Indoor Outdoor Aerosol Measurements for Two Residential Buildings in New Jersey

Abstract

Indoor /outdoor aerosols were studied in two residential homes in New Jersey by making hourly measurements of the concentration and particle size for 2 week intervals in the wintertime. Indoor particle concentrations ranged from 10⁴ to 10⁷ cm⁻³ and were highly dependent on household activities, including cooking, cigarette smoking, and use of a fireplace and a kerosene space heater. Besides producing large amounts of particles, the kerosene space heater also produced concentrations of carbon dioxide, up to 3000 ppm, and carbon monoxide, up to 9 ppm. The ratio of indoor/outdoor aerosol concentrations varied from 0.2 to 41 (correlation coefficients < 0.3), consistent with the low air infiltration rate measured (0.3–0.5 air changes/h). The results indicate that indoor particles were mainly from indoor origins. In addition, radon progeny particle-size distributions were calculated by applying the attachment theory to the measured aerosol size distribution. This mode was found to range from 0.04 to 0.1 μm, a range that is broader than the conventional results, which show the mode at around 0.1 μm.