U.S. Air Pollution Still Kills Thousands Every Year, Study Concludes

This story aired on NPR on June 28, 2017

"The air Americans breathe has been getting cleaner for decades.

But air pollution is still killing thousands in the U.S. every year, even at the levels allowed by the Environmental Protection Agency, according to a study out Wednesday.

'We are now providing bullet-proof evidence that we are breathing harmful air,' says Francesca Dominici, a professor of biostatistics at the Harvard T.H. Chan School of Public Health, who led the study. 'Our air is contaminated.'

Dominici and her colleagues set out to do the most comprehensive study to date assessing the toll that air pollution takes on American lives.

The researchers used data from federal air monitoring stations as well as satellites to compile a detailed picture of air pollution down to individual zip codes. They then analyzed the impact of very low levels of air pollution on mortality, using data from 60 million Medicare patients from 2000 to 2012.

About 12,000 lives could be saved each year, their analysis concludes, by cutting the level of fine particulate matter nationwide by just 1 microgram per cubic meter of air below current standards."

Read or listen to the whole story here

A City That Banned Leaf Blowers Reports on the Results

In a ballot measure last year, the northern California city of Sonoma became at least the 25th city in the state to ban or severely limit use of gas-powered leaf blowers. Now the Sonoma Valley Sun has reported on civic response, as the ban goes into effect. The whole story is here; highlights are below, after the graphic from the California Air Resources Board.

From the Sonoma Valley Sun story:

Adam, a contractor who works in Sonoma, said he “hates gas leaf blowers,” because they’re too loud and smell horrible. He thinks every town should ban them. He felt that, though not as powerful, the battery ones work fine. He pointed out that lithium ion batteries are superior to anything available even five years ago — they last longer and can be recycled.
A homeowner near the Plaza said he purchased a battery blower for his gardeners to use on his property.... 
A west side homeowner “immediately noticed my neighborhood and the town are a lot quieter.” He sees more rakes and brooms in use, and some battery blowers. He noted that his neighborhood was still very tidy. “When driving,” he added, “I don’t have to dodge anyone blowing leaves in the street,” a practice that is now against the law.
A man with an office on the Plaza noted that he used to consider leaf blower noise unavoidable. “Once I became aware of the possibility of eliminating it, I realized how often I was inconvenienced,” maybe ending a phone conversation, or crossing the street to avoid the blower. He also became aware of the health impacts. “Imagine standing in all that dust and noise.” After Measure V passed he noticed guys “happily raking.”
A dog walker said she and her canine companions walked through much less dust and noise now, as more people raked. She said even when there is a leaf blower “It’s so much quieter, and there are no fumes. It still blows up some dust, but much less.”

Oyster Bay, NY, Considers Leaf Blower Limits

The website for the group Huntington C.A.LM., for Citizens Appeal for Leafblower Moderation, has an item about efforts in the town of Oyster Bay, on Long Island, to limit summertime use of two-stroke gas-engine leaf blowers. What happens in Oyster Bay is surprisingly significant, since it's actually a collection of villages and hamlets that together make up one-third of Nassau County, include a population of nearly 300,000, and cover 30 ZIP codes.The C.A.L.M. item is based on a story by Ted Phillips in Newsday, which is here.

Sample from the story:

Planning and Development Commissioner Elizabeth Maccarone said the gas-powered leaf blowers, as opposed to quieter and lower-powered electric blowers, cause problems for residents. 
“When you drive around you see the dust ball, the dirt, the fertilizer and all that is being thrown up into the air and the children are outside playing, people are trying use their back yards,” Maccarone said. “It’s the noise, it’s what being thrown up into the atmosphere.”

The outlook on this QCDC site is that rules like these amount to "accelerating the inevitable." That is: as evidence of the hugely disproportionate environmental impact and public health damage caused by two-stroke engines mounts up, as these engines continue to be phased out or banned in nearly all uses other than lawn equipment, and as battery-powered electric alternatives rapidly increase in efficiency and affordability, dirty and noisy gas-powered equipment will be on its way out. Cities like Oyster Bay are headed where technology and public-health data will eventually lead many more communities. 

The NYT on One City's Proposed Leaf Blower Ban

Screenshot of the story in today's NYT.

Screenshot of the story in today's NYT.

