Comparative analysis of environmental risk factors in nine years in an area polluted by arsenic coal-burning in Guizhou Province / 中国地方病学杂志

ABSTRACT

Objective To comparatively analyze the changes of environmental risk factors in 9 years in an area polluted by arsenic coal-burning in Xingren County of Guizhou Province,in order to provide evidence for reasoning the occurrence and development as well as its effective prevention and control.Methods Epidemiological sampling methods was used to conduct follow-up investigation on 181 arsenism patients who were diagnosed in 1998 in arsenic polluted area.Control group included 65 residents who lived far from polluted area of 12 km.The follow up investigation included age,sexuality,family economic situation,time of use or stop use of arsenic coal, ventilation of the room,desiccation of food etc.Diethyl dithiocarbamate silver(Ag-DDC)method was used to detect arsenic content of coal,soil,air,water and rice,corn,chili;Single factor and multivariate factors non-conditional Logistic regression models were used to analyze exposure factors of patients and related environmental risk factom, and the differences of those in 1998 and 2006 were compared. Results The arsenic content in indoor and outdoor air,coal,chili and corn went down from 0.0880 and 0.0220 mg/m3,397.20,45.07 and 2.64 mg/kg in 1998 to 0.0790 and 0.0070 mg/m3,93.01,3.46 and 1.50 mg/kg in 2006. Arsenic contents of other samples were less than national standard. The analysis of single factor and multivariate factors non-conditional Logistic regression showed that time of using high arsenic coal,age,fluorosis and smoking(x2 = 50.159,12.195,37.69,6.358,P ＜ 0.05 or ＜ 0.01 ) were still the main risk factors for arsenism,while family economic situation was still influential factors (X2 = 4.614,P ＜ 0.05);Ventilation of the room changed from a risk factors at 1998 to an influencing factors at 2006(X2 = 38.093,P ＜ 0.01 ). Single factor non-conditional Logistic regression model analysis showed that food desiccation by arsenic coal-burning and educational level were no longer risk and influencing factors,while food preservation and gender had become influencing factors(x2 = 17.463,11.004,all P ＜ 0.01 ) nine years after. Conclusions Environmental arsenic pollution in arsenism area in Guizhou Province has been obviously improved after nine years. However,the continued existence of low doses of arsenic pollution is still a major cause of failure of controlling arsenism. Time of using high arsenic coal,age,smoking,fluorosis,family economic situation and ventilating room are closely related to the occurrence and the development of arsenism. Prohibition of use of high arsenic coal,furnace improvement,health education and economic development are effective measures: