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EPA-Expo-Box (A Toolbox for Exposure Assessors)

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An exposure route is the way that a contaminant enters an individual or population after contact (IPCS, 2004). Typically, exposure occurs by one of three exposure routes—inhalation, ingestion, or dermal. Inhalation exposure can result from breathing air that is contaminated with particulate matter (e.g., dust), vapors (e.g., volatile or semivolatile contaminants), or aerosols. Individuals can be exposed to contaminated air via the inhalation route during a variety of activities outdoors (e.g., work, recreation) and indoors (e.g., cooking; using heating and cooling systems and humidification devices; using consumer products such as products used for household cleaning and maintenance, personal care, or hobbies). Indoor receptors could also be exposed to outdoor air contaminants that infiltrate the indoor environment. Estimating exposure from inhalation requires information on the concentrations of contaminants in the air and the timeframe over which inhalation exposure occurs. To calculate an inhaled dose, inhalation rates and receptor body weights might also be needed.

Calculations to estimate dose from inhalation are provided in this module as are various tools available for evaluating potential exposure concentrations. Exposure scenarios, exposure factors, and guidance for assessing exposure via inhalation are also provided.

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