POPs Toolkit Glossary

L

Laboratory split samples Two or more representative portions taken from the same sample and analyzed by different laboratories to estimate the inter-laboratory precision or variability and the data comparability.
Latent periodDelay between exposure to a disease-causing agent and the appearance of manifestations of the disease: also defined as the period from disease initiation to disease detection.
Lethal Concentration 50Also referred to as LC50, a concentration of a pollutant or effluent at which 50 percent of the test organisms die; a common measure of acute toxicity.
Lethal Dose 50Also referred to as LD50, the dose of a toxicant that will kill 50 percent of test organisms within a designated period of time; the lower the LD 50, the more toxic the compound.
Limit of quantitationThe minimum concentration of an analyte or category of analytes in a specific matrix that can be identified and quantified above the method detection limit and within specified limits of precision and bias during routine analytical operating conditions.
Lipid SolubilityThe maximum concentration of a chemical that will dissolve in fatty substances. Lipid soluble substances are insoluble in water. They will very selectively disperse through the environment via uptake in living tissue.
Local Standard TimeThe time used in the geographic location of the sample site that is set to standard time. Standard time is used to match continuous instruments to filter-based instruments.
Long-Term Outcomes (of risk management)Changes in the original conditions that resulted from the risk management activities on a long run.
Hatfield Consultants The World Bank funded by the Canadian POPs Trust Fund through the      
Canadian International Development Agency
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