* Cancer agency ranks polluted air alongside tobacco smoke
* Some 23,000 lung cancer deaths in 2010 due to pollution
* Transport and power generation are major air polluters
By Kate Kelland
LONDON, Oct 17 The air we breathe is laced with
cancer-causing substances and should now be classified as
carcinogenic to humans, the World Health Organisation's (WHO)
cancer agency said on Thursday.
The International Agency for Research on Cancer (IARC) cited
data indicating that in 2010, 223,000 deaths from lung cancer
worldwide resulted from air pollution, and said there was also
convincing evidence it increases the risk of bladder cancer.
The WHO is a Geneva-based agency of the United Nations
focused on international public health matters.
Air pollution, mostly caused by transport, power generation,
industrial or agricultural emissions and residential heating and
cooking, is already known to raise risks for a wide range of
illnesses including respiratory and heart diseases.
Research suggests that in recent years, exposure levels have
risen significantly in some parts of the world, particularly
countries with large populations going through rapid
industrialisation such as China.
"We now know that outdoor air pollution is not only a major
risk to health in general, but also a leading environmental
cause of cancer deaths," said Kurt Straif, head of the IARC's
monographs section, which is tasked with ranking carcinogens.
"The air we breathe has become polluted with a mixture of
In a statement released after a week-long meeting of experts
reviewing the latest scientific literature, IARC said both
outdoor air pollution and "particulate matter" - a major
component of it - would now be classified among its Group 1
That ranks them alongside more than 100 other known
cancer-causing substances in IARC's Group 1, including asbestos,
plutonium, silica dust, ultraviolet radiation and tobacco smoke.
IARC's monographs programme, sometimes known as the
"encyclopaedia of carcinogens", aims to be an authoritative
source of scientific evidence on cancer-causing substances.
It has already classified many chemicals and mixtures that
can be components of air pollution, including diesel engine
exhaust, solvents, metals and dusts. But this is the first time
that experts have classified outdoor air pollution as a cause of
"Our task was to evaluate the air everyone breathes rather
than focus on specific air pollutants," said Dana Loomis, deputy
head of the section. "The results from the reviewed studies
point in the same direction: the risk of developing lung cancer
is significantly increased in people exposed to air pollution."
Although both the composition and levels of air pollution
can vary dramatically from one location to the next, IARC said
its conclusions applied to all regions of the world.
IARC's director, Christopher Wild, said the agency's
decision to classify outdoor air pollution as carcinogenic to
humans was an important step towards alerting governments to its
dangers and potential costs.
"There are effective ways to reduce air pollution and,
given the scale of the exposure affecting people worldwide, this
report should send a strong signal to the international
community to take action," he said.
(Editing by Eric Walsh)