Get the facts.
Decades of scientific research make clear that the noise and pollution created by gas-powered leaf blowers undermine community health and well-being.
On this page, we highlight some of the most important findings and provide links to key studies and sources.
You can also visit our Resources page to find fact sheets you can use when speaking to landscapers, neighbors, and elected officials.
If you want to read just one piece, check out James Fallows’ 2019 article in The Atlantic or our two-page fact sheet.
If you prefer video, watch Fallows’ 3-minute brief on the issue from 2018, or a longer 2017 report from the public television station KCET, below.
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Noise
Gas leaf blower noise creates real harm in our community.
Operating a gas leaf blower can easily cause hearing loss. Sound produced by the type of gas leaf blowers most used in Montclair routinely exceeds 100 “A-weighted” decibels (dBA) at the operator’s ear. This is roughly on par with a chainsaw or motorcycle, and the Centers for Disease Control (CDC) recommends no more than 15 minutes of daily exposure without adequate protection.
Bystanders are also at serious risk. Public health experts are increasingly concerned about ambient noise, calling it “the new secondhand smoke.” People within 50 feet of a single gas leaf blower, or within 100 to 200 feet of a typical crew operating multiple leaf blowers, are exposed to noise levels that can cause hearing loss and increased risk of other health problems, such as cardiovascular disease, over time. The problems get worse when leaf blowers are used on hard surfaces or in partially enclosed spaces (e.g., courtyards) that amplify and reflect noise.
Noise affects our ability to concentrate, work, and learn. Even at longer distances, gas leaf blower noise is a significant problem. A typical crew operating multiple pieces of equipment generates enough sound to exceed the Environmental Protection Agency (EPA) community noise standard of 55 dBA at a distance of 800 feet in all directions — a circle covering hundreds of residents.
At this noise level and even lower, numerous studies have documented disruptive effects on concentration and cognition, ability to learn, and productivity at work.
Chronic noise exposure may contribute to dementia and Alzheimer’s. A recent study associated with the Chicago Health and Aging Project found that daily exposure to excessive community noise over a period of years was associated with sleep deprivation, hearing loss, increased heart rate, constriction of blood vessels, and elevated blood pressure, all precursors to increased risk of dementia. The researchers found that a 10-dBA increase in community noise level was associated with a 36% higher likelihood of having mild cognitive impairment and a 29% higher likelihood of having Alzheimer’s disease.
Children are especially vulnerable to environmental noise.
High levels of ambient noise are particularly concerning for children. Multiple studies have demonstrated how community noise affects speech processing, language acquisition, reading comprehension, social behavior, and other developmental concerns. For this reason, organizations like the CDC, Harvard Medical School, and the Medical Society of the State of New York have all expressed concern over the use of gas leaf blowers around schools, parks, and neighborhoods.
Gas leaf blowers produce specifically problematic noise.
Unlike most other machines that produce loud noise, gas leaf blowers emit sound that has a strong low-frequency (LF) component, akin to recorded music with the bass turned way up.
The intensity of LF sound falls only gradually over long distances, so it can be heard far away. High-frequency sound dissipates closer to the source. LF sound also passes easily through walls and windows, making the annoyance and disruption inescapable.
Toxic emissions
Gas leaf blowers are among the dirtiest machines on earth.
“If you’ve seen a tuk‑tuk, one of the noisy tricycle-style taxis in places such as Bangkok and Jakarta, with purple smoke wafting out of its tailpipe, you’ve seen a two-stroke engine in action.”
Most gas leaf blowers in use in the United States, along with chainsaws and edge trimmers, are powered by cheap, extremely inefficient “two-stroke” engines that provide a lot of power without a lot of weight. They burn a mixture of gasoline and oil, emitting high levels of ozone-forming and cancer-causing compounds.
