Exposure to trichloroacetic acid via drinking water during pregnancy – insights from a nested biomarker study

Publication authors

Smith R.B.; Toledano M.B.; Nieuwenhuijsen M.; Wright J.; Raynor P.; Cocker J.; Jones K.; Kostopoulou- Karadanelli M.


Background: We are investigating disinfection by-product exposure during pregnancy and fetal growth in the Born in Bradford (BiB) birth cohort. Previous epidemiological studies have often been limited by potential exposure measurement error and lack of exposure validation. We report findings from a biomarker exposure study nested within the BiB cohort.

Objectives: To evaluate factors driving exposure to trichloroacetic acid (TCAA), validate measures of water-use, and assess a single urinary TCAA biomarker as a measure of exposure during pregnancy.

Methods: A subset of pregnant women (n=39) participated in detailed exposure assessment at 28 weeks gestation. TCAA levels in the women’s urine and home tap water supply were measured, and their water use was assessed by questionnaire and 7-day diary. At 35-37 weeks gestation, repeated urinary TCAA and water-use diary measures were performed (n=14).

Results: There was little correlation between women’s urinary TCAA concentration and TCAA measured in the tap water supply at their homes (rho=0.18, p=0.29). However, urinary TCAA was more strongly correlated with women’s consumption of cold unfiltered tap water at home (rho=0.44, p=0.007). Urinary TCAA correlated strongly with tap water consumption and TCAA ingestion at home for unemployed women, but for employed women these correlations were weak. Repeated measures of urinary TCAA were only weakly correlated.

Conclusions: In this cohort, TCAA exposure variability is largely determined by individual tap water consumption. TCAA exposure assessment is more complex for employed women, with possible differential exposure measurement error in water consumption and TCAA ingestion measures according to employment status.