Mutagenic activity in the River Meuse in Belgium.

Frameshift mutagens have been detected in the river Meuse downstream of Liège In most cases, mutagenic activity could only be demonstrated afte metabolic activation. The effect was inversely related to river flow. The most important sewage outfalls and industrial discharges in the area were controlled on mutagenic activity. Two effluents, both discharging cokes-oven effluents, were found to contain high quantities of frameshift mutagens. The effluents were split up in neutral, acidic and basic fractions. Only neutral and basic fractions showed mutagenic activity. They were further separated in subfractions by gel chromatography and adsorption chromatography. The mutagenic activity was shown to be present in subfractions containing polynuclear aromatic hydrocarbons and aza-arenes. Mutagenic activity in river water samples could only be located in the polynuclear aromatic hydrocarbon fractions.