While industrialization is an essential feature of economic growth in developing countries, industrial practices may also produce adverse environmental health consequences through the release of air and water pollutants and the disposal of hazardous wastes. This is often the case in developing countries, where less attention is paid to environmental protection, environmental standards are often inappropriate or not effectively implemented, and pollution control techniques are not yet fully developed. With rapid economic development, many developing countries, like China and other Asian countries, face some additional environmental problems. One is the environmental pollution from hazardous industries or technologies transferred from developed countries, which are no longer acceptable for occupational and environmental health reasons in developed countries, but still allowable in developing countries due to looser environmental legislation. Another problem is the rapid proliferation of informal small-scale enterprises in townships as well as in rural areas, which often create serious air and water pollution because of lack of sufficient knowledge and funds.
Air pollution in developing countries is derived not only from stack emission of pollutants from relatively large industries, like iron and steel, non-ferrous metals and petroleum products industries, but also from fugitive emission of pollutants from small-scale factories, such as cement mills, lead refineries, chemical fertilizer and pesticide factories and so on, where inadequate pollution control measures exist and pollutants are allowed to escape to the atmosphere.
Since industrial activities always involve energy generation, the combustion of fossil fuels is a main source of air pollution in the developing countries, where coal is widely used not only for industrial, but also for domestic consumption. For instance, in China, more than 70% of total energy consumption relies on direct coal combustion, from which large amounts of pollutants (suspended particulates, sulphur dioxide, etc.) are emitted under incomplete combustion and inadequate emission controls.
The kinds of air pollutants emitted vary from industry to industry. The concentrations of different pollutants in the atmosphere also vary widely from process to process, and from place to place with different geographic and climatic conditions. It is difficult to estimate specific exposure levels of various pollutants from different industries to the general population in developing countries, as elsewhere. In general, the workplace exposure levels are much higher than that of the general population, because the emissions are rapidly diluted and dispersed by the wind. But the exposure duration of the general population is much longer than that of workers.
The exposure levels of the general population in developing countries are usually higher than that in developed countries, where air pollution is more strictly controlled and resident areas are usually far from industries. As discussed further on in this chapter, a large number of epidemiological studies have already showed the close association of reduction in pulmonary function and increased incidence of chronic respiratory diseases among residents with long-term exposure to the common air pollutants.
A case study of air pollution effects on the health of 480 primary school children in Cubatao, Brazil, where large quantities of mixed pollutants were emitted from 23 industries (steel mill, chemical industries, cement factory, fertilizer plants, etc.), showed that 55.3% of the children had decreases in pulmonary function. Another example of health effects of air pollution appeared in the Ulsan/Onsan special industrial zone, Republic of Korea, where many large-scale plants (mainly petrochemical plants and metal refineries) are concentrated. Local residents complained of a variety of health problems, particularly of the nervous system disorder called “Onsan Disease”.
Accidental releases of toxic substances into the atmosphere resulting in serious health risks are usually more common in developing countries. The reasons include inadequate safety planning, lack of skilled technical personnel to maintain proper facilities, and difficulties in obtaining spare parts and so on. One of the worst of such accidents occurred in Bhopal, India, in 1984, where leaking methyl isocyanide killed 2,000 people.
Water and Soil Pollution
Inappropriate and often careless disposal of industrial wastes—uncontrolled discharge into watercourses and uncontrolled disposal on the land, which often causes water and soil pollution—is another crucial environmental health problem, in addition to industrial air pollution, in developing countries, particularly with numerous small-scale township enterprises, like those in China. Some small-scale factories, such as textile dyeing, pulp and paper, leather tanning, electroplating, fluorescent lamp, lead battery and metal smelting, always produce a large amount of wastes, containing toxic or hazardous substances like chromium, mercury, lead, cyanide and so on, which may pollute the rivers, streams and lakes, and soil as well, when they are untreated. The soil pollution in turn may contaminate groundwater resources.
In Karachi, the Lyan river, which runs through the city, has become an open drain of sewage and untreated industrial effluent from some 300 large and small industries. There is a similar case in Shanghai. Some 3.4 million cubic metres of industrial and domestic waste pour into Suzhou creek and Huangpu river, which flow through the heart of the city. Because of serious pollution, the river and creek have essentially become devoid of life and often produce smells and sights that are unpleasant and offensive to the public living in the surrounding area.
A further problem of water and soil pollution in developing countries is the transfer of toxic or hazardous wastes from developed to developing countries. The cost of transporting these wastes to simple storage sites in developing countries is a mere fraction of the cost required for safely storing or incinerating them in their countries of origin in compliance with the applicable government regulations there. This has occurred in Thailand, Nigeria, Guinea-Bissau and so on. The toxic wastes inside the barrels can leak and pollute the air, water and soil, posing a potential health risk to the people living in the vicinity.
Thus the environmental health problems discussed in this chapter tend to apply to an even greater extent to developing countries.