Distribution and Differential Associations of Neonicotinoids and Their Metabolites in Paired Urine and Serum with Liver Function

Simultaneous determination of neonicotinoids and their metabolites in urine and serum captures complementary exposure windows and improves health effect assessment beyond single-matrix analysis. In this study, we investigated the distribution characteristics of neonicotinoids and their metabolites in paired urine and serum in 497 participants from the Guangzhou human biomonitoring program. We explored the similarities and differences in the associations of urinary and serum neonicotinoids their metabolites with liver function biomarkers. Significant positive cross-matrix correlations were observed for the compounds, with correlation coefficients ranging from 0.23 to 0.74. Linear regression analysis indicated that the total concentrations of neonicotinoids and their metabolites in urine were significantly positively associated with those in serum, with a correlation coefficient of 0.62. Urinary neonicotinoid exposure was negatively associated with bilirubin fractions in the quantile g-computation model. However, no significant associations were observed between serum neonicotinoid exposure and liver function biomarkers. Generalized linear models demonstrated notable differences in the associations of urinary versus serum neonicotinoids and their metabolites with liver function biomarkers. Significant positive associations were observed between N-desmethyl-acetamiprid concentrations in both serum and urine and globulin levels. Moreover, we observed significant interactions between neonicotinoid exposure, alcohol consumption, and body mass index in relation to liver function.