A | B | C | D | E | F | G | H | I | L | M | N | O | P | R | S | T | U | V | W


To temporarily or permanently cease production from a well or to cease further drilling operations. (Source: OSHA 2001)

air toxics

The Clean Air Act Amendments of 1990 specify a list of 187 hazardous air pollutants that are known or suspected to cause cancer or other serious health or environmental effects. These hazardous air pollutants are referred to throughout this report as air toxics. The list includes volatile organic compounds (VOCs), such as benzene and formaldehyde, as well as other pollutants, such as diesel particulate matter (PM). (Source: U.S. Environmental Protection Agency 2016)

analytical epidemiology

The study of why and how a health problem occurs. Analytical epidemiology uses comparison groups to provide baseline or expected values so that associations between exposures and outcomes can be quantified and hypotheses about the cause of the problem can be tested. (Adapted from: Centers for Disease Control and Prevention 2014)

Appalachian Basin

An elongate depression in the crystalline basement complex which contains a great volume of predominantly sedimentary stratified rocks. The Appalachian Basin extends from the Adirondack Mountains in New York to central Alabama, encompassing an area of about 207,000 square miles, including all of West Virginia and parts of New York, New Jersey, Pennsylvania, Ohio, Maryland, Virginia, Kentucky, Tennessee, North Carolina, Georgia, and Alabama. (Source: Colton 1961)

applied epidemiology

The application or practice of epidemiology to control and prevent health problems. (Adapted from: Centers for Disease Control and Prevention 2014)

ascertainment bias

The systematic distortion of the assessment of outcome measures by researchers or study participants. (Adapted from: Sedgwick 2014)


The statistical relation between two or more events, characteristics, or other variables. (Adapted from: Centers for Disease Control and Prevention 2014)