Urinary biomarkers of drinking water disinfection byproducts in relation to blood-based liver function parameters among reproductive-aged Chinese women

Toxicological studies have documented that disinfection byproducts (DBPs), the ubiquitous drinking water pollutants, induce hepatotoxicity. Yet epidemiological evidence is sparse.

To assess urinary biomarkers of drinking water DBPs in relation to liver function parameters.

We included 1204 reproductive-aged women from the Tongji Reproductive and Environmental (TREE) study in Wuhan, China between December 2018 and July 2021. Urinary trichloroacetic acid (TCAA) and dichloroacetic acid (DCAA) as biomarkers of drinking water DBPs were assessed. Serum liver function parameters such as albumin (ALB), total cholesterol (TC), and alkaline phosphatase (ALP) were determined. Urinary DCAA and TCAA concentrations in relation to liver function parameters were examined by multivariate linear regression or restricted cubic spline (RCS) models.

There was no evidence of urinary TCAA in relation to serum parameters of liver function. However, monotonic dose-response relationships were estimated between elevated tertiles of urinary DCAA concentrations and increased serum ALP (percent change = 4.25 %; 95 % CI: 0.34 %, 8.32 % for the upper vs. lower tertile) and TC levels (percent change = 3.84 %; 95 % CI: 0.63 %, 7.17 % for the upper vs. lower tertile). These associations remained for urinary DCAA modeled as the continuous exposure variable and were linear in the RCS models. Age, body mass index, and passive smoking status did not modify these associations.

DCAA but not TCAA exposure may contribute to damaged liver function in reproductive-aged women.