Chlorinated drinking water and micronuclei in urinary bladder epithelial cells

Area of Science:

• Environmental Health
• Toxicology
• Cancer Epidemiology

Background:

• The link between disinfection byproducts (DBPs) in chlorinated water and cancer risk remains unclear.
• This research examines the association between DBPs, specifically trihalomethanes (THMs), and genotoxicity in bladder cells.
• Assessing genotoxic potential is crucial for understanding cancer risks associated with water disinfection.

Purpose of the Study:

• To investigate the relationship between exposure to disinfection byproducts in chlorinated water and DNA damage in urinary bladder epithelial cells.
• To evaluate the carcinogenic potential of DBPs by measuring micronuclei frequency as a biomarker of genotoxicity.
• To assess the association using both available dose and intake dose of total trihalomethanes.

Main Methods:

• A cohort study was conducted in 3 Australian communities with varying DBP levels.
• Exposure to total trihalomethanes (THMs) was assessed via available dose and intake dose.
• Micronuclei in urinary bladder epithelial cells served as a preclinical biomarker for genotoxicity.

Main Results:

• Micronuclei were scored for 228 participants; 63% were exposed to DBPs.
• Available THM dose ranged from 38-157 µg/L; intake dose ranged from 3-469 µg/kg/day.
• No significant association was found between THM levels (available or intake dose) and DNA damage in bladder cells for smokers or nonsmokers.

Conclusions:

• The study found no evidence linking trihalomethane concentrations at investigated levels to DNA damage in bladder cells.
• Current levels of DBPs in the studied water supplies do not appear to pose a genotoxic risk.
• Further research may be needed to explore potential long-term effects or effects at higher exposure levels.