A leaf blower is gardening tool that propels air out of a nozzle to move yard debris such as leaves. Leaf blowers are usually powered by two-stroke engine or an electric motor, but four-stroke engines were recently introduced to partially address air pollution concerns. Leaf blowers are typically self contained handheld units, or backpack mounted units with a handheld wand. The latter is more ergonomic for prolonged use. Some units can also suck in leaves and small twigs via a vacuum, and shred them into a bag.
Pollution from gas-powered groundskeeping equipment is a significant source of air pollution. US emission standards specifically limit emissions from small engines. Electric models produce no emissions at the point of use, but may shift pollution to power plants. Emissions may still be reduced by the use of renewable energy in grid generation, or because central power plants generally must have stricter emissions control equipment installed.
Soon after the leaf blower was introduced into the U.S., its use was banned in two California cities, Carmel-by-the-Sea in 1975 and Beverly Hills in 1978, as a noise nuisance. There are currently twenty California cities that have banned leaf blowers, sometimes only within residential neighborhoods and usually targeting gasoline-powered equipment. Another 80 cities have ordinances on the books restricting either usage or noise level or both. Other cities have discussed and rejected leaf blower bans. Nationwide, two states, Arizona and New Jersey, have considered laws at the state level, and five other states have at least one city with a leaf blower ordinance.