Whether it was a smoke incident in London (the London Smog Incident of 1952) or the air pollution incident in Yokkaichi, Japan (asthma in Yokkaichi, Japan), the study on air pollution and health was confined to the health effects of pollutants themselves, namely nitrogen dioxide. What are the health effects of sulfur dioxide and these substances? As our understanding of the complexity of air-pollution mixtures continues to deepen, the limitations of controlling air pollution through the guideline values of individual pollutants have become increasingly apparent.
From studies in Europe, America, and Asia, the harm to health caused by particulate matter, especially long-term damage, is basically the same. Different studies have shown that the health risk caused by particulate matter is about 0.5%. For example, if the PM10 increases by 10 per cubic meter, the mortality rate will increase by 0.6%, and some will increase by 0.45%, which is basically 0.5%. This means that if the original PM10 is 100 and it is now increased to 110, the death rate will increase by about 0.5%. This health risk refers to the increase in total mortality caused by the increase in particulate matter. This is the result of observations in 29 cities in Europe, 20 cities in the United States, and many cities in Asia.
However, the situation in China has a peculiarity. For the aforementioned study with 0.5% values, the concentration range of PM10 is basically below 100 micrograms, which is the background value of Europe and the United States and other countries. In China, PM10 and PM2.5 are many times. Two or three hundred or more, then, when the particles reach such a high level, is it still a linear relationship of 0.5%? We hope that the study can be answered.
In other words, what is the impact of haze on health? How different are the differences in different regions? Which regions are the most serious regions? Which groups of people are most affected by the health hazards? These information and research results are used to formulate preventive measures and evaluate interventions. The effect is very important and very necessary.