California’s OEHHA Synthetic Turf Study: Assessment of health risks from exposure to crumb rubber infill

Crumb Rubber Risks

California's Office of Environmental Health Hazard Assessment released a draft study in March 2025 evaluating health risks from crumb rubber infill, made from recycled tires, in synthetic turf fields. Initiated in 2015 amid public worries about carcinogens, the research sampled 35 fields statewide, analyzing air, particles, and exposure routes for athletes, coaches, and spectators. It concluded exposures pose insignificant hazards, with cancer risks below one in a million for frequent users.

This matters now because the draft's release follows EU restrictions on similar materials in 2023 and coincides with U.S. debates, including EPA reports in 2024 showing comparable low exposures. In California, where drought favors water-saving synthetic fields, the findings could influence pending bills like AB-347 from 2024, which tightened PFAS regulations in products. Cities like Los Angeles have already eyed alternatives, with a 2025 report estimating replacement costs at $10-20 million per district if risks were deemed high.

Affected groups include millions of youth athletes and schoolchildren using these fields daily, plus communities near installations where off-field dust might spread. Risks of inaction, per advocates, involve subtle accumulations of toxins like benzene and lead, potentially exacerbating asthma or developmental issues in vulnerable kids—though the study disputes this with data from video-tracked activities showing limited ingestion or inhalation.

Non-obvious tensions lie in trade-offs: synthetic turf recycles 300 million tires annually nationwide, reducing landfill waste, but critics note unstudied synergies with turf blades containing PFAS, which leach into groundwater. Stakeholder divides are sharp—tire recyclers hail the report as validation, while environmental groups like Sierra Club push for natural grass despite its 50-70% higher water use in arid zones. Surprising data includes higher VOC emissions indoors, prompting ventilation mandates in new facilities since 2025.