Gilli G, Bono R, Scursatone E, Carraro E
Ann Ig. 1989 May-Aug;1(3-4):789-801.
In the last years the interest about acid depositions has been shifted to heterogeneous phase reactions and, particularly, to occult precipitations (fog, mist, ecc.). It is very improbable that some kind of human health hazards could derive from acid rain exposure. Instead, the human exposure to acid fog could represent a possible respiratory vehicle for the assumption of acid pollutants as well as of many other pollutants. This last assertion can be supported by the following considerations: 1) Fog may represent an important chemical reactor that can modify the nature of pollutant material in the atmosphere (acidification and other events). 2) Fog is formed near the ground where pollution sources are located so that pollution is the heaviest. The fog water droplets coalesce around preexisting aerosol which is most highly concentrated near the ground (cities and industrial areas). Since fog water droplets contain muc less water than rain drops, they do not dilute the acidity as much as rain. 3) Finally, fog is partially inhalable. In certain areas of the world, wet deposition by fog can be important to the human health, even if the acqueous concentrations of fog droplets, the acidity per volume of air and the acid deposition rate are all important factors to consider. Particularly the pH of fog does not tell the whole story, but it represents a sufficient information about the severity of the atmospheric situation that can be correlated to seriousness of human risk.
在过去几年中，人们对酸沉降的关注已转向非均相反应，尤其是隐匿性降水（雾、霭等）。酸雨暴露导致某种人类健康危害的可能性极小。相反，人类接触酸雾可能成为吸入酸性污染物以及许多其他污染物的一种途径。这一论断可通过以下几点来支持：1）雾可能是一个重要的化学反应器，能够改变大气中污染物的性质（酸化及其他过程）。2）雾在污染源所在的近地面形成，因此污染最为严重。雾滴在预先存在的气溶胶周围凝聚，而气溶胶在近地面（城市和工业区）浓度最高。由于雾滴所含水分远少于雨滴，它们对酸度的稀释程度不如雨。3）最后，雾有一部分是可吸入的。在世界某些地区，雾的湿沉降对人类健康可能很重要，即便雾滴的水溶液浓度、每单位体积空气中的酸度以及酸沉降速率都是需要考虑的重要因素。特别是雾的pH值并不能说明全部情况，但它代表了有关大气状况严重程度的充分信息，而这种严重程度可与人类风险的严重性相关联。
