Air district report: Leaf blowers present health risks | News | Almanac Online |


Air district report: Leaf blowers present health risks

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• Read Gas-powered leaf blowers are banned from neighborhoods — so why are they being used everywhere?

• Read What to know about 'mow and blow'

Blasting air at up to 185 mph, leaf blowers can whip up hazardous particles and contaminants from the ground at speeds greater than a Category 5 hurricane, sending them long distances.

Epidemiological studies have long recognized the harm these particles — including hydrocarbons from gasoline, animal droppings, spores, fungi, pollens, pesticides and herbicides, fertilizers, brake-lining dust and tire residue and heavy metals — cause to people's respiratory systems, according to Bay Area Air Quality Management District reports.

Exposure to particulate matter is rarely, if ever, cited as the cause of death in a coroner's report when someone dies of a heart attack or stroke or lung disease, a 2012 district study noted. "However, epidemiological studies indicate that exposure to particulate matter is an important contributing factor in hundreds, perhaps thousands, of deaths in the Bay Area each year."

The district has called particulate matter "the air pollutant that poses by far the greatest health risk to Bay Area residents."

The average adult inhales 450 cubic centimeters (roughly one pint) of air per breath, which includes 1 million to 10 million tiny particles with each breath.

"But that figure can spike to much higher levels in close proximity to high-volume roadways or other major outdoor emission sources," the district's "Bay Area 2010 Clean Air Plan" noted.

The contribution of leaf blowers to air pollution isn't to be underestimated. About 5 pounds of particulate matter per leaf blower per hour are swept into the air and take hours to settle, according to a widely cited leaf-blower pollution report by the Orange County, California grand jury in 1999.

An Air District program aimed at replacing up to 50,000 leaf blowers and 10,000 lawn mowers by 2020 would reduce the most dangerous small-particle emissions (sized 2.5 and 10 microns) by 0.12 tons (240 pounds) per day, according to the 2010 Clean Air Plan.

Fine particles measuring 2.5 microns and coarser material measuring 10 microns are more readily absorbed into the lungs. The smaller 2.5-micron particles are associated with hazardous organic compounds and heavy metals, according to the U.S. Environmental Protection Agency (E.P.A.). Particles measuring 10 microns are typically composed of smoke, dirt, dust, mold, spores and pollen.

Particulates in the 2.5-micron range can migrate many hundreds of miles and stay the air for days or weeks; 10-micron particles can travel up to 30 miles and stay aloft for hours, according the U.S. E.P.A.

Besides what they kick up off the ground, gas-powered leaf blowers themselves emit specific pollutants the State of California has identified as of concern: hydrocarbons from both burned and unburned fuel, which combine with other gases to form ozone; carbon monoxide; and toxic contaminants such as benzene, 1,3-butadiene, acetaldehyde and formaldehyde, according to a widely quoted 2000 California Environmental Protection Agency Air Resources Board report.

The Air Quality District in 2010 estimated there were approximately 258,000 two-stroke leaf blowers in the Bay Area, which generate significantly more air pollution than four-stroke engines.

Testing in 2011 by the vehicle reviewer showed just how dirty leaf blowers remain, even 11 years after new emission standards for blowers went into effect.

Pitting leaf blowers against a Ford F-150 SVT Raptor crew cab, the leaf blowers were the big dogs when it came to spewing non-methane hydrocarbons, oxides of nitrogen and carbon monoxide — the three pollutants that the EPA and the California Air Resources Board find most concerning.

The two-stroke blower generated 23 times the carbon monoxide and nearly 300 times more non-methane hydrocarbons as the truck.

"To equate the hydrocarbon emissions of about a half-hour of yard work with this two-stroke leaf blower, you'd have to drive a Raptor for 3,887 miles, or the distance from northern Texas to Anchorage, Alaska," the article noted.

Officials from local lung-health organizations said the contribution of leaf blowers to pollution can't be ignored.

"It should be of great concern," said Lynn Smith, interim executive director of Breathe California of the Bay Area, also noting the huge discrepancy between leaf blower and car emissions.

Various arguments have been made by some environmental groups that blowers should be entirely banned in favor of a return to old-fashioned brooms and rakes.

