vironmental threats, such as global warming and pollution from toxicants found in intercontinental drifts of dust, collaboration on the issues of environmental health monitoring is increasingly needed.
Every country is facing problems similar to those in the United States in assessing the health effects of environmental hazards and monitoring progress toward reducing or preventing the effects, observed Kjellstrom. The environmental hazards faced by a nation depend on the country’s economic development and, to a lesser extent, on its geographic location. In most developed countries, the main focus in recent decades has been chemical pollutants—urban air pollution, exposures to chemicals and agriculture, and long-distance pollution from coal- and oil-powered electricity production. The threats of catastrophic radiation pollution from nuclear power plants and the problems posed by greenhouse gas emissions also are of concern. In developing countries the major environmental concerns are the biological hazards of unsafe drinking water and unsatisfactory sanitation, as well as the hazards of inadequate housing and poor worker health and safety.
A look at Vietnam illustrates the typical environmental health concerns of a developing nation. Most of the country’s 80 million people live in rural areas, and the average gross domestic product is equivalent to USS400 annually. The country still relies heavily on traditional agriculture, which poses hazards of disease vectors, inadequate sanitation, injuries, and pesticide use by farmers. In the inner cities, water supplies, sanitation, housing, and transportation involve tremendous health hazards (see Figure 4.1). Occupational hazards, particularly exposures to toxic chemicals, also are a growing problem, as are traffic crash injuries. Recent progress has been made in some areas, such as access to safe drinking water.
Another enormous health problem in developing countries is air pollution. For example, in Beijing, China, coal burning in industry and households raised PM10 (particulate matter of 10-μm diameter) levels to a staggering 600 μg/m3 on a typical day in November 1995. Air quality concerns are not limited to developing countries. In New Zealand, for example, a large contributor to air particulate matter is the use of wood fires for heating. Chimney density, obtainable from census data, has been found to be a reliable indicator of air pollution levels on calm, cold winter days. It also is an indicator of socioeconomic disparity, because in poor areas the houses are older and people cannot afford electricity for heating.