‘Dramatic’ rise in wildfire smoke triggers decline in US air quality for millions

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Scientists warn that millions of Americans are now regularly exposed to unhealthy plumes of wildfire smoke, which can travel thousands of miles across the country.

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Soot and ash from wildfires are thrown into the air, which then carry tiny particles that people many miles away can breathe, worsening a variety of health conditions. The number of people exposed to unhealthy levels of these particles from wildfires at least one day a year has increased 27-fold over the past decade, a new study finds, with potentially 25 million people in 2020 alone. Breathing in poisonous air. fire

Wildfires erupt across California as sweltering heat engulfs the state


Pockets of deep unhealthy air have emerged primarily in the US West, the staging ground for wildfires of increasing intensity, fueled by years of fire suppression and global warming, burning of forests. six out of seven Largest wildfire in California’s recorded history Happened since 2020.

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Forest fire smoke can result in school closures, suspend flights and even cause cycling Races and concerts of Pearl Jam Cancelled, But its most widespread impact is a regression in air quality since the advent of the Clean Air Act in 1970, which helped lift dangerous, choking haze conditions from many polluted American cities.

“We’re seeing that clean air progress, especially in the West,” said Marshall Burke, a Stanford University scientist and co-author of the study published in Environmental Science & Technology.

“There has been a really dramatic increase in wildfire smoke in the form of air pollution, in some places completely reversing the impact of the Clean Air Act. It has been remarkably quick. Our air pollution regulations are tackling this. It’s not made for. It’s a worrying problem.”

Series of US maps showing the increase in smoke PM2.5 pollution, particularly in the West.

The new study is based on a model that calculates how wildfire smoke increases pollution levels in locations across the US. This PM. measure the presence of2.5Tiny particles about one-thirtieth the width of a human hair that can travel through the air and burrow themselves deep into people’s lungs when they breathe in.

Wildfire smoke added about five micrograms of these particulates to locations in the US West, a huge increase from the national level, which is about 10 micrograms from other sources of particulate pollution, such as cars, trucks and cars. emissions from power plants.

Unlike these other sources, which are controlled by the government, wildfire smoke is less predictable, far reaching and more egalitarian in that it affects – rich and white as well as people of poor color who are around – Pollution from nearby highways and factories are in proportion. ,

On July 20, 2021, the Met Life and Chrysler buildings were covered by a thick haze hanging over Manhattan due to wildfires in the US West. Photograph: Julie Jacobson / AP

“Wildfires produce an amazing amount of particles that travel thousands of miles, unlike other pollution,” Burke said. Last summer, New York experienced some of the worst air quality in the world due to smoke from wildfires several thousand miles away on the west coast of the US.

A decade ago, fewer than 500,000 people in the US were exposed to smoke on any given day of an air quality index of 100 or higher, a level considered unhealthy. Now, Burke said, 5 million Americans are living in areas with such levels at least one day a year.

“Your air quality is likely to be good enough if you don’t live near a highway or power plant, but infiltration by wildfire smoke is changing and there is evidence that it will increase,” he said. “Honestly, it was amazing to see how quickly these extreme risks escalated.”

Bar chart of the number of people exposed to dangerous levels of PM2.5 in at least one day in the US.

The hazards posed by wildfire smoke are of concern to experts in various places around the world – Europe’s largest as a result of the heat of wildfires in Spain, France and Portugal. Highest Wildfire emissions in 15 years. According to the most recent Intergovernmental Panel on Climate Change, the incidence of catastrophic wildfire events around the world will likely increase by 30% by the end of the century, even if planet-heating gases are sharply cut. report good,

Wildfires continue to burn across France and Spain

“As the globe warms, wildfires and associated air pollution are expected to increase even under low emissions scenarios. In addition to human health impacts, it will also affect ecosystems as air pollutants settle to the Earth’s surface from the atmosphere. Let’s go,” said Petri Talas, secretary general of the World Meteorological Organization.

“We’ve seen it this year in heatwaves in Europe and China when stable high atmospheric conditions, sunshine and low wind speeds were conducive to high pollution levels.”

Research has linked wildfire smoke to the worsening of many conditions. Massive wildfires in California in 2020 caused people to inhale smoke, increasing their risk of heart attack by up to 70%, found a studybecause of the smoke Estimated 3,000 deaths among people over the age of 65.

different study published in May found that people who lived within 50 km (31 mi) of a forest fire in the past decade had a 10% higher incidence of brain tumors and a 5% higher chance of developing lung cancer than those who lived far away .

Breathing in wildfire smoke while pregnant, meanwhile, increases the risk of premature birth and even Outcomes worsen for people who contract Covid-19, Harvard University professor Francesca Dominici, who led the research on the link between wildfire smoke and COVID, said Burke’s new study is “well validated” and an “exciting area of ​​research”.

“The results are interesting and relatable,” Dominici said, adding that there is “accidental evidence” that the PM2.5 Smoke is more toxic than particulates from other sources.

There is still more to learn about the effects of wildfire smoke, said George Thurston, an environmental health scientist at NYU School of Medicine. some research The suggestion of fossil fuel combustion is actually more harmful, but this new study is an “important addition” to wildfire smoke risk estimates.

“We need a study like this to assess just how big a risk it is, because the Environmental Protection Agency exempts these fires from air quality standards,” Thurston said. “This kind of work helps us work if new standards are needed.”

Burke said the smoke threat became clear for many people in California in 2020 when the San Francisco Bay Area skies turned orange. Some of the world’s wealthiest neighborhoods suffer from poor indoor air quality due to smoke, only reduced by air filtration.

“The sun never came to the Bay Area, which really brought home this different era we’re living in,” Burke said. “We naively thought we were safe in our homes but the health guidance is inadequate. In my house I closed all the windows and doors and still got a monitor and found that the air quality inside the house was appalling.

Huge reductions in greenhouse gases, better forest management where fuels are reduced or burned in a controlled manner and better guidance on households will be needed, Burke said. He said, “We should think about forest fires not just about the number of houses burned, but also how many people have been exposed to pollution, because there are big impacts that we are not yet aware of. thinking,” he said.

Source: www.theguardian.com

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