P1080 - Heavy Metals in Surface and Ground Water Predict New-Onset Inflammatory Bowel Disease: A Geospatial Case-Control Study Using Open Environmental Data and Electronic Health Records

Mao-Yuan Chen, MD, Aryan Ayati, MD, MPH, Anshu Mukherjee, , Goktug Onal, , Vivek Rudrapatna, MD, PhD
University of California San Francisco, San Francisco, CA

Introduction: Exposure to lead or mercury has been associated with developing inflammatory bowel disease (IBD), but the role of heavy metals (HM) more broadly has not been as well studied. The growth of public data on environmental exposures has enabled new epidemiological studies via linkage to health records at the level of residential zip codes.

Methods: A total of 10,905 Crohn’s disease (CD, ICD-9: 555; ICD-10: K50) and 13,139 ulcerative colitis (UC, ICD-9: 556; ICD-10: K51) cases diagnosed between 1990 and 2023 were extracted from the UCSF data warehouse, which were matched by sex at a 1:10 ratio to 240,440 patients without any ICD code for IBD. Surface and ground water HM concentrations were queried from the California Department of Water Resources and mapped to patient data using the reciprocal of the great-circle distance between water stations and the centroids of patient residential zip codes. A saturated multivariable logistic regression model was used to examine the HM effects.

Results: Only 0.35–3.35% of patients resided in zip codes where lead, mercury, arsenic, and cadmium concentration in surface and ground water exceeded the maximum contaminant level (MCL) defined for drinking water by the Environmental Protection Agency, while 95% resided in zip codes where aluminum was above National Secondary Drinking Water Regulations (Table). Both UC and CD patients had higher odds of residing where lead (odds ratio [OR]: 1.30, 95% confidence interval [CI]: 1.20–1.41) or arsenic (OR: 3.23, 95% CI: 2.68–3.88) were above MCL but lower odds for aluminum (OR: 0.69, 95% CI: 0.66–0.73) or cadmium (OR: 0.63, 95% CI: 0.54–0.74) compared with controls.

Discussion: Lead and arsenic exposure predict IBD, whereas aluminum and cadmium exposure predict a reduced risk. Additional epidemiologic validation from other centers and countries, together with mechanistic studies, can further test the hypothesis that heavy metal exposures explain the rising global incidence of IBD.


Figure: Table. Heavy metal concentrations between IBD patients and control patients. Data are presented as median (first quartile, third quartile) or estimate (95% confidence interval lower limit–upper limit). 1Normal limits for heavy metals (except aluminum) were defined as the maximum contaminant level (MCL) in drinking water regulated by the National Primary Drinking Water Regulations. Aluminum is regulated by the National Secondary Drinking Water Regulations (NSDWR); the upper limit was reported. 2OR was calculated with a saturated logistic regression model. OR greater than 1 favors the occurrence of IBD. Abbreviations: CD, Crohn’s disease; MCL, maximum contaminant limit; NSDWR, National Secondary Drinking Water Regulations; OR, odds ratio; UC, ulcerative colitis; IBD, inflammatory bowel disease.

Disclosures:
Mao-Yuan Chen indicated no relevant financial relationships.
Aryan Ayati indicated no relevant financial relationships.
Anshu Mukherjee indicated no relevant financial relationships.
Goktug Onal indicated no relevant financial relationships.
Vivek Rudrapatna: Acucare – Advisory Committee/Board Member. Blueprint Medicines – Grant/Research Support. Data Unite – Advisory Committee/Board Member. Genentech – Grant/Research Support. Ironwood – Payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events. Merck – Grant/Research Support. Microsoft – Grant/Research Support. Mitsubishi Tanabe – Grant/Research Support. Natera – Payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events. Stryker – Grant/Research Support. Takeda – Grant/Research Support. ZebraMD – Advisory Committee/Board Member.

Mao-Yuan Chen, MD, Aryan Ayati, MD, MPH, Anshu Mukherjee, , Goktug Onal, , Vivek Rudrapatna, MD, PhD. P1080 - Heavy Metals in Surface and Ground Water Predict New-Onset Inflammatory Bowel Disease: A Geospatial Case-Control Study Using Open Environmental Data and Electronic Health Records, ACG 2025 Annual Scientific Meeting Abstracts. Phoenix, AZ: American College of Gastroenterology.