Most studies examining the toxicology of inhaled metal particles have focused on responses in the target organ, the respiratory system. Less information exists regarding the effects associated with the inhalation of metals in extrapulmonary organs, specifically the central nervous system. There is increasing interest in the health effects of airborne incidental and manufactured metal nanoparticles (particles with one dimension <100 nm) in the environment and workplace. These smaller particles may translocate more easily from deposited sites in the respiratory tract to brain structures after inhalation. Mechanisms of particle translocation include uptake and transport along olfactory and sensory neurons, transcellular transport across respiratory epithelium to the circulation, and lymphatic clearance. Chemical composition, oxidation state, and solubility all may affect metal transport and biological responses to inhaled metals. Both animal and human studies have demonstrated that inhaled metals can translocate to the central nervous system, as well as, induce neurofunctional changes. Alterations in markers of neuroinflammation and cellular toxicity have been observed in specific brain regions using animal models after exposure to a variety of occupational particles and ambient air pollution. Cognitive deficits, brain abnormalities, and neurodevelopmental effects have been associated with exposure to metals in healthy children in Europe and North America. Our panel of experts from the fields of inhalation, neurological, metal, and occupational toxicology will highlight neurological findings of animal and human studies after occupational and environmental lung exposures. All aspects of the topic, such as metal chemistry, inhalation exposure of metal particles, metal translocation from the respiratory system to the central nervous system, and neurological responses, will be examined. An increase in the understanding of metal particle inhalation and neurotoxicity may allow for the development of prevention strategies to better protect susceptible populations in the workplace and environment.
Biological-effects; Cell-biology; Cellular-reactions; Cellular-reactions; Chemical-hypersensitivity; Environmental-exposure; Exposure-assessment; Exposure-levels; Exposure-methods; Hypersensitivity; Inhalation-studies; Lung-disorders; Lung-irritants; Lymphatic-system; Metal-dusts; Neurological-reactions; Neurophysiology; Neurotoxic-effects; Occupational-exposure; Occupational-hazards; Particle-counters; Particulates; Pulmonary-disorders; Pulmonary-system; Pulmonary-system-disorders; Respiratory-hypersensitivity; Respiratory-irritants
The Toxicologist. Society of Toxicology 49th Annual Meeting and ToxExpo, March 7-11, 2010, Salt Lake City, Utah