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.
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
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
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 (firstname.lastname@example.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.
Diana Zuckerman, Ph.D.
- 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.
- 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
- 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/
- 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
- 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
- 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
- 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
- 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/
- 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/
- 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
- 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
- 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
- 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
- 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