This guest post is from Science News chemistry and environment writer Beth Mole.
The news and Internet are lush with worrisome reports about synthetic turf: Your child’s playground might be teeming with toxic chemicals. The city park could expose her to noxious dust. And if her soccer team plays on the fake fields, she could get cancer.
Largely absent from many of those popular reports, however, is data. For years, scientists have been digging into artificial turf, which swaps blades of grass for plastic and soil for rubber crumbs to make a low-maintenance green space. So far, most studies have found that artificial fields pose little to no health risk. But none of the studies are all-inclusive; they don’t test each brand of turf or weed out every potentially toxic ingredient. Those gaps in testing fuel public fears, such as the worry that soccer players could be getting cancer from turf. That spiraling concern also highlights the disconnect between the nuanced science of health risks and parents who understandably want assurances.
A closer look at the data may ease many fears; they show that artificial turf is generally safe. Of course, the data aren’t perfect and there are a few issues to be wary of, such as lead levels, especially in older fields. But these concerns are a far cry from the drama-drenched alarm found on some parent Listservs and in the news.
Much of the concern in news reports stems from the morsels of rubber in artificial turf, which are often made from recycled tires. Those tiny crumbs are known to harbor an array of dangerous chemicals, such as toxic polycyclic aromatic hydrocarbons, and metals, such as lead. (There are types of turf with a different infill that some communities are turning to as an alternative.) Then there’s the faux foliage, which can also contain toxic metals like chromium and lead. Parents and consumer groups worry that any of those chemicals could come off in fumes, sink into skin when touched or waft up in inhalable dust.
Academic scientists and government agencies have done small surveys to get at each of those possibilities. With few exceptions, researchers have found no evidence of exposure or exposure at such low doses that there’s little risk of harm. In fact, some studies have found that if there is uptake of chemicals, it’s at doses equivalent to those found in food and the rest of the environment.
And no scientific study has found an association between exposure to artificial turf and cancer. But that didn’t stop California state Sen. Jerry Hill from introducing legislation putting a moratorium on artificial turf, citing concerns that “an increasing number of young athletes have developed leukemia, non-Hodgkin lymphoma, and testicular, prostate and other forms of cancer.” (The press release also claims that New York City banned artificial turf, which is a myth. Though the city’s parks department has moved away from using crumb rubber for reasons not related to health, the city still has more than 100 artificial turf fields.)
And last October, an NBC Nightly News story included the anecdotal claim that 38 soccer players from all over the country developed cancers after playing on artificial turf. Unlike some other news reports, the story did reference scientific studies (which generally found little to no health risks). But the NBC report was quick to undercut the findings, citing the studies’ limitations — scientists didn’t have safety data on every potentially toxic chemical and tests didn’t include enough types of turf.
And this is where the conversation on fake turf gets derailed and data gets ditched. Parents and consumer advocates frequently point to such limitations as evidence that scientists don’t know enough about turf or enough about “their” turf. While there’s some truth to that, the quick dismissal makes for a rapid trip into fear-driven territory.
For example, the NBC report noted that one of the studies didn’t include data on the health risks posed by each of the chemicals found. That’s because safety data hasn’t been collected for certain obscure chemicals. Instead, the authors focused on the dozens of toxic chemicals that scientists do have data on, such as lead and PAHs, such as benzo[a]pyrene, and concluded that there was little cause for concern.
The NBC report also pointed out that another study had found one field with high levels of lead, probably from paint on the fake grass blades. The news report suggests that many other fields might also have dangerously high levels of lead.
Yet, the researchers found no reason to think this. And the one turf sample that did have high levels of lead probably wouldn’t cause harm, says environmental health expert Paul Lioy of Rutgers University in Piscataway, N.J., lead author of the study. Lioy says the lead was unlikely to seep out of the turf, even if eaten.
For the study, he and colleagues tested eight samples of turf and rubber from New Jersey fields and determined if chemicals from the fake fields could leach into simulated body fluids, including sweat, lung mucus and digestive juices. Chemical and metal concentrations in the fluids were well below what is considered hazardous. Some were so low they couldn’t be measured. “We didn’t find much of anything,” Lioy says.
Still, lead is a mucky issue for artificial turf: Some fields have tested positive for high levels, others haven’t, and data is mixed on whether that lead would leach out and expose children to significant amounts. Researchers do have evidence to suggest that as fields age they can literally crumble, creating more inhalable dust that could potentially carry lead into little lungs.
In 2008, reports of the toxic metal in public playing fields spurred the California state attorney general to sueturf makers. The legal action eventually forced the country’s biggest artificial turf manufacturer and supplier to make assurances that future turf would be nearly lead-free. Currently, the Synthetic Turf Council, a trade association, claims that the “issue was resolved” and as of 2009, lead was no longer used to color the turf.
While that statement is perhaps comforting, it’s unclear how many older fields still in use might contain the toxic metal and just how much is in the less-leaded, newer turf. In 2011, another New Jersey–based study that looked at five fields found one, an 8-year-old field, that contained high levels of lead. Despite concluding that even that high lead content did not pose a health risk, the researchers felt the need to make this cautious statement: “Based on this single observation, it appears possible (although not necessarily likely) that individual fields could contain sufficient levels of Pb [lead] to pose a concern for public health, especially with repeated use by the same individuals.” (Emphasis mine.)
Such lingering possibilities help drive public concern.
But toxicologist Gary Ginsberg of the Connecticut Department of Public Health says it shouldn’t — at least he’s not worried about lead or the unknown unknowns of artificial turf. “There are literally thousands of products that children come in contact with every day,” he says. “I think we know a lot more about crumb-rubber fields than a lot of other potential exposures.” Ginsberg and colleagues published three studies on the air above synthetic fields, testing for possible chemicals wafting from the fields. As in other studies, the researchers found little to no cause for concern.
Yet, the studies are not the final word on fake turf, Ginsberg says. With 11,000 synthetic turf fields in use around the country, it’s impossible for such small surveys to get a glimpse of every type, brand and variation in turf. Ginsberg, like Lioy, recommends that cities or school systems consider doing their own tests on the brand of turf they want to buy.
Such a test before a synthetic turf is installed could calm concerns or spare kids from being exposed to surprise ingredients, Lioy says. “It’s never advantageous for scientists to be testing something that’s already widely used,” he adds.