Tradescantia micronucleus test indicates genotoxic potential of traffic emissions in European cities.

Urban atmospheres contain complex mixtures of air pollutants including mutagenic and carcinogenic substances such as benzene, diesel soot, heavy metals and polycyclic aromatic hydrocarbons. In the frame of a European network for the assessment of air quality by the use of bioindicator plants, the Tradescantia micronucleus (Trad-MCN) test was applied to examine the genotoxicity of urban air pollution. Cuttings of Tradescantia clone #4430 were exposed to ambient air at 65 monitoring sites in 10 conurbations employing a standardised methodology. The tests revealed an elevated genotoxic potential mainly at those urban sites which were exposed to severe car traffic emissions. This bioassay proved to be a suitable tool to detect local 'hot spots' of mutagenic air pollution in urban areas. For its use in routine monitoring programmes, however, further standardisation of cultivation and exposure techniques is recommended in order to reduce the variability of results due to varying environmental conditions.

Air pollution impact on the Atlantic forest in the Cubatäo region, SP, Brazil

The rain forest covering the slopes of the Serra do Mar mountains, in the vicinity of Cubatão, SP, has been damaged by a variety of air pollutants emitted by the industrial complex established in the region. In a study by the Instituto de Botânica (São Paulo) and the Universities of Essen and Kassel (Germany) sensitive and cumulative indicator plants were explosed to the environment in an active biomonitoring program, in order to get information on the current air pollution situation and on the spatial and temporal distribution of air pollutants in the region, draw conclusions on the causes of vegetation damage, and facilitate risk prognosis. Native plant species, indigenous to the ecosystem were also studied (passive biomonitoring), in order to evaluate the present state of the vegetation, the effects of air pollution on plant vitality and detect mechanisms of pollution resistance. Both kinds of biomonitoring were performed in four sites: Pilões river valley, Caminho do Mar, Mogi river valley and Paranapiacaba, which are located at different altitudes, at various distances from pollution sources and consequently receive different kinds and loads of air pollution. Based on our results, fluorides, sulfur and metals are considered the main causes of the forest decline at the Mogi valley, whereas ozone. PAN and sulfur are implicated at Caminho do Mar. Native tree species show several chemical and biochemical alterations caused by the air pollution impact, that give information on their resistance or sensitivity to air pollution.