Testimony of Dr. Diana Zuckerman Before the Maryland House of Delegates Appropriations Committee on the Health Risks of Artificial Turf

Diana Zuckerman, PhD, Cancer Prevention and Treatment Fund, February 8, 2018

I am Dr. Diana Zuckerman and I am here today as the president of the National Center for Health Research and as a resident of Montgomery County for more than 25 years.  My children grew up in the county and so this is an issue of great importance to me personally as well as professionally.

I congratulate you on introducing HB 505, to prohibit the use of state funds for artificial turf fields and playgrounds, and I strongly support it.  Public funds should not be used for artificial turf and similarly dangerous playground materials.

There is considerable misunderstanding about the safety and cost-effectiveness of recycled tire material, other synthetic rubber, plastics, triclosan, and other synthetic materials on playing fields and playgrounds.  Your focus today is on whether state funding should be used to install and refurbish these artificial fields.  You will hear from others about the fact that these artificial fields are not cost-effective.  Since my training is in epidemiology and public health, I will focus on why investing in artificial turf fields is bad for our children’s health.

Artificial turf is made from synthetic rubber, plastic, and other materials with known health risks.  For example, the widely used material known as crumb rubber or tire crumb includes carcinogens as well as chemicals that disrupt our body’s hormones. These are called endocrine disrupting chemicals, and studies show that they contribute to early puberty, obesity, and attention deficit disorder.  Since breast cancer and several other cancers are fed by estrogen and other hormones, these materials can also cause cancer in the long-term.

Some endocrine disrupting chemicals have been banned by Federal law from toys and other products for young children.  It does not make sense that chemicals banned from rubber duckies, teething toys, and other products used for a relatively short period of time by children are allowed in playing fields and playgrounds where children are exposed day after day, week after week, and year after year.

The artificial turf industry will tell you that there is no clear evidence that their fields caused any child to develop cancer.  That is true.  But as an epidemiologist, I can also tell you that for decades there was no evidence that smoking caused cancer or that Agent Orange caused cancer.  It takes many years to develop that evidence.  And even then, it is usually impossible to prove that the cancer that any individual has developed was specifically caused by smoking or any other one source of exposure.  However, the weight of the evidence can be clear, even when the specific cause and effect can’t be proven.  There is clear evidence that the materials used in synthetic turf can cause cancer, skin irritation, contribute to obesity, and other health issues.

Artificial grass fields are just part of the problem.  Rubber playground materials used to cover the ground near slides, swings, and other playground equipment are attractive and seem safe, but they are made with the same kind of tire crumb and “virgin rubber” as athletic fields and have the same risks.  At a local park I recently saw particles of synthetic rubber and other potentially harmful material break off – it looks like candy and can end up in children’s mouths, as well as up their noses, in their ears, and on their clothes.  A much safer alternative, which is also ADA-compliant, is engineered wood fiber, which is just as effective as softening any falls and has no dangerous chemicals.

What the Scientific Studies Say

The California Office of Environmental Health Hazard Assessment (OEHHA) conducted three laboratory studies to investigate the potential health risks to children from playground surfaces made from recycled tires. 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 recycled tires compared to wood chips, and whether recycled tire shreds could contaminate air or water.[1]

It would not be ethical to ask children to eat tire shreds, so the researchers created 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. 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.[1]

Out of the 32 playgrounds surfaced in recycled tires that the researchers in California looked at, only 10 met that state’s standard for “head impact safety” to reduce brain injury and other serious harm in children who fall while playing. In contrast, all five surfaces made of wood chips met the safety standard.[1]

A 2012 study analyzing rubber mulch taken from children’s playgrounds found harmful chemicals in all of them, often at high levels.[2] Twenty-one samples were collected from 9 playgrounds, and the results showed that all samples contained at least one hazardous chemical, and most contained high concentrations of several PAHs. 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 (140 degrees Fahrenheit), many of the chemicals also became airborne at a much lower temperature of 77 ºF.  And since rubber playgrounds retain much more heat than grass or dirt, a temperature of 140 degrees can happen even on a sunny spring, summer, or fall day when the temperature near grass is only 70 degrees.  The authors concluded that the use of rubber recycled tires on playgrounds “should be restricted or even prohibited in some cases.”[2]

A 2015 report by Yale scientists analyzed the chemicals found in 5 samples of tire crumbs from 5 different companies that install school athletic fields, and 9 different samples taken from 9 different unopened bags of playground rubber mulch. The researchers detected 96 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. [3]

What the EPA Has Done

The EPA created a working group that collected and analyzed data from playgrounds and artificial turf fields that used recycled 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, there were limitations to this study because they did not measure the concentration of organic chemicals that are known to vaporize during summer heat, such as PAHs.

Due to the small number of samples and sampling sites used, the EPA stated that it is not possible to know if these findings are typical of other playgrounds or fields until additional studies are conducted.[4]  When announcing the results of the study, EPA joined other organizations in recommending that as a precaution, young children wash their hands frequently after playing outside.[4]

A meeting was then convened by the EPA in 2010, bringing together various state and federal agencies to discuss safe levels of chemical exposure on playgrounds made from recycled tire rubber, and opportunities for additional research.[4] In the case of PAHs, the EPA has concluded that while there are currently no human studies available to determine their effects at various levels, based on laboratory findings, “breathing PAHs and skin contact seem to be associated with cancer in humans.” [5]

In February 2016, the U.S. government announced a new action plan to better understand the likely health risks of recycled tire crumb and similar artificial surfaces. This initiative involves 4 U.S. government agencies: the EPA, Centers for Disease Control and Prevention (CDC), Agency for Toxic Substances and Disease Registry (ATSDR) and Consumer Product and Safety Commission (CPSC).  However, I’m sure many of you are aware that the current EPA is unlikely to complete the analysis in an objective, scientific way.

In summary, it is essential that the State of Maryland stop paying for artificial turf fields and playgrounds that can clearly exacerbate our children’s existing health problems and cause new  health problems. Let’s instead invest in safe, natural playing fields, unless any artificial alternatives are proven to be safer, more effective, and as cost-effective as grass.


  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/1206/62206013.pdf Accessed February 2018.
  2. 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 Accessed February 2018.
  3. 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/ Accessed February 2018.
  4. US Environmental Protection Agency (EPA). Fact Sheet – The Use of Recycled Tire Materials on Playgrounds & Artificial Turf Fields. http://www.emcmolding.com/uploads/files/file130102132640.pdf http://wtnh.com/2015/09/03/new-yale-study-reveals-carcinogens-and-skin-irritants-in-synthetic-turf/ Accessed February 2018.
  5. 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-sheetAccessed February 2018.