Ronda Kaysen of the New York Times has a very good new story about the way changing fundamentals of American suburban life, notably including a near-doubling of lawn-care employees since 2002, have brought new attention to the environmental, public health, and noise-nuisance effects of leafblower use. The story is here, and it emphasizes the same phenomenon you'll find discussed on many items in this site: the anomalous persistence of two-stroke, gas-powered engines in lawn-equipment use, even though they have been phased out or prohibited in most other uses (boating, watercraft, small transport vehicles in developing countries). The story centers on a proposal from Maplewood, New Jersey, to ban commercial use of leaf blowers during summer months. 


Leaf blowers are beloved and reviled for the same reason: They are powerful. Strapped in a pack to a worker’s back, these blowers plow through leaves, grass clippings, debris and light snow, making it possible for a landscaper to quickly clear a property. A 2017 Centers for Disease Control and Prevention report lists leaf blowers as a common noise that can contribute to permanent hearing loss.
Most landscapers use leaf blowers with two-stroke engines, which are light enough to carry but produce significant exhaust and noise. The gas and oil mix together, and about a third of it does not combust. As a result, pollutants that have been linked to cancers, heart disease, asthma and other serious ailments escape into the air.

The commercial-gardener aspect of the Maplewood proposal is significant, since day-long use of thje equipment by teams working through a neighborhood has a different effect -- on the neighbors, and on the yard crew -- than homeowners working on their own yards.

An emerging tech possibility offers a solution beyond the ones Maplewood is considering. That is the rapid appearance on the market of much cleaner, much quieter, battery-powered lawn equipment that allows crews to do their work with much less impact on themselves, the community, and the environment. You can read about them here, here, and here. They are the basis of trade-in programs in Los Angeles and many other cities, and their increasing power and affordability is why the shift away from antiquated, dirty gas-powered machines is just a matter of time.

Congrats to Ronda Kaysen, the NYT, and the people of Maplewood.

'In Pursuit of Silence': A New Film

As explained in the other items you'll find on this site, the most compelling new evidence for a shift away from two-stroke gas-powered leaf blowers and related equipment is the outsized environmental damage they do (according to California's air-quality authorities, soon more ozone pollution than all the cars in the state) and the public health risks they pose for communities and, especially, the often low-paid, often non-English-speaking crews who operate them for hours at a time. 

But these machines are also incredibly (and even dangerously) noisy. A film being shown at 6:30pm tonight, March 17, at the National Museum of Natural History in Washington, as part of the Environmental Film Festival, goes into meanings of noise and quiet in modern life.

Here the trailer: 

From the description at the Film Festival's site:


In Pursuit of Silence

In our race towards modernity, amidst all the technological innovation and the rapid growth of our cities, silence is now quickly passing into legend. Beginning with an ode to John Cage’s seminal silent composition 4’33, the sights and sounds of this film delicately interweave with silence to create a contemplative and cinematic experience that works its way through frantic minds and into the quiet spaces of hearts. As much a work of devotion as it is a documentary, In Pursuit of Silence is a meditative exploration of our relationship with silence, sound, and the impact of noise on our lives. Directed by Patrick Shen. Produced by Patrick Shen, Andrew Brumme, and Brandon Vedder; Co-produced by Cassidy Hall.

There's much more about the film, which has a wide screening schedule and has received impressive praise, at its own site. By all means check it out. 

Battery Power Breakthroughs: Tripling Today's Storage Capacity

Two-stroke gas-powered lawn equipment is inevitably on the way out, because it exists at the confluence of two trends.

One is the increasing evidence about the unique environmental and public-health damage this obsolete equipment causes (as detailed in many previous entries on this site). The other is the rapid emergence of cleaner, quieter, more sustainable electric alternatives.

The driving factor in the second development has been the pace of research in improved battery technology. For general background on this field, please see an Atlantic article from 2014. And for the latest news, please see this announcement in the University of Texas newsletter about a breakthrough in battery technology from its labs.

From the announcement:

A team of engineers led by 94-year-old John Goodenough, professor in the Cockrell School of Engineering at The University of Texas at Austin and co-inventor of the lithium-ion battery, has developed the first all-solid-state battery cells that could lead to safer, faster-charging, longer-lasting rechargeable batteries...  
The researchers demonstrated that their new battery cells have at least three times as much energy density as today’s lithium-ion batteries. A battery cell’s energy density gives an electric vehicle its driving range, so a higher energy density means that a car can drive more miles between charges. The UT Austin battery formulation also allows for a greater number of charging and discharging cycles, which equates to longer-lasting batteries, as well as a faster rate of recharge (minutes rather than hours).

As the Atlantic article explains, no one development will be "the" answer in battery technology. The significant point is the breadth and intensity of scientific, engineering, and commercial activity in developing more powerful, cheaper, longer-lasting batteries. This has obvious implications in hastening the advent of electric cars, and some aircraft -- and lawn equipment as well.

