Metal Particles Are Inappropriate for Testing a Postulate of Extrapulmonary Transport

Abstract

Exposure to ambient air pollution particles has been associated with increased human morbidity and mortality, much of which is nonpulmonary. One proposed explanation of this extrapulmonary tissue injury is a transport of the particles outside of the respiratory tract. In the August 2006 issue of EHP, Elder et al. (2006) tested a postulate of extrapulmonary transport of particulate matter (PM). Specifically, the authors focused on the potential translocation of particles by olfactory neuronal pathways to the central nervous system. Comparable to previous studies on systemic transport of PM, they used a metal particle (i.e., a manganese oxide). Elder et al. measured tissue Mn concentrations in an effort to establish transport of the particle