Association Between Bladder Cancer and Environmental Risk Factors in Guilan Province: A Case-Control Study

Abstract

Background: Occupational settings expose workers to various substances linked to cancer risk, influenced by exposure intensity and duration. Considering the diverse work conditions across Iranian cities and the unexplored link between occupation and bladder cancer (BC) in Guilan Province, identifying high-risk occupations and industries is imperative for implementing preventive measures in the region. Objectives: To investigate the effect of people's occupations on bladder cancer in Guilan Province. Methods: The study encompassed 266 diagnosed BC patients in Guilan Province who received treatment at local healthcare centers, along with 191 control individuals aged 18 and over. Data for the cases were meticulously recorded in medical records at the Guilan Cancer Registry. The same checklists, including demographic characteristics, comorbidities, addiction status, water consumption habits, environmental exposures, current and previous occupation, previous history of cancer, and family history of cancer, were recorded for the controls. Odds ratios and their 95% confidence intervals were estimated using adjusted logistic regression (LR). Results: The study found that the odds ratio of bladder cancer (BC) was 2.80 (95% CI: 1.26 - 6.21) for the age group 60 - 70 years and 18.2 (95% CI: 7.31 - 45.6) for individuals above 70 years. Rural dwelling increased the risk by 5.06-fold, while well water consumption and regular opium use amplified it by 6.12-fold and 2.58-fold, respectively. Exposure to tar and carbon derivatives led to a 3.53-fold increase in risk, and exposure to combustion/greenhouse gases showed a 10.72-fold increase. Chemical-related occupations, tar, carbon derivatives, smoking, and opium consumption were significant risk factors. Conclusions: Occupations involving chemical substances such as greenhouse gases, tar, and carbon derivatives are associated with a higher risk of bladder cancer (BC). Furthermore, smoking, opium use, and well water consumption significantly elevate the risk of this cancer.