Coal fly ash and mineral dust for toxicology and particle characterizationstudies: Equipment and methods for PM2.5-and PM1-enriched samples

Laboratory methods to produce particle samples from known, reproducible sou rces with sufficient mass to perform both detailed characterization and rep licated in vitro toxicological assays are described, These samples are bein g used to study the ability of inhalable particles to produce abnormal conc entrations of intracellular iron, resulting in the production of reactive o xygen species in cultured airway epithelial cells, Bulk samples of size fra ctionated particles from laboratory-generated coal fly ash and from simulat ed fugitive mining tailings and road dust were collected as surrogates for important sources of iron-bearing particles in the ambient air, An Andersen cascade impactor was used to produce particle samples enriched in three si ze ranges: >10 mu m, 10-2.5 mu m, and <2.5 mu m aerodynamic diameter, A mul tijet preseparator and rectangular slot virtual impactor were used to produ ce a fraction enriched in particles below 1 mu m. Data on the particle prod uction conditions, production rates, and particle sample quality are provid ed to illustrate the feasibility of the experimental approach, The amount o f iron mobilized from particles by a physiologically-relevant chelator does not correlate with the total iron, This supports the hypothesis that parti cle characteristics and iron speciation are important for the production of abnormal iron concentrations in cultured type A549 human airway epithelial cells, Comparison of results obtained with these surrogate particles to pr evious work with urban particulate standard reference materials (SRM 1648 a nd SRM 1649) suggests particle sources and size fractions that should be em phasized for detailed characterization of particle morphology and mineralog y.