A 1999 study by the University of California Riverside and San Joaquin Valley Unified Air Pollution Control District, the first of its kind, attempted to quantify the differences. Leaf blowers produced about 30 milligrams per square meter of 2.5-micron-sized particulates and 80 mg per square meter of 10-micron particles.

The results were similar for push brooms used on a concrete surface, probably because of the smoother surface, the researchers found. But using a push broom on asphalt produced no 2.5-micron particles and only 20 mg in the 10-micron range.

And raking on either surface produced no particulates in either range, the study found.

The California Landscape Contractors Association, however, disputes the allegations of the air pollution caused by leaf blowers, calling concerns over air emissions "spurious," according to a 1999 letter from its board of directors that was confirmed as current on July 20.

"Properly used leaf blowers do not raise inordinate amounts of dust. Rule 403 of the South Coast Air Quality Management District states that 'a person shall not cause or allow the emissions of fugitive dust from any active operation, open storage pile, or disturbed surface area such that the presence of such dust remains visible in the atmosphere beyond the property line of the emission source.' Blower users can and should follow this rule," the letter states.

In addition to arguing that emissions standards from the California Air Resources Board implemented in 2000 would significantly reduce emissions from handheld equipment, the association pointed to the intermittent use of blowers.

"Portable lawn and garden equipment contributes only 0.8 percent of all U.S. VOC (volatile organic compound) emissions, 0.6 percent of carbon monoxide emissions, and no nitrogen oxide emissions."

Debates over air pollution aside, there's also noise — perhaps the most evident pollution caused by leaf blowers. The City of Palo Alto requires leaf blowers to emit no more than 65 decibels, when measured from 50 feet away.

The Occupational Safety and Health Administration (OSHA) has determined that decibel levels above 85 cause permanent hearing loss. The World Health Organization recommends a general outdoor noise level of 55 decibels or less and 45 or less for sleeping restfully.

Excessive noise has been implicated in higher heart-attack rates, gastrointestinal disturbances, sleep problems, social discord and psychological problems, according to the U.S. E.P.A.

Ironically, metal rakes aren't much quieter, though the sound is less constant: The City of Palo Alto noted in a 2005 report that metal rakes used on concrete can generate 58-60 decibels at 50 feet.

When it comes to encouraging gardeners to forego their gas-powered machines, one air quality district in southern California has had significant success with its leaf blower exchange. The South Coast Air Quality Management District, which covers Orange County, urban Los Angeles, San Bernardino and Riverside, has held a leaf blower buy-back program since 2006 for professional gardeners. In that time, the district has put more than 12,000 reduced-noise and lower-emissions leaf blowers in the hands of professional gardeners.

The agency distributes about 1,500 new leaf blowers annually, said spokesman Sam Atwood.

"According to the E.P.A., a commercial blower emits 93 pounds per year of air pollutants. Multiplied out times 12,000, the units we have distributed have reduced 500 tons of pollutants since 2006," he said.

So far, the district has distributed cleaner blowers manufactured by the company Stihl. The company has supplied trainings at the exchanges. Operators learn to use the blower like a broom, rolling the debris from one area to another where it can be collected, rather than blasting it in a cloud of dust, he said.

The district helped support the development of backpack electric leaf blowers, which are just now becoming commercially available, he said. Atwood said the district hopes that it will get at least one proposal this year for a truly zero-emission, battery-powered leaf blower as part of its request for proposals.

"In demos, they seem to work very well, equal at least to a gas-powered blower. But it's a little premature to say how they will compare in the field to their gasoline counterparts," he said.

For its part, the Bay Area Air Quality Management District is running a program to fund the purchase of new, battery-powered, zero-emission electric lawn and garden equipment in exchange for gasoline-powered lawn and garden equipment. The program is currently only operating in Alameda and Contra Costa counties, however.

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39 people like this
Posted by whatever
a resident of Menlo Park: Central Menlo Park
on Aug 31, 2015 at 10:15 am

The gardening assoc calls "concerns over air emissions spurious."
That's why most of the gardeners I see are wearing face masks (filters) when the blow, cut and trim (no offense intended to barbers).

It's time for an outright ban on the damn blowers - whether they be gas or electric (including battery). It's time for a bit of fresh air and quiet.

