Study On The Relativity Between High Incidence Of Esophageal Cancer And Drinking Water In Tai’an City

ObjectiveThe incidence of esophageal cancer in Tai’an has been at a relatively high level.We study the causes of high incidence of esophageal cancer in Tai’an,discuss whether the nitrate,nitrite,ammonia nitrogen and some chemical elements in the drinking water are associated with the incidence of esophageal cancer,look for environmental factors affecting the incidence of esophageal cancer in Tai’an in order to provides the basis for the prevention and control of the local cancer of the esophagus.MethodsAccording to the death rate of esophageal cancer in the past five years in Tai’an,more than 40 villages and towns in 6 counties and cities were divided into high-risk group,middle-risk group and low-risk group.We collected water samples of surface water,shallow groundwater and deep groundwater in 40 villages and towns.According to "GB/T 5750 Standard Test Method for drinking water standard",villages and towns used NIR reagent spectrophotometric method,ion chromatography,diazo coupling Spectrophotometry to test the content of ammonia nitrogen,nitrate and nitrite in water;tested the content of tin,titanium,arsenic,zinc,lead,cadmium,nickel,iron,manganese,copper and chromium in water by inductively coupled plasma emission spectrometry.All the data measured should be statistically processed and analyzed through SPSS20.0 software.The test level is determined to be 0.05.When P≤0.05,there was statistically significant difference.Result1.The content of three nitrogen in the water of high-risk,middle-risk and low-risk areas of esophageal cancer:In surface water,the difference of ammonia nitrogen(1.607±0.809,0.919±0.574,0.528±0.451)mg/L content in high-risk,middle-risk and low-risk areas has statistical significance(F=18.760,P<0.001),nitrate(30.595±8.363,24.276±5.489,7.381±6.683)mg/L content in high-risk,middle-risk and low-risk areas has statistical significance(F=76.363,P<0.001).In shallow groundwater,the difference of nitrate(37.037±17.826,30.628±19.199,22.394±10.992)mg/L content in high-risk,middle-risk and low-risk areas has statistical significance(F=5.053,P=0.009),nitrite(0.035±0.055,0.007±0.003,0.002±0.001)mg/L content in high-risk,middle-risk and low-risk areas has statistical significance(H=57.482,P=0.001).There is only a difference between the nitrate content of the low-risk and the high-risk area.The conent of nitrite is different between high-risk,middle-risk and low-risk areas and increases with the severity of the area.Correlation analysis shows that in shallow groundwater,the content of nitrite(rs=0.777,P<0.001)was positively correlated with the mortality of esophageal cancer,the content of nitrate(rs=0.425,P<0.001)was positively correlated with the mortality of esophageal cancer,and ammonia nitrogen(rs=0.178,P=0.137)has no significant correlation with the incidence of esophageal cancer.In deep groundwater,the differences of the contents of ammonia nitrogen,nitrite and nitrate between the high,middle and low risk areas has no statiatical significance.2.The elements content of tin,titanium,arsenic,zinc,lead,cadmium,nickel,iron,manganese,copper and chromium:In shallow groundwater,Sn,As and Cu showed an decreasing trend in high-risk,middle-risk and low-risk areas of esophageal cancer,and there are significant differences in the content of Sn(F=7.124,P=0.002)and As(H=43.494,P<0.001)and no significant difference in the content of Cu,Zn(P>0.05).Correlation analysis shows that in shallow groundwater,there is a positive correlation between the mortality of esophageal cancer and the content tin(rs=0.326,p<0.01)and arsenic(rs=0.692,p<0.01).Zn,Fe and Mn showed an increasing trend in high-risk,middle-risk and low-risk areas,and there are significant differences in the content of Zn(H=55.310,P<0.001),Fe(H=18.749,P<0.001)and Mn(F=40.336,P<0.001);There are There was no statistical significance in the difference(P>0.05).Correlation analysis shows that in shallow groundwater,there is a negative correlation between the mortality of esophageal cancer and the content Fe(rs=-0.336,p<0.01)and Mn(rs=-0.514,p< 0.01).In deep groundwater,Sn and Fe showed an decreasing trend in high-risk,middle-risk and low-risk areas of esophageal cancer,and the content of Sn has statistical significance(F=3.938,P=0.024);Cu and Ti showed an increasing trend,and both the differences of Cu(H=16.495,P<0.001),Ti(H=8.890,P=0.012)have statistical significance.There was no significant difference in other elements(P>0.05).Conclusion1.The content of nitrate and nitrite in shallow groundwater in high-risk area of esophageal cancer in Tai’an was higher than that in low-risk area,and have a positive correlation with the mortality of esophageal cancer.One of the causes of local high incidence of esophageal cancer in Tai’an is that previous drinking water,shallow groundwater,contains excessive ammonia,nitrate,and nitrite.2.High content of Sn and arsenic As in Tai’an’s shallow groundwater is a risk factor for high incidence of esophageal cancer;the deficiency of Zn,Fe and Mn is also associated with the high incidence of esophageal cancer.3.The deep water "three nitrogen" and chemical elements in the deep-water of high-risk,middle-risk and low-risk areas of esophageal cancer are less different,and the risk factors are reduced.Water improvement is important in the prevention of primary prevention measures for various diseases.