College-level environmental engineers in California have created a device that attaches to a lawnmower and significantly cuts down the dangerous emissions associated with the gardening tool. The technology could save businesses and Americans millions of dollars in manufacturing and public health costs, respectively.

The summer promises for long grass and even longer afternoons behind a lawn mower. Americans spend three billion hours per year using lawn and garden equipment, according to the Envirionmental Protection Agency (EPA). They also calculate that push mowers spew as much pollution per hour as 11 cars, while a riding mower emits as much as 34 cars.

For decades, small gasoline engines have existed with few regulations, and thus they have become serious contributors to air pollution, which can cause asthma and other respiratory diseases. In 2008, the EPA instituted new standards for small engines and required manufacturers to be compliant by 2011-2012. The mandates should prevent 450 premature death and 500 hospitalizations per year, but could ultimately cost producers and consumers millions of dollars. Some states with substantial high-polluting urban areas, such as California, are adding their own standards for small engines on top of the EPA's.

To help lawnmowers meet these new regulations, student engineers from the University of Califorin-Riverside Bourns created "NOx-Out", a retrofitted air filter for small engines. The device is attached in place of the muffler and reduces harmful pollutants, such as carbon monoxide (by 87 percent), nitrogen oxides (by 67 percent), and particulate matter (by 44 percent).

Estimated price for the filter is $30, which features an innovative pollutant-eradicating compound that was developed by the team. It could also be adapted for leaf blowers, dirt bikes, and snowmobiles. The new gadget won two first place awards at the WERC: A Consortium for Environmental Education and Technology Development competition, which is run by the Institute for Energy & the Environment (IEE).

Press release with more details on the NOx-out filter