20 people like this
Posted by really?
a resident of Menlo Park: other
on Aug 31, 2015 at 10:27 am

really? is a registered user.

let's be clear about the risks of gas blowers- the dust and particulates are one thing, but the harmful emessions coming out of their exhaust is really toxic. Supposedly, a gas leaf blower puts out 120 times the amount of unburned fuel and hydrocarbons as a modern car. Keep the electrics, but ban the gas ones.

28 people like this
Posted by Allen
a resident of Menlo Park: Menlo Oaks
on Aug 31, 2015 at 12:40 pm

The Almanac article and "whatever's" comment say it all. "Really?" misses the point that electric dust blowers are as bad for adding particulate matter to the atmosphere as are gas dust blowers. These things must be endured in my neighborhood nearly any time of day and most every day of the week.

27 people like this
a resident of Atherton: Lindenwood
on Aug 31, 2015 at 1:13 pm

Of course the noise is bad...
What I object to is the blowers used to clean off parking lots and driveways - a la Menlo Safeway parking lot on Tues or Wed am or my neighbor on Wed 9am. No leaves...just dirt. That practice needs to stop. PERIOD.

Think about it...inhaling "animal droppings, spores, fungi, pollens, pesticides and herbicides, fertilizers, brake-lining dust and tire residue and heavy metals" are probably worse for respiratory systems.
This occurs in my neighborhood every weekday. 8am to 5pm.

I admit to using a blower 2-3X per year to get rid of what my broom won't (pine needles, etc.). But I don't need or use a gas powered tool.

Problem in my neighborhood is homeowners won't change their mow and blow guy's behavior because they want their driveways and walkways clean - EVERY WEEK.

Placing restrictions on their commercial use is senseless - another "rule" without teeth.

PLEASE, ban them altogether.

3 people like this
Posted by Mike Keenly
a resident of Menlo Park: Allied Arts/Stanford Park
on Aug 31, 2015 at 1:24 pm

Swapping the gas blowers for electric blowers would immediately solve two problems: harmful emissions and noise pollution.

26 people like this
Posted by Enuff
a resident of Menlo Park: Downtown
on Aug 31, 2015 at 1:29 pm

Deja vu.
Many of us campaigned for banning the gas-powered blowers in the late 1990s, but we lost the referendum.
The blower manufacturing companies put big bucks into defeating the measure, and were joined by landscaping companies that hire out the mow-and-blow gardeners, as well as such gardeners themselves.

Many people in Menlo Park just wanted the cheapest lawn cleanup they could get and didn't care about the noise or pollution they were inflicting on their neighbors.
And because most of the mow-and-blow gardeners were Hispanic, our opposition falsely claimed that wanting to ban the gas blowers was somehow racial discrimination.

Now the hue and cry is on again, in both Palo Alto and Menlo Park.
Perhaps people are finally ready to ban these noisome, noxious machines.
But do our city councils have the guts to ban them and to enforce the bans?
If so, the blower faction will probably seek a referendum once again. But maybe this time the voters would be smarter.
I've always liked the sound of a rake...

27 people like this
Posted by One With Nature
a resident of Menlo Park: Central Menlo Park
on Aug 31, 2015 at 2:19 pm

Leaf blowers are the absolute worst thing about living in Menlo Park. I work at home, and am bombarded with the noise pollution from these things all week long. It sounds like a chainsaw massacre, or a dentist’s drill, or a hornet attack depending on the model of leaf blower. It feels like we just abandon the neighborhood each week to outsiders who pollute the air with dust plumes, engine exhaust, and godawful noise. The only people who even step foot in most of these yards are gardeners. The weekends are the only time you can hear the birds chirping, and the wind rustling through the leaves. It’s like a movie with beautiful cinematography and a death metal soundtrack. I would far prefer to have leaves on the ground than the random assault of leaf blowers any time. Leaf blowers should be banned. Period.

6 people like this
Posted by Menlo Voter
a resident of Menlo Park: other
on Aug 31, 2015 at 3:27 pm

Menlo Voter is a registered user.

"Air district report: Leaf blowers present health risks"

My, what a blinding flash of the obvious.

