Agriculture: Airborne pesticides need surveillance

Katharine Sanderson/San Diego, US

Airborne pesticides must be taken much more seriously when assessing risks of pesticide use, caution environmental chemists.

Pesticides routinely sprayed on crops are found in the air not just immediately where they are sprayed but also throughout the surrounding area and beyond. The health consequences for local residents are not fully known, but ongoing studies are beginning to implicate pesticides in some cancer cases.

'You might expect that the Environmental Protection Agency (EPA) is onto this - you'd be wrong,' said Susan Kegley, a chemist at the Pesticide Action Network North America (PANNA). 'The most shocking thing as a chemist is that the EPA has not been considering airborne exposures in their risk assessments,' she told Chemistry World.

California is particularly at risk from pesticide drift, Kegley told the American Chemical Society's 229th national meeting in San Diego. This state has more crops than any other. Nearly 30 per cent of the total US pesticide use is concentrated in California.

A programme to inform Californians of the risks is under way. Volunteers are equipped with easy to use equipment - so-called drift catchers - to take air samples in communities where pesticides are used.

In one community, the pesticide chlorpyrifos, used on orange groves near the town, was found in every sample taken in the local area.

According to Kegley it is not just a matter of regulating airborne pesticides, but finding alternatives to pest control, such as intercropping - methods that organic farmers already use routinely.

'If there is another way to do it, why are we still using spray pesticides?' she demanded. 'There are many more avenues in integrated pest management.'