California Crumb Rubber Study Finds No Public Health Concerns

Yet another study has exonerated crumb rubber used as infill in artificial turf fields from causing negative health effects.

The report “Safety Study of Artificial Turf Containing Crumb Rubber Infill Made From Recycled Tires: Measurements of Chemicals and Particulates in the Air, Bacteria in the Turf, and Skin Abrasions Caused Contact With The Surface,” was conducted by the California Office of Environmental Health Hazard Assessment (OEHHA).

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The new report follows a 2009 OEHHA report on Artificial Turf Made From Recycled Tires which was criticized for testing the fields in the fall of 2009, when the air temperature did not reflect the higher temperature of a typical summer day in California’s Central Valley. Because of the criticism, OEHHA elected to redo the study.

The Agency conducted the research in the Central Valley during the summer of 2010 at a time when the temperatures were higher and crumb rubber critics contend the product is dangerous to inhale.

There were four components to the study. First, it looked at offgassing of VOC’s from the infill and whether it is affected by temperature. What the testing showed was that, while researchers did find some VOCs in the air near the fields, the presence of these compounds was so low that no public health concern was detected. Also, there was no correlation between the VOCs detected and surface temperature of up to 137 degrees F.

A second parameter of the study considered the inhalation of fine particulates, namely 2.5 million (pm2.5) particles of crumb rubber which could have metals. For this study, testing for fine particles above the artificial turf was conducted during times when the fields were in use.

The study found that the PM 2.5 emitted was either below the level of detection or at similar concentrations above artificial turf fields and upwind of the fields. Heavy metals in the PM 2,.5 were below the level of detection. These included arsenic, cadmium, lead, manganese, mercury, nickel and zinc. No public health concern was identified.

Two other findings in the study addressed concerns over whether artificial turf fields with crumb rubber infill increase the risk of serious skin infections in athletes, either by harboring more bacteria or by causing more skin abrasions than natural turf.

In looking at the presence of the bacteria Methicillin-Resistant Staphylococcus Aureus (MRSA) on the artificial turf compared with natural grass, the study showed that fewer bacteria were detected in artificial turf. This was true for MRSA and other strains of Staphylococci capable of infecting humans.

The final component of the study considered abrasions from the turf and whether such abrasions might make bacterial infection more likely. To answer the question, testing was conducted during the 2008 intercollegiate soccer season. It included information from athletic trainers at 33 colleges and universities in California and Nevada. The test data was gathered from more than 500 games covering soccer teams playing on natural grass and synthetic turf. The report found that soccer players suffered skin abrasions approximately two-to-three fold times higher per 1,000 player hours for college soccer players competing on artificial turf fields compared to natural grass. Skin abrasion seriousness was similar on both surfaces.

Overall, the study concluded that since there were no public health concerns identified regarding the inhalation of VOCs or PM2.5 above artificial turf containing crumb rubber, there is no reason to recommend that field usage be limited when it’s hot outside.

Because the rate of skin abrasions per 1,000 player hours was two-to-three fold higher on artificial turf compared to natural grass, the study recommends ways to prevent those abrasions including the use of protective clothing and equipment.. Finally, the study concluded that the sum of the effects on the skin abrasion rate for athletes competing on artificial turf versus natural grass cannot be predicted from the data.

The full study will be discussed during CalRecycle’s two-day tire recycling conference in Sacramento this month. It can be accessed at

Sources: OEHHA Report, The California Tire Report

© Scrap Tire News, January 2011