At the outset of the pandemic, when lockdowns were widespread, a
remarkable phenomenon occurred. Places that had been saturated with
pollution suddenly cleared. The sky over Los Angeles turned blue. Snow-
capped mountain ranges that were normally obscured by pollution glistened
on the horizon. The white marble of the Taj Mahal, which is normally
wrapped in smog, shone brightly against an azure sky. Even in regions that
aren’t typically considered polluted, the air just smelled fresher.
The reason, of course, is that hardly anyone was driving. Burning fossil
fuels, whether under the hood of an automobile or in a home furnace or
power plant, produces copious amounts of fine particulate pollution, also
known as PM2.5—particulate matter smaller than 2.5 microns. For years,
researchers didn’t understand the impact of these pollutants.
But as scientists have started digging, they have discovered that
particulates have an outsize impact on our health. Previous research
showed that PM2.5 from burning fossil fuels kills more than a million
people a year, mostly in heavily polluted regions of Asia. But now, a new
study from the Health Effects Institute shows that even in the US, where
the air is comparatively clean, PM2.5 current Environmental Protection
Agency guidelines may not be low enough to prevent unnecessary deaths.
Better—but still not great
Air quality in the US has greatly improved since the 1970s, yet
researchers were curious to see if today’s relatively clean air still
contained unhealthy amounts of pollution. The new study, led by Francesca
Dominici at Harvard University, looked at 68.5 million older Americans who
were exposed to ambient air that was cleaner than current EPA guidelines.
The team determined PM2.5 exposure using satellite data along with land-
use details to refine pollution estimates from roads, farms, and so on.
The researchers found that deaths among older Americans, regardless of the
cause, rose 6–8 percent for every additional 10 µg of PM2.5 per cubic
meter of air throughout the year. That’s a relatively small amount; to put
it in context, daily PM2.5 levels classified as “good” would have to
increase by more than twice that number to trigger an air quality alert
for sensitive groups and 14-times to trigger an alert for everyone else.
PM2.5 is particularly deadly because of its size. Our noses are pretty
good at filtering out larger particles, but smaller ones can penetrate
deep into our lungs and circulatory systems. In the lungs, the particles
can inflame tissues, causing or exacerbating asthma, chronic bronchitis,
emphysema, and other problems. In our circulatory system, PM2.5 can drive
up heart rates and lead to heart attacks, strokes, and other
cardiovascular problems. Fine particulate pollution is even associated
with neurological problems, including Alzheimer’s and Parkinson’s
In recent years, the evidence of negative health effects from PM2.5 “has
grown substantially,” Daniel Greenbaum, president of the Health Effects
Institute, told Ars. Two major studies in the late 1980s and early 1990s
were the first to suggest that eliminating visible soot wasn’t enough, he
said, and added “that there are really effects even with those very fine
particles.” Since then, more landmark studies have shown just how
pervasive and pernicious PM2.5 pollution can be.
Subtle changes, big impacts
The EPA didn’t regulate PM2.5 specifically until 1997, when it set the
standard at 15 µg/m3 over the course of a year. In 2012, it reduced the
number to 12 µg/m3, and the standard is again up for review, as it is
every five years.
The researchers found that if the standard were to be lowered slightly,
from 12 to 10 µg/m3, it would save the lives of 143,000 Americans over the
The drive to electrification would go a long way to achieving that end. In
the US, around 40 percent of PM2.5 pollution comes from burning fossil
fuels, with the majority coming from oil and natural gas. Eliminating
those sources could have positive health effects, too. A World Bank review
of pollution studies suggests that PM2.5 from fossil fuel
combustion—particularly coal, gasoline, and diesel—may pose the greatest
risk to people’s health.
Not all particulate matter comes from fossil fuels, of course. Some comes
from farming and ranching, where fields and pastures kick up dust, while
other sources include wildfires, industrial solvents, and waste
incineration. There is probably a floor on how low PM2.5 pollution can
get, but the study suggests that even small reductions could have a major
impact on people’s health.
“Figuring out how we go about dealing with these already very low levels
of pollution and further reducing them is not going to be simple. The
sources are going to be very dispersed over wide areas,” Greenbaum said.
The new study’s results, he added, pose “an even more challenging question
for air quality policy.”
"LOCKDOWN", left-wing COVID fearmongering. 95% of COVID infections
recover with no after effects.
No collusion - Special Counsel Robert Swan Mueller III, March 2019.
Officially made Nancy Pelosi a two-time impeachment loser.
Donald J. Trump, cheated out of a second term by fraudulent "mail-in"
ballots. Report voter fraud: sf.n...@mail.house.gov
Thank you for cleaning up the disaster of the 2008-2017 Obama / Biden
fiasco, President Trump.
Under Barack Obama's leadership, the United States of America became the
The World According To Garp. Obama sold out heterosexuals for Hollywood
queer liberal democrat donors.
President Trump boosted the economy, reduced illegal invasions, appointed
dozens of judges and three SCOTUS justices.