India, Dec. 11 -- Data has always been the backbone of effective policy interventions. The government telling Parliament that "no conclusive national data" that "establishes a direct correlation between deaths or diseases occurring exclusively due to air pollution" exists is, therefore, telling of the deficiencies that afflict the health system's response to the harm caused by toxic air. To be sure, the government does recognise air pollution as a trigger for respiratory ailments and associated diseases and has mounted several initiatives - as have many state and local governments - to lower the pollution burden on health. But it is also true that chronic air pollution in some of India's largest cities has become the lived reality of tens of millions of people. There is a raft of scientific literature and ongoing assessments that covers the population-level health impacts of toxic air in some cities, including the national Capital, where air pollution has sparked public agitation and become a major civic concern. The University of Chicago's Energy Policy Institute (EPIC)'s Air Quality Life Index, which indicates shortened lifespan for Delhi residents because of exposure to deadly pollutants, is one such. This shows that collecting data and analysing it to establish a direct correlation between air pollution and instances of disease or death is a feasible exercise, and there are pathways based on science to make these connections. The government now needs to bridge this gap in its own data at the earliest and map associated morbidity/mortality and other health metrics to air pollution to fine-tune its remedial strategies. This will help design the appropriate health response and also sieve the real picture from narratives that seek to underplay the effects of pollution in the country. Recognising the data gap should become the first step towards correcting it....