title: Automated mineralogical analysis of PM10: new parameters for assessing PM toxicity.
abstract: This work provides the first automated mineralogical/phase assessment of urban airborne PM10 and a new method for determining particle surface mineralogy (PSM), which is a major control on PM toxicity in the lung. PM10 was analyzed on a TEOM filter (Aug.-Sept. 2006 collection) from the London Air Quality Network Bexley, East London, U.K. A cross-section of the filter was analyzed using a QEMSCAN automated mineralogical analysis system which provided 381,981 points of analysis for 14,525 particles over a period of 9 h 54 min. The method had a detection limit for individual mineral components of 0.05 ppm (by area). Particle shape and mineralogical characteristics were determined for particles in the size ranges PM(10-4), PM(4-2.5), and PM(2.5-0.8). The PM(2.5-0.8) fraction contained 2 orders of magnitude more mineral particles than the PM(10-4) and PM(4-2.5) fractions, however the PM(10-4) fraction forms 94% and 79% of the mineral mass and surface area, respectively. PSM of the PM10 was dominated by gypsum (36%), plagioclase (16%), Na sulphates (8%), and Fe-S-O phases (8%) in the PM(10-2.5), which may be important in explaining the toxicity of the coarse fraction. The wider implications of the study are discussed.
authors.affiliation: University of Exeter, Camborne School of Mines, Penryn, Cornwall TR10 9EZ, United Kingdom. b.j.williamson@exeter.ac.uk
authors.forename: Ben J
authors.initials: BJ
authors.lastname: Williamson
authors.forename: Gavyn
authors.initials: G
authors.lastname: Rollinson
authors.forename: Duncan
authors.initials: D
authors.lastname: Pirrie
mesh_terms: D000393:Air Pollutants / Q000032:analysis* / Q000633:toxicity*; D001331:Automation; D002133:Calcium Sulfate / Q000032:analysis; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods*; D005374:Filtration / Q000295:instrumentation; D057230:Limit of Detection; D008903:Minerals / Q000032:analysis*; D052638:Particulate Matter / Q000032:analysis* / Q000633:toxicity; D013431:Sulfates / Q000032:analysis
chemical_list: D000393:Air Pollutants; D008903:Minerals; D052638:Particulate Matter; D013431:Sulfates; D002133:Calcium Sulfate