Nitrosamine carcinogens also swim in chlorinated pools

Area of Science:

• Environmental Chemistry
• Public Health
• Toxicology

Background:

• Chlorinated recreational waters can form disinfection byproducts.
• Nitrosamines are a class of highly carcinogenic compounds.
• Previous studies have not fully quantified nitrosamine levels in various recreational water settings.

Purpose of the Study:

• To quantify N-nitrosodialkylamines (nitrosamines) in chlorinated swimming pools, hot tubs, and aquaria.
• To identify factors influencing nitrosamine occurrence and variability.
• To assess the health implications of detected nitrosamine levels in relation to cancer risk.

Main Methods:

• Quantification of nitrosamines using analytical chemistry techniques.
• Statistical analysis to determine the impact of environmental factors (temperature, enclosure, precursors, chlorine dose) on nitrosamine levels.
• Comparison of detected levels with established safe drinking water standards.

Main Results:

• N-Nitrosodimethylamine was the most abundant nitrosamine detected, with levels up to 500-fold greater than safe drinking water limits.
• Temperature, enclosure, amine/nitrite precursors, and reduced chlorine doses significantly affected nitrosamine occurrence.
• Other nitrosamines like N-Nitrosodibutylamine and N-nitrosopiperidine were present at lower concentrations (<5%).
• N-nitrodimethylamine was detected at levels comparable to N-nitrosodimethylamine, suggesting competing reaction pathways.

Conclusions:

• Chlorinated recreational waters contain high levels of carcinogenic nitrosamines, posing a significant public health concern.
• Environmental factors play a crucial role in the formation and concentration of these disinfection byproducts.
• Further research is needed to clarify the link between swimming in chlorinated pools and bladder cancer, given the detected nitrosamine levels.