Magnetic Properties of Atmospheric PM10 and PM2.5 Collected at Urban and Background Site
Abstract
Atmospheric particulate matter contains particles of natural, anthropogenic and extraterrestrial origin. Their proportion depends on environmental settings of the site where samples are collected. In any case, these particles contain significant portion of minerals with pronounced ferrimagnetic properties. These are, in case of industrial origin, mostly (metal-substituted) iron oxides with typically spherical shape (magnetite and/or maghemite), and can serve as tracers of industrial pollutants at the sites of PM10 collection. These particles can be detected and characterized with very high sensitivity. Furthermore, depending on the pollution sources and sampling site, concentration of these particles may show significant correlation with the total PM10 concentration and several heavy metals. Particles of natural origin may exhibit distinct magnetic properties. In case of wind-carried soil-derived particles, high frequency-dependent magnetic susceptibility may be expected due to significant portion of ultrafine superparamagentic particles. Within our study of magnetic properties of PMx, we collected PM10 and PM2.5 from large city and a small settlement which, in terms of air pollution, can be considered as background site. Hysteresis loops and IRM curves measurements indicate that magnetic properties are able to distinguish between the two fractions. Clear differences were observed in concentration of ferromagnetic portion, as well as in grain-size sensitive parameters. High-volume samplers of atmospheric PMx, installed in clean background site.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2010
- Bibcode:
- 2010AGUFMGP13B0784P
- Keywords:
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- 0345 ATMOSPHERIC COMPOSITION AND STRUCTURE / Pollution: urban and regional;
- 1512 GEOMAGNETISM AND PALEOMAGNETISM / Environmental magnetism