Nyedra W. Booker PharmD MPH and Stephanie Fox-Rawlings PhD, National Center for Health Research.

Is your child playing on rubber instead of grass at the playground? The use of human-made surfaces on playgrounds has increased dramatically over the years. First developed in 1964, the first artificial turf was marketed as “Chemgrass” by Monsanto, and renamed Astroturf more than 2 years later when it was installed at the Houston Astro’s Astrodome football field.¹ 

In recent years, the use of artificial grass has become common, and playgrounds for young children are also made of artificial surfaces that look and feel like colorful rubber. When artificial turf was introduced in the 1960’s and rubber playground surfaces were introduced years later, nobody was concerned about microplastics in our bodies, PFAS forever chemicals, or lead in rubber mulch made from recycled tires.  But, research tells us that regardless of what they look like, artificial turf and rubber playground surfaces are all made with materials that can be dangerous for children and adults, and for our environment.

As the use of artificial turf for various sports activities increased significantly over the years, so did the concerns. Athletes began to complain that the surface was much harder than natural grass, and some studies began to show that the use of artificial turf could increase the risk of sports-related injuries. This prompted a ban on the use of artificial turf by the English Football Association in 1988, and many ballparks and professional sports stadiums in the United States began converting back to using natural grass during the 1990s. Over time,“infill” material such as recycled tire rubber was added to keep the blades of “grass” in place and provide more cushioning.¹ Artificial turf containing rubber and other cushioning materials was also assumed to reduce sports-related injuries, but study results have not supported that assumption.² Many professional athletes dislike playing on artificial turf. It increases the severity of abrasions due to sliding, puts additional stress on joints, and heats up much more than grass does in the sun – and can become dangerously hot.^3,4 Following their failure to force soccer’s international governing body (FIFA) to use sod instead of artificial turf for the 2015 Women’s World Cup, an international group of women players sued FIFA, although they ultimately dropped the law suit when FIFA refused to budge.⁵

Unwanted used tires used to be burned, but doing so released many different harmful chemicals into the air and ground water. We now know that tire rubber doesn’t need to be on fire to release chemicals into the air we breathe.⁶ Those chemicals can also get on our skin and clothes and even be inhaled into our lungs. 

Recycled tire crumb is often still used as an infill for artificial turf, although it is much more controversial than it used to be. Recycled tire material and other rubber is also used on playground surfaces for young children.

Recycling tires for use in artificial turf and playground surfaces seemed like a good idea, because it is a relatively soft surface that seems safer than dirt or grass. And recycling keeps old tires out of landfills where they take up space, harbor rodents and other animals, and trap standing water that serve as breeding grounds for mosquitoes and other disease-bearing insects.

Are Playground Surfaces Made With Rubber or Tire Crumb Safe?

Do you remember when children used to play on tire swings in the backyard or at the park? Those same tires are now being put to use in playgrounds for young children across the country. Recycled rubber tires have become one of the top choice materials for surfacing children’s playgrounds.⁸ Approximately 290 million tires are discarded in the U.S. annually,⁶ of which approximately 12% were processed for sports fields and playground surfaces.⁹

Did you think that rubber comes from a rubber plant and is therefore a safe and natural product? While rubber sold in the U.S. includes some natural rubber (called latex) from rubber trees, it also contains phthalates (chemicals that affect hormones), polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs) and other chemicals known or suspected to cause adverse health effects.¹⁰ PAHs, for example, are natural or human-made chemicals that are made when oil, gas, coal or garbage is burned.¹¹ According to the EPA, breathing air contaminated with PAHs may increase a person’s chance of developing cancer, and the Agency for Toxic Substances and Disease Registry (ATSDR) states that PAHs may increase the risk for cancer and also increase the chances of birth defects.^11,12

There are several different ways that recycled tire mulch and new rubber is
used on children’s playgrounds:

• Loose tire shred (rubber mulch) or “crumb” on a surface 
•  Tire shreds that are combined with a binder and then poured onto a surface that looks like solid rubber (called “Pour in Place”, or PIP)
•  Tiles made from tire shreds and binder that have been factory-molded, then glued to a playground surface.⁸
• Colorful rubber that is “poured in place” (PIP) that is not necessarily made from tires but contains many of the same dangerous materials.

