Particulate Matter

Dr. Lester Kobzik and colleagues at the Harvard School of Public Health used a mouse model of asthma to evaluate how inhaling pollutants affects the airways. The mice were sensitized to the allergen ovalbumin, which induces a lung condition in the mice similar to that found in people with asthma. The investigators hypothesized that exposure to concentrated ambient particles (CAPs) plus ozone would cause a synergistic (or greater-than-additive) response in the mice.

Dr Günter Oberdörster and colleagues at the University of Rochester School of Medicine and Dentistry hypothesized that inhaled ultrafine particles induce an inflammatory response in the airways of mice and rats and that animals with preexisting airway inflammatory conditions may be particularly vulnerable. The investigators focused on inhaled carbon and platinum particles because these elements are constituents of particles found in urban atmospheres.

Dr. Gerde and colleagues at the Lovelace Respiratory Research Institute examined the effects of organic compounds in diesel exhaust such as genotoxic polynuclear aromatic compounds (PAHs). The investigators removed most of the organic compounds from diesel exhaust particles and bound radioactive Benzo[a]pyrene (BaP), a type of PAH is known to cause cancer in laboratory animals, to them. They exposed the lower respiratory tract of three dogs to the particles and measured the levels of particle-bound BaP and free BaP released from particles in the peripheral region of the lungs.

Dr H-Erich Wichmann and colleagues at the National Research Center for Environment and Health in Germany prospectively studied the association of daily mortality data with the number and mass concentrations of ultrafine and fine particles in Erfurt, Germany. Concentrations were measured near a road and a time-series approach was used to look at short-term changes in particle concentration and concurrent deaths due to cardiovascular and respiratory causes over a period of 3.5 years.