Public Health Risks of Artificial Turf

November 29, 2023
70 West Hedding Street
San Jose, CA 95110

Dear President Ellenberg and Santa Clara County Board of Supervisors,

Recently the Sierra Club Loma Prieta Chapter (SCLP) received a copy of a letter dated November 9, 2023, addressed to the Santa Clara Board of Supervisors (see link below). It was from the County of Santa Clara Public Health Department on the Public Health Risks of Artificial Turf.

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The Sierra Club is interested in environmentally related public health impacts of artificial turf. However, reading this letter left us quite concerned as it does not reflect the most current findings regarding artificial turf. Perhaps the use of outdated information was due to constrained time as staff sometimes need to arrive quickly at analyses and determinations.

The unfortunate lack of current or extensive research

The references at the bottom of the public health letter are no more recent than 2018 despite abundant newer research articles, findings, summaries and reviews.

Instead, the bulk of the letter comes directly, and often word for word, from a summary document, which is the letter’s first reference, New York State Center for Environmental Health. Information About Crumb-Rubber Infilled Synthetic Turf Athletic Fields (1). For example, text in sections titled ‘Heat Stress’, ‘Injury’, ‘Infection Risk’, ‘Latex Allergy’, and ‘Chemical Exposure’ quote from this single document (without attribution), while accompanying references 2 - 10 directly list those documents being summarized and, as stated above, are no more recent than 2018.

Below are updated references for those supplied in the public health letter.

Updated references, since 2018, for research articles, findings, summaries and reviews

An updated look at the Introductory Description
In the public letter, the second paragraph describes artificial turf and the stated reasons for its use. Since 2018 there have been changes in both construction of artificial turf and in reasons given by artificial turf proponents for its use.

Today, in 2023, while the highly colored, typically green, artificial turf carpeting rolled out for athletic play, continues to be made from polypropylene, polyethylene, and nylon, there is more information on other concerning chemicals added during manufacturing. Prime among these is PFAS (2), added “to enhance the durability and functionality of turf fibers by incorporating features like UV resistance, static blockers, and antimicrobial protection (3).” Because rubber infill has been found to be toxic (4)(5), infill layers today may be made of any number of other natural or manufactured materials, including but not confined to ground walnut shells, pieces of cork, sand, fused cork and sand, various polymers, etc. (6). There may also be drainage layers and padding underneath the carpet layer (7).

An updated look at Drought Tolerance
It’s important to know that while the letter’s statement “At the same time, concerns for drought and insufficient water supply have imposed limits on the use of grass and other natural materials,” implies that artificial turf might be part of a solution, however in California this understanding became outdated when SB 676, in 2023, was signed and became Chapter 498. The law states, Section 1. Section 53087.7 (b) “For the purposes of this section ‘drought-tolerant landscaping’ shall not include the installation of synthetic grass or artificial turf’ (8).” While the law itself does not explain why artificial turf is not a form of drought tolerant landscaping, architects have long described it as hardscaping where “A hardscape is defined as a ‘non-living or manmade fixture of a planned outdoor area.’ This includes buildings, streets and sidewalks where the soil profile is no longer exposed to the Earth’s surface. (9)(10)”

An updated look at Heat Stress
Heat stress continues to be a problem with plastics in artificial turf despite industry efforts. While industry has managed to lower surface heat on artificial turf carpeting since 2018, surface temperatures continue to be as high as 40°F to 60°F above air temperature and above the surface temperature for other materials, such as concrete, asphalt, gravel and more for natural grass. (11)(12). One recent industry attempt to lower artificial turf surface temperature with a new proprietary material, T°Cool, has resulted in a lawsuit by a South Carolina school district, stating that “Independent testing obtained by the district found that the TCool infill was ‘no different’ than the non-TCool infill on other fields, and that the TCool fields ‘did not perform any better than the field without TCool with regard to high temperatures’. (13)”

An updated look at Injury
Since 2018 many studies have compared injuries on artificial turf with those on natural grass. In a 2023 summary article encompassing the previous two decades of research, the National Center for Health Research found a higher incidence of injuries for knees, ankles, concussions, heat and abrasions for artificial turf, as well as an indication that injury on artificial turf is more severe (14).