Engineered Wood Fiber is a natural alternative to rubber surfaces for playgrounds and feels surprisingly soft and spongy. It looks like wood mulch but is made in a way that does not cause splinters, and they are not made with dangerous chemicals. Researchers at Harvard School of Public Health examined levels of lead in poured-in-place rubber playground surfaces and compared them to levels in soil, sand, and wood mulch materials from 28 randomly selected playgrounds in Boston.¹³ They found that average lead levels were more than twice as high for rubber as for sand or wood mulch. They concluded that the lower concentrations of lead in sand and wood mulch “should be used to inform playground design to optimize children’s health.”

What the Scientific Studies Say About Tire Waste

The California Office of Environmental Health Hazard Assessment (OEHHA) conducted three laboratory studies in 2007 to investigate the potential health risks to children from playground surfaces made from tire waste. One study evaluated the level of chemicals released that could cause harm to children after they have had contact with loose tire shreds, either by eating them or by touching them and then touching their mouth. The other two studies looked at the risk of injury from falls on playground surfaces made from tire waste compared to wood chips, and whether tire shreds could contaminate air or water.¹⁴

It would not be ethical to ask children to eat tire shreds, so the researchers created a chemical solution that mimicked the conditions of a child’s stomach and placed 10 grams of tire shreds in it for 21 hours at a temperature of 37°C. Researchers then measured the level of released chemicals in the solution and compared them to levels EPA considered risky.¹⁴ The study also mimicked a child touching the tire shreds and then touching her mouth by wiping recycled tire playground surfaces and measuring chemical levels on the wipes. To evaluate skin contact alone, the researchers tested guinea pigs to see if rubber tire playground samples caused any health problems. This study assumed that children would be using the playground from the ages of 1 through 12. Results of the OEHHA studies showed that a single incident of eating or touching tire shreds would probably not harm a child’s health, but repeated or long-term exposure might. Five chemicals, including four PAHs, were found on wipe samples. One of the PAHs, “chrysene,” was higher than the risk level established by the OEHHA, and therefore, could possibly increase the chances of a child developing cancer.

It is difficult to determine the level of exposure that can cause cancer. Just think of how many decades it took to prove that smoking causes lung cancer, and how many years after that before research showed that smoking causes breast cancer and other cancers as well. But in 2022, a study published in the Journal of the National Cancer Institute found that greater exposure to phthalates while in utero through age 19 years increased the chances of developing childhood cancer.¹⁵ Although the study is specifically about the phthalates used in medical products, the exposure is clearly relevant to other types of phthalate exposure, including phthalates in artificial turf.

A study for the New Jersey Department of Environmental Protection analyzed lead and other metals in particulate matter (dust) that is kicked up into the air by activity on the field, and thus, able to be inhaled, on 5 artificial turf fields.¹⁶ The study found that there was more particulate matter that could be inhaled in the air around a moving object (such as a child soccer player) than a stationary collection system on the side of the field. This suggests that studies using stationary collection systems underestimate exposures. It also suggests that even low levels of activity on the field can cause particulate matter to get into the air where it can be inhaled and thus be harmful. The oldest field studied (8 years old) had more inhalable particulate matter than the younger fields (1-3 years old) in this study. The authors concluded that, “the results suggest that there is a potential for inhalable lead to be present on turf fields that have significant amounts of lead present as detectable by surface wipes. Since no level of lead exposure is considered safe for children, “only a comprehensive mandated testing of fields can provide assurance that no health hazard on these fields exists from lead or other metals used in their construction and maintenance.”

