GENEVA, 25 March 2014
- In new estimates released today, the World
Health Organization (WHO) reports that in
2012 around 7 million people died - one
in eight of total global deaths as a result
of air pollution exposure. This finding
more than doubles previous estimates and
confirms that air pollution is now the world's
largest single environmental health risk.
Reducing air pollution could save millions
of lives.
In particular, the new
data reveal a stronger link between both
indoor and outdoor air pollution exposure
and cardiovascular diseases, such as strokes
and ischaemic heart disease, as well as
between air pollution and cancer. This is
in addition to air pollution's role in the
development of respiratory diseases, including
acute respiratory infections and chronic
obstructive pulmonary diseases.
The new estimates are
not only based on more knowledge about the
diseases caused by air pollution, but also
upon better assessment of human exposure
to air pollutants through the use of improved
measurements and technology. This has enabled
scientists to make a more detailed analysis
of health risks from a wider demographic
spread that now includes rural as well as
urban areas.
Regionally, low- and
middle-income countries in the WHO South-East
Asia and Western Pacific Regions had the
largest air pollution-related burden in
2012, with a total of 3.3 million deaths
linked to indoor air pollution and 2.6 million
deaths related to outdoor air pollution.
"Cleaning up the
air we breathe prevents noncommunicable
diseases as well as reduces disease risks
among women and vulnerable groups, including
children and the elderly," says Dr
Flavia Bustreo, WHO Assistant Director-General
Family, Women and Children's Health. "Poor
women and children pay a heavy price from
indoor air pollution since they spend more
time at home breathing in smoke and soot
from leaky coal and wood cook stoves."
Included in the assessment
is a breakdown of deaths attributed to specific
diseases, underlining that the vast majority
of air pollution deaths are due to cardiovascular
diseases as follows:
Outdoor air pollution-caused
deaths breakdown by disease:
40% - ischaemic heart
disease;
40% - stroke;
11% - chronic obstructive pulmonary disease
(COPD)
6% - lung cancer;
3% - acute lower respiratory infections
in children.
Indoor air pollution-caused deaths breakdown
by disease:
34% - stroke;
26% - ischaemic heart disease;
22% - COPD;
12% - acute lower respiratory infections
in children;
6% - lung cancer.
The new estimates are
based on the latest WHO mortality data from
2012 as well as evidence of health risks
from air pollution exposures. Estimates
of people's exposure to outdoor air pollution
in different parts of the world were formulated
through a new global data mapping. This
incorporated satellite data, ground-level
monitoring measurements and data on pollution
emissions from key sources, as well as modelling
of how pollution drifts in the air.
"The risks from
air pollution are now far greater than previously
thought or understood, particularly for
heart disease and strokes," says Dr
Maria Neira, Director of WHO's Department
for Public Health, Environmental and Social
Determinants of Health. "Few risks
have a greater impact on global health today
than air pollution; the evidence signals
the need for concerted action to clean up
the air we all breathe."
After analysing the
risk factors and taking into account revisions
in methodology, WHO estimates indoor air
pollution was linked to 4.3 million deaths
in 2012 in households cooking over coal,
wood and biomass stoves. The new estimate
is explained by better information about
pollution exposures among the estimated
2.9 billion people living in homes using
wood, coal or dung as their primary cooking
fuel, as well as evidence about air pollution's
role in the development of cardiovascular
and respiratory diseases, and cancers.
In the case of outdoor
air pollution, WHO estimates there were
3.7 million deaths in 2012 from urban and
rural sources worldwide.
Many people are exposed
to both indoor and outdoor air pollution.
Due to this overlap, mortality attributed
to the two sources cannot simply be added
together, hence the total estimate of around
7 million deaths in 2012.
"Excessive air
pollution is often a by-product of unsustainable
policies in sectors such as transport, energy,
waste management and industry. In most cases,
healthier strategies will also be more economical
in the long term due to health-care cost
savings as well as climate gains,"
says Dr Carlos Dora, WHO Coordinator for
Public Health, Environmental and Social
Determinants of Health. "WHO and health
sectors have a unique role in translating
scientific evidence on air pollution into
policies that can deliver impact and improvements
that will save lives."
The release of today's
data is a significant step in advancing
a WHO roadmap for preventing diseases related
to air pollution. This involves the development
of a WHO-hosted global platform on air quality
and health to generate better data on air
pollution-related diseases and strengthened
support to countries and cities through
guidance, information and evidence about
health gains from key interventions.
Later this year, WHO
will release indoor air quality guidelines
on household fuel combustion, as well as
country data on outdoor and indoor air pollution
exposures and related mortality, plus an
update of air quality measurements in 1600
cities from all regions of the world.
