doseExposure

Dose exposure is a term used to describe the amount of a substance that enters or interacts with a living organism as a result of environmental or occupational exposure over a defined period. It is not a single standardized metric; rather, it represents the delivered dose portion resulting from external exposure, often used when relating external exposure to potential health effects. The concept is used across toxicology, pharmacology, and radiation protection to connect the external amount present in the environment with the internal dose that can produce a response.

Elements of dose exposure include the exposure pathway (inhalation, ingestion, dermal contact), the concentration of the substance in the exposure medium, the duration and frequency of exposure, and the absorption or uptake efficiency that converts external contact into systemic dose. Calculation examples include inhalation dose = concentration in air × inhalation rate × exposure time × absorption fraction; ingestion dose = concentration in food × ingestion rate × absorption; dermal dose uses skin contact parameters. The resulting quantity is typically expressed relative to body weight (e.g., mg/kg) for chemicals, or as absorbed dose units (Gy) for radiation or Sv for effective dose.

Units and reporting of dose exposure can include mg/kg, μg/kg, Gy, Sv, or as air concentration (mg/m3 or Bq/m3), depending on the substance and regulatory framework. The dose exposure concept often precedes or supplements the calculation of internal dose and risk estimates, linking external measurements to potential health outcomes.

Applications and limitations: Dose exposure is used in environmental health assessments, occupational safety, and emergency response planning. It informs regulatory limits and remediation priorities. Limitations include variability in individual physiology, differences in uptake, and uncertainties in exposure data.