A 2013 study analyzing rubber mulch taken from children’s playgrounds in Spain found harmful chemicals in all, often at high levels.¹⁰ Twenty-one samples were collected from 9 playgrounds in urban locations. The results showed that all samples contained at least one hazardous chemical, most contained high concentrations of several PAHs, and all released hazardous chemicals into the air, where they can be inhaled. Several of the identified PAHs can be released into the air by heat, and when that happens children are likely to inhale them. While the heat needed to do this was very high in some cases (140ºF/ 60ºC), many of the chemicals also became airborne at a much lower temperature of 77ºF (25ºC). The authors concluded, “The present study highlights the presence of a high number of harmful compounds, frequently at high or extremely high levels, in these recycled rubber materials. Therefore, they should be carefully controlled, and their final use should be restricted or even prohibited in some cases.” ¹⁰

A 2014 study evaluated recycled rubber infill that was either already installed or was yet to be installed, as well as one new sample from new “virgin” rubber.¹⁷ It found that levels of cadmium and zinc exceeded regulatory requirements for some or all samples, respectively. It also found very high levels of PAHs released into the air from some samples. After calculating a risk assessment for PAH inhalation from synthetic fields, the authors stated that “the quantity of toxic substances it releases when heated does not make it safe for public health.”

A 2018 study examined particulate matter and chemicals from 1 sample of recycled tire rubber, 2 new tire rubber, a single 7-year-old sample of natural rubber, and 1 sample of last-generation thermoplastic elastomer crumb (TPE).¹⁸ The recycled tire rubber had a greater concentration of toxic elements, such as heavy metals. TPE released the lowest amount of elements with high concentrations of only magnesium and calcium. Natural rubber was more sensitive to aging and more easily broke down into small pieces that could be inhaled. The authors concluded, “The use of natural rubber and of not-recycled thermoplastic materials, which are progressively replacing recycled tire scraps as synthetic turf fillers, does not seem to be adequately safe for human health, particularly when considering that children are the most exposed bracket of population. Exposure risks arising from the use of these materials deserve to be further deepened.”

A 2018 study in Spain evaluated the amount of chemicals released into the air from samples of recycled tire rubber infill from 15 soccer fields.¹⁹ They found high levels of PAHs, including the highly toxic B[a]P. The levels of PAHs exceeded REACH Regulations for consumer products. The study also found heavy metals such as cadmium, chromium and lead, as well as phthalates, adipates, vulcanizing agents and antioxidants that could leach into runoff. They concluded that “The environmental and health risks derived from the use of these surfaces have to be considered and some regulations should be adopted.

A 2018 report by Yale University scientists analyzed the chemicals found in 6 samples of tire crumbs from different companies that install school athletic fields, and 9 different samples taken from 9 different unopened bags of rubber mulch intended for household use.²⁰  The researchers detected 92 chemicals in the samples. A little under a half have never been studied for their health effects, so their risks are unknown, and the other chemicals have been tested for health effects, but those tests were not thorough. Based on the studies that were done, 20% of the chemicals that had been tested are considered to probably can cause cancer, and 40% are irritants that can cause breathing problems such as asthma, and/or can irritate skin or eyes. They concluded that “ people routinely ingest, inhale, handle, and have abrasions which contact ground tire material. That being so, it is prudent to assume that any chemicals in the tires or released by them can be transferred to exposed individuals. This study shows that a large number of compounds, many of them carcinogenic or irritants, are released from shredded recycled tires through several potential routes. Caution would argue against use of these materials where human exposure is likely, and this is especially true for playgrounds and athletic playing fields where young people may be affected.”

A 2019 Yale study based on previously published research, identified 306 chemicals found in crumb rubber.²¹ Fifty-two of these chemicals were classified as carcinogens by the U.S. EPA and/or the European ECHA. Then the researchers used the known characteristics of each chemical, such as the structure, to predict whether or not it was likely to be a carcinogen. Using this process, 197 were predicted to be carcinogens. They concluded, “Our study highlights a vacuum in our knowledge about the carcinogenic properties of many chemicals in crumb rubber infill.” “The crumb rubber infill of artificial turf fields contains or emits chemicals that can affect human physiology.”

