Toxic metal contamination of home tap water supply during pregnancy

Many residential tap water samples contain toxic metals; several are on the WHO’s list of Chemicals of Major Public Health Concern. This is of relevance during pregnancy due to associations between metal exposure and adverse pregnancy and early life (infant and child) outcomes. Prospective observational cohort of patients at high-risk for adverse pregnancy outcomes at a tertiary University hospital, 2017-2021. At enrollment, all patients (1) Completed surveys re: their home environment and (2) Collected a home tap water sample, using a provided kit, prior to other water use for the day (min. 6-8 hrs of time ‘in the pipes’). Tap water samples were analyzed for 20 metals (Al, As, Ba, Be, Cd, Co, Cr, Cu, Fe, Hg, Mn, Pb, Sb, Se, Sn, Th, Tl, U, V, and Zn) using a high resolution Inductively Coupled Plasma Sector Field Mass Spec. (ICP-SFMS). Metal levels were considered ‘elevated’ if they exceeded US EPA or State-specific water quality thresholds. Those with ≥1 elevated metal in their home tap water were compared to those with all metals below threshold using Fisher’s exact, t-test, and logistic regression (initial models included Black race, well-water supply, insurance, education). 267 patients returned a home water sample and were included; 50 (19%) had ≥1 elevated metal level (70% with 1, 26% with 2, and 4% with 3 elevated metals). Fe (n=16 samples) and Mn (n=12 samples) were the most common elevated contaminants. Water with ≥1 elevated metal originated from 37 unique zip codes; the geographic distribution of samples is shown in Figure 1. Participant demographics and survey findings are shown in Table 1. In regression models, Black race (aOR 2.46, 95% CI 1.22-4.95) and home well-water supply (aOR 8.29, 95% CI 4.07-16.9) were associated with ≥ 1 elevated metal level. Metal contamination of tap water above EPA/state thresholds is relatively common in the homes of pregnant patients, is not limited to only homes reporting private well-water supply, and disproportionately affects Black pregnant individuals.View Large Image Figure ViewerDownload Hi-res image Download (PPT)