In this time of political polarization there is one topic on which consensus may just be possible: Gas-powered leaf blowers (GLBs) are noisy and stinky, and they stir up dust tornados.  

I concede that leaf blowers do a decent job of blowing leaves around. It’s no accident that there are over 11 million them in California.

But let’s establish the harmful things that GLBs do as well.

Emissions

The most surprising thing I learned in my research for this post is that leaf blowers emit WAY more toxic emissions than cars. WAY WAY WAY more!

For the best-selling commercial leaf blower, one hour of operation emits smog-forming pollution comparable to driving a 2016 Toyota Camry about 1100 miles, or approximately the distance from Los Angeles to Denver. Source: California Air Resources Board Factsheet

The two-cycle engines used in GLBs are very inefficient; each one spews out, for instance, 11 pounds of CO2 per hour of use. This inefficiency relative to cars is a result of GLBs not being equipped with catalytic converters, which were introduced for car engines in 1975. Current versions of the catalytic converter reduce the emission of carbon monoxide, hydrocarbons, nitric oxide, and nitrogen oxide.

The small engines used in GLBs, lawn mowers, and weed whackers also emit large quantities of fine particulate matter, including black carbon.

Black carbon released into the atmosphere raises air and surface temperatures, which of course damages plant and animal ecosystems. Black carbon is also acknowledged as a major cause of premature deaths and disability worldwide. Because it is so finely textured, the carcinogens that it contains are easily inhaled and released into the bloodstream.

Another by-product of incomplete gasoline combustion is benzene, which causes leukemia and other blood cell cancers as well as cardiovascular, neurological and respiratory diseases.

The spewing will continue unabated unless someone invents a mini catalytic converter for GLBs, or until they are banned.

Noise

Most people would agree that GLB are loud, but can we be more precise? According to manufacturer reports, the sound pressure level of commercial-grade machines typically exceeds 95 decibels in the ear of the operator, a level that is directly associated with hearing loss. Even for people standing 50 feet away, the equipment produces a racket that exceeds the daytime sound standards of 55 decibels set by the World Health Organization.

The low frequency of GLB noise is another issue. Low frequency sound travels farther and penetrates buildings more effectively than higher pitched sound. A GLB can negatively impact up to 90 surrounding homes in typical urban densities versus 6 homes for a powerful electric blower. All that ambient noise causes stress responses in humans, including raised cortisol levels. These stress responses are in turn associated with arterial hypertension and cardiovascular disease.

Living in a Dustbowl

On a less catastrophic but nevertheless important note, GLBs can create clouds of whatever is in the air and on the ground. Pollens, fertilizers, pesticides, dirt, and other things are whipped into a cloud that wafts across yards, parks, and playgrounds. This is unpleasant for everyone in the vicinity, but is particularly dangerous for children, people with chronic asthma, and people who are exercising (hello, Marin).

Ironically, all of the blowing also damages the plants themselves. When used in flower beds and lawns, GLBs blow topsoil away from the crowns of plants and damage their roots. They also compact the soil, making it harder for air and water to permeate, and they blow away dry fertilizers. And they kill the beneficial microbes in the soil by starving them to death, resulting in fewer nutrients in the soil for plant uptake.

Looking for Solutions

The inherent problems with GLBs have grabbed the attention of many homeowners. In the chart below, you can see that residential users are far more likely to own electric leaf blowers than gas-powered ones. In contrast, landscaping companies rarely use electric versions of these items. This suggests that community and state regulations should consider carefully the needs and constraints of both types of user.

Source: Town of San Anselmo 2020 report

Community Regulation of Leaf Blowers

Many cities across the US have restricted the use of GLBs. Most town in Marin have adopted some kind of restriction on leaf blowers, starting with Mill Valley in 1993. These range from outright prohibitions on their use to limitations on hours or areas of use.

For example, Corte Madera bans the use of GLBs entirely, but allows the use of electric blowers from 9 to 5 on weekdays and 10 to 4 on Saturdays.  In San Anselmo, motorized leaf blowers -- both gas and electric -- may only be used from 1:00 pm to 4:00 pm on Mondays, Thursdays, and Saturdays for a period not to exceed thirty minutes at a time per property.

Check out this MMWD handbook for great landscaping ideas that require little leaf blowing!

In unincorporated areas of Marin there is no specific restriction on landscaping equipment, including leaf blowers. To find out whether any actions were underway at the County level, I spoke with Crystal Martinez, aide to Marin County Supervisor Katie Rice. Ms. Martinez told me that the County takes the climate impact of GLBs very seriously and has been studying options for mitigating the damage. However, it is challenging to come up with a single policy that is equally well suited to communities as diverse as Kentfield, for example, and Point Reyes Station.

	What works in San Geronimo may not work in Kentfield!

While implementing a policy focused on a single category of landscaping equipment may seem straightforward, the Marin towns that have adopted regulations on GLBs have experienced some challenges. For instance, while fines are theoretically imposed on repeat offenders, enforcing this regulation may not be a top priority for law enforcement officers. Additionally, enforcement officials often do not witness the infraction due to the transient nature of landscape work.

Another challenge is related to the cost of new equipment to homeowners and especially to landscapers, many of whom are low-wage earners. Many are reluctant to impose additional financial burdens on workers from these communities.

Some towns offer rebates toward the purchase of zero emissions equipment or have instituted an equipment buy-back program. These policies pose procedural challenges for towns that have instituted a ban, particularly concerning the process for providing rebates to landscapers who serve multiple communities. For more on the issues towns in Marin are facing, click here.

The state of California also acknowledges the climate impact of GLBs. The California Air Resources Board (CARB) began regulating emissions of equipment that uses two-stroke engines in 1990, with subsequent amendments specifying increasingly stringent standards. In 2019 the State again scrutinized this category of equipment to help meet its goal of reducing pollutant emissions, and evidence from a recent CARB workshop indicates that the agency will be acting on a proposed requirement of zero-emissions equipment in the Fall of 2021.

What Can You Do to Help?

• Communicate your opinion on the topic of GLBs to your elected officials. Contact your County Supervisor or send a note to the California Air Resources Board (sore20201@arb.ca.gov) urging them to ban GLBs in our state.
• Embrace a messier look in your garden. Your yard will be a healthier and happier place for plants and bugs if there is some leaf litter to keep the soil rich and moist. Think of it as the horticultural equivalent of a messy bun – very trendy!

• Reframe raking as bodybuilding. Raking can be an excellent way of strengthening your upper body. Fast raking may even qualify as a cardio activity.
• Create a fun place to play by letting the leaves and grass cuttings pile up for a while!
  
  
• Dig a bit deeper into your pocketbook. If you use a service, pay the landscaper to take the time to rake rather than blow your leaves. If blow you must, invest in an electric blower and ask the landscaper to use your equipment instead of a gas-powered machine.

That’s it for this post! If you are a regular Notebook reader, you may know that this week marks the ONE YEAR ANNIVERSARY of the Notebook! Woohoo! 22 posts!!! It’s been so exciting for me to see this project come together over the past year. Special thanks go to graphic designer Gayle Marsh, who turns each post into a thing of beauty.

And thanks once again to
Rob Badger and Nita Winter
for sharing the image we use
for the Notebook banner!