An updated look at Infection Risk 
Since the 2004 study referenced by the public health letter to the Board, there have been several studies concerning infectious microbes found on athletic fields, including a joint research study between the University of Toledo and Purdue University in which Methicillin- resistant Staphylococcus aureus (MRSA) toxicity over time was compared in artificial turf with differing infills. MRSA is a type of staph bacteria that's become resistant to many of the antibiotics used to treat ordinary staph infections. They found that MRSA cells remained most available for infection over time in artificial turf using crumb rubber, sand, and organic infill materials (cork, walnut shells, coconut shells), in that order (15).

An updated look at Latex Allergy
Some artificial turf backings and underlayers contain latex. Latex is a known allergen. A 2020 review notes that “Latex offers a secure backing, provided it is correctly applied. However, it is susceptible to extremely wet conditions, and a reduction in tuft lock may be seen, leading to fibres coming out after a number of years (16).” In this case little has changed since 2007, though a 2021 summary update on latex allergies provides insight into newer allergen testing procedures for patients. Otherwise the newer update continues to recommend awareness education and avoidance by those found to be susceptible (17).

An updated look at Chemical Exposures
Among the most concerning of chemical exposures is per-and polyfluoroalkyl substances (PFAS). PFAS, or per-and polyfluoroalkyl substances, have been found to be dangerous, and also found to be present in artificial turf, even in artificial turf that claims to be PFAS-free.

Since 2018 there has been a massive increase in knowledge on chemical additives to plastics and their definite and possible effects on health. In particular, a better understanding of PFAS has launched an ongoing barrage of scientific study which, in turn, has warranted governmental and governmentally vetted independent, non profit technical foundation summaries to guide policymaking on both PFAS and substances, such as plastics and artificial turf, into which PFAS is added (18)(19).

The recently released Consumer Products Safety Council White Paper on PFAS states “Even though the literature base is still developing, there is significant evidence pointing to PFAS exposure and a wide array of adverse health effects. Several PFAS are associated with various types of cancers in humans and animal studies. PFAS are also commonly associated with noncancer health outcomes in the liver, immune system, fetal and infant growth and development, and how our bodies regulate cholesterol (18a),” and concludes “PFAS are a national concern and subject to current and proposed regulations. Reduction and, ultimately, elimination of PFAS use in consumer products and other applications would reduce human exposure and associated adverse health outcomes (18b).”

In the recently released Consumer Products Safety Council White Paper on PFAS, artificial turf is mentioned eight times, including “Artificial turf is another ... product that has been subject to regulation (see Section 4.3.1). Peer-reviewed literature on the presence of PFAS in artificial turf is limited; however, PFAS could be used in the plastic and rubber production as a processing aid (Glüge et al., 2020). PFAS may also impart certain functional uses, including enhanced smoothness and reduced friction, to the turf (Stade, 2019). In a press release, the Public Employees for Environmental Responsibility (PEER) and The Ecology Center reported the presence of 6:2 fluorotelomersulfonic acid (6:2 FTSA) in the backing of new turf used at a high school in Massachusetts. Other turf samples had detectable levels of PFOS or total fluorine levels indicative of PFAS presence (Stade, 2019) (18c).”

Finally, while some artificial turf manufacturers now assert their products are “PFAS-free,” the CPSC White Paper notes “Even among products labeled as ‘PFAS-free’ or ‘PFOA/PFOS-free,’ there are sometimes detectable levels of PFAS due to several potential factors ... Even if labeling and reporting requirements were more stringent, some experts have stated that given the environmental impact and safety concerns with PFAS-containing products, the responsibility should <lie> with manufacturers using alternatives ... that are rigorously tested for safety. Additionally, testing for PFAS compounds is costly and is not conducted regularly (18d).”

