2005 – 2009
„Integrated Risk Assessment for the new Generation of Disinfection By-products“, Sub-project 1: “Formation of Disinfection By-products (DBP) in Swimming Pool Water - Identification of the Formation and Risk Assessment” (DNP)
| Contact: | Fritz H. Frimmel, | ||
|---|---|---|---|
| Project Group: | Joint Research Project | ||
| Funding: | |||
Period
Description
Project:
„Integrated Risk Assessment for the new Generation of Disinfection By-products“
Sub-project 1:
“Formation of Disinfection By-products (DBP) in Swimming Pool Water - Identification of the Formation and Risk Assessment”
(DNP - POOL II)
This project is performed in collaboration with the group of Dr. Tamara Grummt (German Federal Environmental Agency, Bad Elster) and is characterized by the close interaction between chemical analysis and toxicological evaluation.
Systematic analysis of DBPs should improve the data basis of the occurring compound pattern and exposure. With modern analysis methods (coupled chromatographic and mass spectrometric methods) a chemical classification by common functional groups is performed. The results are closely connected to toxicological effect by the structure-effect-relationship. The aim is quantitative risk assessment under consideration of the most relevant modes of action and exposure pathways. Finally the risk for bathers will be assessed and technical regulatory measures proposed to minimize DBP formation.
Disinfection of the circulated swimming pool water after flocculation and filtration is very important for the hygienic safety of bathers to prevent diseases from microorganisms. The used disinfectants can also react with constituents of the filling water and of the bather load forming unwanted and partly toxic disinfection by products. Among the well-known trihalogenmethanes, numerous other DBPs like haloacetic acids, carbonyl compounds, chlorinated nitriles or the strong mutagenic compound MX were analysed in SPW [1]. Those toxic and genotoxic compounds have to be identified, monitored and minimized.
Recent epidemiological studies [2,3] show a positive correlation between regularly visits of indoor pools and childhood asthma. Therefore the focus is on volatile DBPs which possibly could be accumulated in the indoor air. Trichloramine is a highly volatile, irritating and odorous compound and has raised concern to have adverse effects on the respiratory tract, having a possible role in developing asthma. In this project the main trichloramine-precursor compounds are analysed. Urea is suspected as a major precursor of NCl3 and introduced to the pool water by bathers in relatively high amounts. It furthermore is only scarcely removed in the treatment cycle. The reaction scheme in figure 1 shows the formation of NCl3 from the chlorination of urea [4]:
Figure 1: Formation of NCl3 from the chlorination of urea [4]
Literature:
[1] C. Zwiener, S.D. Richardson, D.M. DeMarini, T. Grummt, T. Glauner, F.H. Frimmel:
Drowning in disinfection by-products? - Assessing swimming pool water – Critical review.
Environ. Sci. Technol. 41 (2007) 363.
[2] A. Bernard, S. Carbonnelle, S. Burbure, O. Michel, M. Nickmilder:
Chlorinated pool attendance, atopy and the risk of asthma during childhood.
Environ. Health Perspec. 114 (2006) 1567.
[3] Bernard et al:
Lung hyperpermeability and asthma prevalence in schoolchildren: unexpected associations with the attendance at indoor chlorinated swimming pools.
Occup. Environ. Med. 60 (2003) 385.
[4] E. Stottmeister, K. Voigt:
Trichloramin in der Hallenbadluft.
A.B.Arch.Badew. 3 (2006) 158.
