Environmental Terms and Definitions

Quality assurance and quality control (QA/QC)
A system of procedures, checks and audits to judge and control the quality of measurements and reduce the uncertainty of data. Some quality control procedures include having more than one person review the findings and analyzing a sample at different times or laboratories to see if the findings are similar.

acute health effect
Health effects that usually occur rapidly as a result of short-term exposures, and are of short duration. Some examples are irritation, corrosivity (tissue destruction), narcosis, and death

World Health Organization (WHO)
WHO, an agency of the United Nations, carries out public and environmental health programs throughout the world.

Remedial Investigation (RI)
An in-depth study (including sampling of air, soil, water and waste) of a contaminated site needing remediation to determine the nature and extent of contamination. The remedial investigation (RI) is usually combined with a feasibility study (FS).

Route of exposure
The way in which a person may contact a chemical substance. For example, drinking (ingestion) and bathing (skin contact) are two different routes of exposure to contaminants that may be found in water. See "Exposure".

Odor threshold
The lowest concentration of a chemical that can be smelled. Different chemicals have different odor thresholds. Also, some people can smell a chemical at lower concentrations than others can.

Biological monitoring
Analyzing chemicals, hormone levels or other substances in biological materials (blood, urine, breath, etc.) as a measure of chemical exposure, health status, etc. in humans or animals. A blood test for lead is an example of biological monitoring.

Aerobic treatment
Process by which microbes decompose complex organic compounds in the presence of oxygen and use the liberated energy for reproduction and growth. Types of aerobic processes include extended aeration, trickling filtration, and rotating biological contactors.

ACM
Asbestos-Containing Material

HMIS
The hazardous materials identification system, developed by NPCA to provide information on the acute health hazards, reactivity, and flammability encountered in the workplace at room temperatures.