Synthetic pitches: Are health fears totally groundless?

Fears about cancer and carcinogens continue to surface for synthetic grass industry

Leinster Rugby played on one last Saturday in the Cardiff Arms Park and trained on one in UCD during the week. Numerous GAA clubs around the country ran out on them and countless Irish sports complexes rented them out to five-a-side soccer players and children’s teams.

Opponents of synthetic grass pitches have described them as toxic tyre dumping grounds for children to play on and the biggest experiment ever carried out on the effects of carcinogens on a human population.

A Yale professor of Environmental Chemistry and Engineering, Gaboury Benoit, described the shredded tyres used as infill on the pitches as a ‘witches brew’ of toxic substances, adding that it seemed irresponsible to market hazardous waste as a consumer product.

That the European Commission (EC) science community is discussing the use of rubber infill on synthetic pitches as a possibly dangerous substance means it is a serious and credible health issue.


The elevation of the subject from emotive declarations from parents that claimed it has caused cancer in their children to consideration by the US Environmental Protection Agency (EPA) and EC is a red flag as it indicates they believe the science behind the claims that the rubber may cause cancer stacks up enough to be considered.

To what extent has yet to be seen.

The issue is not whether the rubber infill on Irish 3G pitches, Dundalk’s soccer pitch, Donnybrook’s rugby pitch or the GAA surface in Cavan’s Breffni Park contains carcinogens because it has been shown they do.

The question is not whether the harmful chemicals in the rubber infill called PAHs can move into the human body through the skin, by ingestion or inhalation because they can. Just ask any child who has played on the surface if they have ever swallowed particles of the rubber.

The question is what volumes of toxic material get into the body and what precise effects they have, if any, when they get there. Are they carcinogenic and are they mutogenic? This is where the science runs aground.

Despite the noise around the issue last week in Britain from concerned parents claiming their children’s health has been ruined and counter claims by a ‘Fifa approved’ toxicologist saying the rubber is no more harmful than children’s toys, nothing conclusive has been found to definitively show the grains cause cancer.

Nor has there been anything to prove ingesting, inhaling or rubbing the infill into grazed knees and elbows, does not cause cancer. There is, though, enough circumstantial evidence linking the chemicals contained in the rubber and cancer to ensure it’s taken seriously.

Central to the concerns are presence of poisonous substances called PAHs (Polycyclic Aromatic Hydrocarbons ) contained in the 150 tonnes or so recycled tyres that go into making the pitch infill. Links between many PAH chemicals and cancer are well documented.

In a study published in the Journal of Environmental Health and Toxicology (v27, 2012) and listed as a reference on the US EPA website, researchers looked at the risk of lead poisoning in children by ingesting the crumb rubber.

They simulated digestion of the rubber by three laboratory methods (using humans is unethical) and measured the results using a hazard index. A reading higher than 0.1 is deemed a potential hazard.

In the smaller particle sizes some readings showed averages of 0.689 and a worst case scenario of 1.723. Californian research stated that if a child ingested 10g of rubber powder it would have a Hazard index of 0.226 by one measuring method and 0.174 by another. Both are higher than 0.1 and potential for hazard.

In a Dutch publication, the Journal of Chemisphere, Vol 90, Issue 2, January 2013 scientists studied hazardous chemicals in products used from recycled tyres.

The conclusion: Uses of recycled rubber tires, especially those targeting play areas and other facilities for children, should be a matter of regulatory concern.

But linkage and causation are two different things. Causation is much harder to show and until sustained research can prove that infill causes cancer, the industry will continue to deny the pitches are harmful.

Many studies have been carried out in both Europe and the USA (rubber tyres in both continents contain PAHs) that concludes the turf to be non-hazardous with the US leading the way.

From 2009-2011, New York City and the states of New York, Connecticut and New Jersey conducted studies on tire crumb infill. Also, in 2008 and 2009 the Consumer Product Safety Commission and the Agency for Toxic Substances and Disease Registry evaluated synthetic turf "grass blades" in response to concerns about lead exposure.

Their evaluations estimated that any potential releases of toxic chemicals from the grass blades, such as lead, would be below levels of concern.

The US EPA added: “Limited studies have not shown an elevated health risk from playing on fields with tire crumb, but the existing studies do not comprehensively evaluate the concerns about health risks from exposure to tire crumb.”

In Ireland pitch laying and crumb rubber is a big business and the industry is not unaware about the controversy surrounding the product. But they too insist it is not harmful and point to supportive research.

“The studies and risk assessment says that the infill is safe. Research has shown that the PAHs are not migrating (from the rubber),” said an Irish industry spokesman.

“If Europe has restrictions then we have obligations. We are taking the issue very seriously because it is our livelihood. But 20 per cent of a tyre is lost on the road. People are breathing them every day. Do we take tyres off the road?”

The most compelling circumstantial evidence against the use of the rubber has been anecdotal and arose when, Amy Griffin, a 1991 FIFA World Cup winner with the USA and goalkeeping coach for the US under-20 soccer team became aware of the number of cancer victims who were goalkeepers.

She noticed that several goalkeepers she knew had been diagnosed with the same type of cancer and began to question whether it could be the carcinogens – mercury, lead, benzene and arsenic have been found – in the crumb rubber.

She began to collect data about athletes with cancer who had played on artificial turf containing the rubber.

As of June 2015 there were 153 cancer cases on the growing list and of those, 124 were soccer players with 85 being soccer goalkeepers, many of them student athletes

The focus then fell on the goalkeepers because of the nature of their position. They are the players who are regularly diving onto the surface and therefore are the most exposed to the rubber granules.

Rugby players because of the nature of the game played on the ground would be exposed to similar or more sustained periods of time with the rubber surface, especially those players in the pack, whose faces are literally pushed into the ground.

Because the infill is loose it also flies up, which also increases the possibility of ingestion and inhalation to all players.

Two weeks ago the US Environmental Protection Agency launched a multi agency action plan under the heading – ‘Federal Research on Recycled Tire Crumbs Used on Playing Fields’ which will produce findings by the end of 2016.

It noted: “Concerns have been raised by the public about the safety of recycled tire crumb used in playing fields and playgrounds. Limited studies have not shown an elevated health risk from playing on fields with tire crumb, but the existing studies do not comprehensively evaluate the concerns about health risks from exposure to tire crumb.”

The deficit of hard scientific evidence now puts parents between a rock and a hard place. Recognising that sport is healthy and often plays a large part of children’s lives, do parents decide that the pitches are a hazardous recycling dump where their kids can play.

Should they stop their children from using the surface for rugby, soccer and Gaelic games until independent researchers in Europe clear them, or do they accept the industry claims that ground down tyres are no more than inert pieces of granulated rubber and perfectly safe.

In Ireland the issue has largely fallen under the radar, although the Irish EPA is part of the European debate. But In the US it has become a political war zone between lobbyists and legislators.

In early 2015, Senator Jerry Hill, a Californian Democrat, introduced a bill that would have implemented a two-year moratorium on the installation of crumb rubber fields and playgrounds until the state produced a new study.

The turf and scrap tire trade groups, as well as labour groups, spent tens of thousands of dollars lobbying against the bill. In California, as in Virginia and Minnesota, the industry won.

There is no slowing down to the laying of the pitches across Irish countryside with the FAI last week allaying fears about the surface.

“There is a large body of reports that contradict the claims that artificial turf or crumb rubber is a risk to health. We will continue to be guided by Fifa and the appropriate health agencies.”

Johnny Watterson

Johnny Watterson

Johnny Watterson is a sports writer with The Irish Times