An updated look at Cancer
The Washington State coach’s apprehension concerning former players’ presumed cancer cluster, mentioned in the public health letter to the Santa Clara County Board, was long ago shown to be unsupported and is not today seriously considered.

A more recent and concerning episode, notably though not conclusively tied to artificial turf, involves the Philadelphia Phillies baseball team. In March of 2023, the Philadelphia Inquirer reported “In all, six former Phillies have reportedly been felled by glioblastoma — a particularly aggressive and deadly form of brain cancer — including catcher Darren Daulton, catcher Johnny Oates, and relief pitcher David West, who died in 2022. The rate of brain cancer among Phillies who played at the Vet between 1971 and 2003 is about three times the average rate among adult men ... The Inquirer decided to test the Vet’s turf. Athletes had dreaded playing on the surface, which was notorious for causing serious knee and ankle injuries. Through eBay, the newspaper purchased four souvenir samples of the fake grass that had blanketed the stadium’s field from 1977 to 1981 ... Tests run on two of the samples by Eurofins Lancaster Laboratories Environmental Testing found the turf contained 16 different types of PFAS .. ... which the EPA has said cause ‘adverse health effects that can devastate families.’ Researchers at the University of Notre Dame tested two other samples, and also found PFAS (20).”

Taking a more up to date look at Safe and Inclusive Play Spaces for Children and Young Adults
This public health letter section is puzzling. The letter implies that artificial turf is an important solution to inclusive and safe play spaces. However, something as simple as a natural grass field and a ball can provide children with healthy outdoor play and physical movement. Artificial turf is not necessary. As for outdoor play by children with disabilities, the specific disability in question will determine the best play or movement for a child. For example, a blind individual may play well on natural grass while a wheelchair bound individual might require a more specific setting or equipment. There is no reason, however, that the setting must be on artificial turf (21).

Taking a more up to date look at Environmental Effects
In the public health letter, the section on Environmental Effects is spot on, though more can be said about how the lack of recycling options for plastics make the crisis more acute. Despite progress on plastics recycling, excluding faux-recycling (e.g., cutting used athletic turf and selling it to homeowners) or breaking plastics into small pieces and then pressing them into use in a lesser product (e.g., turning artificial turf into single use plastic bags), the actual rate for plastics recycling, 1960 through 2018, in the United States hovered under 9%, with 75% of plastic currently buried in landfills (22).

The remaining 16% was incinerated, primarily to produce energy (22). Unfortunately incineration itself produces pollutants and carbon-dioxide (CO2). Heating plastics also generates new toxic chemicals that can become part of a follow-on product (e.g., when plastics containing flame retardants are heated, a stabilizer can degrade to become a “brominated” compound of the type just barred from food products by the recently enacted “California Food Safety Act”) (23)(24). On top of the foregoing, The Smithsonian has reported that, in 2021, plastics going into landfill increased, to 85%, while recycling decreased to between 5% and 6% (25).

Furthermore, plastic fades and cracks as it degrades in landfills or after being rolled onto athletic fields. This causes small bits of plastic to flow into our storm drains, watersheds, and into the ocean. Japanese researchers have even found micro plastic particles in cloud matter at the top of Mount Fuji (26). Current research has stated that such micro plastics can “affect the human body by stimulating the release of endocrine disruptors” (endocrines produce hormones for growth, fertility and reproduction) (27)(28).

Conclusion
Given the outdated nature and inaccuracies of the letter from the County of Santa Clara Public Health Department, the SCLP recommends the letter be withdrawn. Because the public health and environmental impact of continued usage of petroleum products such as artificial turf can be devastating, we ask that the Santa Clara County Board of Supervisors take time to thoroughly research the issue so that decisions will be based on the most current and reliable independent evidence-based information. We, the Loma Prieta Chapter of the Sierra Club, stand ready to assist you, and we will be more than happy to provide you with the latest research on this critical issue.

