2 million deaths yearly worldwide linked with air pollution

Air pollution may be responsible for more
than 2 million deaths around the world
each year, according to a new study.
The study estimated that 2.1 million
deaths each year are linked with fine
particulate matter, tiny particles that can
get deep into the lungs and cause health
Exposure to particle pollution has
been linked with early death from heart
and lung diseases, including lung cancer,
the researchers said; meanwhile,
concentrations of particulate matter have
been increasing due to human activities.
The study also found that 470,000 deaths
yearly are linked with human sources of
ozone, which forms when pollutants from
sources such as cars or factories come
together and react. Exposure to ozone has
been linked to death from respiratory
diseases .
Most of the estimated global deaths likely
occur in East and South Asia, which have
large populations and severe air pollution,
said study researcher Jason West, an
assistant professor of environmental
sciences at the University of North
Carolina at Chapel Hill.
"Air pollution is an important problem.
It's probably one of the most important
environmental risk factors for health,"
West said. The study suggests that
improving air quality around the world
would increase life expectancy for some,
he said.
While some studies have suggested
that climate change can make air
pollution more deadly, the new study
found that climate change had only a
small effect on air pollution-related
Pollution and climate interact in several
ways. Climate-related factors such as
temperature and humidity can affect the
reaction rates of particles in the air, which
in turn determine the formation of
pollutants; additionally, rainfall can affect
accumulation of pollutants, the
researchers said.
However, in the researchers' analysis,
changes in climate were linked with just
1,500 yearly deaths from ozone pollution,
and 2,200 yearly deaths from fine
particulate matter.
The researchers used a number of climate
models to estimate concentrations of air
pollution around the world, in the years
1850 (the pre-industrial era) and 2000.
Focusing on these two years allowed the
researchers to determine what proportion
of air pollution was human-caused
(attributable to industrialization).
Then, the researchers used information
from past studies on air pollution and
health to determine how many deaths
are linked with particular concentrations
of air pollution, West said.
The new study had an advantage over
previous work in that it did not rely on
just one climate model, but instead
included several. However, because the
study used information from previous
research on air pollution and health, the
estimates are subject to the same
uncertainties that characterized those
previous studies.
In addition, most of the studies on air
pollution and health were conducted in
the United States, so applying those
results globally, as the current study did,
introduces some uncertainty, West said.
The study will be published in the July 12
issue of the journal Environmental
Research Letters.