Percy K E, Karnosky D F
Natural Resources Canada, Canadian Forest Service - Atlantic Forestry Centre, 1350 Regent Street, Fredericton, New Brunswick E3B 5P7, Canada.
Environ Pollut. 2007 Oct;149(3):256-67. doi: 10.1016/j.envpol.2007.05.023. Epub 2007 Jul 12.
Natural areas are important interfaces between air quality, the public, science and regulation. In the United States and Canada, national parks received over 315million visits during 2004. Many natural areas have been experiencing decreased visibility, increased ozone (O(3)) levels and elevated nitrogen deposition. Ozone is the most pervasive air pollutant in North American natural areas. There is an extensive scientific literature on O(3) exposure-tree response in chambered environments and, lately, free-air exposure systems. Yet, less is known about O(3) impacts on natural terrestrial ecosystems. To advance scientifically defensible O(3) risk assessment for natural forest areas, species-level measurement endpoints must be socially, economically and ecologically relevant. Exposure-based indices, based on appropriate final endpoints, present an underused opportunity to meet this need. Exposure-plant indices should have a high degree of statistical significance, have high goodness of fit, be biologically plausible and include confidence intervals to define uncertainty. They must be supported by exposure-response functions and be easy to use within an air quality regulation context. Ozone exposure-response indices developed within an ambient air context have great potential for improving risk assessment in natural forest areas and enhancing scientific literacy.
自然区域是空气质量、公众、科学与监管之间的重要交汇点。在美国和加拿大，2004年期间国家公园的游客接待量超过3.15亿人次。许多自然区域的能见度在下降，臭氧（O₃）水平在上升，氮沉降也在增加。臭氧是北美自然区域中最普遍的空气污染物。关于在有隔离设施的环境中以及最近在自由空气暴露系统中臭氧暴露与树木反应的科学文献十分丰富。然而，对于臭氧对自然陆地生态系统的影响却知之甚少。为了推进对天然林区具有科学依据的臭氧风险评估，物种层面的测量终点必须在社会、经济和生态方面具有相关性。基于适当最终终点的基于暴露的指数，为满足这一需求提供了一个未得到充分利用的机会。暴露-植物指数应具有高度的统计显著性、良好的拟合优度、生物学合理性，并包括用于界定不确定性的置信区间。它们必须有暴露-反应函数的支持，并且在空气质量监管背景下易于使用。在环境空气背景下制定的臭氧暴露-反应指数在改善天然林区风险评估和提高科学素养方面具有巨大潜力。
