Risk Assessment For Health Hazard Of SO₂ And NO₂ In The Air Of Suzhou City

This paper aims to evaluate the human health risk caused by the air pollution of SO₂ and NO₂ in Suzhou, using the method of health risk assessment to provide scientific evidence in judgement of the air quality and occupational hazard.Based on the database of mortality rate resulted from respiratory diseases from 1993 to 2002 and the air concentrations of SO₂ and NO₂ in the urban area of Suzhou, the individual health risk in 2002 was calculated as 0.0078*10^-6 for SO₂ and 0. 0059*10^-6 for NO₂. Compared with the mortality rates caused by respiratory disease, pulmonary cancer and both of them, the health risks by exposure to air SO₂ and NO₂ was quite low (about 10^-6-10^-5) , indicating a slight health effect of the SO₂ and NO₂ pollution.In 213 workers with occupational exposure to SO₂, a positive correlation was revealed between the total exposure concentrations and the abnormal items of physical examination. In 2002,for example, annual health risk fromoccupational exposure was calculated as 0.1440*10"*, with the peak risk as 0. 294*10"6 which were 18. 46 and 37. 69 times of that in general population of Suzhou, suggesting that the health risk for occupational workers exposed to S02 was much more significant and occupational protections should be further strengthened.