The direct impact of air pollution on human body is firstly discomfort, then physiological reversible reaction, and then acute harmful symptoms. The harm of air pollution to people can be roughly divided into three types: acute poisoning, chronic poisoning and carcinogenesis.
(a) acute poisoning, when the concentration of pollutants in the atmosphere is low, it usually does not cause acute poisoning, but under some special conditions, such as special accidents in the production process of factories, a large number of harmful gases leaking out, and sudden changes in external meteorological conditions. It can cause acute poisoning. For example, methyl isobutyl ester leaked from Indian Pabor pesticide plant directly harms human body, with 2,500 people killed and100000 injured.
(2) Chronic poisoning, the chronic toxic effect of air pollution on human health is mainly manifested in the phenomenon that the prevalence rate increases after long-term low-concentration exposure to human body. The incidence of lung cancer among urban residents in China is very high, among which Beijing is the highest, and the respiratory diseases of urban residents are significantly higher than those in suburbs.