Acid Rain — Gone?

Abstract

The term acid rain denotes one of the most serious environmental problems we have dealt with, the acidification of our environment. Remarkably, a treatise on acid rain was published in England in 1872 by Robert Angus Smith. In his 1872 book, “Air and Rain: The Beginning of a Chemical Climatology,” he noted three types of areas as one moved from the city to the surrounding countryside: “that with carbonate of ammonia in the fields at a distance, that with sulphate of ammonia in the suburbs and that with sulphuric acid or acid sulphate, in the town.” In the 1840s Smith was in Germany, as a student of Justus von Liebig, who was probably the first who mentioned the chemical interaction between the atmosphere and the biosphere (Liebig 1843). I think Smith achieved a more distinguished idea establishing the term Chemical Climatology than linking Air and Rain. However, for about l00 years air chemistry had been limited almost only to precipitation chemistry, despite the known fact that the chemical composition of rainwater is a result of chemical processes which occur both in the rainwater and external to it (Drischel 1940). The 1944 vegetation injury in the Los Angeles County (Middleton et al. 1952) and the 1952 London air pollution incident (Wilkins 1954) finally initiated an extensive study of chemical processes in the atmosphere. Since then, these episodes, representing different types of air pollution, have been dubbed London (sulphurous) smog and Los Angeles (photochemical) smog.