9 people like this
Posted by More than enough
a resident of Menlo Park: Central Menlo Park
on Aug 31, 2015 at 4:28 pm

The robust response to the mow and blow issue speaks for itself in reflecting feelings about this noxious practice. All the opinion being expressed here is on one side -- ban or modify blowers dramatically to cut down on the air and noise pollution. Since I'm now retired/work at home, I'm exposed to this neighborhood cacaphony on a daily basis. Remembering back when I was away at the office all day, I had much less awareness of the degree of the environmental insult. My sense is that those who are tolerant of it just to get their yards all cleaned up for the weekend, are also those who are away when it's being done. Of course, that doesn't mean that they are not exposed to the micro particulants when they come home, like the rest of us. If we can achieve pollution control in a major source like automobiles, there's no reason not to require that these ubiquitous blowers be controlled or replaced with alternative devices (rakes, brooms, new clean/quiet technology -- this is Silicon Valley after all). I would press my City Council and Palo Altos' to ban the blowers now -- even if this means moving to rake and broom in the short run while acceptable new technology is developed to replace them.

18 people like this
Posted by David Roise
a resident of Menlo Park: Allied Arts/Stanford Park
on Sep 1, 2015 at 7:49 am

As someone who works from a home office, I am also appalled at the daily onslaught of noise, dust, and exhaust from these obnoxious and unnecessary devices. I agree with “More than enough” that anyone who is away at work during the day probably isn’t even aware of what a problem this has become in our otherwise quiet neighborhoods.

I am personally in favor of an outright ban on leaf blowers in Menlo Park and think there would be significant support for such a ban. In fact, I recently posted a poll on this topic in our Allied Arts Nextdoor group. Out of 25 total respondents, 68% were in favor of an outright ban, and an additional 16% favored a ban if it didn’t increase the cost of their garden service or compromise the look of their yard. Only 16% were opposed.

While we are waiting for the City Council to institute a outright ban, you should be aware that the current city code (chapter 8.07) requires that leaf blowers only be used from 8 am to 5 pm Monday through Friday, from 11 am to 3 pm Saturday, and never on a “Spare the Air” day. In addition, only “Certified Leaf Blowers” may be used in Menlo Park. A certified leaf blower is defined as one that is “measured at sixty-five (65) dB(a) or less at a distance of fifty feet (50’) by an independent laboratory per American National Standards Institute ("ANSI") standard B175.2-1996, as certified by the manufacturer. (Ord. 895 § 3 (part), 1999).”

It is my understanding that very few leaf blowers meet this standard, and it is likely that most gardeners in Menlo Park are already in violation of the ordinance. If we could get the police to enforce the existing ordinance, at least the noise from leaf blowers would decline. Unfortunately, until we get an outright ban, the dust, toxic particles, and exhaust will remain.

3 people like this
Posted by Downtowner
a resident of Menlo Park: Central Menlo Park
on Sep 1, 2015 at 1:00 pm

I rake & don't have a gardener. My neighbors on both sides use garden services with gas (or kerosene?) blowers, one of which has chokingly noxious emissions. Guess where they both end up blowing their debris?
At least ban gas-powered blowers. For what the gardening guys get paid cumulatively, they can invest in better equipment.

2 people like this
Posted by MP Resident
a resident of Menlo Park: Downtown
on Sep 1, 2015 at 2:10 pm

Los Gatos has a really sensible policy - Web Link

Gas powered blowers are banned, electric blowers must meet noise limits and be used during reasonable hours (similar to the MP ordinance)

18 people like this
Posted by Clint
a resident of Menlo Park: Suburban Park/Lorelei Manor/Flood Park Triangle
on Sep 1, 2015 at 2:56 pm

Leaf blower noise is way more annoying than the fleeting Surf Air overflights. Surf Air does not bother me but having blowers operating from various yards around me, several on the same day, probably add up to an hour of almost continuous disturbance.

Blowers are the most vexing type of noise because of their non-intermittent nature.

13 people like this
Posted by And Besides
a resident of Menlo Park: The Willows
on Sep 1, 2015 at 3:10 pm

And besides, the drought has created very dirty and dusty streets so the clouds of dirt in the air makes for large clouds of dust. As a cyclist, I have to hold my breath to bike through these dust explosions. Many people are removing their grass and replacing with drought tolerant plants. The soil under these plants need protection from mulch and a leaf blower strips exactly what the plants need.

