Objective To establish an accurate, rapid and practical method for determination of lead in whole blood by graphite furnace atomic absorption spectrometry. Methods It can improve the accuracy and precision of the method by digesting blood sample in nitric acid at constant 135℃, adding matrix to standard series, using matrix modifier and changing ashing temperature of the graphite furnace. Results The linear range, detection limit, mean recovery rate and combination coefficient of variation of the method were 0-50 ?g/L, 1.96 ?g/L, 92.2% and 6.5% respectively. Conclusion This method shows some advantages such as low background, little interference, simple, rapid, sensitive, repeatable and accurate.

Objective To understand the status of soil-transmitted nematode infections,as well as the awareness and healthy behavior on soil-transmitted nematodiasis in rural residents of Dezhou City. Methods Six villages were selected according to the stratified sampling method;the permanent resident population aged 3 years or above was determined as the investigation objects. The modified Kato-Katz technique was adopted to detect the eggs of Ascaris lumbricoides,hookworm and Trichuris trichiura in the feces of the residents,and the method of cellophane anal swab was used to detect the Enterobius vermicularis infection in children under 12 years old. More than 50 households in each investigated site were randomly selected to investigate the awareness status on nematodiasis prevention and treatment and the condition of healthy behavior formation. Results A total of 2 294 residents were detected by Kato-Katz methods,11 of them were positive,and the total infection rate of soil-transmitted nematodes was 0.48%. To-tally 260 children were detected and 40 were infected with E. vermicularis,and the infection rate was 15.38%. A total of 898 resi-dents were investigated in the household survey and the awareness rate of nematodiasis prevention and treatment was 44.99%,the proportion of residents with healthy behavior was above 70%. Conclusions The infection rate of soil-transmitted nematode is low in rural areas of Dezhou City,but the infection rate of E. vermicularis in children is higher. The condition of healthy behavior forma-tion is satisfying,but the awareness rate of nematodiasis prevention and treatment of the residents is low. Therefore,the control measures as well as healthy education still should be strengthened.

Objective To explore the relationship between the soil components along the areas of the east route of the South?to?North Water Diversion Project and the survival situation of Oncomelania hupensis snails. Methods Four study sites were se?lected along the project,and soil samples were collected to analyze the components. The amounts of components among the dif?ferent study sites were compared statistically. Results Except zinc,sodium,and phosphorus,the contents of the soil compo?nents where the snails survived were different from those where snails were dead(t=-19.150 to 12.810,all P<0.01). Howev?er,the logistic regression analysis did not obtain a model with statistical significance. Conclusions O. hupensis snails live in the soil with adequate organic matter and neutral pH value. Along with the global warming and the operation of the South?to?North Water Diversion Project,O. hupensis snails may survive in the northern area,and therefore,the surveillance work should be strengthened.