A contact between an agent and a target occurring over a short time, generally less than a day. (Other terms, such as ‘‘short-term exposure’’ and ‘‘single dose,’’ are also used).
Information on human activities used in exposure assessments. These may include a description of the activity, frequency of activity, duration spent performing the activity, and the microenvironment in which the activity occurs.
Under the Massachusetts Contingency Plan, in cases when a chemical release cannot be cleaned to MCP standards (e.g., contaminated soil found under a building that cannot be removed), the responsible party may place an AUL on the contaminated area. This AUL is a deed restriction that prohibits unsafe usage of property by current or future owners.
The rate and extent to which an agent can be absorbed by an organism and is available for metabolism or interaction with biologically significant receptors. Bioavailability involves both release from a medium (if present) and absorption by an organism.
A chemical, biological, or physical entity that contacts a target .
A volume containing the mass of agent that contacts the exposure surface.
A continuous record of instantaneous values over a time period (e.g., exposure, dose, medium intake rate)
The integral of instantaneous exposures over the exposure duration. An example is the area under a daily time profile of personal air monitor readings, with units of concentration multiplied by time.
The process by which an agent crosses an absorption barrier (see dose).
The origin of an agent for the purposes of an exposure assessment.
Any entity, stimulus, or condition that can modulate normal functions of the organism or induce an adverse response (e.g., agent, lack of food, drought).
Another name for the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA), which created ATSDR.
A behaviour characterized by deliberate ingestion of non-nutritive substances such as soil.
A contact between an agent and a target of intermediate duration between acute and chronic
Any biological entity that receives an exposure or a dose (e.g., a human, human population, or a human organ).
The rate at which the medium crosses the outer exposure surface of a target, during ingestion or inhalation.
A combination of facts, assumptions, and inferences that define a discrete situation where potential exposures may occur. These may include the source, the exposed population, the time frame of exposure, microenvironment(s), and activities. Scenarios are often created to aid exposure assessors in estimating exposure.
The way an agent enters a target after contact (e.g., by ingestion, inhalation, or dermal absorption).
The time of continuous contact between an agent and a target
The course an agent takes from the source to the target.
The amount of agent present in the contact volume. For example, the total mass of residue collected with a skin wipe sample over the entire exposure surface is an exposure mass.
The occurrence of continuous contact between an agent and a target.
.The length of time over which continuous or intermittent contacts occur between an agent and a target. For example, if an individual is in contact with an agent for 10min a day, for 300 days over a 1-year time period, the exposure duration is 1-year.
The exposure mass divided by the contact volume or the exposure mass divided by the mass of contact volume depending on the medium.
Contact with a chemical by swallowing, by breathing, or by direct contact (such as through the skin or eyes [exposure surfaces]). Exposure may be short term (acute) or long term (chronic), and the duration of exposure may be relevant.
Substances containing carbon and different proportions of other elements such as hydrogen, oxygen, fluorine, chlorine, bromine, sulfur, or nitrogen; these substances easily become vapors or gases. A significant number of the VOCs are commonly used as solvents (paint thinners, lacquer thinner, degreasers, and dry cleaning fluids).
