Seasonal Variation of Urinary Trichloroacetic Acid (TCAA) Concentrations Measured on Multiple Consecutive Days in a Prospective, Pre-Conception Cohort

Abstract

Seasonal Variation of Urinary Trichloroacetic Acid (TCAA) Concentrations Measured on Multiple Consecutive Days in a Prospective, Pre-Conception CohortAbstract Number:1826 Kyley Cox*, Christina Porucznik, James VanDerslice, Joseph Stanford, Diana Wilkins, Eric Brozek, David Anderson, and Nicole Bailey Kyley Cox* University of Utah Department of Family and Preventive Medicine, United States, E-mail Address: [email protected] Search for more papers by this author , Christina Porucznik University of Utah Department of Family and Preventive Medicine, United States, E-mail Address: [email protected] Search for more papers by this author , James VanDerslice University of Utah Department of Family and Preventive Medicine, United States, E-mail Address: [email protected] Search for more papers by this author , Joseph Stanford University of Utah Department of Family and Preventive Medicine, United States, E-mail Address: [email protected] Search for more papers by this author , Diana Wilkins University of Utah Center for Human Toxicology, United States, E-mail Address: [email protected] Search for more papers by this author , Eric Brozek University of Utah Center for Human Toxicology, United States, E-mail Address: [email protected] Search for more papers by this author , David Anderson University of Utah Center for Human Toxicology, United States, E-mail Address: [email protected] Search for more papers by this author , and Nicole Bailey University of Utah Department of Family and Preventive Medicine, United States, E-mail Address: [email protected] Search for more papers by this author AbstractBackground: Control of bacterial contamination of drinking water by disinfectants leads to the production of disinfection-by-products (DBPs). TCAA is the second most prevalent haloacetic acid in chlorinated water. Urinary TCAA is a validated biomarker of TCAA exposure by ingestion of chlorinated drinking water. Objective: Evaluate variation of urinary TCAA concentrations by season.Methods: A prospective, pre-conception cohort of couples (women 18–35, men 18–40) was recruited in Utah beginning in early 2012. Recruitment is ongoing. Women observed cervical mucus to identify the fertile window. Participants collected first-morning urine samples beginning at the onset of the fertile window, after which men discontinued collecting but women collected for the remainder of the cycle. TCAA was measured in each urine sample using quantitative GC-MS. Geometric means (GM) with 95% confidence intervals (CI) were calculated for each season using STATA ver. 12. Seasons were defined as follows: spring (Mar – May); summer (June – Aug); fall (Sept – Nov); winter (Dec – Feb).Results: The GM for all specimens (n=1521) was 2.42 ng/mL (95% CI 2.32, 2.53). The highest concentrations were observed in specimens collected during spring months (n=212, GM 3.04 ng/mL, 95% CI 2.76, 3.35), followed by fall (n=428, GM 2.69 ng/mL, 95% CI 2.47, 2.93), and summer (n=519, GM 2.53 ng/mL, 95% CI 2.37, 2.69). These levels were significantly higher than the levels observed during winter (n=362, GM 1.76 ng/mL, 95% CI, 1.61, 1.93). Men had slightly higher levels than women (GM 2.64 vs. 2.36 ng/mL) but the difference was not statistically significant.Conclusions: These preliminary findings suggest that TCAA exposures vary seasonally in a pattern similar to the levels of disinfection byproducts in tap water.