Laserfiche WebLink
INITIAL RELEASE DDIC Tracy <br /> National Priorities List (NPL) <br /> The Environmental Protection Agency's (EPA) listing of sites that have undergone <br /> preliminary assessment and site inspection to determine which locations pose immediate threats to <br /> persons living or working near the release. These sites in need of cleanup. <br /> Parts per billion (ppb) <br /> A common basis of reporting water quality analysis. <br /> Parts per million (ppm) <br /> A common basis of reporting soil analysis. <br /> Public Health Assessment <br /> The evaluation of data and information on the release of hazardous substances into the <br /> environment in order to assess any current or future impact on public health, develop health <br /> advisories or other recommendations, and identify studies or actions needed to evaluate and <br /> mitigate or prevent human health effects; also, the document resulting from the evaluation. <br /> Plume <br /> An area of chemicals in a particular medium, such as air or groundwater, moving away from <br /> its source in a long band or column. Aplume can be a column of smoke from a chimney or <br /> chemicals moving with groundwater. <br /> Potentially Exposed <br /> The condition where valid information, usually analytical environmental data, indicates the <br /> presence of contaminant(s) of a public health concern in one or more environmental media <br /> contacting humans (e.g., air, drinking water, soil, food chain, surface water), and there is evidence <br /> that some of those persons have an identified route(s) of exposure (e.g., drinking contaminated <br /> water, breathing contaminated air, having contact with contaminated soil, eating contaminated <br /> food). <br /> Risk <br /> In risk assessment, the probability that something will cause injury, combined with the <br /> potential severity of that injury. <br /> Route of Exposure <br /> The way in which a person may contact a chemical substance. For example, drinking <br /> (ingestion) and bathing (skin contact) are two different routes of exposure to contaminants that <br /> may be found in water. <br /> A-2 <br />