According to the statistics of the World Health Organization, in 20 12, the number of deaths caused by air pollution in the world was 7 million, but the mortality caused by indoor air pollution was higher than that caused by outdoor air pollution, accounting for 40% and 3 million, accounting for 5.4% of the total number of deaths in that year.

According to their statistics, the death toll in China is 1032833, accounting for 1/7 of the global air pollution deaths. Therefore, it can be estimated that the number of deaths due to outdoor air pollution in China in 20 12 is about 400,000. It should be noted that the air pollution mentioned here only refers to PM2.5, please refer to their accounting methods for details. If only Beijing is considered, the paper also concludes that from 2000 to 20 12, 5 100 people died in Beijing every year due to the influence of PM2.5.