Risk Analysis Glossary: V - X

Washout

1. The removal of a pollutant by precipitation below clouds.

Water pollution

1. The addition of sewage, industrial wastes, or other harmful or objectionable material to water in concentrations or in sufficient quantities to result in measurable degradation of water quality.

Water quality criteria

1. Levels of pollutants in bodies of water that are consistent with various uses of water, i.e. drinking water, sport fishing, industrial use.

Watershed

1. Land area from which water drains toward a common watercourse in a natural basin.

Weathering

1. The group of processes, such as the chemical action of air and rain water and of plants and bacteria and the mechanical action of changes of temperature, whereby rocks, on exposure to the weather, change in character, decay, and finally crumble into soil.
2. The disappearance of substances from vegetation or soil through the action of wind and precipitation. [S. L. Brown]

Wet deposition

1. The removal of atmospheric particles to the earth's surface by rain or snow.

Workers

1. All persons gainfully employed, including owners, managers, other paid employees, the self-employed, and unpaid family workers, but excluding domestic servants.

Work injuries

1. Those which arise out of and in the course of gainful employment regardless of where the accident occurs. Excluded are work injuries to domestic servants and injuries occurring in connection with farm chores which are classified as home injuries.