Malaysia is one of the world's most successful ‘developing’ countries. As such it provides some excellent examples of rapidly changing man–environment relationships of a type that are soon to be expected in many other Third World nations.

The examples selected for this paper have been chosen to show both the degree of Man's impact on the natural environment of Peninsular Malaysia and also the changing relationships between Man and his environment. These two themes are inextricably related. The case-studies used illustrate these themes on different areal scales.

The impact of oil spillage from grounded supertankers using the Straits of Malacca and Singapore illustrates the international implications of a potentially widespread ecological disaster. The need for international control is stressed. In Malaysia, effluent from palm-oil processing mills is becoming an increasingly serious water-pollution problem in many of the Peninsula's rivers. Although the effects may be confined to individual drainage-basins, the results can be catastrophic to both aquatic and marine ecosystems and to the people who obtain their livelihood from them.

Land development and forest clearance have resulted in the opening up of vast areas to new rural settlements, a process paralleled by rapid urbanization. The third case-study considers Man's changing relationship to his disease environment in both rural and urban areas from the point of view of man–mosquito relationships. Finally, as a local problem, the Batu Caves situation is taken to illustrate conflicting resource demands for a unique limestone habitat. The impact of industrial pollution on the local population is emphasized.

These problems are finally considered from the point of view of the quality of life and human welfare in developing countries. It is argued that raising levels of human welfare through development without giving due consideration to environmental impact may be a self-defeating process. Local issues probably make the individual aware of this paradox. Perhaps only when the cumulative environmental and individual impact of human activities is appreciated at local, regional, and national, scales will effective legislative controls be introduced.

The objective of interest-groups is to influence policy. Conflict is inevitable when two or more interest-groups are in competition for scarce resources. It then becomes the responsibility of the state to accommodate or resolve the conflict. However, an additional complexity occurs if the state agencies are themselves undergoing transformation, as has recently occurred in South Africa.

These issues are explored, using as a case-study the conflict that occurred between environmental interestgroups and a mining company over an application to dredge-mine the sand dunes that line the eastern shores of Lake St Lucia in Natal. The nature and objectives of these groups is discussed, and the role of the press in the controversy is analysed. The interests of black settlers who wish to return to their ancestral lands following the collapse of apartheid are shown to complicate further the dilemma that confronts state policymakers. The changing nature of the ‘decision environment’ in South Africa is addressed, and group theory is used to explain the relationship between state agencies and the mining, environmental, and black settler group, interests. Stages in the policy environment to match the modes of change over the period of political transformation in South Africa are identified by levels of conflict and ambiguity in a contingency model.

The overall objective of development should be to improve the quality of people's lives, yet economic development without due environmental protection commonly leads to ecological or environmental impacts which have the reverse effect of reducing the quality of human life. A table showing some of the major environmental impacts that can result from uncontrolled rural development is presented to illustrate the fact that developmental activities with no environmental protection can be very seriously detrimental to the rural environment. Therefore, an environmental impact assessment, both short-term and long-term in scope, should be made of any major development scheme as a basis for drawing up strategies for minimizing undesirable impacts. Although a number of techniques are available for such impact assessment, the checklist and matrix approaches appear to be the most suitable for use in Southeast Asia, where impact studies are only just beginning to be introduced.