For more, please see articles in CleanTechnica, Digital Trends, Yahoo Finance, Mashable, and Fox News. The original scientific paper is here, in Energy and Environmental Science. And here is a video describing this latest breakthrough:

'More Pollution Than Cars?' A Remarkable Report from California

From KQED's California Report on February 13, 2017. 

From KQED's California Report on February 13, 2017. 

A story this week from The California Report, for the San Francisco public broadcasting station KQED, stresses the surprisingly important public-health and environmental-justice aspects of the seemingly trivial practice of using dirty, noisy, gas-powered lawn equipment. As the story by David Gorn begins:

They may look pretty innocuous — those leaf blowers, hedge trimmers and gas mowers wielded by a small army of gardening crews across the state
They’re not.
According to state air quality officials, those machines are some of the biggest polluters in California. In fact, by 2020, leaf blowers and other small gas engines will create more ozone pollution than all of the passenger cars in the state.
Yes, really, there will be more pollution from gas-powered gardening equipment than from cars, confirms Michael Benjamin, division chief at the California Air Resources Board.

How can this be?

There’s a reason for that: Regulations on car exhaust have gotten tighter and tighter over the years, substantially reducing their ozone-damaging emissions. At the same time, while there have been some controls on the smaller gas engines, there haven’t been enough, says Benjamin.


The story also very clearly emphasizes the environmental-justice aspect of hired lawn crews, which in California are mainly staffed by lower-wage Latino workers, being chronically exposed to dangerous emissions. It quotes the head of the American Green Zone Alliance, Dan Mabe:

Mabe has worked these gardening crews himself — “since I was 7 years old” — and has the health scares and breathing problems to prove it. Mabe’s crusade to trade in gas for electric machinery is based on a desire to improve air quality and workers’ health. But there’s another motivation for him. Many gardening crews across California are Latino, he says, and that takes the discussion to another level.
You can call it environmental justice. It’s a demographic that isn’t really being addressed.”

It's a very strong report that deserves wide attention, especially the next time you hear that eliminating these obsolete, hyper-polluting machines is a "First World Problem." 

Latest Bad News on Particulate Pollution: the Dementia Factor

As a reminder, the main problem with gas-powered two-stroke engines is not the most obvious one: that they are so loud. Rather it is that the engines are so disproportionately dirty, emissions-heavy, and polluting. That's why they have been outmoded or outlawed for most other uses in Europe and North America, except for leaf blowers and other lawn equipment. 

Over the past half-century, emissions from car and truck engines have gone down by 95% or more (depending on the measure you use). Power-generation is rapidly shifting toward renewable and less polluting sources. But the antique technology of two-stroke engines, which very inefficiently burn a mixture of oil and gas, remains an exception. Developing-world metropolises like Bangkok, Jakarta, Manila, and New Delhi have mounted major efforts to get two-stroke engines off their roads, because they contribute so heavily to pollution. (For more on the third-world aspects of this drama, see a list of references at the bottom of this item.) Fifty years ago, these engines were common in a variety of transport uses in the U.S. and Europe. These days they survive mainly in lawn equipment.

And now comes a report by Emily Underwood in Science magazine, whose subhead conveys its message: "Evidence builds that dirty air causes Alzheimer’s, dementia." That is, fine-particulate pollution, of which there are many sources but that two-stroke engines create to a disproportionate degree, is associated with mental problems in addition to its other known health effects. Sample:   

Some of the health risks of inhaling fine and ultrafine particles are well-established, such as asthma, lung cancer, and, most recently, heart disease. But a growing body of evidence suggests that exposure can also harm the brain, accelerating cognitive aging, and may even increase risk of Alzheimer’s disease and other forms of dementia. 

Please read the full story for more. It explains some of the fascinating biological and neurological hypotheses about how the mental damage might occur. Again the main point is: these engines are an outlier exception to the pace of cleaner and safer equipment in most other uses. And in much of the United States, the people are most at risk from long-term exposure to their effects are the hired lawn crews -- who are generally low-wage and not protected by long-term health insurance.

The Science story concludes, quoting a USC neuroscientist named Caleb Finch:

If PM2.5 is guilty as charged, they say, the goal for policymakers worldwide should be to push down levels as far as possible. When all the research is in, Finch says, “I think [air pollution] will turn out to be just the same as tobacco—there’s no safe threshold.”