In the last few years, scientists have learned more about lead and PFAS in artificial turf, as well as the risks of some of the newer infill materials that are available to replace tire crumb. Tire crumb has well-known risks, as noted in the studies above, containing “hormone-disrupting chemicals” also known as “endocrine-disrupting chemicals.” By affecting the hormones that children need for healthy development, these chemicals have the potential to increase obesity; contribute to early puberty; cause attention problems such as ADHD; exacerbate asthma; and eventually cause cancer. 

The use of silica sand and other infill materials also has substantial risks.  For example, it is well known that tiny, often microscopic particles known as “particulate matter” can cause lung problems and eventually cause lung cancer.  For that reason, silica sand and zeolite used as infill are of great concern. Envirofill is a brand of infill that used to advertise its product as made of polymer coated “silica sand” but now that the American Lung Association and other experts explain that inhaling silica can cause lung damage and even lung cancer, the company now refers to their product as containing “sand” instead of “silica sand.” The manufacturers and vendors of these products claim that the silica stays inside a plastic coating. However, sunlight and the grinding force from playing on the field breaks down the plastic coating. For that reason, the Envirofill product warranty used to specify that only 70% of the silica will remain encapsulated, which would imply that the other 30% can be very harmful as children are exposed to it in the air as particulate matter that can harm the lungs. The currently worded warranty states that the warranty lasts 16 years but does not specify the percentage of pieces of infill where the sand remains intact inside the plastic coating.

PFAS chemicals 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. Although manufacturers often claim that their products do not contain PFAS, that is based on very limited testing. There are thousands of PFAS chemicals, and some worrisome PFAS chemicals have been found by independent researchers studying artificial turf, including but not limited to BrockFILL artificial turf.  Please note that while the manufacturer claims that BrockFILL “meets the requirements of the FIFA quality programme for synthetic turf systems as well as those of World Rugby” those requirements do NOT evaluate long-term safety for either children or adults. Unfortunately, there are zero testing criteria for artificial turf materials’ long-term safety, making such claims misleading as well as meaningless.

In addition to the infill, the plastic grass itself exposes children and adults to dangerous levels of PFAS, microplastics, and other toxic chemicals as well.

Injuries

Out of the 32 playgrounds surfaced in recycled tires that researchers in California looked at, only 10 met that state’s 2007 standard for “head impact safety” to reduce brain injury and other serious harm in children who fall while playing.¹⁴ In contrast, all five surfaces made of wood chips met the safety standard.

Artificial turf fields get hard over time which is why they need to be watered regularly to comply with the warranty. 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. When concerned parents and public health advocates convinced Washington, D.C. government officials to test the hardness of artificial turf fields at schools, more than 20% of the 52 fields tested failed, even though the city used less stringent standards for failing than the turf industry recommends.²²

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. 

It is well known that artificial turf fields and rubber surface playgrounds are much hotter than the air or grass on summer days. Our own research found that on warm or sunny days, the heat of the air just above artificial turf and rubber playground surfaces can be 50-60 degrees hotter than the temperature of the air or of natural grass. So, for example on a 90 degree day, the grass is also approximately 90 degrees, but artificial turf and rubber playgrounds often exceed 150 degrees Fahrenheit. That can cause “heat poisoning” as well as burns.

Lead

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.²³ Some children are more vulnerable than others, and that can be difficult or even impossible to predict. The Centers for Disease Control and Prevention (CDC) warns that the “plastic grass” made with nylon or some other materials also contains lead.²⁴ Whether from infill, plastic grass, or rubber playground surfaces (including PIP, which is made with tire crumb on the top layer or underneath the top “poured in place” layer), the lead doesn’t just stay on the surface. With wear, the materials used in rubber playground surfaces turn to dust containing lead and other chemicals that is invisible to the eye and is inhaled by children when they play. In addition, PIP surfaces wear out and crack, and the tire crumb are then on the surface where small children like to play with it and put it in their mouths.

