POPs Toolkit Glossary

D

Data Quality Objectives (DQOs)Qualitative and quantitative statements of the overall level of uncertainty that a decision-maker will accept in results or decisions based on environmental data. They provide the statistical framework for planning and managing environmental data operations consistent with user's needs.
DDTThe first chlorinated hydrocarbon insecticide chemical name: Dichloro-Diphenyl-Trichloroethane. It has a half-life of 15 years and can collect in fatty tissues of certain animals. EPA banned registration and interstate sale of DDT for virtually all but emergency uses in the United States in 1972 because of its persistence in the environment and accumulation in the food chain.
Decision-Making FrameworkA structured process for making risk management decisions. The process consists of three phases: issue identification, risk assessment, and risk management (identification and analysis of options, selection of a strategy, implementation of the strategy, and monitoring and evaluation of the strategy).
DecompositionThe breakdown of matter by bacteria and fungi, changing the chemical makeup and physical appearance of materials.
DecontaminationProcess of rendering harmless (by neutralization, elimination, removal etc.) a potentially toxic substance in the natural environment, laboratory areas, the workplace, other indoor areas, clothes, food, water, sewage etc.
DeficiencyAn unauthorized deviation from acceptable procedures or practices, or a defect in an item.
DermalPertaining to the skin.
Dermal Absorption/PenetrationProcess by which a chemical penetrates the skin and enters the body as an internal dose.
Dermal ExposureContact between a chemical and the skin.
Dermal irritationSkin reaction resulting from a single or multiple exposure to a physical or chemical entity at the same site, characterized by the presence of inflammation; it may result in cell death.
Dermal ToxicityThe ability of a pesticide or toxic chemical to poison people or animals by contact with the skin.
DesignThe specifications, drawings, design criteria, and performance requirements. Also, the result of deliberate planning, analysis, mathematical manipulations, and design processes.
Design changeAny revision or alteration of the technical requirements defined by approved and issued design output documents and by approved and issued changes thereto.
Detection LimitThe lowest concentration of a chemical that can reliably be distinguished from a zero concentration.
Determinants of HealthThe collective label given to the factors and conditions that are thought to have an influence on health, including things such as income and social status, social support networks, education, employment and working conditions, social and physical environments, personal health practices, and coping skills. Some determinants play a more prominent role than others for given health issues, and interact in complex ways to affect population health.
DioxinAny of a family of compounds known chemically as dibenzo-p-dioxins. Concern about them arises from their potential toxicity as contaminants in commercial products. Tests on laboratory animals indicate that it is one of the more toxic anthropogenic (man-made) compounds.
Direct RunoffWater that flows over the ground surface or through the ground directly into streams, rivers, and lakes.
Disability Adjusted Life Year (DALY)A health gap measure that extends the concept of potential years of life lost due to premature death (PYLL) to include equivalent years of ‘healthy’ life lost by virtue of being in states of poor health or disability. The DALY combines in one measure the time lived with disability and the time lost due to premature mortality.
DocumentAny written or pictorial information describing, defining, specifying, reporting, or certifying activities, requirements, procedures, or results.
Dose EquivalentThe product of the absorbed dose from ionizing radiation and such factors as account for biological differences due to the type of radiation and its distribution in the body in the body.
Dose ResponseShifts in toxicological responses of an individual (such as alterations in severity) or populations (such as alterations in incidence) that are related to changes in the dose of any given substance.
Dose Response CurveA graph of the relationship between the dose of a contaminant and the biological response.
Dose-Response Assessment1. Estimating the potency of a chemical. 2. In exposure assessment, the process of determining the relationship between the dose of a stressor and a specific biological response. 3. Evaluating the quantitative relationship between dose and toxicological responses.
Dose-Response RelationshipThe quantitative relationship between the amount of exposure to a substance and the extent of toxic injury or disease produced.
Duplicate samples Two samples taken from and representative of the same population and carried through all steps of the sampling and analytical procedures in an identical manner. Duplicate samples are used to assess variance of the total method, including sampling and analysis
DustFine particulate matter which is easily suspended in air and can be inhaled.
DWQGDrinking water quality guidelines.
Hatfield Consultants The World Bank funded by the Canadian POPs Trust Fund through the      
Canadian International Development Agency
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