More on what the rest of the world is doing about two-stroke engines:


Newton, Mass., Adopts a Summer Ban on Gas-Powered Blowers

This article from the Newton TAB describes a new measure approved by the city council. Among its other provisions, it (a) says that leaf blowers used at any time during the year must put out sound of 65 decibels or less (which is well below the level of most current gas-powered machines), and (b) says that gas-powered blowers cannot be used at all in the summer months.

Sample from the story:

The City Council approved a new leafblower ordinance, 20-4, around 12:30 a.m. Wednesday morning after four hours of debate and votes on 11 proposed amendments.
Councilors spent two years working towards last night's vote, with many residents demanding the council take steps to address the noise and air pollution of leafblowers....
For years, Newton's sound ordinance has limited leafblowers to 65 decibels. But the rule is widely ignored and never enforced, with landscapers using much louder 77-decibel devices.
The new ordinance maintains the 65-decibel level and – to ease and boost enforcement – will require all leafblowers bear a manufacturer's label showing they are 65 decibels or quieter.

The full TAB story is here.


The ongoing argument for moving away from dirty, hyper-polluting two-stroke gas engines is that public health information is making their dangers more evidence, and technology is rapidly offering realistic alternatives. Cities like Bangkok, Jakarta, Manila, and Dhaka have over the past decade imposed increasingly stiff bans on two-stroke engines, because their use (mainly in scooters, tuktuks, and other transport vehicles) was such an important source of pollution and related health dangers. The United States long ago forced its transportation system onto a less-polluting path. Now cities like Newton are catching up with the main remaining, outlier use of an antique technology.

Electric Leaf Blowers Come to DC -- in an Unexpected Form

Quiet, clean, yet demonstrably powerful electric leaf-blower in use in DC, as shown in screenshot from Saturday Night Live on February 11, 2017.  Embedded video of the "cold open" is below.

Quiet, clean, yet demonstrably powerful electric leaf-blower in use in DC, as shown in screenshot from Saturday Night Live on February 11, 2017.  Embedded video of the "cold open" is below.

The effort to bring cleaner, more sustainable, quieter, and healthier maintenance practices to neighborhoods across the country knows no partisan bounds. So in an above-politics, enjoy-the-comedy spirit, we offer this scene from last night's cold open of Saturday Night Live. In it, Melissa McCarthy, playing White House press secretary Sean Spicer, uses a new electric-powered leaf blower (rather than a dirty old two-stroke gas-powered model) to "blow away their dishonesty" as she deals with a reporter played by Cecily Strong.

The relevant part of the clip starts at around time 7:00 of the segment below.

Note how much quieter and cleaner this machine is than the outdated ones it is destined to replace! Thanks to SNL for illustrating technology's promise.

'A Quarter of Adults Have Hearing Loss' -- and external noise is causing it: CDC

The Washington Post has a story on an under-appreciated, and spreading, public-health issue. The story, which is based on a new report from the Centers for Disease Control and Prevention, is about hearing damage and hearing loss among adults, starting with people in their 20s. The story begins:

Forty million American adults have lost some hearing because of noise, and half of them suffered the damage outside the workplace, from everyday exposure to leaf blowers, sirens, rock concerts and other loud sounds, the Centers for Disease Control and Prevention reported Tuesday.
A quarter of people ages 20 to 69 were suffering some hearing deficits, the CDC reported in its Morbidity and Mortality Weekly Report, even though the vast majority of the people in the study claimed to have good or excellent hearing.

The story goes on to name the sources of the damage, and some of its implications (with emphasis added):

The review's more surprising finding — which the CDC had not previously studied — was that 53 percent of those people said they had no regular exposure to loud noise at work. That means the hearing loss was caused by other environmental factors...
“Noise is damaging hearing before anyone notices or diagnoses it,” said Anne Schuchat, the CDC's acting director. “Because of that, the start of hearing loss is underrecognized.”
The study revealed that 19 percent of people between the ages of 20 and 29 had some hearing loss, a finding that Schuchat called alarming....
Hearing damage results from a combination of volume and the length of the exposure. One minute of hearing a 120-decibel siren can damage hearing, the CDC said. So can two hours of exposure to a 90-decibel leaf blower

As the National Institute of Deafness has explained, hearing damage of this sort is likely to be cumulative and permanent, since repeated exposure to loud noises lastingly damages the stereocilia, or sensor hairs, inside the ear on which hearing depends. Further NIH information on hearing loss is at this site. The full Post story is worth reading, here. The CDC report itself is here. (Direct link: https://www.cdc.gov/media/releases/2017/p0207-hearing-loss.html)