Question & Answer

Do 4G and 5G sports pitches (Astro turf) cause cancer due to the breakdown of the rubber base?

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The Evidence

  • The bases of some artificial turf pitches for indoor and outdoor sports are made from ‘crumb rubber’. Crumb rubber or ‘infill’ can be made from recycled tyres that contain a variety of substances that can be dangerous to health. These include chemicals known as PAHs (polycyclic aromatic hydrocarbons), microplastics and heavy metals such as lead.
  • We found 2 studies from the USA that looked at whether people who regularly play sports on artificial turf pitches with crumb rubber get cancer more than people who don’t.
  • The first was based on a group of soccer players in Washington State, USA who had developed cancers after playing on artificial turf pitches. The study was based on a list of soccer players made by a soccer coach. The Washington State Department of Health examined the data to compare rates of cancer in soccer players exposed to astroturf to rates of cancer that would be expected in people of a similar age in the state. The researchers said the results do not suggest that artificial turf is a risk to the public, but the study was limited as it could not be known whether the coach’s list included all cancers in soccer players exposed to astroturf in that age group and State.
  • The second study looked at whether a type of cancer called lymphoma was associated with the amount of artificial turf pitches in different parts of California, USA. The study found no evidence that the pitches caused cancer in adolescents and young adults.
  • We also found 8 studies known as ‘risk assessments’ (study 1, study 2, study 3, study 4, study 5, study 6, study 7, study 8) that tested artificial turf samples for chemicals that are known to cause cancer. The aim was to examine whether the type and amount of chemicals found would be dangerous to health if they were inhaled, touched or swallowed. Most of these studies found that there were chemicals in artificial turf that can cause harm. Some of the studies found that the amounts of these chemicals were not high enough to cause harm, but some found that they were above safe levels. However, we can’t be sure how applicable these studies are because they did not look at what happened in people exposed to artificial turf.
  • We don’t know for certain whether artificial turf pitches could cause cancer because there have not been sufficiently large-scale studies over long periods to see if people who use them frequently have a higher rate of cancer than people who do not.
  • There is no information about the safe levels of some chemicals in crumb rubber infill, so researchers can’t say if the levels found in samples are dangerous.

Guidelines and recommendations

  • We found official reports from national agencies of investigations into possible harms to health from artificial turf pitches in the EU and USA.
    • The European Chemicals Agency (EU) reported that there is no clear evidence of a potential harm to human health but given this uncertainty they reduced the safe level for eight high-risk chemicals called ‘polycyclic aromatic hydrocarbons’ (PAHs) in 2023 to minimise the risk of cancer and other health concerns. They are doing further tests on certain chemicals that could be harmful to people or the environment.
    • The US Environmental Protection Agency is doing research to check the possible health risks of artificial turf pitches. So far, they have found that chemicals are present in the crumb rubber but they judge that risk to human health is low.

Things to Remember

  • Just because something is associated with something else doesn’t mean it caused it. It could have just happened by chance.
  • We would need very large studies with lots of people in them to figure out whether something causes disease, particularly rare disease.

Reviewers

  • Lead Researcher: Kayleigh Kew, Freelance researcher in evidence synthesis methods and technology, UK
  • Reviewed by: Dr. Paula Byrne, Senior post-doctoral researcher, iHealthFacts, Evidence Synthesis Ireland and Cochrane Ireland, College of Medicine, Nursing and Health Sciences, University of Galway.
  • Topic advisor: Prof. Susan M. Smith, Professor of General Practice, Discipline of Public Health and Primary Care, Trinity College Dublin and General Practitioner in Inchicore Family Doctors, Dublin 8.
  • Public and Patient advisor: Deirdre Mac Loughlin, Public and Patient Involvement in research (PPI) advisor, PPI Ignite, University of Galway.
  • Journalist Advisor: Dr. Claire O’Connell, PhD in cell biology, Masters in Science Communication. Contributor to The Irish Times, writing about health, science and innovation.

Conflict of Interest Statement: The authors have no financial or other conflicts of interest for this health claim summary.