Environmental health programmes aim at preventing needless morbidity and mortality by protecting people from unnecessary exposure to environmental hazards. Unfortunately, despite the increasing knowledge about potentially harmful exposures, preventative action is often slow to follow. The mismatch between knowledge and application or translation is often most acute in developing countries, where environmental and occupational exposures often exceed national and international guideline levels, yet where corrective action to control these problems is limited. To reduce this growing deficit of action, research findings and monitoring data need to be translated more effectively and efficiently into public health practice. This requires the provision of the right type of information, and its communication to decision-makers in an easily understandable and appropriate form. Better tools to help decision-makers use the available epidemiological data also need to be developed. It has been argued that decisions are hardly ever taken because of evidence, but instead that evidence is usually used to support existing positions and policies (Hunt, 1993). Under this paradigm, individual decision-makers have been able to dictate actions on the basis of what is seen as politically favourable rather than responding to society's concern. Increasingly, however, ideals such as equity in health, environmentally sustainable development, public accountability and liability, and the formation of partnerships and involvement of the community and other important groups are changing this paradigm.
Decision-making is, certainly, a complex process. It involves choosing among alternative ways of meeting objectives. Implicit in this definition is the notion that there are a number of alternatives, and that their effects can be measured or estimated and compared (Warner et al., 1984). This, in turn, implies that there is adequate information on which to make an informed choice. Often, however, these ideals are not met. Commonly, there is limited
*This chapter was prepared by C. Corvalán, F. Barten and G. Zielhuis