Are artificial football pitches linked to cancer?

Question

There is a lot of weather in the UK and this interacts with normal grass pitches used for sports such as soccer and rugby to cause the pitches to be unplayable. As a response many teams have adopted the use of "artificial" pitches made from combinations of materials including shredded rubber from used car tyres. These pitches are playable in all weather conditions. They are widely used as the BBC reports:

The surfaces have been widely introduced in the UK because they can be used continuously in bad weather, avoiding postponements throughout winter, particularly at grassroots level.

The pitches are also used by 12 of 42 clubs in the top four leagues in Scottish football, two Premiership rugby union teams and rugby league team Widnes Vikings, who also share the pitch with Women's Super League teams Liverpool Ladies and Everton Ladies.

But a father whose son has contracted cancer after playing goalkeeper on the pitches claims there is a link:

Nigel Maguire says son Lewis, 18, has Hodgkin lymphoma after being exposed to the 'crumb rubber' on the surface which gives it more bounce.

This is not a new worry as this NBC report from 2014 shows.

Is there any evidence that there could be a link between the materials used in artificial pitches and cancer?

Answer 1

Evidence:

Several studies mentioned here and here do not confirm the link between crumb rubber turf and cancer.

According to Dr. Joel Forman, associate professor of pediatrics and preventive medicine at New York's Mt. Sinai Hospital, in all these studies, data gaps make it difficult to draw firm conclusions. "None of [the studies] are long term, they rarely involve very young children and they only look for concentrations of chemicals and compare it to some sort of standard for what's considered acceptable," said Dr. Forman. "That doesn't really take into account subclinical effects, long-term effects, the developing brain and developing kids."

A mutagenicity assessment of artificial turf football fields in 2013 found that artificial turf football field produce no more exposure risks than the rest of the city.

No significant differences were found between artificial football fields and urban sites. No differences were found between artificial football fields and ‘‘natural’’ football fields. There would not be any more risk on an artificial turf football field than there would be in the rest of the city. Further work will be necessary to assess the actual scenarios of exposure by inhalation and the corresponding risks.

Meaning:

As of 2016, the only thing known is that crumb rubber turf contains hazardous chemicals but it is unknown whether crumb rubber turfs can cause cancer. Future research such as the one mentioned below might measure the range of long term exposure to confirm or deny the definitive link between crumb rubber turfs and cancer.

These data gaps are, in fact, a large reason why the state of California is doing its third study on synthetic turf fields. This $2.9 million, three-year study, slated to finish in June 2018, is being performed by the California Office of Environmental Health Hazard Assessment (OEHHA). In October, Sam Delson, deputy director for external and legislative affairs at OEHHA, said this new study differs from the past two California studies. "We acknowledge that there were data gaps [in the past two studies]. We focused on inhalation and chemicals in the air. We did not address the issue of absorption in that study."