An investigation on arsenide valence and speciation in urine of people in the endemic arsenism areas in the south of Shaanxi Province / 中华地方病学杂志

ABSTRACT

Objective To investigate the urinary arsenic levels of exposed population in various forms of and total arsenic (TAs) content as well as their relationship with arsenic poisoning in southern Shaanxi arsenic poisoning area.Methods According to the historical data of the investigation on arsenic poisoning,11 disease villages were chosen as survey sites in Ziyang and Pingli counties,Ankang city;three neighbor villages were chosen as control sites in Baihe.Baihe was a non-endemic arsenic poisoning area county,which had the same natural environment and living habits.In the survey sites,people over the age of 40 were selected for epidemiological investigation in both heating and non-heating seasons,and 40 urine samples were collected at each severity levels of the disease and in different seasons.Meantime,20 urine samples of the same age group were collected in the control sites in each season.Hydride generation-atomic fluorescence spectrometry (HG-AFS) was used to determine TAs,liquid chromatography-hydride generation-atomic fluorescence spectrometry (LC-HG-AFS) was used to determine the amount of inorganic trivalent arsenic (As3+),dimethylarsine (DMA),monomethylarsine (MMA) and inorganic pentavalent arsenic (AS5+),and the various forms and TAs were compared between different survey sites,severity levels,ages,sexes,and seasons.Results The medians of TAs,As3+,DMA,primary methylation index (PMI),and secondary methylation index (SMI) in diseased area (35.3,2.2,24.5 μg/L;0.84,0.90) were significantly higher than those of the control group (16.0,0.6,10.3 μg/L;0.78,0.81;Z =-9.069,-7.314,-8.913,-2.183,-3.853,P ＜ 0.01 or ＜ 0.05),and the medians of TAs,As3+,DMA,and SMI (31.6,2.0,23.1 μg/L;0.91) of the normal population in the diseased area were significantly higher than those of the control group (16.0,0.6,10.3 μg/L;0.81;Z =-7.164,-6.136,-7.023,-2.916,all P ＜ 0.01).Illness had positive correlations with TAs,DMA,and ages (r =0.370,0.367,0.594,all P ＜ 0.01).Men arsenic poisoning detection rate,TAs,As3+,and DMA (59.9％,37.4,2.5,25.2 μg/L) were significantly higher than those of women (22.4％,30.0,1.6,20.9 μg/L;x2 =54.878,P ＜ 0.01;Z =-3.332,-4.449,-2.681,all P ＜ 0.01).The medians of As3+,MMA,As5+,PMI,and SMI in the heating season (1.5,2.1,1.4 μg/L;0.87,0.92) were significantly different from those in the non-heating season (2.6,3.3,3.0 μg/L;0.82,0.88;Z =-6.870,-5.512,-8.542,-2.262,-4.544,P ＜ 0.01 or ＜ 0.05).Conclusions The TAs,As3+,and DMA of urine samples are related to local arsenic background,so they have some reference value for determination of diseased areas.Men are more susceptible to arsenic poisoning than women.