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Testern Amesa stwierdzono mutagenne działanie zanieczyszczeń zaadsorbowanych na pyle zawieszonym w atmosferze pobranym w różnych punktach Wrocławia latem i zimą. Objętość zanieczyszczonego pyłem powietrza wywołująca efekt mutagenny wobec szczepu Salmonella typhimurium TA 98 bez aktywacji frakcją S9 wykazywała zależność od stężeń pyłu zawieszonego (współczynnik korelacji - 0,35), związków organicznych zaadsorbowanych na pyle (współczynnik korelacji - 0,58), WWA z listy EPA (współczynnik korelacji - 0,52) i benzo(a)pirenu (współczynnik korelacji - 0,52).
Stwierdzono aktywność mutagenną zanieczyszczeń organicznych zaadsorbowanych na pyle zawieszonym w powietrzu atmosferycznym w centrum Wrocławia. Badania prowadzono przy użyciu testu Amesa. W okresie zimowym działanie mutagenne wykazywały frakcje węglowodorów aromatycznych oraz związki polarne. Frakcja węglowodorów alifatycznych nie wykazywała działania mutagennego. Latem działanie mutagenne wykazywała frakcja związków polarnych, działania mutagennego nie wykazywały węglowodory alifatyczne i aromatyczne.
In the 1988/1989 and 1989/1990 seasons, the winter grouping of corvids in the city of Wrocław (Lower Silesia, Poland) included 200,000-250,000 individuals, of which 92-94% were Rooks, 6-8% Jackdaws Corvus monedula and about 0.1% Hooded Crows Corvus corone cornix. Young Rooks made up 5-6% of the population. Numbers were estimated by counting flocks during their flights to the roosts. Rooks wintering in Wrocław nest on the Russian Plain, but probably also include a small number of birds grom the dty itself. In the course of the last 30 years, the size of the grouping of corvids has increased 10-fold, with numbers of Rooks increasing 20-fold and numbers of Jackdaws increasing by up to a half. Mean mortality of Rooks at the roosts was 0.74 individuals per night i e. 0.3%₀ of the whole population per wintering season. Of the birds dying, one-third were young. Corvids roosted in several roosts which were used to different extents. At least two were used regularly as primary roosts and the oldest roost had been used for over 40 years. Corvids foraged within 15-20 km of the roosts. Flights between the roosts and the foraging areas followed regular, permanent air corridors, according to a permanent scheme of gathering in places which were stages in the flight. The Rooks kept quiet at the roosts and during their flights. They foraged by actively seeking out food and by passively waiting for food to be thrown out by people. Their behaviour was wary.
The aim of our study was to compare the efficacy of extraction of genotoxic pollutants from soils performed by means of several solvents. Soil pollutants were extracted in the Soxhlet apparatus. Extract genotoxicity was assessed using the Ames Test. All the examined soils (12) contained genotoxic pollutants. Extraction with hexane allowed detection of pollution genotoxicity in 11 soils, whereas with methanol and dichloromethane in 10 soils each. The other solvents allowed detection of genotoxicity in fewer soil samples. Methanol extract had the highest genotoxicity in the majority of soils (7 out of 12). Results obtained in the present study and literature data allow recommendation of methanol for extraction of genotoxic pollutants from soils. Methanol is more versatile, efficient, common, and less harmful for laboratory workers than dichloromethane and hexane.
Rooks show a growing tendency to winter in cities. The aim of this study was to determine the influence of meteorological factors on the selection of feeding habitats and to discuss the diversity of feeding strategies in urban environments of different sizes and housing densities. The study was carried out in two cities in south-western Poland, Wrocław and Brzeg (populations of 636,000 and 39,000, respectively), in the years 2004–2008. Nineteen research areas differing in housing density were controlled once a week. In multiple regression, the number of rooks feeding in urban environments showed a correlation with air temperature and the thickness of snow cover. The densities of feeding rooks were higher in urban environments than in agrocenoses. They were also higher in Wrocław than in Brzeg, and in built-up areas than in undeveloped ones. Feeding groups were smaller in Brzeg than in Wrocław. They were also smaller in built-up areas in Brzeg than in undeveloped ones. More rooks fed individually in Brzeg than in Wrocław. The diversity in the frequency of individually feeding rooks in built-up and undeveloped environments was specific to each city. Rooks feeding in Brzeg were more active in searching for food than those in Wrocław, and birds feeding on optimum, undeveloped feeding grounds were more active than those in built-up areas . In both cities, rooks were fed by humans, mainly in built-up areas.
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