Fireworks release high levels of pollution on July 4 weekend
Average concentrations for the 24-hr period beginning 8 pm on July 4 are 5 μg/m3 (42%) greater than on control days, on national average.
Spectators
watch rockets from the Macy’s Fourth of July fireworks show explode
over the East River in New York, July 4, 2014. New studies show that
fireworks may adversely affect peoples’ health because of the high
levels of pollutants they release into the air. Photo by Eric
Thayer/Reuters
A new study published this week in the journal Atmospheric Environment found that fireworks release high levels of pollution into the sky on July 4 and 5.
“When people think of air pollution, they think of other kinds of things—smoke stacks, automobile exhaust pipes, construction sites,” study author Dian J. Seidel told TIME. “I don’t think most people think of fireworks.”
As a national average, culled from 315 different testing sites, Independence Day fireworks introduce 42 percent more pollutants into the air than are found on a normal day.
Part of that increase is a spike in emissions of perchlorate, a chemical that the Environmental Protection Agency says may “disrupt the thyroid’s ability to produce hormones needed for normal growth and development.”
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Abstract
Previous
case studies have documented increases in air pollutants, including
particulate matter (PM), during and following fireworks displays
associated with various holidays and celebrations around the world.
But
no study to date has explored fireworks effects on air quality over
large regions using systematic observations over multiple years to
estimate typical regional PM increases.
This study uses observations of
fine PM (with particle diameters < 2.5 μm, PM2.5) from 315 air
quality monitoring sites across the United States to estimate the
effects of Independence Day fireworks on hourly and 24-hr average
concentrations.
Hourly PM2.5 concentrations during the evening of July 4
and morning of July 5 are higher than on the two preceding and
following days in July, considered as control days.
On national average,
the increases are largest (21 μg/m3) at 9–10 pm on July 4
and drop to zero by noon on July 5. Average concentrations for the 24-hr
period beginning 8 pm on July 4 are 5 μg/m3 (42%) greater
than on control days, on national average.
The magnitude and timing of
the Independence Day increases vary from site to site and from year to
year, as would be expected given variations in factors such as PM2.5
emissions from fireworks, local meteorological conditions, and distances
between fireworks displays and monitoring sites.
At one site adjacent
to fireworks, hourly PM2.5 levels climb to ∼500 μg/m3, and 24-hr average concentrations increase by 48 μg/m3
(370%). These results have implications for potential improvements in
air quality models and their predictions, which currently do not account
for this emissions source.