THE ANALYSIS AND OCCURRENCE OF HALOGENATED ALDEHYDES IN DRINKING WATER
Report No FR0377
P J Tynan, D O Lunt and G O'Neill
Information on the likely occurrence of chloroaldehydes in chlorinated drinking water.
Chlorinated aldehydes have been identified as by-products of the chlorination of humic acid solutions and have been detected in chlorinated pulp mill effluent. It was found that these compounds accounted for a major part of the mutagenicity in these samples. There is concern that chlorination of raw water, during drinking water treatment, may result in the formation of chloroaldehydes and that this may pose a potential risk to human health.
The PFBOA method, commonly used for the analysis of non-halogenated aldehydes, was found to be unsuitable for the analysis of chlorinated aldehydes in water. GC-MS was selected as a suitable alternative technique.
No chlorinated aldehydes were detected in any of the chlorinated water samples. These samples included humic acid solutions, chlorinated under a variety of conditions, chlorinated surface water and treated water.
Chlorinated propanones were detected in most of the chlorinated samples.
Chlorinated aldehydes are unlikely to be produced at significant levels during drinking water treatment. Chlorinated ketones may be formed and be present in drinking water. There are less toxicological data on the halogenated ketones and it could not be determined how significant they are as a threat to human health.
Further work should be carried out on the toxicology of chlorinated ketones. More widespread monitoring should be undertaken before the formation of chlorinated aldehydes can be completely discounted.
This report presents the work carried out on the assessment of analytical methods for determining halogenated aldehydes in water, and provides information on their toxicity and likely formation from the chlorination of drinking water.
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