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Twelve mildly asthmatic and four healthy adults were exposed to filtered air (FA) and concentrated ambient coarse particles (CCP) supplied to a whole-body exposure chamber via a coarse particle concentrator with 15 parallel virtual impactors. Exposures were conducted in a Los Angeles suburb with high levels of motor-vehicle pollution and lasted 2 h with(More)
Information about health effects from controlled exposure to particulate matter (PM) air pollution is relatively limited but potentially critical in urban locations such as Los Angeles, where abundant mobile sources generate combustion-related particles. Nonsmoking healthy (n = 12) and asthmatic (n = 12) volunteers, age 18-45 yr, were exposed to(More)
This article describes a systematic evaluation of factors affecting the stability of the performance of Harvard ambient fine-particle concentrators, an essential requirement for controlled animal and human exposure studies that utilize these technologies. Phenomenological problems during the operation of the concentrator, including pressure drop increase(More)
To study the possible chronic respiratory effects of air pollutants, we designed and initiated a 10-yr prospective study of Southern California public schoolchildren living in 12 communities with different levels and profiles of air pollution. The design of the study, exposure assessment methods, and survey methods and results related to respiratory(More)
To study possible chronic respiratory effects of air pollutants, we initiated a 10-yr prospective cohort study of Southern California children, with a study design focused on four pollutants: ozone, particulate matter, acids, and nitrogen dioxide (NO2). Twelve demographically similar communities were selected on the basis of historic monitoring information(More)
The elderly and individuals who have chronic obstructive pulmonary disease (COPD) may be sensitive to particulate matter (PM) air pollution. We evaluated short-term health responses of 13 elderly volunteers with COPD and 6 age-matched healthy adults to controlled exposures of ambient PM pollution in suburban Los Angeles. Using a Harvard particle(More)
Epidemiologic studies report health effects associated with exposure to ambient particulate matter (PM), but underlying biologic mechanisms remain unclear. We evaluated pulmonary and systemic effects in twelve healthy human adult and twelve asthmatic volunteers exposed once for 2 hours in a whole-body chamber to approximately 200 microg/m3 concentrated(More)
We used daily time-series analysis to evaluate associations between ambient carbon monoxide, nitrogen dioxide, particulate matter [less than and equal to] 10 microm in aerodynamic diameter (PM(10)), or ozone concentrations, and hospital admissions for cardiopulmonary illnesses in metropolitan Los Angeles during 1992-1995. We performed Poisson regressions(More)
Although acute adverse effects on asthma have been frequently found for the U.S. Environmental Protection Agency's principal criteria air pollutants, there is little epidemiologic information on specific hydrocarbons from toxic emission sources. We conducted a panel study of 22 Hispanic children with asthma who were 10-16 years old and living in a Los(More)
The Nebulizer Chronolog (NC) is a portable electronic device that attaches to standard metered-dose inhalers (MDIs) and records and stores the date and time of each MDI actuation. We evaluated the long-term performance of the NC and compared its data to concurrent recordings of self-administered MDI usage in daily diaries. Eighty-three subjects with asthma(More)