Application of benchmark dose on the study of people's liver dysfunction induced by arsenic-coal burning and its significance / 中国地方病学杂志

ABSTRACT

Objective To explore the biological exposure limit of liver dysfunction induced by arsenic-coal burning, and screen sensitive biornarkers for its' liver dysfunction monitoring. Methods One hundred and eighteen subjects from the exposed area and 50 control from non-pollution area were studied. Their urinary and hair contents of arsenic were tested as exposure biomarkers by Ag-DDC assay. Total bile acid(TBA, detected by enzymatic cycling method), glutathione S-transferase (GSTs, detected by chemical colorimetry) and γ-glutamyl transpeptidase (γ-GT, detected by colorimetry of diazotization reagent) were used as biomarkers indicating liver cell damage. were used as liver fibrosis biomarkers. The benchmark dose (BMD) and the lower confidence limit of benchmark dose(BMDL) of urinary and hair arsenic were calculated. Sensitivity of each biomarker was estimated according to the BMD and BMDL value. Results The geometric mean of urinary and hair arsenic(98.50 mg/kg Cr, 7.42 mg/kg) μg/L) in the exposed group were significantly higher than urinary and hair arsenic (22.98 mg/kg Cr, 1.28 mg/kg) and each biomarker in the control group(4.63 μmol/L, 13.76 U/L,36.45 U/L,54.62 μg/L,74.45 μg/L,54.81 μg/L, P<0.01). Significant dose-effect relationship existed between urinary and hair arsenic contents and each biomarker. BMD and BMDL value of urinary arsenic was 49.53-101.96 mg/kg Cr and 39.02-70.15 mg/kg Cr, respectively. Those of hair arsenic were 3.04-5.02 mg/kg and 2.36-3.25 mg/kg, respectively. According to BMD and BMDL value of urinary and hair arsenic, the sensitivity of biomarkers decreased in the order of GSTs, TBA and Conclusions According to the lowest BMD and BMDL of urinary and hair arsenic, averaged reference value of urinary and hair arsenic in the local normal population, we suggest urinary 35.0 mg/kg Cr and hair 2.5 mg/kg as their biological exposure limits for those with liver dysfunction induced by arsenic-coal burning. GSTs, TBA, γ-GT and HA, Ⅳ. C, PC-Ⅲ can respectively reflect liver cell damage and liver fibrosis caused by arsenic-coal burning in different degrees, among which, GSTs and HA are the most sensitive biomarkers respectively for liver cell damage and liver fibrosis.