Concept of high quality simultaneous measurements of the indoor and outdoor aerosol to determine the exposure to fine and ultrafine particles in private homes

摘要

Simultaneous measurements of indoor and outdoor aerosol particles are crucial for determining the relationship of indoor to outdoor particle concentrations (Indoor/Outdoor ratio; I/O ratio) as well as the indoor particle exposure. This article describes an improved concept to determine the exposure to indoor particles, including the indoor and outdoor measurements of particle number size distribution (PNSD) of fine and ultrafine particles, and coarse mode particle mass concentrations. Special mobility particle size spectrometers (Mobility Particle Size Spectrometer; MPSS), designed and built at TROPOS, have been employed to determine the indoor and outdoor PNSD (0.01 to 0.8 mu m). The MPSS should be calibrated against a reference MPSS at a calibration facility (e.g. the World Calibration Center for Aerosol Physics; WCCAP) every second month. This article describes the set up and quality assurance of the indoor and outdoor measurement system, as well as the logistic of the measurement. Examples of yearlong measurements at Leipzig are shown as illustrative results. Ultrafine aerosol particles are especially produced due to cooking activities or candle burning. The median I/O shows that the indoor aerosol is increasingly decoupled from outdoor during nighttime. During daytime, the influence of the outdoor aerosol is more significant and the I/O ratio is close to 1.0.