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

As noted earlier in this article, numerous studies indicate that the hormone-disrupting chemicals found in rubber and plastic cause serious health problems. That is why the Consumer Product Safety Commission has banned several endocrine-disrupting chemicals from toys and products used by young 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.

Scientific Evidence of Cancer and Other Serious 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 is no conclusive evidence that a specific 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. For example, 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.  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.

We are sorry to say that when NCHR experts have testified at public meetings, we have seen and heard scientists paid by the artificial turf industry 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).

What the U.S. Government Says

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, no federal agencies have concluded that artificial turf is safe. For example, the 2024 EPA report that the artificial turf industry claims as proof that artificial turf is safe was not a “risk assessment” evaluating the impact of artificial turf fields on children. If focused only on tire crumb, not on PFAS, microplastics, or other exposures typical of artificial turf fields whether or not they have tire crumb infill.  Unfortunately, the EPA report was focused on issues that were selected many years ago, and not on the exposures or the health issues and environmental issues of greatest concern today.

The EPA created a working group that collected and analyzed data from playgrounds and artificial turf fields that used tire material. Samples were collected at six turf fields and two playgrounds in four study sites (Maryland, North Carolina, Georgia and Ohio). In a report released in 2009, the agency concluded that the level of chemicals monitored in the study and detected in the samples were “below levels of concern.” However, the study did not measure the concentration of organic chemicals that are known to vaporize during summer heat (called SVOCs). SVOCs include PAH. And, the EPA concluded that while there were currently no human studies available to determine the effects of PAHs at various levels, based on laboratory findings, “breathing PAHs and skin contact seem to be associated with cancer in humans.” ¹¹

What is the Impact on Our Environment?

Although this article focuses on the impact of artificial turf on health, it is worth noting that artificial turf also has a negative impact on the environment. Artificial turf fields are made of polyethylene and sometimes nylon so they produce greenhouse gasses.²⁵ The “outgassing” from the plastic is higher during the day but continues at lower levels at night. Because the artificial turf fields have millions of fragments, they have a very high surface area that produces much more greenhouse gas than a flat carpet would.

Approximately three tons of infill materials migrate off each synthetic turf field into the surrounding 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.²⁶ The fields also continuously shed microplastics as the plastic blades break down.^{27, 28} 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.^{29, 30, 31}Tire crumb from artificial turf washes away into nearby grass and waterways, and when the fields are replaced after approximately 8 years, the plastic and the rubber end up in landfills. Despite claims to the contrary, most artificial turf is not recycled because most of the components cannot be recycled.⁷ 

Synthetic surfaces also create heat islands.^{32, 33} 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.³⁴

How to Protect your Children

So how can you protect your child at the playground? Remember that children are much more likely to be harmed by exposure to chemicals in their environment than adults because they are smaller (so the exposure is greater) and because their bodies are still developing. This is why it’s important to significantly reduce (or try to eliminate) any contact your child may have with substances that are known or suspected to be harmful. If you have more than one playground in your area, choose the one that doesn’t have a recycled rubber play surface or other types of rubber or synthetic surface.

Parents can actively persuade local officials that playgrounds should use wood chips rather than rubber or other substances that are less safe when children fall, and more dangerous in terms of chemicals that they breathe or get on their hands.

