Environment

Pollution causes rise in cancer cases

Air pollution contributes to a 10 per cent rise in people being diagnosed with cancer, a study has found.

US researchers believe it causes an extra 44 cases per 100,000 people – equivalent to more than 28,600 cancer diagnoses in Britain.

The study, published in the journal Cancer, is the first to examine the link between environment and cancer, although previous research has found diesel fumes could cause women to give birth prematurely.

Its authors say developing the disease is 50 per cent due to genetics, but environment also damages our DNA, changes the way genes work and can even alter important hormones.

They examined the populations of almost 2,700 counties across America, where cancer affected an average of 451 people in every 100,000 between 2006 and 2010.

The extra 44 cases found in the worst polluted counties compared to the cleanest represents a rise of around 10 per cent, while socio-economic circumstances and roads also increased risk.

Lung cancer had already been linked to diesel exhausts and polycyclic aromatic hydrocarbons, produced by cars and also thought to cause asthma and heart disease. But an extra ten cases of prostate cancer per 100,000 men were also attributed to air pollution, with almost four extra cases of breast cancer per 100,000 women. The reasons behind this increase are still being examined, but the study states: ‘Environmental exposures can alter or interfere with a variety of biological processes, including hormone production and function, inflammation, DNA damage and gene suppression or over-expression.’

Previous research has suggested particles of pollution can mimic oestrogen, which is known to fuel breast cancer.

They can also make women’s breasts denser, which raises their danger of the cancer.

To investigate the effects of overall environmental quality, the researchers looked at air, water and land quality, as well as the built environment and social factors. When adjusting for age, the annual incidence was 451 cancer cases per 100,000 people.

But counties with poor environmental quality had on average 39 more cases per 100,000 people than those of high quality.

Water quality had little or no effect on cancer rates when taken in isolation, with land quality, including the use of pesticides, having a small effect.

Air quality alone was found to cause an extra 44.19 cases per 100,000 over the four years.