The Centre told the Rajya Sabha on Monday that there was no conclusive data to establish a direct correlation between air pollution and death or disease, PTI reported. However, the government said air pollution could be one of the “triggering factors” for respiratory ailments and associated diseases.

“Health effects of air pollution are synergistic manifestation of factors, which include food habits, occupational habits, socio-economic status, medical history, immunity, heredity etc., of the individuals,” Minister of State for Environment Mahesh Sharma said. The government also said that it had formulated the National Clean Air Programme, or NACP, to combat air pollution in a time-bound manner in the long run.

Sharma was replying to a question on a study in the Lancet Medical Journal in November 2017, which said that Indians were the worst affected in the world by air pollution.

The study said the five leading risk factors for Disability-Adjusted Life Years, or DALY, in 2016 were child and maternal malnutrition, air pollution, dietary risks, high systolic blood pressure and high fasting plasma glucose. It added that the DALY due to air pollution decreased by 23.6% in India from 1990 to 2016.

Sharma said that the government had taken several steps to combat air pollution. This include notifying National Ambient Air Quality Standards, setting up a monitoring network for the assessment of air quality, introduction of cleaner and alternate fuels like gaseous fuel and Compressed Natural Gas etc.