Revision of the WHO guidelines for drinking water quality.

This paper describes the activity of the World Health Organization in the field of drinking water quality, particularly the revision of the Guidelines for drinking water quality published in 1984. This process will be completed with the publication of new guidelines in 1993. The paper reports the physical, chemical and biological agents considered in the revision process, the procedure used to define the new guidelines, their meaning and their relationships with statutory limits.

Some international activities in environmental health monitoring and surveillance.

Environmental health monitoring and surveillance include activities such as collection of information on the production and use of chemicals; preparation of inventories of waste discharges; measurement of physical, chemical and biological agents in air, water and food, at work place and at home; epidemiological investigations, and collection and analysis of environmental, and health statistical data. There are two main objectives of these activities: estimation of human exposure to potentially harmful environmental factors and timely detection of adverse health effects; and the assessment of environmental conditions in relation to established guidelines and standards. Environmental health monitoring and surveillance projects initiated, organized and implemented by the Specialized Agencies and other bodies of the United Nations system include monitoring of air and water quality and of food and animal feed contamination; pilot projects on air pollution exposure assessment and biological monitoring; and ionizing radiation surveillance.

Air pollution surveillance systems.

Atmospheric surveillance is necessary in order to identify airborne pollutants, to establish ambient concentrations of these pollutants, and to record their trends and patterns. Air pollutants may occur in the form of gases, liquids, and solids, both singly and in combination. Gaseous pollutants make up about 90 percent of the total mass emitted to the atmosphere with particulates and aerosols accounting for the remaining 10 percent.