Effects of fresh and aged vehicular exhaust emissions on breathing pattern and cellular responses--pilot single vehicle study.

The study presented here is a laboratory pilot study using diluted car exhaust from a single vehicle to assess differences in toxicological response between primary emissions and secondary products resulting from atmospheric photochemical reactions of gas phase compounds with O₃, OH and other radicals. Sprague Dawley rats were exposed for 5 h to either filtered room air (sham) or one of two different atmospheres: (i) diluted car exhaust (P)+Mt. Saint Helens Ash (MSHA); (ii) P+MSHA+secondary organic aerosol (SOA, formed during simulated photochemical aging of diluted exhaust).

A novel platform for pulmonary and cardiovascular toxicological characterization of inhaled engineered nanomaterials.

A novel method is presented which is suitable for assessing in vivo the link between the physicochemical properties of engineered nanomaterials (ENM) and their biological outcomes. The ability of the technique to generate a variety of industry-relevant, property-controlled ENM exposure atmospheres for inhalation studies was systematically investigated. The primary particle size for Fe(2)O(3), SiO(2), Ag and Ag/SiO(2) was controlled from 4 to 25 nm, while the corresponding agglomerate mobility diameter of the aerosol was also controlled and varied from 40 to 120 nm.

Laboratory evaluation of a prototype photochemical chamber designed to investigate the health effects of fresh and aged vehicular exhaust emissions.

Laboratory experiments simulating atmospheric aging of motor vehicle exhaust emissions were conducted using a single vehicle and a photochemical chamber. A compact automobile was used as a source of emissions. The vehicle exhaust was diluted with ambient air to achieve carbon monoxide (CO) concentrations similar to those observed in an urban highway tunnel.

Toxicological evaluation of realistic emission source aerosols (TERESA)--power plant studies: assessment of breathing pattern.

Our approach to study multi-pollutant aerosols isolates a single emissions source, evaluates the toxicity of primary and secondary particles derived from this source, and simulates chemical reactions that occur in the atmosphere after emission. Three U.S.

Chronic social stress and susceptibility to concentrated ambient fine particles in rats.

Background: Epidemiologic evidence suggests that chronic stress may alter susceptibility to air pollution. However, persistent spatial confounding between these exposures may limit the utility of epidemiologic methods to disentangle these effects and cannot identify physiologic mechanisms for potential differential susceptibilities.

Objectives: Using a rat model of social stress, we compared respiratory responses to fine concentrated ambient particles (CAPs) and examined biological markers of inflammation.