Air pollution was the leading risk for chronic obstructive pulmonary disorder in several parts of India in 2016, according to a new study published in The Lancet on Wednesday.

Air pollution led to 53% of the chronic obstructive pulmonary disorder cases in India in 2016, while 25.4% is attributed to tobacco use and about 16.5% to occupational hazards, according to a Lancet study called ‘The Global Burden of Disease Study 1990–2016’. Smoking, meanwhile, causes more than 80% of the lung disease cases across the world.

Chronic respiratory diseases, which includes chronic obstructive pulmonary disorder and asthma were responsible for 10.9% of all deaths in 2016. The number of cases of chronic obstructive pulmonary disorder in India increased from 28.1 million in 1990 to 55.3 million in 2016, according to the study. The number of asthma cases increased from 22.9 million in 1990 to 37.9 million in 2016.

“One striking finding is that the rate of increase in the prevalence of ischaemic heart disease and diabetes is the highest in less developed states where the COPD and communicable diseases burden is already high and where health infrastructure is less than optimal,” said Professor Lalit Dandona, director of India State-level Disease Burden Initiative, according to the Hindustan Times.

Deaths from heart diseases and stroke almost doubled, up from 15.2% of all deaths in 1990 to 28.1% in 2016, according to the study.

Diabetes contributed to 3.1% of the total deaths in India, with more deaths among women (3.4%) than men (2.9%). “The number of people with diabetes in India increased from 26 million in 1990 to 65 million in 2016,” the study said. “The prevalence of diabetes in adults aged 20 years or older in India increased from 5.5% in 1990 to 7.7% in 2016.”

India accounted for nearly 37% of global suicide deaths among women and around 24% among men in 2016, according to the study. Around 63% of all suicides reported in India were in the age group 15 to 39 years.