---
title: "Drinking water source and exposure to regulated water…"
description: "Even with average contaminant levels below regulatory limits, drinking water exposures vary significantly among California women based on their…"
url: "https://magellanlongevity.com/study/x18.md"
canonical: "https://magellanlongevity.com/study/x18.html"
html: "https://magellanlongevity.com/study/x18.html"
type: "study"
study_key: "x18"
journal: "J Expo Sci Environ Epidemiol"
year: 2024
pmid: "39003368"
doi: "10.1038/s41370-024-00703-9"
citations: 1
updated: 2026-09-02
author: "Gabriel Radu, DO"
author_credentials: "Physiatrist (PM&R). NY medical license 275110. NPI 1376861765."
publisher: "Magellan Longevity"
content_format: "markdown"
---

# Drinking water source and exposure to regulated water contaminants in the California Teachers Study cohort

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## Citation

| Field | Value |
| --- | --- |
| Journal | J Expo Sci Environ Epidemiol |
| Year | 2024 |
| PMID | [39003368](https://pubmed.ncbi.nlm.nih.gov/39003368/) |
| DOI | [10.1038/s41370-024-00703-9](https://doi.org/10.1038/s41370-024-00703-9) |
| Study key | x18 |

## Takeaway

Even with average contaminant levels below regulatory limits, drinking water exposures vary significantly among California women based on their demographics and neighborhood characteristics.

## The question

What are the drinking water sources and exposures to regulated water contaminants among participants in the California Teachers Study cohort?

## Hypothesis

The study implicitly hypothesizes that there may be variations in drinking water sources and contaminant exposures across different demographic and neighborhood subgroups within the California Teachers Study cohort, even if average levels are below regulatory limits.

## Methods

The study linked geocoded addresses of 115,206 California Teachers Study participants (1995-1996) to Community Water System (CWS) service area boundaries and monitoring data. Average concentrations (1990-2015) of arsenic, uranium, nitrate, gross alpha (GA), five haloacetic acids (HAA5), total trihalomethanes (TTHM), trichloroethylene (TCE), and tetrachloroethylene (PCE) were computed. Generalized linear regression was used to estimate geometric mean ratios of CWS exposures across demographic subgroups and neighborhood characteristics. Self-reported drinking water source and consumption from a 2017-2019 follow-up were also described.

## Results

Medians of average concentrations for all contaminants were below regulatory limits. For example, arsenic was 1.03 µg/L, uranium 3.48 µg/L, GA 2.21 pCi/L, nitrate 0.54 mg/L, HAA5 8.67 µg/L, and TTHM 12.86 µg/L. Among participants who lived within a CWS boundary and reported their water source (2017-2019), approximately 74% reported municipal, 15% bottled, 2% private well, 4% other, and 5% did not know/missing. Black, Hispanic, and Native American participants had higher average arsenic, uranium, GA, and nitrate concentrations compared to non-Hispanic white participants. Participants in higher socioeconomic status (SES) quartiles had lower arsenic, uranium, GA, and nitrate, but higher HAA5 and TTHM. Non-metropolitan participants had higher arsenic, uranium, and nitrate, while metropolitan participants had higher HAA5 and TTHM.

## Conclusion

While average water contaminant levels were generally below regulatory limits in this large cohort of California women, significant heterogeneity in exposures was observed across sociodemographic subgroups and neighborhood characteristics. These data will be used for future assessments of drinking water exposures and disease risk.

## Limitations

The abstract does not explicitly state limitations, but it implies that the study focuses on describing exposures and will be used for future assessments, suggesting it is not a health outcomes study itself.

## Verbatim from the abstract

> heterogeneity in contaminant exposures across sociodemographic subgroups and neighborhoods

## Self-Reported Drinking Water Sources (2017-2019)

| Measure | Percentage |
| --- | --- |
| Municipal | 74 |
| Bottled | 15 |
| Private Well | 2 |
| Other | 4 |
| Did Not Know/Missing | 5 |

*Distribution of self-reported drinking water sources among participants within a CWS boundary who provided information.*

## Where this study is used on Magellan

This paper is one of the citations behind the evidence grade on the pages below. Grades are assigned from the published research and are independent of affiliate commissions.

| Compound or device | Evidence grade | Graded pages |
| --- | --- | --- |
| Water Purification (Reverse Osmosis & Ultrafiltration) | Emerging evidence | [SimPure Reverse Osmosis System](https://magellanlongevity.com/p/42.md), [Waterdrop Undersink Reverse Osmosis](https://magellanlongevity.com/p/44.md) |

## Reference

1. **Drinking water source and exposure to regulated water contaminants in the California Teachers Study cohort**
   J Expo Sci Environ Epidemiol 2024 · [PMID 39003368](https://pubmed.ncbi.nlm.nih.gov/39003368/) · [DOI 10.1038/s41370-024-00703-9](https://doi.org/10.1038/s41370-024-00703-9)

   > heterogeneity in contaminant exposures across sociodemographic subgroups and neighborhoods

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## Related on Magellan Longevity

- [SimPure Reverse Osmosis System](https://magellanlongevity.com/p/42.md) — product graded on this and related evidence
- [Waterdrop Undersink Reverse Osmosis](https://magellanlongevity.com/p/44.md) — product graded on this and related evidence
- [Prevalence of exposure of heavy metals and their impact on health consequences.](https://magellanlongevity.com/study/water_metals.md)
- [Disinfection By-Products in Drinking Water and Bladder Cancer](https://magellanlongevity.com/study/d35536285.md)
- [Longevity research map](https://magellanlongevity.com/longevity-research-map.html)
- [Evidence-based longevity supplements](https://magellanlongevity.com/longevity-supplements.md)

## Scope and disclosures

Educational information, not medical advice. Nothing here is intended to diagnose, treat, cure, or prevent any disease. Talk to your physician before starting any supplement or device, especially if you are pregnant, nursing, or taking medication.

Editorial firewall: evidence grades are assigned from the published research and are independent of any affiliate commission. As an Amazon Associate, Magellan Longevity earns from qualifying purchases.

Reviewed for accuracy by a board-certified physician (DO).