Ban leaf blowers completely. Bring back real gardeners who understand healthy gardens.

1 person likes this
Posted by Menlo Voter
a resident of Menlo Park: other
on Sep 1, 2015 at 3:32 pm

Menlo Voter is a registered user.

"Bring back real gardeners who understand healthy gardens."

That will happen when people are ready to pay for it. That's what killed the ban the last time. Everyone thinks it's a great idea until they find out how much more it's going to cost THEM.

12 people like this
Posted by danna
a resident of Portola Valley: Central Portola Valley
on Sep 2, 2015 at 12:23 pm

We have become prisoners in our own homes. In Portola Valley we don't even have silence on weekends. It is a constant onslaught. What the article does not address is that these leaf blowers destroy the very gardens on which they are used. They destroy soil. It takes many years for the homeowner who doesn't undertsnad gardens to see that their properties fail to thrive, nothing grows. But it happens. Menlo park and Atherton are losing tons of trees. Leafblowers. Nothing grows in your gardens and they now and then pour on miracle grow. See what it looks like in five years. You will have a desert.Ry
So they are horribly unhealthy, terrible for the atmosphere and ozone, violate most noise ordinance decibels. And kill the very gardens upon which they are used. WHY? Are we subjects to this nightmare?

4 people like this
Posted by Joseph ashton
a resident of Menlo Park: The Willows
on Sep 4, 2015 at 10:32 pm

We all agree that the leaf blowers are causing extreme anxiety and is very invasive and unhealthy for humans and gardens and makes it impossible for some of us to work at home. SO WHAT IS THE FIRST STEP TO GET THEM BANNED???

3 people like this
Posted by Milica Boghunovich
a resident of another community
on Dec 16, 2015 at 9:10 am

Whether gas-operated or electric blower (publicly used)the health-hazard impact is not diminished because any type of blower blows toxic and carcinogenic dust particles in the air that are causing more and more health problems - these particles are directly blown into our respiratory system daily. More and more law-suits are going to arise due to the negligence of the city heads ( I am form Los Angles County) who have chosen the cheapest and the deadliest way to "clean" the streets and parking lots.

7 people like this
Posted by Sebastian Vale
a resident of another community
on Jun 29, 2017 at 8:54 pm

I bike in L.A. as much as possible. I try to turn when I see a leaf blower ahead, but it's more than likely yet another leaf blower will be on that block. I ride through the cloud of oil, gas, dog poo and poison, the same cloud that's entering all the houses for babies, elderly, and everyone else to inhale. Powerful engines toss the junk 30 feet up or more, and most "gardeners" just move debris to the street or the next yard whose leaf blower will return it tomorrow. Tiny plants get uprooted, the land becomes more vulnerable to scorching, and the gardeners get cancer. When I get home, I realize I've left open my window and all my stuff is covered in grime the same as my house exterior from the neighbor's leaf blowers. When do we finally were these off as a failed experiment? Lots of Ill-intending terrorists do less damage than these things. Enough!

7 people like this
Posted by Cyndy Crogan
a resident of another community
on Aug 22, 2017 at 8:20 am

We live in a redwood forest in Santa Cruz. Prior to the rainy season the redwood feathers are reduced to a fine dust. This is the time of year when winds come up and drop thousands of redwood feathers. Neighbors and maintenance crews use blowers which produce fine clouds of dust at least sixty feet high on a daily basis. For the last five days I have had a serious sinus infection and have not been able to work. I am self employed and this takes a substantial toll on my income. For some reason people think their surroundings should be absolutely spotless in the redwood forest. Instead of allowing the feathers to decompose naturally as they have for thousands of years they remove them. Green Waste employees have said to me "we throw your forest away". I would not be surprised if someone told me my life along with this redwood forest is being cut short by the use of these blowers.

2 people like this
Posted by whatevr
a resident of Menlo Park: Central Menlo Park
on Aug 23, 2017 at 10:21 am

It's time for MP or perhaps the county to revisit this major health concern. It is time to ban the use of these public nuisances. Protect your residents city council.

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