Why Science Over Speculation Matters When It Comes to the Turf Debate

Football playground corner on heated artificial green turf ground with painted white line marks. Milled black rubber in basic
Football playground corner on heated artificial green turf ground with painted white line marks. Milled black rubber in basic of ground.

Many of us have seen headlines and reports about the "turf wars" in cities and towns across the country, and perhaps wondered if there is merit to claims of health effects from recycled rubber infill in artificial turf fields. Currently, recycled rubber from worn out tires is diverted from landfills and used in over 11,000 artificial turf fields as well as in many playgrounds across the country.

Driven by news reports of children and young adults coping with various types of cancer, parents understandably have become concerned and have been left trying to figure out whether or not their children's health is at risk.

The case against crumb rubber has manifested itself in the form of debates we've seen locally throughout the country, as voices such as a well-known women's soccer coach in Washington state have suggested links to cancer through anecdotal evidence. What's been absent and sorely needed is further attention to reputable science on the issue, in addition to the reporting of context for the seemingly scary claims being made about recycled rubber.

Recently, the federal government stepped in. Three agencies, including the Environmental Protection Agency (EPA), have announced they will conduct a comprehensive study of these products. This is obviously welcome news for parents, as well as city, state and local officials who have had to sort through the information on their own.

While this federal, multi-agency study will hopefully be the end of the story, it's hardly the beginning. The reality is that recycled rubber infill has been studied extensively--with over 90 analyses and reports on the issue already. As a toxicologist, I have personally analyzed the risks associated with chemical exposures from recycled rubber, and what I've concluded is that the evidence does not indicate that recycled rubber in turf fields causes cancer or any other negative health effects. This is also the consensus of all of the regulatory bodies that have evaluated the studies to date.

The state of Connecticut, for example, conducted a comprehensive study, and the state's Department of Public Health (DPH) published three peer-reviewed studies evaluating the safety of synthetic turf fields with recycled rubber. They concluded that their analysis found "no scientific support for a finding of elevated cancer risk from inhalation or ingestion of chemicals derived from recycled tires used on artificial turf fields." Massachusetts' Department of Health also looked into the issue and noted, "The scientific literature continues to suggest that exposure opportunities to artificial turf fields are not generally expected to result in health effects."

While there are a multitude of reports that have found that the evidence does not support possible health effects from recycled rubber, very few have found evidence to suggest otherwise. In general, the few studies that have raised concern lack key scientific attributes, such as being peer-reviewed--which is a fundamental part of the scientific process, and is of critical importance when evaluating studies.

In addition, of the few studies typically cited as cause for alarm, most do not actually measure exposure or risk, and simply measure whether or not a chemical is present. This is misleading, as the mere presence of a chemical within a consumer product does not necessitate a risk. Many of the products we use every day--from carpets, to mobile phones, to automobiles--contain chemicals (and carcinogens) that may be toxic, but not if the actual exposure is below levels of concern.

The fact is, many of the chemicals in recycled rubber that are the subject of concerning reports--heavy metals and PAHs--are found in similar concentrations in natural soil. In addition, PAHs are also found in higher levels in many grilled foods like steak or chicken than in recycled rubber. Interacting with chemicals at low levels is an unavoidable part of life, so to look at recycled rubber in a vacuum is not sound science.

When it comes to issues like this, there's nothing wrong with additional research. As a scientist, I'm fully behind further study, and am pleased that the federal government is looking into the issue. But parents and officials across the country should also know that recycled rubber has been studied extensively, and that the best available data do not support that there are health concerns for users of these fields. Let's hope that reasonable, scientific analysis prevails in this debate, and that it ultimately trumps unscientific speculation.

Michael Peterson is a board-certified toxicologist at Gradient, an environmental and risk sciences consulting firm. He serves as scientific adviser to the Recycled Rubber Council.