摘要
临界负荷概念已成公认的制定减少区域空气污染控制措施的理论依据。根据一鱼类受危害情况的逻辑回归模型,由1986年挪威"千湖调查"数据推导出鱼群落受危害概率的剂量-反应超临界负荷量函数。由鱼类危害数据库(鳟鱼、北极红点鲑和河鲈)以及挪威国家临界负荷量数据库所得的相应函数与我们所推导的剂量-反应函数相比较,非常吻合。当临界负荷不超标时,鱼类种群受到危害的概率很小;当临界负荷量超标时,危害的机率随着超量的数量增大而增加。在临界负荷时,鱼类种群受到危害的概率约为20。这些结果证实临界负荷概念确实是估测长期空气污染对生物所造成的危害程度的一种十分有效手段,基于这种方法的预测能够可靠地估测将来在酸沉降的情况下,鱼类受到危害程度。
The concept of critical loads has been widely accepted as a basis for designing control strategies to reduce regional air pollution. Data from the '1000 lake survey' carried out in Norway in 1986 were used to derive a dose-response function for the probability of damage to fish populations as a function of the critical load exceedance, by means of a logistic regression model for fish damage. A corresponding function based on a fish damage database (brown trout, arctic char, and perch) and the national critical load database for Norway compared well with the derived dose-response function. When the critical load is not exceeded there is only a very small probability that the fish population will be damaged, but when the critical load is exceeded the chance of damage increases with the amount of exceedance. At critical load the probability of damage to fish populations is about 20. These results confirm that the critical load concept is a strong tool for estimating the extent of biological damage caused by long-range transported air pollution, and that prognoses based on this method can give reliable estimates of the extent of fish damage under future scenarios of acidic deposition.
