The road from Irkutsk to Lake Baikal crosses the taiga, magnificent, open forestland where in June pine and birch trees rise from a thick multicoloured carpet of flowers. Here and there, however, even in this Siberian wilderness, clusters of yellowed leaves blemish the soft green foliage. Meanwhile, several thousand kilometres away in Athens, Phidias' sculptures in the Parthenon, which had survived 2,000 years of history intact, have been replaced by fibreglass copies after being disfigured by a century of pollution.
Like the Parthenon, the Taj Mahal in India, the Coliseum in Rome and Rheims cathedral in France, the taiga is a victim of what has come to be known as acid rain, caused by emissions of sulphur dioxide and nitrogen oxides from coal-fired power plants and metal foundries, as well as from vehicles and heating systems.
The wind carries these particles over long distances. While the Parthenon sculptures were bound to be victims because they are located in the heart of a city where air pollution is rampant, today even a seeming natural paradise like the Baikal region is affected, graphically demonstrating that our planet is indeed a village. The effects of burning coal with a high sulphur content are not limited to the immediate vicinity in which the coal is burned. Once the smoke-borne pollutants are in the air, they are beyond human control and travel wherever the wind takes them.
Floyd Elder, a Canadian expert on acid rain, notes that the British chemist Robert Angus Smith coined the term more than a century ago. Although the technology at Smith's disposal was rudimentary by today's standards, he demonstrated as early as 1872 that smoke and steam contain substances that cause important changes in the chemical composition of rain. He noted that these changes could be detected not only in the immediate area around the point of emission but also "in the fields, at a great distance from the source." He also discovered some of the harmful effects of acid rain, such as the discolouring of fabrics, the corrosion of metal surfaces, the deterioration of building materials and the withering of plants.
Although the term "acid rain" is evocative, it is often inappropriate: "acid deposits" is more accurate. Drifting air pollutants are deposited not only by rainfall but also by snow, clouds and fog (so-called "wet" deposits), as well as by gases and dust ("dry deposits") during the dry season. Even normal rain is mildly acidic, with a pH that varies between 5.6 and 5.0. (Distilled water has a pH of 7, which is considered neutral. Substances with a pH over 7, such as limewater and ammonia, are alkaline. Those such as wine and lemon juice with a pH under 7 are acidic.)
Despite the early warning given by Robert Smith, industrial countries only began to take acid deposits seriously in the 1950s. In 1953, the Canadian Government launched a programme to study and monitor the water in the lakes of Nova Scotia, where acidity was increasing at an alarming rate. In the 1960s, Scandinavian countries reported that fish populations were declining and that some lakes had even become completely sterile. Trout don't like swimming in vinegar.
In Japan pollution was at its worst after World War II. Between 1946 and 1954, the need to rebuild the country, feed the population and keep factories working called for the use of fertilizers and pesticides, the extraction of raw materials, the burning of fossil fuels, and a dam construction programme. Japan's number one priority was to achieve a high level of development. Pollution would be attended to later. …