Detection of ultrafine particles in the lung macrophages of healthy people

Modern environmental air pollution control strategies are designed to reduce airborne particulate mass by reducing the size of effluent particles to less than lOOnm. Recently, Dockery et al have clearly shown that fine-particulate air pollution (<2.5(μm) can be directly related to excess mortality in humans. Although ultrafine metal fumes (<100nm) have been shown to produce adverse effects in occupational settings, little is known of the extent to which they contribute to ambient environmental particulate air pollution. The purpose of this study is to determine to what extent ultrafine particles are present in lung macrophages of healthy human volunteers studied by electron energy loss spectroscopy (EELS) and electron spectroscopic imaging (ESI).Lung macrophages were obtained by bronchoalveolar lavage from 14 current non-smokers, 7 of whom work at an oil-fired power plant but were not considered to have significant occupational exposure, 4 of whom were welders at the power plant with the possibility of metal fume (ultrafine particulate) exposure, and 3 of whom were university employees with no known occupational or environmental exposure.