Probing the Safety of Synthetic Fields of Green

For athletes who play on synthetic turf, it is a post-game ritual to empty cleats of the black rubber pellets that accumulate during play. Otherwise, parents cry foul when they inevitably track indoors. Now, California health officials are evaluating whether crumb rubber and synthetic turf poses a safety hazard to players and their fans. COEH Director John Balmes is chair of a scientific panel tasked with advising members of the new synthetic turf study launched by the California Office of Environmental Health Hazard Assessment (OEHHA). COEH affiliates on the panel include Amy Kyle and Thomas McKone from the UC Berkeley School of Public Health.

Synthetic turf contains crumb rubber made from recycled tires to support and soften artificial blades of grass. In a literature review of the release of chemicals from recycled tires in field and laboratory settings, OEHHA identified 49 chemicals (pdf) - some were carcinogens. Chemical exposures can occur through ingestion during play or dermally through cuts and scrapes from skids and falls. Synthetic blade grass is another product with the potential to release chemical concentrations into ambient air. School tracks and ground cover mats in thousands of California playgrounds contain recycled tire material. The OEHHA study, therefore, will evaluate how exposures vary by age group and examine how sensitive populations, such as children, may be more vulnerable than others to exposures of concern.

The investigation will fill in gaps and limitations identified by two previous OEHHA studies of synthetic turf conducted in 2007 and 2010 where, based on a limited sample, authors found no public health concerns related to ambient air particulate matter less than 2.5 micrometers in diameter (PM2.5). The U.S. Environmental Protection Agency (US EPA) recognizes fine particles, or PM2.5, as an important health risk due to their capacity to lodge deep in the lungs. Air samples collected at playing fields showed concentrations of volatile organic compounds were below the limit of detection. The study authors found, however, the rate of skin abrasions due to contact with the turf was two- to three-fold higher for college soccer players competing on artificial turf compared to natural turf.

The 3 year, 2.8 million dollar study is funded by CalRecycle, the regulatory agency that provides grants to encourage the re-use of recycled tires to reduce landfill stockpiles. Stakeholder consultation began in the fall of 2015 with public meetings in Berkeley, San Diego, and Los Angeles. The project will include hazard identification, exposure scenario development, sampling and analysis of new and in-field synthetic turf, and the development of a biomonitoring study protocol. Prior to completing the study in 2018, OEHHA will gather comments on a draft of their findings through a series of public workshops.

At a public meeting in February 2016, the scientific advisory panel heard public testimony and presentations from OEHHA scientists. Panel members expressed their opinions about various aspects of the studies planned by OEHHA. Shortly after this meeting, the US EPA announced that it would also be conducting studies on potential health risks to synthetic turf. OEHHA and the US EPA plan to work together on their research endeavors.

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