastics to the marine environment, a review of existing data. Stockholm: IVL- Swedish Environmental Research Institute. 2016. https://www.naturvardsverket.se/upload/miljoarbete-i-samhallet/miljoarbete-i-sverige/regeringsuppdrag/utslapp-mikroplaster-havet/RU-mikroplaster-english-5-april-2017.pdf
  6. Kole PJ, Löhr AJ, Van Belleghem FGAJ, Ragas AMJ. Wear and tear of tyres: A stealthy source of microplastics in the environment. Int J Environ Res Public Health. 2017 14(10). pii: E1265. https://www.ncbi.nlm.nih.gov/pubmed/29053641/
  7. Kosuth M, Mason SA, Wattenberg EV. Anthropogenic contamination of tap water, beer, and sea salt. PLoS One. 2018. 13(4): e0194970. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5895013/
  8. Oehlmann J, Schulte-Oehlmann U, Kloas W et al.  A critical analysis of the biological impacts of plasticizers on wildlife. Phil Trans R Soc B. 2009. 364: 2047–2062. http://rstb.royalsocietypublishing.org/content/364/1526/2047
  9. Thompson RC, Moore CJ, vom Saal FS, Swan SH. Plastics, the environment and human health: Current consensus and future trends. Philos Trans R Soc Lond B. 2009. 364: 2153–2166.
  10. Thoms AW, Brosnana JT, Zidekb JM, Sorochana JC. Models for predicting surface temperatures on synthetic turf playing surfaces. Procedia Engineering. 2014. 72: 895-900. http://www.sciencedirect.com/science/article/pii/S1877705814006699
  11. Penn State’s Center for Sports Surface Research. Synthetic turf heat evaluation- progress report. 012. http://plantscience.psu.edu/research/centers/ssrc/documents/heat-progress-report.pdf
  12. Stier JC, Steinke K, Ervin EH, Higginson FR, McMaugh PE. Turfgrass benefits and issues. Turfgrass: Biology, Use, and Management, Agronomy Monograph 56. American Society of Agronomy, Crop Science Society of America, Soil Science Society of America. 2013. 105-145 https://dl.sciencesocieties.org/publications/books/tocs/agronomymonogra/turfgrassbiolog