'Health risks' of mowing the lawn

Petrol-driven mowers should be fitted with catalytic converters, says a scientist

Gardeners who use a petrol-driven lawnmower could be breathing in cancer-causing chemicals along with the smell of freshly-mown grass.

A Swedish-based scientist has found that just one-hour's mowing could produce the same amount of carcinogens as an average car does in a 150km drive.

But lawnmower manufacturers said most mowers sold in the UK were electric, and that all modern petrol lawnmowers met EU emission regulations.

Dr Peter Westerholm, of Stockholm University, is calling for petrol-driven mowers to be fitted with pollution-reducing catalytic converters, which are fitted in cars.

We believe there is no cause for concern

Spokesman for Atco-Qualcast - lawnmower manufactures

Dr Westerholm, an analytical chemist whose work is detailed in the New Scientist, found in a study that lawnmowers emit polycyclic aromatic hydrocarbons (PAHs).

He told BBC News Online: "People who use these mowers will be exposed to this kind of chemicals."

In tests, a typical Swedish lawnmower emitted 4milligrams of PAHs in an hour, which Dr Westerholm said contained "relatively large amounts of carcinogenic PAHs".

Twenty-six different PAHs were found in the exhaust of the mowers, including 100microgrammes of benzo[a]pyrenes, which have been mentioned as a carcinogen in cigarette smoke.

Other chemicals emitted include half a kilogram of carbon monoxide and several grams of methane, hydrocarbons, nitrogen oxide and smoke particles.

Now Dr Westerholm is calling for petrol-driven lawnmowers and other garden tools like chainsaws and leaf blowers should be fitted with catalytic converters, like cars.

Emissions cut

Dr Westerholm said: "In tests, catalytic converters cut PAH emissions by more than 90%.".

He said emissions of other pollutants were cut by between 30% and 50%.

"Using a catalyst would help prevent most emissions from small engines.

"Of course people could use an electrically powered lawnmower instead."

A spokesman for Atco-Qualcast, one of Britain's largest lawnmower manufacturers, said: "All modern petrol lawnmowers meet stringent emission regulations laid down by the EU.

"In Britain, more than 70% of all lawnmower sales are electric. Petrol mowers are used mainly in larger private gardens or public parks. In these open space environments there is no concentration of emissions."

She added that manufacturers were continuing to work to reduce emissions and noise from mowers, and added: "For the reasons stated, we believe there is no cause for concern".

Peter Marsh, director of the Garden Industry Manufacturers Association told the Daily Mail newspaper there had been no previous evidence to show lawnmowers produced cancer-causing chemicals.

He added that fitting mowers with catalytic converters would add "excessively" to the cost.