Samar Halarnkar October 23, 2013, HT
The International Agency for Research on Cancer (IARC) announced, for the first time, that air pollution causes lung cancer.
It also said that poisoned air’s major component, particulate matter — smoke, dust and other dirty byproducts of road traffic, factories and construction — must now be classified a carcinogen, a cancer-causing substance, alongside tobacco, asbestos and ultraviolet radiation.
This is an announcement on par with the first warnings against tobacco or global warming. The IARC reviewed 1,000 scientific papers on five continents before going public. Previously only specific components of air pollution, such as diesel exhausts, were implicated in cancers.
Some of the cities whose citizens are most at risk lie in India and China (though the most poisoned cities are in Iran). Although India is less industrialised than China, Indian cities, according to the IARC, are far worse off.
Air pollution levels in Lanzhou, China’s most-polluted city, are lower than all of India’s top five. Bangalore is worse than Shanghai and Beijing is better than Mumbai. The city with the most poisoned air? Ludhiana, with pollution levels 10 times higher than Los Angeles.
A complex mix of toxic particles and gases, air pollution is the now the mother cause of many so-called lifestyle diseases that have emerged as the leading reasons for death in India and much of the emerging world. Before the new link to cancer, toxic air has already been implicated in the rise of heart and respiratory diseases.
Many studies have shown how poisoned air leads to lower productivity and widespread ill-health, enough to lower a nation’s output. Air pollution costs India about $30 billion, or 3% of GDP, according to the World Bank.
Three years ago, air pollution was the fifth biggest killer in India, responsible for a quarter of all strokes, 48.6% of ischemic heart disease and 620,000 premature deaths — the last, a 600% increase over a decade — according to the World Health Organisation’s Global Burden of Disease study.
Although no one has teased out the numbers, add cancer, heart and respiratory diseases caused by the toxins we breathe and air pollution might rocket to the top of Indian kill charts.
Particulate matter less than 10 micrometres — officially called PM10, many times finer than a human hair — is the primary measure of air pollution in India. These microscopic bits and bobs of progress burrow deep into the respiratory system.
India faces a grim predicament. Of 400 locations monitored by the Central Pollution Control Board — the word “control” is a misnomer — 99% report unsafe levels of PM10, according to a 2013 analysis of national air quality data by the Centre for Science and Environment. Ninety cities and town report critical air-pollution levels and 23 are most critical, which means they exceed safety limits by 300% or more.
Delhi is the only metropolis in CSE’s top five. The rest are Gwalior, Ghaziabad, Raipur and West Singhbhum. The cancer report from earlier this week has a top five list with only Delhi in common. The others are Ludhiana, Kanpur, Lucknow and Indore.