文摘
Ambient urban particulate matter (PM) contains varioustransition metals. When the PM is inhaled into the lung, notall but some part of metals from the particles might bemobilized to participate in a reaction that can damage variousbiomolecules, such as DNA and proteins. The dustparticle size as well as organic acids may influence themetal mobilization. Thus, the mobilization of the metal fromtwo standard reference materials (SRM; NIST, USA) andurban PM (PM2.5 and PM10) collected in the Seoul area wasmeasured in the presence of artificial or biologicalchelator with or without reductant. The degree of themobilization was higher with the artificial or biologicalchelator than the control with saline. In some cases, areductant increased the mobilization as much as about 5times the control without the reductant. Especially, themobilization of Fe was greatly influenced by the presenceof reductants. In general, the degree of the mobilizationof the transition metal was higher with PM2.5 than with PM10.Therefore, it is expected that, considering the previouslyknown toxicities of the transition metals, PM2.5 is moredamaging to various biomolecules than PM10. The resultsalso suggest that not the total amount but the mobilizablefraction of the metal in the ambient PM should be consideredwith regard to the toxicity of the urban particulatematter.