The association between increases in nitrate in drinking water and colorectal cancer incidence rates in California, USA
Menée à partir de données californiennes portant sur 56 631 patients atteints d'un cancer colorectal diagnostiqué entre 2010 et 2015, cette étude analyse l'association entre une exposition à long terme au nitrate contenu dans l'eau potable et le risque de développer la maladie
Purpose: The water resources in California are polluted with nitrate (NO3) due to the ever-increasing application of nitrogen-based fertilizers. Considering the potential connection between NO3 in drinking water and the incidence rate of colorectal cancer, this study aims to investigate the association between long-term exposure to NO3 via drinking water and the incidence of colorectal cancer from 2010 to 2015 in California.
Methods: A total of 56,631 diagnoses of colorectal cancer were recorded from 2010 to 2015. A generalized linear model was used to obtain the risk ratio (RR) and 95% confidence interval associated with a 1 mg/l-NO3 increase in NO3 concentration across five latency periods. The potential effect modification by sex, race/ethnicity, and age (> 40, 41–64, 65–90, and > 90) was explored through stratification.
Results: The association between increases in the concentration of NO3 at lag 0–1, lag 0–5, lag 0–10, lag 0–15, and lag 0–20 (RRs: 1.056 [1.055, 1.058]; 1.066 [1.063, 1.069]; 1.030 [1.028, 1.031]; 1.017 [1.016, 1.018]; 1.035 [1.034, 1.037], respectively) was positively associated with the RR of colorectal cancer. Sex was not found to be a significant modifier. The RRs for Hispanics, Blacks, and other races were greater than those for Whites; the RRs across different age categories were all significantly positive.
Conclusion: This study confirms an association between long-term NO3 exposure in drinking water and the incidence of colorectal cancer in California, emphasizing the need for stringent water quality control and public health strategies to address this risk, particularly in vulnerable populations.
Cancer Causes & Control , article en libre accès 2025