The name or designation “leaf blower” is misleading. As more people realize this fact, the term “dirt blower” and “noise blower” are becoming popular descriptions. The City of Lawndale’s (CA) ordinance refers to them as “. . .weed and debris blowers.”
 
One landscape contractor stated they are used primarily on hardscape (defined) to move leaves, dirt, grass clippings and debris.  Another landscaper says, “It’s not a leaf blower, it’s a power broom” (97.8.3).  The power blower was described by the editor of a lawn-care industry magazine as the “elegant alternative” to broom sweeping (98.2.4) for grass clippings.

An education video made specifically for professional gardeners and other workers shows five times more blowing of hardscape than of landscape.  A landscape contractor’s association opposes full bans claiming it would make cleaning parking lots and parking structures more difficult.
 
They are what the book “Small is Beautiful” calls “inappropriate technology”, what one magazine called “Technological overkill” (97.10.1), and were included in The Learning Channel production of "Inventions We Love to Hate."  Some people consider them “modern toys”.  They are a Triple Jeopardy of emission, noise and fugitive dust air pollution.
 
The most recently produced blowers should run cleaner than those mentioned in articles and studies referred to on this web site.  However, the majority of blowers in use in residential areas are older machines.  Even if they met the emission standards in force at the time they were manufactured, after years of use the older units may produce even more pollution than noted herein.

For this reason, if a blower is going to be used, we join manufacturers in urging regular upkeep and maintenance, and the purchase of new technology to replace older, more polluting machines.

“Two stroke” and “four stroke” designations refer to the number of piston movements during an engine cycle.  In a four-stroke engine, two revolutions require four piston strokes.  Two-stroke engines have only one revolution and must use a mixture of oil and fuel that burns incompletely.  Researchers say as much as 25% of that oil and fuel is then spit out, unburned, through exhaust.” (98.2.5) and (98.1.1)  Blowers “. . .use fuel as a coolant, spitting unburned gasoline – an ingredient of smog—into the air to keep themselves from overheating”  (98.1.12) 
 
The web site “howstuffworks” points out that two-stroke engines [such as those used for blowers, edgers, scooters, snow blowers, Ski Jets], wear a lot faster than four-stroke engines, their use of 4 ounces of special oil per gallon of gas is expensive, and they “produce a lot of pollution,” due to the “leaking hydrocarbons from the fresh fuel combined with the leaking oil. . .”  Go to this site to see an animation of an engine at work.
 
Gasoline lawn mowers have four-stroke engines, which are “7 to 10 times cleaner than the new two-stroke models [blowers] on the drawing board [in 1998]” (98.2.5).
 
It is illegal under California Motor Vehicle Code 27156 to alter or modify the original design of gasoline blowers manufactured after 1995, all of which are distinct from pre 1995 models.  On the top of the carburetor on newer models, a raised metal housing (border) surrounds two screws that are next to each other.  Both of these screws are recessed within the housing and covered with a plastic cap, also recessed within the housing. The two screws on older machines are exposed and wrapped in coils. See carburetor graphic here.
 
However, a few “test cases” have modified older machines to operate on methanol.  This is not recommended by manufacturers.  AlsoSee Methanol Report.
 
The two-stroke motor was banned in the form of water scooters on Lake Tahoe because it polluted the water, leaving a shimmer of oil around two-stroke motor boats.  Two-stroke pollution includes the carcinogen benzene.  Yet, this motor is used daily throughout California in the form of dirt blowers and lawn edgers.  They waste the same gas and oil, and “belch” the same air pollution from fuel as the banned water scooters.  They disrupt the peace and quiet of residents and visitors alike.