Objective To get the quantitative result of the impact of air sulfur dioxide on human health in the urban districts of Shanghai. Methods The approach recommended in this paper is based on the internationally accepted quantitative risk assessment framework and the unit increase in mortality or morbidity per unit increase of air pollutant level. Results In 1990,1998,the air sulfur dioxide caused 450～2 400,30～170 attributable deaths,accounting also for 54 600,4000 of chronic bronchitis,515 800,32 200 of outpatient visits of internal medicine,157 000～7 000 of outpatient visits of paediatrics medicine, 101 900～334 600, 6 600～23 200 of emergency room visits,23.3%,1.6% increase of cough,53.3%,3.6% increase of out of breath. Conclusion The impact of air sulfur dioxide in the urban districts of Shanghai on public health is considerable,although there is a decline trend.

Objective To study the effects of anatoxin-a (ANTX-A) on the activity of ATPase in PC12 cells.Methods PC12 cells were activated by different concentrations of ANTX-A stimulation for an hour or 10-7 mol/L ANTX-A for different time.PC12 cells were desensitized using twice incubation method.The activities of Na+-K+-ATPase and Ca2+-ATPase were determined by colorimetry method.Results 10-9,10-8,10-7 mol/L ANTX-A activated PC12 cells for an hour and 10-7 mol/L ANTX-A activated PC12 cells for 30,60,120 min,the activity of Na+-K+-ATPase in PC12 cells,in all of the cases,showed an reduction tendency,the activity of Ca2+-ATPase decreased significantly in different activation situation compared to the control group(P

Objective To study the genotoxicity of bromate,a chief by-product of ozonated drinking water.Methods Genotoxicity at gene,DNA and chromosome levels induced by bromate DBP was determined using Ames test,unscheduled DNA synthesis(UDS)assay and micronucleus test(MNT)of mice bone marrow polychromatic erythrocytes respectively.Results In Ames test,bromate showed no mutagenic effect on salmonella typhimurium TA98and TA100strains with or without S9(rat liv-er metabolic activation system)compared with the negative control group,but the results of UDS assay showed that bromate could induce unscheduled DNA synthesis in rat primary hepatocytes and the results of MNT indicated that bromate increased the micronucleus rate of bone marrow polychromatic erythrocytes of mice.Conclusion It was suggested that bromate DBP might have genotoxicity at DNA and chromosome levels.

Objective To make a further study on the character and mechanism of hepatotoxic effect of microcystin(MC),which stands for the extractions of cyanobacteria Methods The enzymology and morphology effects of different concentrations of 0.1,1,10 ?g/ml extractions of cyanobacteria on primary cultured hepatocyte were observed Results It was shown that the concentrations of LDH and AST increased in the culture medium after exposure to MC at concentrations of 0.1 ,1 and 10 ?g/ml No significant changes of concentrations of AKP, GGT, ALT and GSH were observed in the culture media of tested groups.An active proliferation of cultured hepatocytes with apopotosis or necrosis were observed in the center of the proliferation foci in the treated groups.Characterisitic morphological alterations such as irregular shape,cytoplasmic cavity,plasma membrane blebs and protrusions were viewed in scanning electronic microscope as well as in cultured cell. Conclusion The extractions of cyanobacteria could promote the proliferation of hepatocyte and might influence the physiological and biochemical function and the integrity of hepatocyte