The pathological response in relation to physical/chemical and morphological properties of ambient particulates from Iraq has become an area of great interest. This study investigated the role of metal contaminants present in ambient dust in the induction of pulmonary injury and examined the potential pulmonary risks from exposure to Iraqi particulate matter. Adult male Sprague-Dawley [Hla(SD) CVF] rats were dosed via intratracheal instillation (IT) with phosphate buffered saline (PBS) as control, ambient dust collected from Camp Victory, Iraq (CV), or NIST SRM1649b U.S. urban particulate matter suspended in PBS at doses of 2.5, 5, or 10 mg/kg/body weight. Responses were then examined at 60, 120, and 150 days post IT. Blood collection via cardiac puncture and bronchoalveolar lavage (BAL) were performed. Measurement of lactate dehydrogenase (LDH), albumin, TNF-alpha, and cell differentials were conducted to access lung damage and inflammation. Differences in lung cell proliferation were examined via BrdU assay. Histopathological analysis was investigated using Mason's Trichrome, Alcian Blue PAS, and H & E grading. The results from the LDH, albumin, and TNF-alpha showed no significant differences from control in all exposures. However, a significant difference was found in macrophage and neutrophil response in NIST (10mg/kg) at 150 days and CV (10 mg/kg) at all exposures compared to control. CV (5 mg/kg) dose also showed a significant difference in macrophages and neutrophil response at the 150 day time point compared to control. Our results indicate that a high dose of CV and NIST can induce pulmonary inflammation, but to a lesser degree than a highly fibrogenic particle (Min-U-Sil) at the same time point and concentration as determined by a previous study. Opinions, interpretations, conclusions, and recommendations are those of the authors and are not necessarily endorsed by the US Army or NIOSH.
Respiratory-system-disorders; Respirable-dust; Military-personnel; Dusts; Dust-exposure; Dust-particles; Airborne-dusts; Airborne-particles; Pathogenicity; Air-contamination; Metal-dusts; Metallic-dusts; Particulate-dust; Particulates; Environmental-exposure; Risk-analysis; Pulmonary-function; Pulmonary-system; Laboratory-animals; Laboratory-testing; Lung-cells; Bioassays; Dose-response; Immune-reaction
The Toxicologist. Society of Toxicology 51st Annual Meeting and ToxExpo, March 11-15, 2012, San Francisco, California