Tag Archives: PM 2.5

Leaf blowers are not only annoying but also bad for you (and the environment)

The seemingly-innocuous leaf blower may actually cause a lot more damage than you’d think — to both your health and the climate.

A groundskeeper blows autumn leaves in the Homewood Cemetery, Pittsburgh.
Image via Wikimedia.

It’s that time of the year: trees are shedding their leaves, and people are blowing them off the pavement. According to the Centers for Disease Control and Prevention (CDC), this quaint image actually hides several health concerns for operators and the public at large.

The inefficient gas engines typically used on leaf blowers generate large amounts of air pollution and particulate matter. The noise they generate can lead to serious hearing problems, including permanent hearing loss, according to the CDC.

Sounds bad

Some noise may not seem like much of an issue, but the dose can make it poison. The CDC explains that using your conventional, commercial (and gas-powered) leaf-blower for two hours has an adverse impact on your hearing. Some emit between 80 and 85 decibels (dB) while in use. Most cheap or mid-range leaf blowers, however, can expose users to up to 112 decibels (a plane taking off generates 105 decibels). At this level, they can cause instant “pain and ear injury,” with “hearing loss possible in less than [2 to] 5 minutes”.

The low-frequency sound they emit fades slowly over long distances or through building walls. Even at 800 meters away, a conventional leaf blower is still over the 55 dB limit considered safe by the World Health Organization, according to one 2017 study. Because they’re so loud, they can be heard “many homes away” from where they are being used, Quartz explains.

This ties into the greater issue of noise pollution. The 2016 Greater Boston Noise Report (link plays audio,) which surveyed 1,050 residents across the Boston area, found that most felt they “could not control noise or get away from it,” with leaf blowers being a major source of noise. Some 79% of responders said they believed no one cared that it bothered them. Leaf blowers are also seeing more use — in some cases becoming a daily occurrence. As homeowners and landscaping crews create an overlap of noise, these devices can be heard for several hours a day.

Image credits S. Hermann & F. Richter / Pixabay.

With over 11 million leaf blowers in the U.S. as of 2018, this adds up to a lot of annoyed people. Most cities don’t have legislation in place that deals with leaf blower noise specifically, and existing noise ordinances are practically unenforceable for these devices. However, there are cities across the U.S. that have some kind of leaf blower noise restrictions in place or going into effect.

Noisy environments can cause both mental and physical health complications, contributing to tinnitus, hypertension, and generating stress (which leads to annoyance and disturbed sleep).

Very polluting

A report published by the California Environmental Protection Agency (CalEPA) in the year 2000 lists several potential hazards regarding air quality when using leaf blowers:

  • Particulate Matter (PM): “Particles of 10 Fm and smaller are inhalable and able to deposit and remain on airway surfaces,” the study explains, while “smaller particles (2.5 Fm or less) are able to penetrate deep into the lungs and move into intercellular spaces.” More on the health impact of PM here.
  • Carbon Monoxide: a gas that binds to the hemoglobin protein in our red blood cells. This prevents the cell from ‘loading’ oxygen or carbon dioxide — essentially preventing respiration.
  • Unburned fuel: toxic compounds from gasoline that leak in the air, either through evaporation or due to incomplete combustion in the engine. Several of these compounds are probable carcinogens and are known irritants for eyes, skin, and the respiratory tract.

To give you an idea of the levels of exposure involved here, the study explains that landscape workers running a leaf blower are exposed to ten times more ultra-fine particles than someone standing next to a busy road.

Additionally, these tools are important sources of smog-forming compounds. It’s not a serious issue right now, but as more people buy and use leaf blowers, lawnmowers, and other small gas-powered engines, these are expected to overtake cars as the leading cause of smog in the United States.

What to do about it

Well, the easiest option is to use a rake — or just leave the leaves where they are, which is healthier for the environment.

But leaf blowers didn’t get to where they are today because people like to rake. Electrical versions, either corded or battery-powered, would address the air quality and virtually all of the noise concerns (albeit in exchange for less power).

While government regulation might help with emission levels, noise concerns might best be dealt with using more social approaches. Establishing neighborhood-wide leaf blowing intervals, or limiting the activity to a single day per week, would help make our lives a little better. As an added benefit, this would also help people feel that their concerns are being heard, and foster a sense of community.

Air mask statue.

New research shows air pollution sours our mood and makes us unhappy

Air pollution may take a more personal toll on us than we’d suspected: happiness.

Air mask statue.

Image via Pixabay.

China is notorious for the heavy pollution affecting its cities. It’s a product of the massive uptick in industrialization, coal use, and the number of cars China has seen in the last few decades. While definitely good from an economic point of view — the country can boast an annual economic growth rate of 8% — air pollution has become a major public concern in China, with significant effects on the quality of life in its urban areas.

