Many cities, high schools, universities, and professional sports teams believe they have made suitable investments in switching from natural grass to artificial turf fields. Artificial turf fields are on the rise because they are more cost-effective in the long term than natural fields, and synthetic fields do not need to be watered or fertilized [1]. However, are the financial savings from these investments worth the possible price of athletes’ health? Artificial turf fields are composed of painted synthetic fibers resembling grass and pellets made from tires to resemble soil [1]. These tire pellets typically contain carcinogens, mutagens, and endocrine disruptors [2].
The health effects of these pellets are still largely unknown to scientists. Despite this, the anecdotal evidence about athletes who have played on synthetic fields and developed health conditions years later is enough to scare many parents and coaches. For example, Amy Griffin, an assistant coach for the women’s soccer team at the University of Washington, created a list of all her current and former players who were diagnosed with cancer [1]. In 2014, there were 53 players on her list, and more than 60% of the players were goalkeepers [1]. If the tire crumbs contribute to the occurrences of cancer, it would make sense that more goalkeepers would develop cancer due to their increased exposure to the pellets. Goalkeepers constantly dive towards the ground to protect the goal which makes ingesting, inhaling and absorbing the pellets through open cuts more likely [1].
Due to Griffin’s list, the Washington State Department of Health conducted a study, but it determined that soccer players were not at an increased risk for cancer due to playing on synthetic fields with tire crumbs [1]. However, the study only measured whether the rate of cancer diagnoses in soccer players in the area was higher than the expected cancer rates for a standard population [1]. Therefore, the conclusion of the Washington State Department of Health does not undermine the possibility that exposure to tire pellets may increase one’s risk of developing cancer.
There is also conflicting scientific evidence about whether the chemicals in the pellets and blades of artificial fields, such as polycyclic aromatic hydrocarbons (PAHs) and phthalates, are absorbed by humans at high enough levels to pose a significant health risk [2]. The National Toxicology Program conducted a study where they exposed mice to rubber crumbs in various ways. The mice fed the crumbs had statistically significantly lower ovary and thymus weights and different hematology values than the control group [2]. The mice with rubber crumbs in their beds had statistically significantly higher liver weights [2]. Despite these findings, they concluded that these results were not biologically relevant and that the leaching of chemicals from the rubber pellets was low [2]. This study suggests that chemicals in rubber pellets do not contribute to adverse health outcomes.
Other studies have found opposing results. For example, one study conducted in Japan examined the risk of cancer amongst children who played on a playground with a natural soil surface and children who played on rubber surface playgrounds [3]. Scientists calculated the absolute risk of developing cancer by adding the risk of ingesting, inhaling, and contacting PAHs through the skin for rubber playgrounds and soil playgrounds [3]. From this, results were confirmed through the Monte Carlo simulation (MCS), a statistical program which allows researchers to input variables and determine how the variable changes the outcome. Through the MCS tool, researchers found the risk of cancer was about 10 times higher for children exposed to rubber surface playgrounds vs. soil playgrounds [3].
There are other adverse effects of playing on synthetic fields that are empirically supported by data. Synthetic fields tend to retain more heat than grass fields which increases the chances of skin burns. According to Penn State University’s Center for Sports Surface Research, synthetic fields can reach temperatures between 140° F and 170° F when the weather is hot and sunny, whereas grass fields rarely reach above 100ºF due to evaporative cooling and transpiration [4]. Human skin burns within two seconds of contact at temperatures above 120ºF [4]. In addition, studies have found higher injury rates among athletes on synthetic fields. A systematic review published in the American Journal of Sports Medicine evaluated the results of 53 studies between 1972 and 2020 which examined the risk of overall and lower extremity injuries on both old-generation and new-generation artificial turf [5]. This review found that among both types of turf, there was a higher rate of foot and ankle injuries on artificial turf than on natural grass [5].
Future studies are necessary to further clarify how detrimental artificial turf with tire crumbs may be to human health. However, the potential risks of synthetic fields outweigh their benefits, especially as universities and professional sports teams continue to invest in their athletic teams. Since the research is still ongoing, all organizations should protect athletes’ short-term and long-term health by utilizing natural grass fields.
References:
Howard, J. (2017, January 27). Soccer players' cancers ignite debate over Turf Safety. CNN. Retrieved October 23, 2022, from https://www.cnn.com/2017/01/27/health/artificial-turf-cancer-study-profile
Murphy, M., & Warner, G. R. (2022). Health impacts of artificial turf: Toxicity studies, challenges, and Future Directions. Environmental Pollution, 310, 119841. https://doi.org/10.1016/j.envpol.2022.119841
Tarafdar, A., Oh, M.-J., Nguyen-Phuong, Q., & Kwon, J.-H. (2019). Profiling and potential cancer risk assessment on children exposed to PAHs in playground dust/soil: A comparative study on poured rubber surfaced and classical soil playgrounds in Seoul. Environmental Geochemistry and Health, 42(6), 1691–1704. https://doi.org/10.1007/s10653-019-00334-2
Myrick, S. (2019, May 8). Synthetic sports fields and the Heat Island Effect: Operations: Parks and Recreation Magazine: NRPA. National Recreation and Park Association. Retrieved October 23, 2022, from https://www.nrpa.org/parks-recreation-magazine/2019/may/synthetic-sports-fields-and-the-heat-island-effect/
Gould, H. P., Lostetter, S. J., Samuelson, E. R., & Guyton, G. P. (2022). Lower extremity injury rates on artificial turf versus natural grass playing surfaces: A systematic review. The American Journal of Sports Medicine, 036354652110695. https://doi.org/10.1177/03635465211069562