Arsenic speciation analysis of urine samples from individuals living in an arsenic-contaminated area in Bangladesh

Abstract

Objectives Chronic inorganic arsenic (iAs) exposure currently affects tens of millions of people worldwide. To accurately determine the proportion of urinary arsenic metabolites in residents continuously exposed to iAs, we performed arsenic speciation analysis of the urine of these individuals and determined whether a correlation exists between the concentration of iAs in drinking water and the urinary arsenic species content. Methods The subjects were 165 married couples who had lived in the Pabna District in Bangladesh for more than 5 years. Arsenic species were measured using high-performance liquid chromatography and inductively coupled plasma mass spectrometry. Results The median iAs concentration in drinking water was 55 lgAs/L (range \0.5-332 lgAs/L). Speciation analysis revealed the presence of arsenite, arsenate, monomethylarsonic acid (MMA), and dimethylarsinic acid in urine samples with medians (range) of 16.8 (7.7-32.3), 1.8 (\0.5-3.3), 13.7 (5.6-25.0), and 88.6 lgAs/L (47.9-153.4 lgAs/L), respectively. No arsenobetaine or arsenocholine was detected. The concentrations of the 4 urinary arsenic species were significantly and linearly related to each other. The urinary concentrations of total arsenic and each species were significantly correlated with the iAs concentration of drinking water. Conclusions All urinary arsenic species are well correlated with each other and with iAs in drinking water. The most significant linear relationship existed between the iAs concentration in drinking water and urinary iAs ? MMA concentration. From these results, combined with the effects of seafood ingestion, the best biomarker of iAs exposure is urinary iAs ? MMA concentration.

Homicidal arsenic poisoning

“…29,30 For example, in a report of 330 Pakistani subjects, the median urine concentration was 1.6 mmol/L in exposed individuals but these ranged up to 28.9 mmol/L (2166 mg/L). 31 In another study, urine concentrations as high as 24.6 mmol/L were found. 32 Although urine arsenic concentrations are usually lower than those found in fatal poisoning, on occasions this is not the case.…”

A biological indicator of inorganic arsenic exposure using the sum of urinary inorganic arsenic and monomethylarsonic acid concentrations

“…In a Bangladeshi study 15 ) , arsenite ( AsIII ) , arsenate (AsV), MMA, and DMA were detected in urine samples, whereas AsBe, which is excreted as a result of seafood ingestion, were not detected. The unidentified arsenic compounds are together termed "others."…”

“…We used the following two different populations: 1) the residents of 17 villages in the Pabna District of Bangladesh who were chronically exposed to inorganic arsenic through drinking water; and 2) Japanese male workers without occupational iAs exposure. The profiles of these subjects were described in our previous reports 11,15 ) .T h e 330 Bangladeshi participants (165 men and 165 women) had a mean age of 38.8±11.0 years (range, 20-77 years), whereas the 172 Japanese participants were healthy male workers with a mean age of 46.5±13.6 years (range, 18-74 years) who had no occupational arsenic exposure for at least 6 months. Urine samples were collected and stored as described in our previous reports 11,15 ) .…”

“…The profiles of these subjects were described in our previous reports 11,15 ) .T h e 330 Bangladeshi participants (165 men and 165 women) had a mean age of 38.8±11.0 years (range, 20-77 years), whereas the 172 Japanese participants were healthy male workers with a mean age of 46.5±13.6 years (range, 18-74 years) who had no occupational arsenic exposure for at least 6 months. Urine samples were collected and stored as described in our previous reports 11,15 ) . These studies were approved by the relevant ethics committees.…”

“…Because DMA is a major metabolite of iAs but is also excreted in urine after seafood consumption [12][13][14] , the use of urinary DMA level for the biological monitoring of occupational iAs exposure is inadequate. Therefore, to provide a possible method for the biological monitoring of occupational iAs exposure, we used the data of two arsenic speciation analyses of urine 11,15 ) .W e attempted to use the sum of the urinary levels of iAs and MMA as an indicator of iAs exposure by using urinary samples from Bangladeshi who did not eat seafood but had chronic iAs exposure from drinking water. In addition, we used the 95th percentile value of urinary levels obtained from healthy Japanese workers without occupational iAs exposure as the background level as well as the DFG definition 16) .…”