California Synthetic Turf Study Group Holds Third Meeting

“A lot has happened in terms of laboratory work and field work since our last meeting,” Dr. John Balmes, Chair of the Synthetic Turf Scientific Advisory Panel said in opening the group’s third meeting May 25, 2018 at the CalEPA headquarters in Sacramento, CA.

The Synthetic Turf Scientific Advisory Panel (SAP) is a group of expert scientists that the California Office of Environmental Health Hazard Assessment (OEHHA) convened to provide scientific advice on its Synthetic Turf Study.

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The goal of the study, launched in 2016, is to assess the potential health impact associated with the use of synthetic turf and playground mats made of crumb rubber.

The panel has held two previous meetings to advise OEHHA on study plans, data interpretation and reporting of study results.

OEHHA Section Chair Patti Wong gave a brief overview of progress to date for the multi-task study. The first task involved consultation with experts in the field and communication with the public. She said the OEHHA research team is also in constant communication with SAP as well as with the U.S. EPA which is conducting the Federal Research Action Plan on Recycled Tire Crumb Used on Playing Fields and Playgrounds and European agencies conducting health and environmental studies on crumb rubber infill in synthetic turf. OEHHA also conducted a series of workshops with industry and community stakeholders to listen for input during the first phase of the study.

OEHHA’s next task involved identifying chemicals of concern and toxcity and how to compile them, which, Wong said, the team discussed in detail during the 2017 SAP meeting. The third task was to develop an exposure exposure scenario that included identifying pathways of exposure and receptor categories. The fourth task and subject of the May meeting involves categorization of fields and playgrounds through sample collections and analysis.

Field sampling took place throughout 2017 and was broken down by five different climate zones and regions in the state and age of fields. Thirty-five fields in all were sampled, five new (0-9 yrs.) and five old (< 9 yrs.) fields.

Field testing of the crumb rubber was conducted in the goal area and in seven locations on the field, researchers said. The test parameters included weather and surface/subsurface temperature, particles in air. Preliminary metal data for crumb rubber and volatile organic compounds in air was also collected.

Researchers identified four human receptor categories and a selected a range of potential pathways of exposure. Receptor categories include athletes, coaches/referees and bystanders, They looked at inhalation pathways, direct and indirect dermal pathways, direct ingestion and indirect ingestion routes including hand-to-mouth, hand-to-object-to-mouth, and object-to-mouth.

For the Playground Characterization Study, researchers developed a draft playground sampling protocol that includes an environmental data and air sampling strategy and a surface sampling strategy to study potential exposure to chemicals released from playground mats made from crumb rubber. Next steps include collecting samples to characterize chemical exposures of young children playing on playground mats, researchers said. They asked the panel for any additional input.

Several industry stakeholders attending the meeting spoke during the public comment period including, Amy Brackin, Liberty Tire Recycling, Denise Kennedy, DK Enterprises, Nick Lapis, Californians Against Waste and Steve Crouse, CRM. Overall they complimented the researchers and panel for the work done so far and for the clarity of the presentations, saying the meeting was “very informative and easy to understand for those of us who are not scientists”.

In her comments, Amy Brackin asked that when the slides and information presented during the meeting are made public, they are put in context with some qualifying language so that the information presented at the meeting is not left to interpretation as a finding to any kind of risk. Brackin noted that in the playground component it needs to be made clear that the material being tested is tire rubber and not some other surface, like EPDM which typically is placed on top of the crumb rubber layer in a pour-in-place surface.

Finally, she called for the panel to include a baseline reference in the final study report identifying where crumb rubber falls within the whole picture of the field or playground, whether natural grass or a synthetic surface.

Denise Kennedy called on the panel and researchers to recognize that there needs to some controlled comparative playground study that looks at other materials including loose fill rubber nuggets, EPDM, sand and engineered wood fiber.

The biggest weakness in the study methodology so far is lack of a control, Nick Lapis of Californians Against Waste said. “You can’t make any claims about the impact of chemicals in a synthetic turf field if you don’t test the soil adjacent to the field and if you don’t use a natural grass field as a comparison. Similarly with playgrounds, you need to look at playgrounds with surfaces other than pour-in-place,” he said.

CRM representative Steve Crouse also expressed concern over lack of test controls and called on the panel to look at natural grass fields as well as some of the alternative infill materials such as EPDM, sand, husk or cork. Crouse also asked for clarification on how to differentiate the VOCs (volatile organic compounds) that are native to crumb rubber as opposed to sand infill or the carpet or blade components of the synthetic turf. “We need to be able to isolate those (VOCs) and say with a degree of certainty which are native to the crumb rubber or to other parts of the synthetic turf. This clarification is very important and needs to be communicated in the study’s findings,” he said.

© Scrap Tire News, July 2018