Impact of air pollution on the forests of Central and Eastern Europe.

AbstractOver the past 50 yr, there has been an unprecedented deterioration of the environment of Central and Eastern European (CEE) countries. Air pollutants from fossil fuel combustion and heavy industry threaten productivity and in some places the future survival of forests. Political changes at the end of the 1980s were followed by economic transformations and significant declines in pollutant emissions. The decline in emissions was particularly noticeable (more than 50% in some countries) for sulfur dioxide. However, reductions in the atmospheric concentrations of toxic gases have not eliminated local and regional forest declines or the existence of pollution 'hot spots' with average daily concentrations of SO2 up to 1000 µg m-3. Changes in defoliation levels have not followed reductions in pollutant emissions and remain high throughout the region. Imbalanced nutrition is an important factor affecting tree health and reducing the resistance of forest ecosystems to combinations of other stresses. The reasons for the lack of a direct relationship between regional pollution loads and tree crown condition are uncertain and need further investigation. A new type of intensive monitoring (UN-ECE level II) should provide regional information about the ecological risks facing forest ecosystems, and should also lead to recommendations for forest management in areas impacted by air pollution. In Belarus, the Russian Federation and Ukraine, over 3.5 million hectares of forests were affected by the Chernobyl nuclear disaster, resulting in the withdrawal of the wood and secondary products from the market and up to 10 times higher than normal costs of forest operations.</p

Coréia familiar benigna: relato de dois casos

São apresentados dois casos (irmãs) de coréia familiar benigna. O estudo do heredograma mostra padrão compatível a herança autossômica dominante com penetrância incompleta. Discute-se o diagnóstico diferencial dessa doença e faz-se breve revisão da literatura