Chemical contaminants in swimming pools: Occurrence and health risk assessment

Abstract

A wide variety of chemical substances may be present as trace contaminants in swimming pools. These include chemicals which may be formed as by-products of swimming pool disinfection processes, as well as chemicals, which may be derived from bathers, such as from bodily excretions or wash-off of cosmetics or lotions. In other circumstances, chemicals may have been present in the fill water used to fill swimming pools, or may be leached from bathing equipment such as flotation devices. Bathers may be exposed to trace chemical contaminants in swimming pools via a variety of exposure routes including accidental ingestion, inhalation and dermal absorption. However, the range of chemicals present, their concentrations and potential levels of exposure have scarcely been investigated.

The aim of this research was to investigate the concentrations of anthropogenically-derived chemicals in swimming pools and to provide a risk assessment corresponding to the chemicals detected. Various types of swimming pools were analysed including indoor pools, outdoor pools, spa pools and seawater pools.

Swimming pool water samples were analysed for 30 pharmaceuticals and personal care products and 7 N-nitrosamines. Caffeine, ibuprofen and three N-nitrosamines were detected in swimming pool water samples. Daily monitoring of caffeine revealed high variations throughout the day roughly reflecting bather loads.

A rapid and reliable analytical method was developed for the analysis of five organophosphate flame retardants (PFRs) in water using isotope dilution gas chromatography tandem mass spectrometry. The method was applied to investigate the occurrence and source of PFRs in swimming pools. Laboratory experiments were carried out to investigate the potential leaching of PFRs from commonly used swimming equipment to identify the sources of PFRs in swimming pools.

A quantitative risk assessment revealed that exposure health risk to these chemicals via swimming pools were generally very low and below commonly applied health risk benchmarks.

The potential application of fluorescence as an online monitoring tool in swimming pools was assessed by investigating the relationships between fluorescence signals at various excitation and emission wavelengths and changes in water quality over time.