WASHINGTON, Feb. 12 (UPI) -- Every year, dirty air sends some 5.5 million people to an early grave.
That's according to researchers at the University of British Columbia, who on Friday presented new data on air pollution at the annual meeting of the American Association for the Advancement of Science.
"Air pollution is the fourth-highest risk factor for death, globally, and by far the leading environmental risk factor for disease," Michael Brauer, a professor at UBC's School of Population and Public Health, said in a press release. "Reducing air pollution is an incredibly efficient way to improve the health of a population."
The main culprit is particulate matter -- aerosols, smoke, soot, dust and other toxins and fumes suspended in air.
Though industrial fumes and trash fire smoke can fatally suffocate, most of the 5.5 million air pollution-related deaths tallied in the latest research are the result of health complications -- mostly heart disease. Exposure to particulates has been linked to a range of cardiovascular problems, as well as pulmonary diseases, respiratory infections and cancer.
Though air pollution remains a problem in Europe and the United States -- especially for minority communities -- a majority of the 5.5 million deaths are happening in the developing world and Asia.
More than 55 percent of annual air pollution deaths occur in India and China, two countries with expanding economies and serious air quality control problems.
"Our study highlights the urgent need for even more aggressive strategies to reduce emissions from coal and from other sectors," said Qiao Ma, a PhD student in the School of Environment at Tsinghua University in Beijing.
Ma's research suggests pollution from coal alone was responsible for the deaths of 366,000 people in China in 2013.
The new research is meant to inspire action and includes analysis aimed at helping Asia's maturing economies curb air pollution and save lives.
"India needs a three-pronged mitigation approach to address industrial coal burning, open burning for agriculture and household air pollution sources," explained Chandra Venkataraman, professor of Chemical Engineering at the Indian Institute of Technology Bombay, in Mumbai.
The latest study suggests air pollution is even deadlier than previous thought.
A 2015 study put the total at only 3.3 million deaths, but the new numbers suggest those predictions underestimated the human health consequences of air pollution in India, where coal factories and open pit trash fires continue to cost hundreds of thousands of lives.
Those that live in China and India likely won't be surprised by the news. Air pollution in the two nations, especially in big cities, is regularly visible from space and significant enough to consistently block out the sun.