In its broad sense, environmental health reduces exposure to adverse environmental conditions and is often discussed as "occupational and environmental" health. In a narrow sense it looks at diseases and injuries associated with: water supply and sanitation, and solid waste disposal, e.g., diarrhea; poor water resources management and poor drainage, e.g., malaria and schistosomiasis; crowded housing and poor ventilation of household smoke, e.g., respiratory infections; exposures to vehicular and industrial air pollution, e.g., respiratory diseases and cancers; alterations in feeding and breeding grounds of disease vectors like mosquitoes, e.g., dengue fever; "occupational health" problems which become public health problems because of their extent, e.g., pesticides intoxication; exposures to naturally occurring toxic substances, e.g., arsenic poisoning; and alterations to the natural resource base which create safety problems, e.g., mudslides and flooding.
The inextricable links between people and their environment constitute the basis for a socioecological approach to health.
There is increasing concern that the immune systems of living organisms are becoming overloaded and breaking down. Human illnesses like cancer, multiple sclerosis, M.E., asthma, allergies, depression and TATT (Tired-All-The-Time) are becoming commonplace in polluted and stressful environments. Research is also suggesting that children are increasingly susceptible to disease with each new generation.
The key to preventing environmental health risks is to define and address health concerns in all the relevant sectors and to facilitate the implementation of the various systems and principles on which environmental activities are based, i.e. international cooperation, producer responsibility, community planning, life cycle analyses, quality assurance, the precautionary principle and the substitution principle, environmental legislation and its enforcement, environmental impact assessments, environmental monitoring, research, and education and training. Health concerns must be accorded a central role where environmental issues emerge.
The fundamental conditions and resources for health are peace, shelter, education, food, income, a stable ecosystem, sustainable resources, social justice and equity. Improvement in health requires a secure foundation in these basic prerequisites. Good health is a major resource for social, economic and personal development and an important dimension of quality of life. Political, economic, social, cultural, environmental, behavioural and biological factors can all favour health or be harmful to it.
Many states have drawn up national environmental health action plans (NEHAPs) and are now preparing to implement them. In most NEHAPs, high priority has been given to improving the prevention and control of specific environmental health hazards. The hazards and actions to deal with them will vary from country to country. Central governments should have or create a mechanism for implementing their NEHAP activities through the coordination of policy instruments promoted by various ministries and the actions of other actors.
Recommendation D from the European Environment and Health Committee, in their paper, Economic Perspectives on Environment and Health (June 1999), states: European Member States are recommended to: (a) ensure that research on the health risks of environmental conditions is designed so that the results can be used to demonstrate the potential economic impact of these risks; (b) assess the implicit degrees of willingness to pay for reducing health risks that can be derived from the health measures taken by the various government authorities; and (c) apply policies based on the precautionary principle when serious health risks are suspected.