"Gasoline powered blowers are two stroke. Two stroke designation refers to the number of piston movements during an engine cycle. 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. and blowers . . . use fuel as a coolant, spitting unburned gasoline – an ingredient of smog—into the air to keep themselves from overheating. Two-stroke pollution includes the carcinogen benzene. Yet, this motor is used daily . . . in the form of dirt blowers and lawn edgers."
There are also four-stroke engines, larger and less noisy but still emitting the high pitch, high velocity air flow.
How many of these machines are there?
In the year 2000, the State of California estimated 410,000 "gas blowers" in that State alone (405,000 were two-stroke and 5,000 four stroke - bigger and less polluting) plus 600,000 electric blowers. They operate an estimated 114,000 hours per day. Some have estimated up to 26 million in use in the US (Steinberg: "American Green").
Who uses "blowers"
A high number of Lincoln home-owners hire landscape contractors. So,too, for the Town and local businesses to maintain outdoor areas both green and hard surfaces such as parking lots. All such contractors use "blowers' as a tool. Blowers are used year-round and can no longer be termed 'leaf-blowers'. Hence the use of the words: "Dust, Debris and Leaf Blowers" by the CCBL. SEE one company's product description which includes a 177 mph (miles /per/hour) air stream.
Noise and Pollution
The most common complaint is about noise from "gas blowers.' High decibels and high-frequency pitches are disturbing to the ear and intrude on home conversations, home business offices,or calm outdoor days. Pollution is a second most stated concern. Two-stroke engines are considered the most inefficient gasoline powered engine in use. You might be surprised at the extent of the polluting effects and fuel waste. See Table 9 from scientific studies comparing blowers and cars by the California EPA.
Controlling water and air pollution is considered critical to human health but also to the vitality of the natural flora and fauna. If "gas blowers" are indeed the least efficient internal combustion engines why do we permit their use at the very same time that we seek to limit fuel consumption and pollution in cars or trucks?
Outright bans and noise ordinances - 350 communities in the U.S.
An increasing number of communities, most recently Palo Alto (see), decided to issue outright bans for air "blowers." These bans differentiate in some cases between 'gas' and 'electric' blowers; or 'residential' and 'commercial' zones. Other communities have resorted to noise" regulations. The latter are harder to monitor and enforce especially when involving neighbors and lack of precise metering equipment or on-the-spot enforcement.
Cost-benefit: two sides to the story
Those favoring use of blowers, generally commercial landscapers and gardening services, argue that the 'blower' tools are important labor saving devices and thus lower the costs they charge. Those against blowers argue that there is little time saving and in fact only a very small labor cost differential and a high environmental price. For a substantive commentary: read.