Ultimately, the Loma Prieta Chapter of the Sierra Club believes that there is enough evidence to say that artificial turf is not a necessary plastic and that there are suitable alternatives. For centuries humans have played outdoor sporting games on natural grass. Natural grass is a suitable and proven surface for sport games, especially when well managed, and we should prevent unnecessary plastics pollution by leaving artificial turf behind.

Susan Hinton
Chair, Plastic Pollution Prevention Subcommittee
Environmental Stewardship Program
Loma Prieta Chapter, Sierra Club

References

  1. 2018, New York State Center for Environmental Health. Information About Crumb-Rubber Infilled Synthetic Turf Athletic Fields.
  2. 2023, New Jersey Department of Environmental Protection Technical Memorandum. PFAS in Artificial Turf.
  3. 2023, TurfNetwork. Types of Artificial Fibers.
  4. 2023, YaleEnvironment360. Road Hazard: Evidence Mounts on Toxic Pollution from Tires.
  5. 2022, Yale & other universities. Artificial turf and crumb rubber infill: An international policy review concerning the current state of regulations.
  6. 2023, ProGreen Synthetic Turf Systems. Different Types of Infill for Artificial Turf.
  7. 2023, PST Sport. PST Sport Typical Cross Sectione
  8. 2023, The State of California Legislative Information.
  9. 2014, Michigan State University. Hardscaping ideas for stormwater management.
  10. 2014, Santa Clara Valley Water District. Water Conservation Fact Sheet.
  11. 2022, U.C. Agriculture and Natural Resources. Healthy Soil-Heat Island Effect.
  12. 2022, Napa Master Gardener Column. The Heat Island Effect -- No, it’s not a Summer Blockbuster Movie.
  13. 2023, Post and Courier, Columbia, SC. Columbia school district sues contractors over $3.7M athletic field work.
  14. 2023, The National Center for Health Research. Injuries Related to Artificial Turf.
  15. 2020. Sports Health. The Fate of Methicillin-Resistant Staphylococcus aureus in a Synthetic Turf System.
  16. 2020. CCGrass. A key component in artificial turf - Backings.
  17. 2021. World Allergy Organization Journal. Update on latex allergy: New insights into an old problem.
  18. 2023. Consumer Product Safety Commission. CPSC PFAS White Paper.
    1. Section 5.5 Potential Exposure and Human Health Risks, page 5-4
    2. Section 8 Conclusions, page 8-1
    3. Section 4.1.2 PFAS in Current or Prior Commercial Use, page 4-17
    4. Section 5.1 PFAS Sources in U.S. Consumer Products, page 5-2.
  19. 2017-2023. Interstate Technology Regulatory Council. PFAS - Per- and Polyfluoroalkyl Substances: Welcome, Technical Resources for Addressing Environmental Releases of Per- and Polyfluoroalkyl Substances (PFAS).
  20. 2023 The Philadelphia Inquirer. Field Of Dread.
  21. 2013-2023 Green Schoolyards America. Inclusive Design for Outdoor Spaces.
  22. 2020 EPA. Advancing Sustainable Materials Management 2018 Facts and Figures (Tables 2, 3, 8).
  23. 2023 The Los Angeles Times. Newsom signs bill to make California first state in nation to ban ‘toxic’ food additives.
  24. 2023 California Legislative Information. AB-418 The California Food Safety Act; Chaptered 10/10/2023.
  25. 2022 Smithsonian Magazine. At Least 85 Percent of U.S. Plastic Waste Went to Landfills in 2021; Only five percent of the material was in the correct condition to be recycled.
  26. 2023 Environmental Chemistry Letters. Airborne hydrophilic microplastics in cloud water at high altitudes and their role in cloud formation.
  27. 2023 Yonsei Medical Journal. Health Effects of Microplastic Exposures: Current Issues and Perspectives in South Korea.
  28. 2023 National Institute of Environmental Sciences. Endocrine Disruptors.