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Acute Dose Rate (ADR)
Concentration of Concern (CoC or CC)
Higher Tier Tools
Lifetime Average Daily Dose (LADD)
Screening Level Tools
Standard Industrial Classification (SIC)
Surface Area to Body Weight Ratio
Time-varying Emission Rate
Wastewater Treatment Facility
Bounding Estimate: An estimate of exposure, dose or risk that is higher than that incurred by the person in the population with the highest exposure, dose or risk. Bounding estimates are useful in developing statements that exposures, doses, or risks are "not greater than" the estimated value.
CoC: Concentration of Concern (sometimes called CoC): The concentration of concern (sometimes reported in parts per million, parts per billion, or parts per trillion) provides the concentration of a given chemical in a stream. This measure is determined by dividing the lowest chronic toxicity value by a factor of 10. Harm to the aquatic environment is more likely to occur if the CoC is exceeded.
High-end: A plausible estimate of an individual exposure, dose or risk for those persons at the upper end of an exposure, dose or risk distributions, above the 90th percentile, but no higher than the individual in the population who has the highest exposure.
Higher Tier Tools: Tools developed to be tailored to the specific exposures and the specific environment in which exposures occur. When used appropriately, these models can provide comprehensive exposure estimates with a greater level of accuracy.
Standard Industrial Classification: A system developed by the Office of Management and Budget that characterizes industries by numeric code. For example, a petroleum refining facility might have the SIC code 2911. The classification system currently used by E-FAST is based on the 1987 SIC system. In 1999, the Office of Management and Budget initiated efforts to replace the SIC system with the North American Industry Classification System (NAICS).
Surface Area to Body Weight Ratio: The ratio between the surface area of an individual and their body weight. This approach is preferred for E-FAST since combining surface area distributions with unrelated body weight data may lead to biases in estimating exposures.
Time-varying Emission Rate: E-FAST uses a set of differential equations whereby the time-varying emission and subsequent concentration of the chemical in each zone is a function of the rate of the pollutant loss and gain for the zone.
Wastewater: Water exiting a potential source of contamination (e.g., industrial facility or residence). Wastewater could either enter into a wastewater treatment facility, or be discharged directly into a water body.
Wastewater Treatment Facility: Utilities that treat waste water and usually discharge treated water to nearby surface water bodies.