Model Analysis of Upper Digestive Tract Cancer and Environmental Pollution in Huaihe River Watershed

Abstract

The Huaihe River watershed has been suffering from industrial point pollution and other non-point pollution since 1970s.The media has reported the emergence of 'cancer village'.Spatial distribution pattern on upper digestive tract cancer and environmental factors was studied in 14 pilot counties including 5810 villages in Huaihe River watershed.From the multiple perspectives such as watershed and jurisdictional areas,Ordinary Least Squares(OLS) and Robust regression model were used for environmental factors selection.Robust regression model can detect abnormal value and put the weight for each of them.Surface water,phreatic water,river density,soil PAHs,fertilizer,population density and economical density(GDP) were imported into the model.Geographically Weighted Regression(GWR) model was used to locally detect the impact of different environmental factors on Empirical Bayes smoothed upper digestive tract cancer mortality.Through the correlative analysis of them,the risk assessment model of upper digestive tract cancer mortality was developed.Based on the regression coefficient of each environmental factor and statistical test in each pilot,the local main environmental factors were extracted.Even six factors were imported into the global regression model,the impact of each factor was different in distinct areas.In general,all the selected environmental factors show the positive correlation with the upper digestive tract cancer mortality except the surface water quality level and GDP.However the pollution type was diverse in different area based on the regression coefficient of each factor.The main findings were listed as follow: fertilizer amount,soil PAHs,GDP and river density are the main factors in Jiangsu segment in Huaihe River watershed;main factors in Anhui segment included soil PAHs and fertilizer amount;main factors in Henan segment included phreatic water,river density and fertilizer amount,With Shenqiu County,as one of the pilots in Henan,showed the strong positive correlation between surface water and cancer mortality;some kind of environmental risk factors were also detected in Shandong segment,but the result showed no correlation between these risk factors and cancer mortality,which needed to be studied any further.