Poisons in the Air

Union Environment Minister Anil Madhav Dave is in denial. While he cannot ignore the fact that air pollution in India is a serious problem, he does not want to be told this by people from outside the country. In response to the State of Global Air 2017, a report produced jointly by the Boston-based Health Effects Institute and the Institute for Health Metrics and Evaluation in Seattle, which stated that India is not far behind China in the number of deaths attributable to air pollution, Dave complained that we Indians “seem to be far more influenced by things out of India.” Instead, he suggested, we should heed our own experts on this subject who he trusts “as much as I do our army.” This strange comparison of science experts with the army notwithstanding, the minister’s defensive response to the report is perplexing. Even if some might quibble over the methodology used to arrive at a specific figure of the number of deaths attributable to the increase in air pollution, surely there is little to argue over the reality that air pollution is a serious environmental problem in India that is contributing to increased morbidity and mortality.

Relying on official statistics on air pollution levels and the comprehensive Global Burden of Disease (GBD) report, the State of Global Air has calculated the health impacts of air pollution. The GBD is an impressive compilation of health data and analysis from 195 countries spanning 25 years, from 1990 to 2015, which is updated every year. It facilitates comparison of health data across populations, age groups and over a span of time. This kind of information, combined with data about the levels of air pollution, particularly fine particulate matter termed PM_2.5, as well as ozone, provides the basis for calculations on the number of deaths that are attributable to the increase in air pollution levels as well as the number of disability-adjusted life years. Long-term exposure to these pollutants, particularly PM_2.5, exacerbates cardiovascular conditions and respiratory problems and leads to a noticeable reduction in life span, particularly of the very young and the old. It is also now well-established that exposure to ozone leads to conditions like chronic obstructive pulmonary disease. Given this, the State of Global Air report has concluded that of the 4.2 million deaths globally attributable to air pollution in 2015, India and China together account for 52% of them. However, while China has taken steps that have steadied the rate of increase of air pollution–related mortality, the graph in India continues to climb.