Studies on exposure status of inhabitants to water-arsenic valence states in areas with endemic arsenism in the Datong basin in Shanxi

This study aimed to describe the distribution of water-arsenic(As)valence states and its relationship to areas with endemic arsenism in the Datong basin.Drinking water samples of patients with endemic arsenism and a control group were examined using hydride generation atomic fluorescence spectrometry(HG-AFS).We analyzed the data using SPSS10.0 for Windows.The As(III)/As ratio was 52.1%in the water sample,exceeding the national standard of 0.05 mg/L.The As(III)/As ratio significantly varied among the different stages in the disease-state groups,and with the control group(χ^(2)=22.4,P<0.01).The As(III)/As(V)ratio significantly varied in the four groups(χ^(2)=26.19,P<0.01),with a tendency to increase along with the seriousness of the disease state.The most common type of drinking water arsenic valence state was As(III)in the endemic diseaseareas.Endemic arsenism was positively correlated with As(III).This led us to conclude that the fraction of each water-arsenic valence state should be studied when determining the arsenic content of drinking water.