An astonishing 99 per cent of the world’s
population breathes polluted air that exceeds
internationally approved limits, with negative health
impacts kicking in at much lower levels than previously
thought, UN medical scientists .
fossil fuels are responsible for most of the harmful
emissions that are linked to acute and chronic sickness, the
World Health Organization ( ) called
for tangible steps to curb their use.
The UN agency
also urged more governments to take note that it has made
significant revisions to its air quality indicators,
including for particulate matter – known as PM2.5 – that can
enter the bloodstream, along with nitrogen dioxide (NO2),
another common urban pollutant and precursor of particulate
matter and ozone.
“It has been recognised that
air pollution has an impact at a much lower level
than previously thought,” said Dr. Sophie Gumy,
Technical Officer at WHO’s Department of Environment,
Climate Change and Health.
“So, with all the new
evidence that has come up over the last 15 years since the
last WHO air quality guideline update, most of the
values of the guidelines levels have been reduced.
So (for) particulate matter it has been reduced by two, and
for nitrogen dioxide it has been reduced by
According to the WHO, low and middle-income
countries still experience greater exposure to unhealthy
levels of particulate matter compared to the global average,
but nitrogen dioxide patterns “are different, showing less
difference between high and low and middle-income
The agency’s data indicates that
4.2 million people die from exposure to outdoor air
pollution, in addition to the 3.8 million whose deaths are
linked to household smoke produced by dirty stoves
And based on WHO’s mathematical modelling
of available air pollution data from 80 per cent of the
world’s urban areas, it indicates that almost every one of
us faces an increased risk of heart disease, stroke, lung
disease, cancer and pneumonia.
As depressing and as
dangerous as this situation is, the UN health agency insists
that momentum has been growing for better air
quality everywhere in the last decade.
of this is the fact that more than 6,000 cities in
117 countries now monitor air quality, compared to
1,100 cities in 91 countries a decade ago.
cleaner air is also one of the 17 and an increasing number of UN
agencies have passed resolutions urging Member States to
address the health impacts of smog-filled
Welcoming the increasing number of cities that
have begun to measure air quality for the first time, Dr.
Maria Neira, Director, WHO Department of Environment,
Climate Change and Health, said that it was particularly
significant that data is also being gathered on nitrogen
NO2 “is a proxy indicator for
traffic and it’s telling us what is happening at
urban level and how this gas that we know that is so
damaging and causing so many of respiratory diseases – one
of them being asthma – is increasing in many cities around
Despite this progress, “the bad news
is that we still have a majority of cities who do
not comply with the air quality guidelines,” said
Dr. Gumy. “The people living in them are still breathing
unhealthy levels of fine particulate matter and nitrogen
dioxide, with people in low and middle-income countries
suffering the highest exposures.”
Released ahead of
Health Organization’s includes for the first time ground
measurements of nitrogen dioxide (NO2) and particulate
matter with diameters equal or smaller than 10 microns
(PM10) or 2.5 microns (PM2.5). Both groups of
pollutants originate mainly from human activities related to
fossil fuel combustion.
The new air quality database
is the most extensive yet in its coverage of air pollution
exposure on the ground, WHO says. Some 2,000 more
cities/human settlements now record ground monitoring data
for particulate matter, PM10 and/or PM2.5, than the last
update. This marks an almost six-fold rise in
reporting since the database launched in