This pollution may have a much more direct effect on the country’s urbanites than previously believed, according to a paper lead-authored by, Siqi Zheng, associate professor of Real Estate Development and Entrepreneurship Faculty Director at MIT Future City Lab. The study found a strong inverse correlation between air pollution levels and locals’ happiness.

Bad air

“Pollution also has an emotional cost,” Zheng says. “People are unhappy, and that means they may make irrational decisions.”

“So we wanted to explore a broader range of effects of air pollution on people’s daily lives in highly polluted Chinese cities.”

Air pollution is a major concern around the world, especially in developing or developed countries. Just last year, the State of Global Air/2018 report — published by the non-profit Health Effects Institute — estimated that roughly 95% of the world’s population lives in areas with unsafe levels of outdoor air pollution (10 µg pollutants/square meter of air, as per the World Health Organization’s guidelines). Around 60% live in areas where air pollution exceeds even the WHO’s least-stringent air quality target of 35 µg/m3.

PM 2.5 levels across the world.
Image credits Health Effects Institute / State of Global Air/2018.

Roughly one-third of the world, the report adds, also has to contend with unsafe levels of indoor air pollution. The main culprits were the burning of fossil fuels in cars, power plants, and factories (outdoor pollution) or for heating and cooking (indoor), respectively.

The problem is definitely global, but China does stand out in regards to bad air. The clouds of Chinese smog have made headlines again and again over the last few years, due to their striking appearance and cost in human lives. Combined with Prof. Zheng’s background — environmental economics, urban development, and real estate market, with a special focus on China — this made the country a perfect place to study the effect of air pollution on our emotional well-being.

The team used real-time data drawn from social media microblogging platform Sina Weibo (similar to Twitter) to track the happiness levels in 144 Chinese cities. Roughly 210 million geotagged tweets posted between March and November of 2014 were processed using a machine-algorithm the team developed to measure which emotions each post conveyed. The team explains that they opted for this method of measuring people’s happiness levels instead of using questionnaires (the more usual approach) because questionnaires tend to reflect individuals’ overall feelings of well-being; what they wanted was snapshots of the happiness people felt on particular days.

This data was pooled to generate a median value per day for each city (which the team calls the “expressed happiness index”, or EHI) ranging from 0 to 100, with 0 indicating a very negative mood and 100 a very positive one.

Bad mood

Deaths SoGA report.

Air pollution (highlighted in yellow) definitely has a health cost, but it also seems to have a happiness cost, according to Prof. Zheng’s team.
Image credits Health Effects Institute / State of Global Air/2018.

“Social media gives a real-time measure of people’s happiness levels and also provides a huge amount of data, across a lot of different cities,” Zheng says.

Zheng’s team also looked at daily readings of ultrafine particulate matter — or PM 2.5 — concentrations in urban areas recorded by China’s Ministry of Environmental Protection. Airborne particulate matter has become the primary pollutant in China’s cities in recent years, the authors note, with PM 2.5 particles being particularly hazardous to lung health.

Finally, the team put the two datasets together. They found a very solid negative correlation between pollution and happiness levels. As a whole, women seemed to be more sensitive to the effects of pollution than men, as were individuals with higher incomes. Interestingly, both people in the most polluted and cleanest of China’s cities were most affected by air pollution, the team writes. Their hypothesis is that people who are particularly concerned about air quality and their own health tend to move to cleaner cities — making the EHI of these urban centers particularly sensitive to pollution levels — while those in very dirty cities are more aware of the damage to their health from long-term exposure to pollutants.

Past research has shown that people are more likely to engage in impulsive and risky behavior that they may later regret on days with heavy pollution, possibly as a result of short-term depression and anxiety, according to Zheng. Air pollution also has a well-documented negative effect on health, cognitive performance, labor productivity, and educational outcomes, she adds.

Together with their own findings, Zheng believes such data showcases how important it is for politicians to respond to public demand for cleaner air and take measures to curb air pollution. People may move to cleaner cities, buildings, or green areas, buy protective equipment such as face masks and air purifiers, and spend less time outdoors, to avoid the effects of air pollution. Prof. Zheng plans to continue researching the impact of pollution on people’s behavior in the future.

The National Institute of Environmental Health Sciences has more details on types of air pollution and preventive measures here. There’s a growing body of evidence that houseplants help improve indoor quality by scrubbing various pollutants like allergy-irritating dust and volatile organic compounds.

The paper “Air pollution lowers Chinese urbanites” has been published in the journal Nature Human Behaviour.