The CDC, Consumer Product Safety Commission (CPSC) and EPA all recommend that you teach your child the importance of frequent hand washing, especially after playing outside and before eating.²⁰ The President’s Cancer Panel advised to “minimize children’s exposure to toxics” and “both mothers and fathers should avoid exposure to endocrine-disrupting chemicals and known or suspected carcinogens prior to a child’s conception and throughout pregnancy and early life, when risk of damage is greatest.” ³⁵

The Consumer Product Safety Commission recommends the following precautions:

1. Avoid mouth contact with playground surfacing materials, including mouthing, chewing, or swallowing playground rubber. This may pose a choking hazard, regardless of chemical exposure.
2. Avoid eating food or drinking beverages while directly on playground surfaces, and wash hands before handling food.
3. Limit the time at a playground on extremely hot days.
4. Clean hands and other areas of exposed skin after visiting the playground, and consider changing clothes if evidence of tire materials (e.g., black marks or dust) is visible on fabrics.
5. Clean any toys that were used on a playground after the visit.³⁶

To learn more about artificial turf and concerns about cancer risks for kids and young adults, watch this ESPN news video here.

Conclusions

There have never been any safety tests required prior to sale that prove that any artificial turf products or rubber playground surfaces are safe for children who play on them regularly, given normal use. 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, or Engineered Wood Fiber for playground surfaces.

Related Articles

NCHR Letter to the DC City Council on Artificial Turf
Risks of Head Injuries on Artificial Turf Fields in Washington, DC
Nearly a Dozen Artificial Turf Fields in DC Failed Last Round of Safety Tests

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

1. Claudio L. Synthetic Turf-Health Debate Takes Root. Environmental Health Perspectives. 2008;116(3):A117-22. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2265067/
2.  New York State Department of Health. Fact Sheet: Crumb-Rubber Infilled Synthetic Turf Athletic Fields. August 2012 (last revised). http://www.health.ny.gov/environmental/outdoors/synthetic_turf/crumb-rubber_infilled/fact_sheet.htm
3. Dubois L. Artificial Turf Controversy a Constant in Backdrop of Women’s World Cup. Sports Illustrated. June 24, 2015. http://www.si.com/planet-futbol/2015/06/23/womens-world-cup-artificial-turf-canada.
4. Goff S. Women’s World Cup will be played on lush, green artificial turf. Washington Post. June 5, 2015. https://www.washingtonpost.com/sports/womens-world-cup-will-be-played-on-lush-green-artificial-turf/2015/06/05/a786a0ac-0b8d-11e5-951e-8e15090d64ae_story.html

5. Baxter K. Women’s World Cup to Go Forward on Artificial Turf. Los Angeles Times. January 21, 2015. https://www.latimes.com/sports/sportsnow/la-sp-sn-womens-world-cup-lawsuit-artificial-turf-20150121-story.html

6. US Environmental Protection Agency (EPA). Wastes-Resource Conversation-Common Wastes & Materials – Scrap Tires (Frequent Questions). http://www.homepages.ed.ac.uk/shs/Hurricanes/Frequent%20Questions%20%20%20Scrap%20Tires%20%20%20US%20EPA.html

7. Woodall C. ‘Running out of room’: How old turf fields raise potential environmental, health concerns. York Daily Record. November 18, 2019. https://www.ydr.com/in-depth/news/2019/11/18/old-artificial-turf-fields-pose-huge-waste-problem-environmental-concerns-across-nation/2314353001/

