--- title: "Bladder cancer and exposure to water disinfection by-products…" description: "Long-term exposure to trihalomethanes (THMs) from chlorinated water, through drinking, showering/bathing, and swimming, is associated with an increased…" url: "https://magellanlongevity.com/study/s190.md" canonical: "https://magellanlongevity.com/study/s190.html" html: "https://magellanlongevity.com/study/s190.html" type: "study" study_key: "s190" journal: "Am J Epidemiol" year: 2006 pmid: "17079692" doi: "10.1093/aje/kwj364" 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" --- # Bladder cancer and exposure to water disinfection by-products through ingestion, bathing, showering, and swimming in pools. [Home](https://magellanlongevity.com/) › [Research map](https://magellanlongevity.com/longevity-research-map.html) › Bladder cancer and exposure to water disinfection… **HTML version:** https://magellanlongevity.com/study/s190.html · **In the Magellan app:** https://magellanlongevity.com/#/study/s190 ## Citation | Field | Value | | --- | --- | | Journal | Am J Epidemiol | | Year | 2006 | | PMID | [17079692](https://pubmed.ncbi.nlm.nih.gov/17079692/) | | DOI | [10.1093/aje/kwj364](https://doi.org/10.1093/aje/kwj364) | | Study key | s190 | ## Takeaway Long-term exposure to trihalomethanes (THMs) from chlorinated water, through drinking, showering/bathing, and swimming, is associated with an increased risk of bladder cancer. ## The question Is bladder cancer risk associated with exposure to trihalomethanes (THMs) through ingestion of water, and through inhalation and dermal absorption during showering, bathing, and swimming in pools? ## Hypothesis The authors hypothesized that bladder cancer risk would be associated with exposure to THMs through various routes, including ingestion, inhalation, and dermal absorption. ## Methods A case-control study was conducted in Spain between 1998 and 2001, involving 1,219 bladder cancer cases and 1,271 controls. Lifetime personal information on water consumption and water-related habits was collected and linked with THM levels in geographic study areas. ## Results Long-term THM exposure was associated with a twofold bladder cancer risk, with an odds ratio of 2.10 for average household THM levels of >49 versus 35 micro g/day had an odds ratio of 1.35 compared to not drinking chlorinated water. The odds ratio for duration of shower or bath weighted by residential THM level was 1.83 for the highest compared with the lowest quartile. Swimming in pools was associated with an odds ratio of 1.57. ## Conclusion Bladder cancer risk was associated with long-term exposure to THMs in chlorinated water at levels commonly found in industrialized countries. ## Limitations The abstract does not explicitly state any limitations of the study. ## Verbatim from the abstract > shower or bath weighted by trihalomethane level was associated with increased bladder cancer risk ## Bladder Cancer Risk (Odds Ratio) by THM Exposure Route | Measure | Odds Ratio | | --- | --- | | Household THM levels (>49 vs <=8 micro g/liter) | 2.1 | | Ingestion THM exposure (>35 micro g/day) | 1.35 | | Highest quartile shower/bath duration weighted by THM | 1.83 | | Swimming in pools | 1.57 | *Odds ratios for bladder cancer risk associated with different types and levels of THM exposure.* ## 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 | | --- | --- | --- | | Shower Dechlorination Filter | Emerging evidence | [Shower Dechlorination Filter](https://magellanlongevity.com/p/190.md) | ## Reference 1. **Bladder cancer and exposure to water disinfection by-products through ingestion, bathing, showering, and swimming in pools.** Am J Epidemiol 2006 · [PMID 17079692](https://pubmed.ncbi.nlm.nih.gov/17079692/) · [DOI 10.1093/aje/kwj364](https://doi.org/10.1093/aje/kwj364) > shower or bath weighted by trihalomethane level was associated with increased bladder cancer risk ## Structured data ```json {"@context":"https://schema.org","@graph":[{"@type":"MedicalWebPage","@id":"https://magellanlongevity.com/study/s190.html#page","url":"https://magellanlongevity.com/study/s190.html","name":"Bladder cancer and exposure to water disinfection by-products through ingestion, bathing, showering, and…","description":"Long-term exposure to trihalomethanes (THMs) from chlorinated water, through drinking, showering/bathing, and swimming, is associated with an increased…","inLanguage":"en","isPartOf":{"@type":"WebSite","name":"Magellan Longevity","url":"https://magellanlongevity.com/"},"author":{"@type":"Person","name":"Gabriel Radu, DO","jobTitle":"Physiatrist (PM&R)","identifier":[{"@type":"PropertyValue","name":"NPI","value":"1376861765"},{"@type":"PropertyValue","name":"NY medical license","value":"275110"}]},"publisher":{"@type":"Organization","name":"Magellan Longevity","url":"https://magellanlongevity.com/"},"encoding":{"@type":"MediaObject","encodingFormat":"text/markdown","contentUrl":"https://magellanlongevity.com/study/s190.md"},"dateModified":"2026-09-02"},{"@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://magellanlongevity.com/"},{"@type":"ListItem","position":2,"name":"Research map","item":"https://magellanlongevity.com/longevity-research-map.html"},{"@type":"ListItem","position":3,"name":"Bladder cancer and exposure to water disinfection…","item":"https://magellanlongevity.com/study/s190.html"}]},{"@type":"ScholarlyArticle","@id":"https://magellanlongevity.com/study/s190.html#study","name":"Bladder cancer and exposure to water disinfection by-products through ingestion, bathing, showering, and swimming in pools.","headline":"Bladder cancer and exposure to water disinfection by-products through ingestion, bathing, showering, and…","datePublished":"2006","isPartOf":{"@type":"Periodical","name":"Am J Epidemiol"},"identifier":"PMID:17079692","url":"https://pubmed.ncbi.nlm.nih.gov/17079692/","sameAs":"https://doi.org/10.1093/aje/kwj364","abstract":"Long-term exposure to trihalomethanes (THMs) from chlorinated water, through drinking, showering/bathing, and swimming, is associated with an increased risk of bladder cancer."}]} ``` ## Related on Magellan Longevity - [Shower Dechlorination Filter](https://magellanlongevity.com/p/190.md) — product graded on this and related evidence - [Disinfection By-Products in Drinking Water and Bladder Cancer](https://magellanlongevity.com/study/d35536285.md) - [Disinfection by-products in drinking water and risk of colorectal cancer: a…](https://magellanlongevity.com/study/d37551954.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).