Monitoring personal fine particle exposure with a particle counter

Abstract

Numerous epidemiological studies have demonstrated associations between ambient combustion-source particulates and adverse health outcomes. In order to better understand exposure to particles, we evaluated a portable particle counter for its ability to measure short-term peaks in personal particle exposure associated with various activities, such as proximity to vehicular traffic. In a series of laboratory and field measurements, a hand-held particle counter was evaluated by collecting simultaneous filter samples of particulate matter less than 2.5 m (PM 2.5 ) using a personal monitor. Time activity information was collected using a Personal Digital Assistant (PDA) which allows for linking of exposure events and particle measurements with 1 min temporal resolution. Laboratory and field experiments comparing the particle counter with the personal PM 2.5 samples indicated low correlations (R 2 0.39) for all size ranges. Despite these rather poor correlations, field measurements collected during different commuting modes (walking/cycling, car, bus, subway) and in different microenvironments indicated the ability of the particle counter to measure short-term particle exposures, especially those associated with combustion sources. Stratifying the measured particle counts by proximity to different particle sources enabled us to identify activities/microenvironments which were associated with higher exposures. Outdoor particle counts were significantly higher than indoor counts for particles smaller than 5.0 m. Significantly elevated particle exposures were associated with proximity to environmental tobacco smoke (ETS), cooking emissions, wood smoke and with travel in vehicles powered with internal combustion engines.

Elevated personal exposure to particulate matter from human activities in a residence

“…Figure 4 indicates that the PEM/SIM ratio increases with increasing particle size during periods of human activity, ranging from near 1 for the 0.3-0.5 mm size fraction to more than 2 for the 45 mm size fraction. The results agree with findings by Brauer et al (1999), who measured personal and area counts using light scattering particle counters for a subject walking about a small dormitory room. They found PEM/SIM ratios of approximately 1.1 for the 0.3-1.0 mm size range, 1.3 for the 1.0-5 mm size range, and 1.8 for the greater than 5 mm size range.…”

“…Unlike the present study, the PTEAM subjects performed normal nonscripted human activities and were not necessarily at home or in the same room as the PEM during the monitoring period. As discussed previously, Brauer et al (1999) reported PEM/SIM ratios for a subject walking for four 15-min activity periods that ranged from approximately 1.1 for the o1 mm size range to 1.8 for the 45 mm size range.…”

“…These studies found that walking, dusting, vacuuming, and general cleaning dramatically increased indoor concentrations of PM greater than 1 mm. Brauer et al (1999) measured personal exposure directly for a subject walking about a small dormitory room and found that the personal cloud was more pronounced when the subject was walking about than when the subject was sedentary. Ferro et al (1999) found that pushing a vacuum cleaner, with the vacuum cleaner on or off, increased human exposure to coarse PM by approximately 20 times as compared with background concentrations.…”

Particulate matter and polycyclic aromatic hydrocarbon concentrations in indoor and outdoor microenvironments in Boston, Massachusetts

“…Although these data can assist in preliminary source attribution (Brauer et al, 1999;Levy et al, 2000), only one instrument was available at the time of the study and therefore it was not possible to perform a complete indoor -outdoor analysis with the APC -1000. Standard environmental parameters (carbon dioxide, temperature, and relative humidity) were measured using a TSI Q -Trak Model 8551.…”

“…Although nonresidential microenvironmental studies have been conducted in the past ( e.g., Brauer et al, 1999;Levy et al, 2000 ), they have generally been based on a small number of measurements. This makes it difficult to discern whether microenvironmental concentration patterns are functions of inherent characteristics of the microenvironments or temporal /spatial variability in outdoor concentrations and meteorological conditions in the region.…”