Environmental monitoring and the development of health standards.

The relationship of environmental monitoring to health protection control measures is described and the monitoring programs divided into those that measure targets and those that measure factors. The models are illustrated by descriptions of Canadian programs on the monitoring of chemicals in the media-food, drinking water, and air-and the factor monitoring of a physical agent, radiation. With lead it has proved possible to combine all the monitoring data from the principal sources of human exposure and derive the received dose. Finally, the manner in which some risk acceptability decisions are developed from risk estimations of chemical and radiation is described.