Procedure to Quantify Variability in Air Pollution Infiltration Factors for a Selected Pollutant and Selected Homes

Exposure to air pollutants causes adverse human health effects. Indoor air pollution is caused by infiltration of ambient air pollution indoors and indoor generated sources (e.g., cooking). Infiltration of ambient air pollution into homes depends on type and age of home, pollutant, and type of ventilation. Stochastic exposure models quantify variability in air pollutant exposures for a microenvironment based on probabilistic inputs of pollutant infiltration factors. This work develops a procedure to quantify inter-home variability in air pollution infiltration factors. The procedure was developed and demonstrated for a selected pollutant and selected homes in a selected city, with a focus on PM2.5 and selected ventilation conditions. Infiltration factors were estimated based on simultaneous indoor and outdoor concentrations with different averaging times. Three scenarios were implemented: (1) linear regression for all homes combined; (2) linear regression for each home individually; and (3) use of a linear mixed effects model (LMM). The procedure developed in this work will help in quantification of air pollution infiltration factor distributions for indoor microenvironments for use in stochastic exposure models. © 2022 Air and Waste Management Association. All rights reserved.