Chemical and Physical Characteristics of Outdoor, Indoor, and PersonalParticulate Air Samples Collected in and Around a Retirement Facility

摘要

The United States Environmental Protection Agency (US EPA) recently conducted the1998 Baltimore Particulate Matter (PM) Epidemiology-Exposure Study of the Elderly. Personal, indoor, and outdoor sampling of particulate Matter was conducted at a retirement center in the Towson area of northern Baltimore County. Concurrent sampling was conducted at a central community site. The main objective of this work was to use computer-controlled scanning electron microscopy with individual-particle X-ray analysis (CCSEM) to measure the chemical and physical characteristics of geological and trace element particles collected at the various sampling locations in and around the retirement facility. The CCSEM results show that the relative abundances of some geological and trace element particle classes identified at the outdoor and community locations differ from each other and from the indoor location. Particle images acquired during the computer-controlled analyses played a key role in the identification of certain particle types. Review of these images was particularly useful in distinguishing spherical particles (usually indicative of combustion) from non-spherical particles of similar chemical, composition. Manual SEM examination of personal samples suggest personal care products and hobby activities as possible sources of particle exposure.