The use of XAD-resins for the detection of mutagenic activity in water: II. Studies with drinking water

The combined XAD-4/8-Ames test procedure for concentrating and detecting trace amounts of organic mutagens, as already described for surface water, is shown to be suitable for drinking water as well. DMSO is as effective as acetone in eluting the adsorbed mutagens, and optimal recovery of overall mutagenic activity is observed at a flow rate of 2–4 bed volumes/min. The drinking water of 6 cities in The Netherlands, which prepare their drinking water from the rivers Rhine and Meuse, has been tested for mutagenic activity. Mutagenic activity could be demonstrated in 4 cities. Dose-related responses are observed with concentrates of as little as 500 ml of drinking water and the 4 cities clearly differ with regard to the type of mutations induced (TA 98 or TA 100) and the effect of metabolic activation. The absence of mutagenic activity in drinking water of 2 cities indicates that by a proper combination of treatment processes the organics which are responsible for the detected mutagenic activity in drinking water can be removed to a high degree.