Longitudinal assessment of personal air pollution clouds in ten home and office environments

Abstract

Elevated exposure to indoor air pollution is associated with negative human health and well‐being outcomes. Inhalation exposure studies commonly rely on stationary monitors in combination with human time–activity patterns; however, this method is susceptible to exposure misclassification. We tracked ten participants during five consecutive workdays with stationary air pollutant monitors at their homes and offices, and wearable personal monitors. Real‐time measures of size‐resolved particulate matter (within range 0.3–10 μm) and CO2, and integrated samples of PM10, VOCs, and aldehydes were collected. The PM10 cloud magnitude (excess of PM10 beyond stationary room concentration) was detected for all participants in homes and offices. The PM10 cloud magnitude ranged within 5–37 μg/m3 and was the most discernible in the coarse particle size fraction. Particles associated with “Urban mix,” “Traffic,” and “Human activities” sources contributed the most to PM10 exposures. The personal CO2 clouds were detected for participants with the SEMs in their living rooms and private or low‐occupancy offices. The stationary monitors placed in bedrooms were better predictors of personal PM10 and CO2 exposures. An overall of 33 VOCs and aldehydes were detected in both microenvironments, with the majority exhibiting high correlation between personal and stationary stations.

Optimal Sensor Placement for Personal Inhalation Exposure Detection in Static and Dynamic Office Environments

“…Aerosol particles, especially coarse ones (PM 10 ), have several orders of magnitude lower diffusion coefficients than CO 2 molecules and are sensitive to gravitational settlement [38], which likely explains why correlations were lower for particles. A Similar result was reported in a study of González Serrano et al [29], where 20% lower correlations were found between personal and stationary sensor in a shared office in case of CO 2 compared to PM 10 . Under static occupancies, however, the correlation r between stationary and BZ PM levels were higher than that of dynamic occupancies, where the greater particle mass exchange associated with exogenous sources (vigorous activity of other occupants) could strongly influence personal exposures to PM [5].…”

“…Air pollutant emission from occupants themselves is an important determinant of spatio-temporal variation of indoor air pollution and personal exposure [23,28,29]. Specifically, a significant factor influencing the spatial-temporal indoor air pollution and exposures in buildings is the occupancy dynamics, namely the number of occupants and their activities [30][31][32].…”

Physiology or Psychology: What Drives Human Emissions of Carbon Dioxide and Ammonia?

“…In addition, in typical indoor environments with pronounced spatial gradients of air pollutants, CO 2 and NH 3 levels can be elevated in the perihuman microenvironment beyond those represented by the assumption of a well-mixed indoor environment, leading to elevated personal exposure. − Future work exploring the effect of human gaseous emissions on personal exposure is warranted.…”

Influence of Ventilation on Formation and Growth of 1–20 nm Particles via Ozone–Human Chemistry

“…6) alternated between the table and the sampling station every 30 min while staying in the chamber. This adjustment aimed to investigate the potential difference in ultrafine particle levels between the bulk air and the peri-human microenvironment (termed the “personal cloud effect” − ).…”