title: Indoor/Outdoor Relationships and Anthropogenic Elemental Signatures in Airborne PM2.5at a High School: Impacts of Petroleum Refining Emissions on Lanthanoid Enrichment.
abstract: Outdoor emissions of primary fine particles and their contributions to indoor air quality deterioration were examined by collecting PM2.5inside and outside a mechanically ventilated high school in the ultraindustrialized ship channel region of Houston, TX over a 2-month period. By characterizing 47 elements including lanthanoids (rare earth elements), using inductively coupled plasma-mass spectrometry, we captured indoor signatures of outdoor episodic emissions arising from nonroutine operations of petroleum refinery fluidized-bed catalytic cracking units. Average indoor-to-outdoor (I/O) abundance ratios for the majority of elements were close to unity providing evidence that indoor metal-bearing PM2.5had predominantly outdoor origins. Only Co had an I/O abundance ratio >1 but its indoor sources could not be explicitly identified. La and 17 other elements (Na, K, V, Ni, Co, Cu, Zn, Ga, As, Se, Mo, Cd, Sn, Sb, Ba, W, and Pb), including air toxics were enriched relative to the local soil both in indoor and outdoor PM2.5demonstrating their noncrustal origins. Several lines of evidence including receptor modeling, lanthanoid ratios, and La-Ce-Sm ternary diagrams pointed to petroleum refineries as being largely responsible for enhanced La and total lanthanoid concentrations in the majority of paired indoor and outdoor PM2.5.
authors.affiliation: Department of Civil Engineering, Texas A&M University , College Station, Texas 77843-3136, United States.
authors.forename: Ayse
authors.initials: A
authors.lastname: Bozlaker
authors.affiliation: Department of Chemical and Environmental Engineering, Yale University , New Haven, Connecticut 06520, United States.
authors.forename: Jordan
authors.initials: J
authors.lastname: Peccia
authors.affiliation: Department of Civil Engineering, Texas A&M University , College Station, Texas 77843-3136, United States.|Department of Chemical Engineering, Texas A&M University , College Station, Texas 77843-3122, United States.
authors.forename: Shankararaman
authors.identifier: http://orcid.org/0000-0001-9173-1439
authors.initials: S
authors.lastname: Chellam
mesh_terms: D000393:Air Pollutants; D016902:Air Pollution, Indoor; D004784:Environmental Monitoring; D028581:Lanthanoid Series Elements; D010316:Particle Size; D052638:Particulate Matter; D010578:Petroleum
chemical_list: D000393:Air Pollutants; D028581:Lanthanoid Series Elements; D052638:Particulate Matter; D010578:Petroleum