Deadly air

Being in denial on pollution is dangerous

Is India’s air killing its citizens? It is well known that the country, particularly urban India, has among the worst pollution in the world, if not the worst. However, a recent study on the number of premature deaths caused by pollution has been met with some ire from the government. The 2017 State of Global Air report by institutes at the University of Washington and the University of British Columbia found annual premature deaths due to air pollution in India were around 1.1 million, and just a few thousand less than the number in China, which is much more industrialised and has higher emissions. This was about a quarter of the total pollution-related premature deaths worldwide. In response, Environment Minister Anil Madhav Dave reportedly said, “We tend to believe reports on the impact of air pollution by foreign agencies and media and we do not rely on our own institutions.” He went on to say that Indians should trust institutions just as much as they did the army.

This may not be the most helpful attitude for a minister in this context. If there are problems with the methodology of the survey, which is entirely transparent and based on well-understood research, then they should be elucidated. Errors and exaggeration are possible, but simply denying the evidence is not the answer. If anything, such defensiveness leads to underestimating the major public health problem associated with unrestricted emissions and increasing particulate matter (PM) concentrations in Indian towns and cities. The methodology used for studies such as the State of Global Air report is straightforward. Baseline estimates of the effect of pollution on death rates have been conducted in various major peer-reviewed epidemiological studies. These estimates are then cross-referenced with measured pollution levels locally to produce overall estimates. There is no voodoo science or back-of-the-envelope guesswork here, although there is plenty of scope for disagreement and argument.

What there can be no argument about, however, is the scale of the problem. Since the minister has expressed a preference for Indian examinations of the problem — although he chose not to name any particular studies when pressed — it might be worthwhile to examine the work of, say, the Centre for Atmospheric Sciences at the Indian Institute of Technology, Delhi. In 2015, while admitting that “cause-specific premature death from ambient PM 2.5 exposure is poorly known for India”, it attempted to remedy this gap by conducting state-specific calculations. It found that, depending on the risk function involved, 500,000 to over 800,000 premature deaths occurred annually in India as a result of PM 2.5 exposure. This is not a million deaths a year, but it is not far off either. It certainly does not justify denial about the scale of the problem.

It can no longer be questioned that air pollution is one of India’s most severe public health concerns, if not the most severe. Aside from the obvious moral and ethical considerations, such high levels of pollutants mean that India becomes a less attractive investment destination and has a workforce that continually suffers from enervating respiratory diseases. Certainly, more local epidemiological work would be interesting, but that should not be the priority. The priority must be addressing poor regulation and strengthening public health. Those are the Indian institutions Mr Dave should worry about.