A new study of air pollution measurements in China has found that at least 84 percent of the country’s population lives in areas with “unacceptably high” levels of air pollution, and that polluted air caused 1.37 million premature deaths in 2013.
The study was carried out by researchers from Peking University, and published in the journal Science of the Total Environment.
A team of researchers led by Professor Zhu Tong from Peking University used PM2.5 data from over 500 ground observation stations in China, re-analyzing them using a newly developed integrated exposure-response (IER) model to estimate the risk of premature death due to exposure to PM2.5 particulate pollution.
PM2.5 are extremely fine particles, mainly from the combustion of fossil fuels, that have a diameter less than 2.5 micrometers. They are thought to penetrate deep into the lungs and cause long term health effects in humans.
“Air quality has a significant influence on human health, however, controversy still exists over the different exposure assessments and choice of air quality indicator,” Zhu wrote in the report. “Depending on whether data from scattered city sites or combined satellite remote sensing was used, the impact of PM2.5 measurements on premature mortality can fluctuate from 0.35 to 1.6 million people per year.”
The study found that 84 percent of China’s population live in areas where the yearly average PM2.5 exceeded 35 micrograms per cubic meter, the upper limit set in ambient air quality standards by the World Health Organization (WHO).
In addition, for the year 2013 alone, their model predicted that this exposure to high PM2.5 levels resulted in 1.37 million premature deaths, of which 50 percent, 28 percent and 12 percent were due to cerebrovascular disease, ischemic heart disease and chronic obstructive pulmonary disease respectively.
The study also points out that if the concentration of PM2.5 meets the WHO standards, the risk of premature death from those three causes can decrease by 39 percent, 23 percent and 66 percent respectively, revealing the non-linear relationship between the decrease of PM2.5 and the improvement of different health conditions, the researchers said.
The authors concluded that it is necessary to raise ambient air quality standards for the sake of China’s health.