BackgroundModern health concerns related to air pollutant exposure in buildings have been exacerbated owing to several factors. Methods for assessing inhalation exposures indoors have been restricted to stationary air pollution measurements, typically assuming steady-state conditions.ObjectiveWe aimed to examine the feasibility of several proxy methods for estimating inhalation exposure to CO2, PM2.5, and PM10in simulated office environments.MethodsIn a controlled climate chamber mimicking four different office setups, human participants performed a set of scriptedsittingandstandingoffice activities. Three proxy sensing techniques were examined: stationary indoor air quality (IAQ) monitoring, individual monitoring of physiological status by wearable wristband, human presence detection by Passive Infrared (PIR) sensors. A ground-truth of occupancy was obtained from video recordings of network cameras. The results were compared with the concurrent IAQ measurements in the breathing zone of a reference participant by means of multiple linear regression (MLR) analysis with a combination of different input parameters.ResultsSegregating data ontosittingandstandingactivities could lead to improved accuracy of exposure estimation model for CO2and PM by 9–60% duringsittingactivities, relative tocombinedactivities. Stationary PM2.5and PM10monitors positioned at the ceiling-mounted ventilation exhaust in vicinity of the seated reference participant accurately estimated inhalation exposure (adjustedR² = 0.91 andR² = 0.87). Measurement at the front edge of the desk near abdomen showed a moderate accuracy (adjustedR² = 0.58) in estimating exposure to CO2. Combining different sensing techniques improved the CO2exposure detection by twofold, whereas the improvement for PM exposure detection was small (~10%).SignificanceThis study contributes to broadening the knowledge of proxy methods for personal exposure estimation under dynamic occupancy profiles. The study recommendations on optimal monitor combination and placement could help stakeholders better understand spatial air pollutant gradients indoors which can ultimately improve control of IAQ.