摘要
本文评论了酸雨和其他空气中毒素研究中出现的一些问题。长期的酸雨消耗了许多地方土壤中的盐基阳离子,并使湖泊不能完全从中恢复。气候变暖和干旱所引起流域中硝酸沉降增加和硫的复氧化同样阻碍了湖泊的恢复。气候变暖、干旱和湖泊酸化也导致湖泊中有色有机物浓度的下降,结果其对常见太阳辐射的衰减下降,使得水生群落在UV中的暴露程度大大增加。包括气候变暖、UV辐射加大、挥发性受温度的控制以及污染物在寒冷地区凝结等在内的诸多因素均有利于有机氯污染物和汞从温暖地区向高海拔和高纬度地区迁移。在高海拔区域,污染物通过食物链生物放大,对当地居民构成了巨大的威胁。
Emerging problems with acid rain and other airborne toxins are reviewed. Long-term acid precipitation has depleted base cations in soils of many areas, so that complete recovery of lakes cannot occu r. Increased deposition of nitric acid and reoxidiation of sulfur in catchments as the result of climate warming and drought also inhibit lake recovery. Climate warming, drought, and lake acidification also cause decreased concentrations of colored organic matter in lakes. The resulting decrease in attenuation of incident solar radiation greatly increases the exposure of aquatic communities to UV radiation. Several factors including climate warming, increased UV, temperature-dependent volatility, and greater condensation in cold regions appear to be enhancing the movement of organochlorine pollutants and mercury from warm regions to high altitudes and latitudes. At high latitudes, biomagnification in food chains poses a significant threat to indigenous people.
