In California the air pollution control agency AQMD is offering a program to replace traditional 2-cycle leaf blowers with models that are much cleaner. This is why:
“These machines are a significant source of smog-forming emissions. In one year, the average two-stroke backpack leaf blower emits as much pollution as 80 new cars.” The blowers in the exchange program, manufactured by STIHL Inc., are nearly five times cleaner than the California Air Resources Board’s most stringent standard for new blowers. By scrapping 1,500 old blowers and replacing them with low-emission STIHL blowers, the program will reduce at least 14 tons per year of smog-forming emissions.