The rise in India’s air pollution over a quarter century has been staggering, according to a new report on the State of Global Air website.

The collaborative study released Tuesday by the Health Effects Institute and the Institute for Health Metrics and Evaluation found that India’s worsening air pollution causes 1.1 million people to die prematurely each year.

From 1990 to 2015, India’s rate of air pollution-related deaths jumped 50 percent, up to 14.7 for every 100,000 people.

Combined with China, the two countries contributed 52 percent of the 4.2 million global deaths related to air pollution in 2015. While they tie for the number of such fatalities in 2015, China recorded only 5.9 air pollution-related deaths per 100,000 people that year, down from 13.2 in 1990.

The report cites India’s “increasing exposure and a growing and aging population” for the uptick.

The findings should be no surprise to those living in India’s dense, traffic-clogged cities like Delhi, where the streets resemble “a gas chamber,” Delhi Chief Minister Arvind Kejriwal said in November, requiring people to wear face masks and schools to be shut down. The poor air quality is largely due to emissions from coal-fired power plants and fires fueled by wood and dung, The Washington Post reports.

NurPhoto via Getty Images The eastern city of Bhubaneswar, India, is shrouded on Feb. 11.

India joins a number of countries, including Bangladesh and Saudi Arabia, whose air pollution levels pose increasing harm to their residents. The Guardian reported on Monday that air pollution in 15 cities across the world is so bad that exercising for 60 minutes or more could do more harm than good. More than half of these 15 cities are in India.

Unlike China, India has made little progress in effective policymaking to combat rising air pollution levels. While Delhi introduced its “odd-even” rule ― a policy that allows cars with license plates that end in an odd number to drive only on odd-numbered days, and vice versa ― air quality remains poor as coal-fired power plants continue to operate.

The report’s findings underscore the importance of the Paris Climate Agreement, which India formally joined in October. Under the pact, India has committed to a goal of producing 40 percent of its electricity with non-fossil fuel sources by 2030.

Other regions of the world, such as the United States and Europe, saw decreasing air pollution levels following wide-ranging efforts to limit carbon emissions.

Some environmental experts worry that U.S. air quality progress could come to a halt under President Donald Trump, who has pledged to dismantle the Environmental Protection Agency, repeal former President Barack Obama’s Clean Power Plan and cancel the Paris agreement.