China faces about 1.6 million premature deaths a year as a result of air pollution, the U.S.-based Health Effects Institute (HEI) said in a report, based on data going back to 1990, published on Tuesday.
China cut concentrations of hazardous particles known as PM2.5 by 6.5 percent in 338 cities last year. Smog-prone northern regions also met 2013-2017 air quality targets after a winter campaign to cut industrial output, coal consumption and traffic.
Nevertheless, deaths could still rise as China ages and overall air quality remains below the country's own standards, the study showed.
"People are living longer and older people are more susceptible to the diseases most closely linked to air pollution - the major causes of death in China like stroke, heart attack, and lung cancer," HEI president Dan Greenbaum told Reuters in an interview.
"We have done some projections in China up to 2030, and even with improvements in air quality, you see the number of deaths going up as the population gets older," he added.
The number of Chinese people over 60 reached 240 million at the end 2017, accounting for 17.3 percent of the population and up 55 million since 2011, according to the National Bureau of Statistics.
The China Association of Social Security, a government-registered research group, expects the number to reach 400 million by 2035.
As the government prepares a new smog action plan for 2018-2020, the next round of measures could prove harder to implement, Greenbaum said.
"The pollution itself gets harder to treat and even though China has been making progress, it has pretty much levelled off," he said.