HSE RESEARCH QUANTIFIES CANCER RISK FROM EXPOSURE TO PAHS

HSE press release E016:03 - 5 March 2003

The risk of getting lung or bladder cancer following occupational exposure to polycyclic aromatic hydrocarbons (PAHs) has been quantified for the first time, in a research report published by the Health and Safety Executive (HSE).

PAHs are a group of chemicals that are found in every industry, especially where substances are burned, such as in aluminium smelting and coke production. They are air-based and can be breathed in.

Exposure to PAHs has long been known to cause lung and bladder cancer, but, until now the overall risks had not been quantified.

This research report, commissioned by HSE, 'Cancer risk following exposure to polycyclic aromatic hydrocarbons (PAHs): a meta-analysis', found that people who are exposed to one microgram per metre cubed of PAHs through work over 40 years, are eight per cent more likely to contract lung cancer, i.e. their lung cancer risk increases from 80 per 1000 to 86 per 1000.

The results for the risks of contracting bladder cancer were less certain, due mainly to the much smaller number of cases of this rarer cancer.

John Thompson, Head of Chemicals Policy in HSE said: "This research will help HSE determine an occupational exposure limit for polycyclic aromatic hydrocarbons, which we will propose to the Health and Safety Commission's (HSC) Advisory Committee on Toxic Substances (ACTS). If ACTS supports the proposal, HSC will hold a consultation exercise with stakeholders before approving the new limit."

Notes to editors

1. This research was commissioned to inform the development of a Maximum Exposure Limit (MEL) for benzo (a) pyrene, a PAH which has been identified as a suitable marker for exposure to all PAHs of concern. MELs are set under the Control of Substances Hazardous to Health Regulations 2002 (COSHH). To comply with COSHH, exposure to hazardous substances should be reduced as far below the MEL as is reasonably practicable, and should not exceed the MEL when averaged over a specified reference period.

2. Commissioned by HSE, the work was carried out by researchers from the Environmental Epidemiology Unit at the London School of Hygiene and Tropical Medicine. They reviewed all the scientific papers that provided quantified risk estimates for lung and bladder cancer and combined the results from 39 separate groups of workers, to produce overall lung cancer and bladder cancer risk estimates. Exposure to one specific type of PAH, benzo (a) pyrene was used as a marker for total PAH exposure.

Cancer risk following exposure to polycyclic aromatic hydrocarbons (PAHs): a meta-analysis. Research Report 068 is available on the HSE website at www.hse.gov.uk/research/rrhtm/

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