Dose-response relationship between arsenic exposure and the serum enzymes for liver function tests in the individuals exposed to arsenic: a cross sectional study in Bangladesh

<p>Abstract</p> <p>Background</p> <p>Chronic arsenic exposure has been shown to cause liver damage. However, serum hepatic enzyme activity as recognized on liver function tests (LFTs) showing a dose-response relationship with arsenic exposure has not yet been clearly documented. The aim of our study was to investigate the dose-response relationship between arsenic exposure and major serum enzyme marker activity associated with LFTs in the population living in arsenic-endemic areas in Bangladesh.</p> <p>Methods</p> <p>A total of 200 residents living in arsenic-endemic areas in Bangladesh were selected as study subjects. Arsenic concentrations in the drinking water, hair and nails were measured by Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). The study subjects were stratified into quartile groups as follows, based on concentrations of arsenic in the drinking water, as well as in subjects' hair and nails: lowest, low, medium and high. The serum hepatic enzyme activities of alkaline phosphatase (ALP), aspartate transaminase (AST) and alanine transaminase (ALT) were then assayed.</p> <p>Results</p> <p>Arsenic concentrations in the subjects' hair and nails were positively correlated with arsenic levels in the drinking water. As regards the exposure-response relationship with arsenic in the drinking water, the respective activities of ALP, AST and ALT were found to be significantly increased in the high-exposure groups compared to the lowest-exposure groups before and after adjustments were made for different covariates. With internal exposure markers (arsenic in hair and nails), the ALP, AST and ALT activity profiles assumed a similar shape of dose-response relationship, with very few differences seen in the higher groups compared to the lowest group, most likely due to the temporalities of exposure metrics.</p> <p>Conclusions</p> <p>The present study demonstrated that arsenic concentrations in the drinking water were strongly correlated with arsenic concentrations in the subjects' hair and nails. Further, this study revealed a novel exposure- and dose- response relationship between arsenic exposure metrics and serum hepatic enzyme activity. Elevated serum hepatic enzyme activities in the higher exposure gradients provided new insights into arsenic-induced liver toxicity that might be helpful for the early prognosis of arsenic-induced liver diseases.</p

Status of groundwater arsenic contamination in all 17 blocks of Nadia district in the state of West Bengal, India : a 23-year study report

A comprehensive study was conducted in Nadia, one of the nine arsenic (As) affected districts in West Bengal, India to determine the extent and severity of groundwater As contamination and its health effects in particular, dermatological effects and neurological complications. We collected 28,947 hand tube-well water samples from all 17 blocks of Nadia district and analyzed for As by the flow injection-hydride generation atomic absorption spectrometer (FI-HG-AAS). We found 51.4% and 17.3% of the tube-wells had As above 10 and 50 lg/L, respectively and observed that groundwater of all 17 blocks contained As above 50 lg/L with maximum observed level of 3200 lg/L. We estimated that about 2.1 million and 0.6 million people could be drinking As contaminated water above 10 and 50 lg/L, respectively, while 0.048 million could be at risk of drinking As-contaminated water above 300 lg/L, the concentration predicted to cause overt arsenical skin lesions. We screened 15,153 villagers from 50 villages and registered 1077 with arsenical skin lesions resulting in a prevalence rate of 7.1%. Analyzing 2671 biological samples (hair, nail and urine), from people with and without arsenical skin symptoms we found 95% of the samples had As above the normal level, indicating many people in Nadia district are sub-clinically affected. Arsenical neuropathy was observed in 33% of 255 arsenicosis patients with 28.2% prevalence for predominant sensory neuropathy and 4.7% for sensorimotor. As groundwater is still the main source of drinking water, targeting low-As aquifers and switching tube-well from unsafe to nearby safe sources are two visible options to obtain safe drinking water