Notorious pollutants emitted at significant levels by gas leaf blowers include volatile organic compounds (VOCs) such as benzene and formaldehyde; nitrogen oxides (NOx); carbon monoxide (CO); and fine particulate matter (PM2.5). While car, jet, and other types of engines have become enormously cleaner over the past several decades, gas-powered lawn and garden equipment has lagged far behind.
The California Air Resources Board has concluded that operating the best-selling commercial leaf blower for one hour emits as much smog-forming pollution as driving 1,100 miles in a 2017 Toyota Camry. This is happening all over Montclair, every day, most months of the year.
In addition, two-stroke engines can expel about 30% of their gas-oil fuel mixture, unburned, as aerosol exhaust. If you’ve ever wondered why clothes smell like gasoline after using these machines, now you know.
Gas leaf blower pollutants cause major health problems.
VOCs. The main VOCs emitted by gas leaf blowers are benzene; 1,3 butadiene; and formaldehyde. These compounds pose more cancer risk than almost any other organic air pollutants in the United States.
Ozone. Ground-level ozone is the major component of smog. It is produced by a chemical reaction of VOCs and NOx — compounds emitted by gas leaf blowers — in the presence of heat and sunlight.
Breathing in ground-level ozone can cause serious health effects, including respiratory symptoms, reduced lung function, and airway inflammation. Many studies have also established clear links between ozone exposure and heart attacks, increased hospital admissions and ER visits, and death. People with respiratory conditions such as asthma are especially at risk.
Fine particulate matter. Emissions of PM2.5 also pose grave public health risks. Exposure to this type of pollution has been linked in thousands of studies to cardiovascular effects, including heart attack, heart failure, and stroke; respiratory problems, from coughing and shortness of breath to the development of asthma; and premature death. In 2013, the International Agency for Research on Cancer concluded that particle pollution causes lung cancer.
Emerging research also suggests that exposure to PM2.5 raises the risk of infant mortality, birth defects, and the severity of asthma in children.
COVID-19 makes the threat worse.
In April 2020, researchers at the Harvard School of Public Health released a nationwide study showing a clear connection between long-term exposure to PM2.5 and elevated death rates from COVID-19. The study showed that individuals living in counties with high levels of PM2.5 were substantially more likely to die from COVID-19 than those living in counties with low levels, all else held equal.
Effects on lawns, gardens, and wildlife
Decades of horticultural research have shown that returning short grass clippings to the lawn and mulching, rather than removing, fallen leaves provide enormous benefits to the health of your soil and plants. Eliminating every speck of fallen organic matter robs lawns and gardens of natural fertilizers and soil-improvers while wreaking havoc on natural ecosystems. Our Quiet Alternatives page provides much more detail on how you can put your fallen leaves and clippings to use.
Leaf blowers cause ecosystem damage in other ways, too. It should not be surprising that jets of air strong enough to move huge piles of leaves are also strong enough to desiccate the sap, pollen, and seeds that help plants reproduce and sustain critical insects and small animals, or to break tender stems and branches, opening plants up to disease. The natural ground cover that keeps plants protected over the winter and provides habitat to many types of bees, butterflies, frogs, and other wildlife is destroyed when leaf blowers are used to remove every last speck from our yards in the fall.
Moreover, the air pollutants that gas leaf blowers emit produce acid rain and smog, change nutrient balances in coastal waters and river basins, and reduce biodiversity, among other effects.
Battery-powered alternatives
Over the last 10 years, a “battery revolution” in industry has resulted in rapidly accelerating gains in the power, longevity, and cost-effectiveness of battery-electric tools, including leaf blowers. Virtually all the leading manufacturers now offer commercial-grade battery-electric equipment with nearly as much power as their gas counterparts — at a fraction of the operating costs.
Further, rigorous field testing has demonstrated that commercial battery-electric leaf blowers are far quieter and less disruptive to neighborhoods than their gas counterparts. In typical neighborhood settings, gas leaf blowers sound up to 4 times louder to the human ear than battery-electrics, and their sound intensity levels, which affect health outcomes, can be 20 times higher.