Lawn mowers produce several types of pollutants, including polycyclic aromatic hydrocarbons, ozone precursors, and carbon dioxide.
One type of pollutant emitted by lawn mowers is polycyclic aromatic hydrocarbons (PAHs). These are classified as probable carcinogens by the CDC. Testing found that operating a typical gasoline mower with a four-cycle engine produced as much PAH as driving a modern car about 150 km or about 95 miles. This means that unless you drive more than 95 mph, your mower actually produces more pollution per hour than your car!
Another source claims that operating a gas mower for one hour will produce the same pollution as driving a car 1300 miles.
Yet another source claims the figure is about 3400 miles of car travel per hour of mower use.
In an hour’s mowing, 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.
Another pollutant caused disproportionately by gas-powered lawn equipment is ozone. Hydrocarbons from mowers react with nitrogen oxides in the presence of sunlight to produce ozone. Since lawn mowing occurs during the summer months, it exacerbates the already high levels of ground-level ozone present in the summer. Ozone irritates the lining of the lungs and agravates athsma and other respiratory conditions. Ozone is the principal pollutant that causes “Red Alert” warnings about air quality in the summer.
An EPA study found that approximately 9 percent of some types of air pollutants nationwide come from lawn and garden equipment small engines. In metropolitan areas, the concentration of lawns causes this percentage to increase, in some instances to 33%.
The author of one pollution study had this to say: “Using a catalyst would help prevent most emissions from small engines. Of course, people could also use an electrical powered lawn mower instead.”
In Britain, more than 70% of lawn mowers sold are electric.
The concern about toxic pollutants emitted by gas mowers is heightened due to the concentrations experienced by the operator.
Government programs offering deep discounts on electric mowers in exchange for the “surrender” of a gas mower are springing up all over the country.
Source: “Types of pollution emitted by gas lawn mowers,” Lawn Mower Pollution: http://greengrasscutters.com/id7.html [accessed on May 9, 2008].
