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The predicted no-effect concentration (PNEC) is the concentration of a chemical which marks the limit at which below no adverse effects of exposure in an ecosystem are measured. PNEC values are intended to be conservative and predict the concentration at which a chemical will likely have no toxic effect. They are not intended to predict the ...
In the standard tests groups of animals are exposed to different concentrations of chemicals and different effects such as survival, growth or reproduction are monitored. These toxicity tests typically result in a no-observed-effect concentration (NOEC, also called a no-observed-effect level, or NOEL).
Le Chatelier–Braun principle analyzes the qualitative behaviour of a thermodynamic system when a particular one of its externally controlled state variables, say , changes by an amount , the 'driving change', causing a change , the 'response of prime interest', in its conjugate state variable , all other externally controlled state variables remaining constant.
Long and co-workers also [10] conducted a meta-analysis using 1068 sediment toxicity assays to evaluate the predictive ability of the ERL/ERM, PEL (predicted effects level), and TEL (threshold effects level) sediment quality guidelines. They found that the ERL most accurately predicted no-effects toxicity in benthic organisms. Furthermore, it ...
Different RCP scenarios result in different predicted greenhouse gas concentrations in the atmosphere (from 2000 to 2100). RCP8.5 would result in the highest greenhouse gas concentration (measured as CO 2-equivalents). Representative Concentration Pathways (RCP) are climate change scenarios to project future greenhouse gas concentrations.
MEC is to be used as a reference in the context of Chemical Safety Assessments (CSA) and should be compared with the respective Predicted Environmental Concentration (PEC) and Predicted No-Effect Concentration (PNEC) in order to decide whether exposure model is valid and the compound related risk is controlled.
Calculated value of a chemical in the environment on the basis of exposure models such as the European Union System for the Evaluation of Substances (EUSES). Used in the context of Chemical Safety Assessments (CSA) and referenced in Chemical Safety Reports (CSR).
Most originate from industrial activity in the more populated northern hemisphere. Time-series data from measurement stations around the world indicate that it typically takes 1–2 years for their concentrations to become well-mixed throughout the troposphere. [9] [10] The residence time of a trace gas depends on the abundance and rate of ...