During the summer and fall of 1984 and 1985, the eutrophic Lake Akersvatn in south-eastern Norway, used as reserve drinking water reservoir, was found to produce heavy water-blooms of the colonial blue-green alga Microcystis aeruginosa. Samples of the water-bloom were found to be toxic using the mouse bioassay. No toxin was found free in the water as detected by HPLC and mouse bioassay. The toxic cells (minimum lethal dose 8-15 mg/kg body weight in mice) and purified toxin (minimum lethal dose 50 µg/kg body weight in mice) showed signs of poisoning in laboratory rats and mice identical to that of other hepatotoxin-producing

No abstract

The emission of particles and organic micropollutants (PAH, PCDD and PCDF) was measured from three intermittently operated municipal waste incinerators of medium size. The mutagenicity of the stack gas samples were measured as well. The results show a good agreement between the PAH emitted and the mutagenicity in the stack gases, but none of these parameters correlate with the PCDD/PCDF content.

Acetone-extracted samples of airborne particulate matter collected in three restaurants were analysed for their content of polynuclear aromatic hydrocarbons (PAH) and related polynuclear aromatic compounds (PAC) as well as for genotoxic activity using the Salmonella/microsome assay (strains TA98 and TA100) and sister chromatid exchange (SCE) induction in Chinese hamster ovary (CHO) cell cultures. The total particulate matter varied considerably in the restaurants, being 1.37 mg/m3 at the highest; in the same restaurant the highest amount of total PAHs (168 ng/m3) was also detected. Altogether, 13-22 individual PACs were identified in the samples, ranging from phenanthrene to benzothionaphthene. All of the six samples caused significant increases both in bacterial revertant and SCE frequencies. In the Salmonella assay, the mutagenic activity detected was primarily with metabolic activation. However, in the CHO cell cultures the induction of SCEs was also seen without an exogenous metabolic activation system. The cytotoxicity of the extracts limited the concentration range tested in the SCE assay. Only a partial correspondence of the total PAH content with the genotoxic activity of the samples was found. The genotoxicity of restaurant air exceeded by one to two orders of magnitude the previously reported activities detected by similar methods in urban outdoor and indoor air samples.

No abstract