EPA Releases Findings From Crumb Rubber Study

Long-awaited research study differentiates between what is present in the recycled tire crumb from what people may actually be exposed to from recycled tire crumb.

The U.S. Environmental Protection Agency (EPA) released the Synthetic Turf Field Recycled Tire Crumb Rubber Characterization Research Final Report: Part 1 -Tire Crumb Rubber Characterization, July 25, 2019.

The report is part of the Federal Research Action Plan (FRAP) on Recycled Tire Crumb Used on Playing Fields and Playgrounds, a multi-agency effort that includes the U.S. Environmental Protection Agency (EPA), Centers for Disease Control and Prevention/Agency for Toxic Substances and Disease Registry (CDC/ASTDR), and the U.S. Consumer Product Safety Commission (CPSC)performing research that seeks to improve the understanding of potential health effects of recreational exposures to recycled tires. The EPA and CDC are studying the chemical characteristics of recycled tire materials and the exposures on athletic fields. The CPSC is assessing the risk to consumers associated with the use of recycled tire materials in playground surfaces, which will utilize the information from EPA and CDC once the studies are complete. The study was initiated in 2016 after the public, media, and government agencies expressed concern that the chemicals in surfaces derived from recycled tires may be hazardous to human health.

EPA is reporting findings in two parts

The EPA Part 1 report presents the results and findings of the crumb rubber characterization research. It addresses exposure (that is, chemicals and how people come in contact with these) to tire crumb rubber on synthetic turf fields.

In general, the agencies found that, while chemicals are present as expected in the tire crumb rubber, human exposure to chemicals in the crumb rubber ‘appears to be limited’ based on what is released into the air or simulated biological fluids. All tire crumb rubber samples tested positive for bacteria. “This is not surprising, as bacteria are present in soil and on surfaces in our environment,” EPA said in its press release.

Tire and rubber recyclers and the synthetic turf industry welcomed release of the report saying the Part 1 report “ highlights what we already know about crumb rubber infill in synthetic turf fields: crumb rubber is made of the same components found in everyday consumer products, and hospital and classroom floors.”

“The report reconfirms that the mere presence of a substance does not equate with human exposure, and recognizes substances are also present in grass fields and other types of surfaces,” Dan Bond, President of the Synthetic Turf Council said. Furthermore, when the EPA tested for dozens of substances it found low- and below-detection limits emissions, which is consistent with previous studies. “We look forward to the EPA finishing their human exposure characterization in a timely manner in order to provide parents and communities the certainty they deserve,” he said.

“We’ve also learned that the National Toxicology Program has released its report The Chemical and Physical Characterization of Recycled Tire Crumb Rubber which examined the potential human exposure to crumb rubber and its biological activity,” Bond said.

The Part 1 Tire Crumb Rubber Characterization Research Report summarizes results on a range of chemicals, including metals and organic chemicals, that were found in the tire crumb rubber.

Prior to the FRAP being initiated, most studies examining these potential risks have been considered inconclusive or otherwise incomplete. The information and results from the effort will fill specific data gaps about the potential for human exposure to chemical constituents associated with recycled tire crumb rubber used in synthetic turf fields.

Part 2, to be released later, will include data to characterize potential human exposures to the chemicals found in the tire crumb rubber material while using synthetic turf fields. Part 2 will be released along with results from a biomonitoring study being conducted by CDC/ATSDR to investigate potential exposure to constituents in tire crumb rubber. These research activities and the resulting findings do not provide an assessment of the risks associated with playing on or contact with the tire crumb rubber used for synthetic turf fields. Instead, these research results should inform future risk assessments, the EPA said.

Highlights of the report:

• This research represents the largest and most robust study of synthetic turf fields and tire crumb rubber to date in the United States.

• Findings from this study support the premise that while many chemicals are present in the recycled tire crumb rubber, exposure may be limited based on what is released into air or biological fluids.

• The presence of a substance does not directly equate with human exposure. While there are many chemicals associated with recycled tire crumb rubber, [the EPA] laboratory experiments suggest that the amount of chemicals available for exposure through release into the air and simulated biological fluids is relatively low.

• Emissions of many organic chemicals into air were typically found to be below detection limits or test chamber background, and releases of metals into simulated biological fluids were very low (mean bioaccessibility values averaged about 3% in gastric fluid and less than 1% in saliva and sweat plus sebum).

• In general, concentrations [of measured metal and extractable semivolatile organic compounds in this study were consistent with, and within the range of, concentrations found in previous studies.

• While there is concern about chemical exposures resulting from the use of recycled tire and other materials in synthetic fields, it is important to recognize that some of the chemicals are likely to be present in other types of fields, including natural grass fields. For example, metals (including lead) and PAHs (including benzo[a]pyrene) of potential concern at synthetic turf fields with tire crumb rubber infill are also often found in surface soil in the U.S. and may be present at natural grass playing fields.

• This report is not a risk assessment.

According to the Synthetic Turf Council, there are currently 12,000 to 13,000 synthetic turf fields in the United States, with 1,200 to 1,500 new installations each year. Fields often use recycled tire rubber as infill material, sometimes mixed with sand. Fields are at municipal and county parks; schools, colleges, and universities; professional sports stadiums and practice fields; and military installations. It is estimated that millions of people use or work at these fields each year.

EPA presented findings from the tire crumb rubber characterization research activities during a webinar on August 6, 2019.

© Scrap Tire News, August 2019