What is the link between mortality and pollution ? Comment on whether evidence provides a relation between the two.

The Union Environment Minister recently mentioned that no Indian studies have shown a direct correlation between mortality and pollution and International studies which estimate that thousands will die from causes linked to air pollution has caused a fear psychosis among people. 

His comment is untenable, as the India State-Level Disease Burden Initiative (ISLDBI), reports that one in eight deaths in India was attributable to air pollution and the average life expectancy in India would have been 1.7 years higher if the air pollution levels were less than the minimal level. ISLDBI is funded by the Health Ministry and involve the Indian Council of Medical Research, Institute for Health Metrics and Evaluation and Public Health Foundation of India. These studies were also a part of the Global Burden of Disease Study 2017. 

Researchers and public health professionals have routinely rely on correlation between the two to draw countrywide estimates of the health risk posed by a particular pollutant. 

Evidence to determine mortality from pollution – 

A number of studies have been done in the U.S. and Europe to gauge exposure response in cities that have a good air quality on average. It is because an increase in particulate matter concentrations above background levels can be estimated precise and be correlated to the rise in mortality (present in hospital records). 

Most studies have found a linear relationship between mortality and PM 10 levels. However beyond a certain level it’s hard to estimate if concentrations, say, 10 times more, would result in 10 times more mortality spike. Such information is relevant for India to gauge as pollutant concentration is much higher than in Europe. The ISLDBI relies on these computations computed exposures, calculates state levels of pollution to find out the number of Indians exposed and compute death rate while adjusting cause of mortality.