Farm pesticides linked to skin cancer

Ecologist

7th April, 2010

Large-scale study highlights agricultural chemicals as a possible risk factor behind rising rates of melanoma in the US

Repeated exposure to pesticides can increase the risk of developing skin cancer, according to research conducted on farm workers in the US.

The study looked at more than 55,000 pesticide sprayers working in Iowa and North Carolina and asked them to detail their exposure to 50 pesticides. Using that data researchers were able to compare their cancer rates with their use of certain pesticides.

Six chemicals in all, including two fungicides (Benomyl and Maneb/mancozeb) and two insecticides (Carbaryl and methyl/ethyl parathion) were found to double the risk of developing skin cancer with repeated exposure of more than 50 lifetime days.

Sun exposure

The researchers, led by Professor Leslie Dennis from the University of Iowa, admitted their study was limited by being unable to control for sun exposure.

‘Sun exposure, perhaps the strongest risk factor for melanoma, is difficult to capture via questionnaire. Since farmers spend a great deal of time in the sun, we cannot rule out the possibility that these pesticides-specific results are driven by sun exposure.’

However, they concluded that agricultural chemicals should now be considered as a risk factor.

‘Most of the previous melanoma literature has focused on [personal] factors and sun exposure, but our study suggests more research is needed on chemicals and other environmental factors that may increase the risk of cutaneous [skin] melanoma,’ they said.

A study published by the EU Parliament in 2008 found increased cancer rates among children of farm workers and children living on farms.

Nick Mole, from the Pesticides Action Network-UK (PAN), said he hoped the current UK consultation on pesticide use, which ends on May 4th, would bring in greater protection for farm workers, including restrictions on re-entering sprayed areas and greater use of non-chemical alternatives.

Useful links
Full study: ‘Pesticide Use and Cutaneous Melanoma in Pesticide  Applicators in the Agricultural Heath Study’, published in the Environmental Health Perspectives journal