Air pollution has become a serious issue in China and the government there is facing rising public criticism. Concern in Japan is also increasing as winds carry the pollution here. The Chinese government must take drastic measures to rectify the situation. Having experienced and overcome similar problems that cropped up during its period of high economic growth, Japan should provide whatever technical assistance it can.
Especially problematic are fine particles called PM2.5, whose diameter is 2.5 micrometers or less (1 micrometer is one-millionth of a meter). These particles can penetrate deep into lungs, causing asthma and bronchitis and increasing the risk of lung cancer. It is also feared that inhalation of PM2.5 can lead to hardening of the arteries, which in turn can result in myocardial or cerebral infarction.
Automobiles, factories, coal-burning power plants and heaters at home using coal are the sources of PM2.5 in China. Japan's standard is a daily average of 35 micrograms in one cubic meter of air. The corresponding Chinese standard is 75 micrograms.