China and India together were responsible for over half of the total global deaths attributable to air pollution, a new study has said. The study also finds that increasing exposure and a growing and aging population have meant that India now rivals China for among the highest air pollution health burdens in the world, with both countries facing some 1.1 million early deaths from outdoor air pollution in 2016.

China has made initial progress, beginning to achieve air pollution declines; in contrast, Pakistan, Bangladesh, and India have experienced the steepest increases in air pollution levels since 2010. Seven billion people, more than 95% of the worldÂs population, live in areas of unhealthy air. Air pollution is the leading environmental cause of death worldwide according to the State of Global Air 2018, the annual report and interactive website published by the Health Effects Institute (HEI).

The report said long-term exposure to outdoor and indoor air pollution contributed to 6.1 million premature deaths from stroke, heart attack, lung cancer, and chronic lung disease. That makes air pollution the 4th highest cause of death among all health risks, exceeded only by high blood pressure, diet, and smoking.

For the first time this yearÂs report and website include worldwide estimates of exposure to and health burdens of burning of solid fuels in their homes; in 2016 a total of 2.5 billion people  one in three global citizens  were exposed to household air pollution from the use of solid fuels (for example, coal, wood, charcoal, dung, or other biomass) for cooking and heating. Most live in low- and middle-income countries in Asia and Africa, and face a double burden: exposure to both indoor and outdoor air pollution.

And household air pollution can be a major source of impact in outdoor air: with indoor pollution emitted to the outdoor air the largest cause of health impacts from among all sources in India, contributing to 1 in 4 air pollution-related deaths India, and nearly 1 in 5 such deaths in China.

ÂAir pollution takes a huge personal toll worldwide, making it difficult to breathe for those with respiratory disease, sending the young and old to hospital, missing school and work, and contributing to early death said Bob OÂKeefe, Vice President of HEI. ÂThe trends we report show real progress in some parts of the world  but serious challenges remain to eliminate this avoidable affliction, he added.

The State of Global Air 2018 annual report and accompanying interactive website are designed and implemented by the Health Effects Institute in cooperation with the Institute of Health Metrics and Evaluation (IHME) at the University of Washington and the University of British Columbia. IHME is an independent population health research center that coordinates the annual Global Burden of Disease (GBD) study, a systematic scientific effort to quantify the magnitude of health loss from all major diseases, injuries, and risk factors in populations across the world.