8. Toxics Use Reduction Institute. (2023). Playground Surfacing. University of Massachussets — Lowell. https://www.uml.edu/docs/Playground_surfacing_report_Dec2023_tcm18-377890.pdf
9. Rubber Manufacturers Association. US Scrap Tire Markets 2013. November 2014. https://rma.org/sites/default/files/US_STMarket2013.pdf
10. Llompart M, Sanchez-Prado L, Lamas JP, Garcia-Jares C, et al. Hazardous Organic Chemicals in Rubber Recycled Tire Playgrounds and Pavers. Chemosphere. 2013;90(2):423-431. http://www.sciencedirect.com/science/article/pii/S0045653512009848
11. US Environmental Protection Agency (EPA). Polycyclic Aromatic Hydrocarbons (PAHs)-Fact Sheet. November 2009. https://www.epa.gov/north-birmingham-project/polycyclic-aromatic-hydrocarbons-pahs-fact-sheet
12. Agency for Toxic Substances and Disease Registry (ATSDR). Polycyclic Aromatic Hydrocarbons. September 1996. http://www.atsdr.cdc.gov/toxfaqs/tfacts69.pdf
13. Almansour KS, Arisco NJ, Woo MK, et al. Playground Lead Levels in Rubber, Soil, Sand, and Mulch Surfaces in Boston. PLoS One. 2019;14(4):e0216156. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0216156
14. 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
15. Thomas P Ahern, PhD, MPH, Logan G Spector, PhD, Per Damkier, MD, PhD, Buket Öztürk Esen, MS, Sinna P Ulrichsen, MS, Katrine Eriksen, MS, Timothy L Lash, DSc, MPH, Henrik Toft Sørensen, MD, PhD, DMSc, Deirdre P Cronin-Fenton, PhD, Medication-Associated Phthalate Exposure and Childhood Cancer Incidence, JNCI: Journal of the National Cancer Institute, 2022, djac045, https://doi.org/10.1093/jnci/djac045
16. Shalat SL. An evaluation of potential exposures to lead and other metals as the result of aerosolized particulate matter from artificial turf playing fields. 2011. New Jersey Department of Environmental Protection. http://www.nj.gov/dep/dsr/publications/artificial-turf-report.pdf
17. 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 & Analytical Toxicology. 2014;5(2):265 http://dx.doi.org/10.4172/2161-0525.1000265
18. Canepari S, Castellano P, Astolfi ML, et al. Release of particles, organic compounds, and metals from crumb rubber used in synthetic turf under chemical and physical stress. Environmental Science and Pollution Research International. 2018;25(2):1448-1459. https://doi.org/10.1007/s11356-017-0377-4
19. Celeiro M, Dagnac T, Llompart M. Determination of priority and other hazardous substances in football fields of synthetic turf by gas chromatography-mass spectrometry: A health and environmental concern. Chemosphere. 2018;195:201-211. https://doi.org/10.1016/j.chemosphere.2017.12.063
20. 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(3):64. https://doi.org/10.1007/s11270-018-3711-7
21. Perkins AN, Inayat-Hussain SH, Deziel NC, et al. Evaluation of potential carcinogenicity of organic chemicals in synthetic turf crumb rubber. Environmental Research. 2019;169:163-172. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6396308/
22. Sadon R. Hardness test results reveal wider scope of artificial turf failures. DCist. October 12, 2017. https://dcist.com/story/17/10/12/even-more-artificial-turf-fields-fa/
23. American Academy of Pediatrics (AAP). Lead Exposure in Children. Last updated January 2, 2025. https://www.aap.org/en/patient-care/lead-exposure/lead-exposure-in-children/?srsltid=AfmBOorWd8ylTWKA9xcj3qAzBk9p9B0NL8D_IDMqQUGwmglgUPnOEWrJ
24. CDC. About Lead in Soil. Childhood Lead Poisoning Prevention. August 30, 2024. https://www.cdc.gov/lead-prevention/prevention/soil.html
25. Astroturf. https://www.astroturf.com/synthetic-turf-products/sports-grass-infill/
26. 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
27. 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
28. 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/
29. 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/
30. 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
31. 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
32. 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
33. 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
34. 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
35. Reuben S. Reducing Environmental Cancer Risk What We Can Do Now. Annual Report President’s Cancer Panel. U.S. Department of Health and Human Services. 2010. https://deainfo.nci.nih.gov/advisory/pcp/annualReports/pcp08-09rpt/PCP_Report_08-09_508.pdf.
36. CPSC. Crumb Rubber Information Center. https://www.cpsc.gov/Safety-Education/Safety-Education-Centers/Crumb-Rubber-Safety-Information-Center