May 18, 2006

Yard care season has begun for most of the country, and that's bad news for the environment. Lawn mowers, hedge trimmers, chain saws and leaf blowers emit carbon monoxide, smog-forming hydrocarbons and nitrogen oxides.

In one hour, the average lawn mower emits as much smog-forming pollution as eight new cars traveling at 55 miles per hour over that same period.

The good news is that there are some simple steps people can take to keep yards looking good while doing less harm to the environment.

The best way to eliminate pollution entirely is by using old-fashioned manual tools such as push mowers, pruning shears and rakes or brooms. These are especially appropriate for small yards or projects.

Electric-powered models are also good options. They may have a higher price tag than their gasoline-powered counterparts, but they are up to 50 percent less expensive to operate over a 10-year life span because of lower fuel costs. Electric tools are also cleaner even if the electricity they use is generated from fossil fuels, since it is easier to control the pollution from a single power plant than from thousands of individual tools.

But if you absolutely need gasoline-powered equipment, choose models with a four-stroke engine rather than a two-stroke engine. Four-stroke engines are far more efficient and generate fewer pollutants.

For people who already own mowers but are looking for ways to reduce pollution without having to buy new equipment, one solution is to perform routine maintenance as recommended in the owner's manual. This helps cut down on emissions. Changing the motor oil, cleaning or replacing air filters and getting periodic tune-ups will help ensure that your engine runs smoothly and efficiently.

Maintain sharp blades on cutting tools so you spend less time running the motor.

Clean the underside of your lawn mower's deck to reduce resistance and maximize efficiency.

Also, use the proper fuel/oil mixture for equipment with two-stroke engines. An improper mixture will decrease efficiency and increase pollution. (Four-stroke engines do not use a fuel-oil mixture.)

And don't get sloppy when you pour gas into your tank. Spilling gasoline contributes to air pollution when the gasoline evaporates. Use a funnel to pour gas into the tank, and be sure not to overfill it.

Technology is available to make gasoline-powered equipment much cleaner, yet engine manufactures like Briggs and Stratton have resisted, claiming emission controls can undermine safety.

The Environmental Protection Agency (EPA) recently issued a report debunking these claims. Now the EPA should follow California's lead in establishing strict standards to clean up lawn mowers.

People should write to the EPA's Office of Transportation and Air Quality to demand tougher regulations so the cleanest mowers possible are offered to consumers. Our lawn mowers should be as green as our lawns.

Patricia Monahan is a senior analyst with the Union of Concerned Scientists, based in Berkeley, Calif. The organization is the leading science-based nonprofit working for a healthy environment and a safer world. She can be reached at pmproj@progressive.org.