leaf blowers zero air pollution
research regarding leaf blower laws

Account of Participation in the February 26, 1998


Conducted By The

Los Angeles Department of Water and Power

Leaf Blower Task Force


Volunteer Participant: A Member of the Grassroots Organization Zero Air Pollution

Throughout the efforts to gain a ban on leaf blowers in Los Angeles, claims were made regarding the difference in work time between the use of machines and manual labor with a rake and broom. Ban advocates made claims ranging from zero to 5% to perhaps 15% additional work time. Blower supporters claimed 300% to 500% more work time. These claims were still being made in other cities in the year 2001.

The press quoted workers as saying they would "have to go on welfare" if they could not use blowers, and businesses claimed they would have to "double" their rates, and would, therefore lose customers. They would, as claimed by one speaker, have to "fire workers", on the one hand, and "hire more workers to use rakes", on the other hand. These claims, in turn, influenced the votes of City Council members.

In order to gain an impartial investigation, Zero Air Pollution requested to be allowed to take part in the Los Angeles City Department of Water and Power February 1998 Assessment and Performance Testing designed to compare electric leaf blowers with gas blowers. No vacuums or any other method of leaf and debris collection were to be tested. Though told we would not be considered an "official" participant of the comparison, we were given permission join the demonstration. Our volunteer was a grandmother. We were denied permission to videotape.

The Task Force which oversaw the test was formed by the Los Angeles City Council, and was composed of two representatives from gardeners' associations, one representative each from a landscape contractors' association, leaf blower dealers, the Los Angeles Department of Water and Power, Department of Parks and Recreation, General Services, the City Council and the homeowners.

It was a well-designed experiment. The machines and manual tools were measured and rated by up to seven task force members for balance, vibration, noise, emissions, safety, maintenance, ease of operation, flexibility, dust and portability. The machines were also compared by cost, weight, electro/mechanicals (input and output), air movement (velocity, volume), and noise. A few of the participants were amateurs; the operator of the gas blower was a professional gardener who was also part of the task force and judging committee.

Each competitor performed three timed tests, in turn.

Because we would use the rake on the patio, it was the tool to be measured for noise level, rather than a broom. It was first used by a ZAP member in the same manner which would be applied later, in the timed test. The gardener objected, stating that gardeners did not use rakes that way. He was allowed to manipulate the rake for the noise test. However, rather than using it as one would on a patio or on grass, he dug and chopped into the cement frantically, as though working solid clumps of damp leaves and debris out from under hedges. This, of course, raised the decibel reading to an unrealistic level.

The ZAP volunteer used only the rake for the first and second test. For the third test, first leaves and pine needles were raked down the slope. Then a push broom was used for the remaining dirt and small leaves. In this third test, the gas blower was noteworthy for the noise that echoed from wall to wall, and the wet dirt and leaves that shot ten feet up and bounced off the side of the building.

Total work time with broom and/or rake in the three tests added up to only 32 seconds longer than that of the gas blower, and shorter than any other blower tested.

 This figure worked out to a 20% increase from the gas blower time.

That is not greatly different from the Air Quality Management District estimate of up to a 15% increase. It is consistent with an evaluation of the raw footage from The Learning Channel production, Inventions We Love To Hate, which showed a 25% difference where a gardener using a blower worked at a faster pace than the volunteer using a rake. Working at the same speed, as previously agreed upon, would have resulted in about a 15% difference.

These are all much more manageable figures for gardeners to discuss with employers than is the threat that they will "have to double" their rates. That phrase indicates an increase of 100% of their total work time (wherein they mow, trim bushes, edge lawn and remove debris), not just of the time they spend clearing grass clippings, leaves, dirt and debris.

This Department of Water and Power demonstration seems more relevant to residential landscape comparisons than does the "Pasadena" calculations made after a game at the Rose Bowl.

If you plan to conduct leaf blower, leaf vacuum, or other pertinent studies, contact ZAP for suggestions that will help make them well-rounded, accurate, and unbiased. See our suggestions for future studies. See also, Account of Participation in the TLC production of "Inventions We Love to Hate."