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). 
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. 
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.”
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. 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. 
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 (firstname.lastname@example.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.
Diana Zuckerman, PhD
- 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
- 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/
- 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/
- 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.
- 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. Int J Environ Res 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. Phil Trans R Soc 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. Philos Trans R Soc Lond B. 2009. 364: 2153–2166.
- 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