Scientists have confirmed that today’s major air pollution – the air that millions of people in cities breathe – is cancer-causing. The International Agency for Research on Cancer, IARC, says this air is a leading environmental cause of cancer deaths.
The World Health Organisation agency said this is the first time it has evaluated the whole mixture of air, rather than focus on specific air pollutants. The conclusions apply to all regions of the world.
Dr Kurt Straif, Head of the IARC Monographs Section, at a press conference in Geneva said: “In this more than 40 year history of the Monographs Programme, there have been more than 950 agents that have been evaluated either once or repeatedly if there is important new evidence, and more than 100 of these have been classified as carcinogenic to humans, this is the highest classification group, meaning that we know that it is causing cancer in humans.”
The predominant sources of outdoor air pollution are transportation, stationary power generation, industrial and agricultural emissions and residential heating and cooking.
Particulate Matter is a major component. PM of a ten micron diametre is the sort that blackens buildings. PM of 2.5 microns or smaller goes through respiratory passages and is small enough to enter the blood system. These material comes from wood smoke, burning diesel and factory output.
Then there is low atmospheric level ozone (or tropospheric ozone), not emitted directly by cars or industry but formed by the reaction of sunlight on air containing hydrocarbons and nitrogen oxides. Ozone damages mucus and respiratory tissues in animals, and damages plants.
Of nitrogen oxides, nitric oxide and dioxide are the most dangerous – by-products of combustion in automobile engines and fossil fuel power plants. They can cause nausea, irritated eyes and nose, fluid buildup in lungs, swelling of the throat and reduced oxygen intake.
Environmental campaigners in countries with massively growing economies say the fast pace of motorisation using dirty technology and dirty fuels translates into accelerating death rates and suffering, notably in China and India.
Anumita Roychowdhury with the campaign Right to Clean Air said: “The emission standards that we follow in Delhi today, they are more than seven years behind Europe and the rest of the country, that’s nearly twelve years behind Europe.
Environmental authorities in Europe say that air pollution there costs 400,000 people their lives each year, and hundreds of billions of euros for health care. They warn that 90 percent of those living in EU cities are breathing concentrations that far exceed the World Health Organisation recommended safe levels.