Quantitative determination of bromochloroacetamide in mice urine by gas chromatography combined with salting-out assisted dispersive liquid-liquid microextraction.

Bromochloroacetamide (BCAcAm) is the main haloacetamide (HAcAm) detected in drinking water in different regions and exhibits strong cytotoxicity and genotoxicity. However, there is no appropriate method for detecting BCAcAm in urine or other biological samples, and thus, the internal exposure level in the population cannot be accurately assessed. In this study, a gas chromatography-electron capture detector (GC-ECD) was combined with salting-out assisted dispersive liquid-liquid microextraction (SA-DLLME) to develop a rapid and robust method for BCAcAm detection in urine of mice continuously exposed to BCAcAm. The factors influencing the pre-treatment procedure, including the type and volume of extraction and disperser solvents, extraction and standing time, and the amount of salt, were evaluated systematically. Under the optimised conditions, the analyte achieved good linearity in the spiked concentration range of 1.00-400.00 µg L-1, and the correlation coefficient was higher than 0.999. The limit of detection (LOD) and the limit of quantification (LOQ) were 0.17 µg L-1 and 0.50 µg L-1, respectively. The recoveries ranged from 84.20% to 92.17%. The detection of BCAcAm at three different calibration levels using this method afforded an intra-day precision of 1.95-4.29%, while the inter-day precision range was 5.54-9.82% (n = 6). This method has been successfully applied to monitor the concentration of BCAcAm in mouse urine in toxicity experiments and can provide technical support for assessing human internal exposure levels and health risks in later studies.

Occurrence and multi-pathway health risk assessment of trihalomethanes in drinking water of Wuxi, China.

Chlorination is widely used to disinfect drinking water to keep humans safe from microorganisms. During chlorination, chlorine and its compounds react with contaminants to form disinfection by-products (DBPs). Toxicological and epidemiological studies have demonstrated that trihalomethanes (THMs) are the most widely investigated DBPs in drinking water, and their exposure has been associated with some adverse health effects. However, studies about risk characteristics in this field are limited. We estimated the health risks of THMs exposure in drinking water through multi-pathways, and systematically analyzed the factors influencing health risks of THMs in Wuxi, China. A total of 488 drinking water samples were collected and analyzed for THMs from four water treatment utilities from 2008 to 2016 in Wuxi. And water exposure parameters were obtained from 602 participants by structured questionnaires. The median concentration of THMs ranged from 6.71 µg/L to 9.18 µg/L. The cumulative cancer risk of THMs exposure through multi-pathways was 1.26 × 10-4, and CHBr2Cl made the largest contribution to the total cancer risk (48.25%). The non-cancer risk of THMs exposure was 2.02 × 10-1. Health risks of the exposure to THMs in drinking water in summer were significantly higher than that in winter (P = 0.0003 for cancer risk, and P = 5.95 × 10-7 for non-cancer risk). In our study, the average individual disability-adjusted life years (DALYs) lost was 1.27 × 10-4 per person-year (ppy). This study attempted to use DALYs for risk assessment of THMs, which will provide useful information for risk comparison and prioritization of hazards in drinking water. This suggested that potential higher risk might exist, and possible measures could be considered to decrease the health risks.

Urinary trihalomethane concentrations and liver function indicators: a cross-sectional study in China.

While it is known that exposure to disinfection by-products (DBPs), including trihalomethanes (THMs), impairs liver function, few epidemiological studies have explored this association. Here, we determined the concentrations of four urinary trihalomethanes (chloroform [TCM], and three Br-THMs, bromodichloromethane [BDCM], dibromochloromethane [DBCM], and bromoform [TBM]), and nine serum liver function indicators in 182 adults ≥ 18 years of age, examined at a medical examination center in Wuxi, China, in 2020 and 2021. Generalized linear model analysis revealed positive associations between urinary DBCM and alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), total protein (TP), and albumin (ALB). Urinary Br-THMs and total THMs (TTHMs) were positively associated with ALT, AST, TBIL, indirect bilirubin (IBIL), TP, and ALB (all P < 0.05). Urinary THMs were not associated with alkaline phosphatase (ALP) or glutamine transaminase (GGT) (all P > 0.05). Generalized additive model-based penalized regression splines were used to confirm these associations. In conclusion, THM exposure was associated with altered serum biomarkers of liver function.