In September, 2013, Brian Palmer of the Washington Post had an introduction to the environmental and public-health challenges created by two-stroke engines in leaf blowers and lawn mowers. Sample:
Cities where two-stroke engines are in particularly wide use suffer terribly from air pollution. Some of India’s urban centers, for example, are draped in heavy soot, a problem due in large part to auto-rickshaws powered by two-stroke engines. More than a decade ago, Delhi phased out tens of thousands of auto-rickshaws with two-stroke engines in favor of those with four-stroke engines that run on natural gas....
In leaf blowers, two-stroke engines have been shown to emit contaminants comparable to large automobiles. A 2011 test by the car experts at Edmunds showed that “a consumer-grade leaf blower emits more pollutants than a 6,200-pound 2011 Ford F-150 SVT Raptor.” The company subjected a truck, a sedan, a four-stroke and a two-stroke leaf blower to automotive emissions tests and found that under normal usage conditions — alternating the blower between high power and idle, for example — the two-stroke engine emitted nearly 299 times the hydrocarbons of the pickup truck and 93 times the hydrocarbons of the sedan. The blower emitted many times as much carbon monoxide and nitrogen oxides as well. The four-stroke engine performed significantly better than the two-stroke in most of the categories, but still far worse than the car engines.
The takeaway is that if you fret about the air pollution coming out of your car’s tailpipe, you should avoid gas-powered leaf blowers.