Differences in estimates of beryllium aerosol size distribution for toxicity studies using phase contrast microscopy, scanning electron microscopy, and liquid particle counter techniques.
Stefaniak AB; Hoover MD; Day GA; Breysse PN; Scripsick RC
Proceedings of the Seventh International Aerosol Conference, September 10-15, 2006, St. Paul, Minnesota. Biswas P, Chen DR, Hering S, eds. Mount Laurel, NJ: American Association for Aerosol Research, 2006 Sep; :928-929
Relating the physicochemical properties of an aerosol to its toxicity following inhalation is of specific interest for beryllium (Stefaniak et aI., 2004) as well as of general interest for a wide range of particles, e.g., nanomaterials (Oberdorster et aI., 2005). Various hypotheses have been put forth regarding particle mass, surface area, and number as metrics of toxicity of inhaled particles. Detailed control and physicochemical characterization of aerosols generated for inhalation toxicology studies is essential for obtaining meaningful study results. A high priority of research is characterization of the exposure material as encountered by workers and as administered in an inhalation toxicology study. Characterization of bulk material as produced or supplied may not accurately reflect the properties of the particles in the workplace atmosphere or delivered by inhalation, installation, or pharyngeal aspiration to laboratory animals. For example, current methods for characterizing dry material using microscopy can reveal general morphology and particle size, but are not capable of determining whether material consists of solid particles or clusters, or whether material will deagglomerate in lung surfactant. Similarly, current methods for characterizing material in suspension can reveal "equivalent" particle diameter, but are not capable of determining particle morphology. Thus a suite of techniques are needed to understand the multiple particle properties that may influence toxicity. The purpose of this study was to characterize the morphology and investigate the size distributions of four beryllium materials using thre" standard sizing techniques as they may reveal important characteristics of the study material.
Nanotechnology; Particulates; Chemical-properties; Aerosols; Aerosol-particles; Toxins; Toxic-effects; Toxicology; Exposure-levels; Workers; Work-environment; Risk-factors; Animals; Laboratory-animals; Lung; Lung-irritants; Lung-function; Lung-tissue; Particulates; Respiration; Pulmonary-function; Pulmonary-system; Pulmonary-disorders; Pulmonary-system-disorders;
Author Keywords: Aerosol generation; Respiratory deposition
Biswas P; Chen DR; Hering S
Proceedings of the Seventh International Aerosol Conference, September 10-15, 2006, St. Paul, Minnesota
Johns Hopkins University, Baltimore, Maryland