Indoor/Outdoor Relationships and Anthropogenic Elemental Signatures in Airborne PM_2.5 at 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 PM inside 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 PM had 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 PM demonstrating 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 PM.

Physicochemical Properties of Indoor and Outdoor Particulate Matter 2.5 in Selected Residential Areas near a Ferromanganese Smelter

“…Our indoor and outdoor PM 2.5 mass concentration results are similar to those of previous studies [70][71][72], which also found that the outdoor mass concentration was greater than the indoor concentration. Studies by Martuzevicius et al [73] and Abdel-Salam [74] found a significant correlation between the distance from major traffic roads and outdoor PM 2.5 mass concentrations in residential areas.…”

“…The positive correlation between indoor and outdoor PM 2.5 concentrations, R-square values close to one, and the corresponding I/O ratios of less than one, confirm that indoor concentrations were influenced by PM 2.5 from the outdoor environment. Similar results were reported by Massey et al [77] and Bozlaker et al [72], who also found a strong and positive relationship between indoor and outdoor PM 2.5 mass concentrations. The results are expected because it has been reported that approximately 35-70% of indoor PM 2.5 comes from the outdoor environment [64,78].…”

Predictors of the Indoor-to-Outdoor Ratio of Particle Number Concentrations in Israel

“…We were able to examine the impact of some of these factors using a generalized linear model with one-year field data. The outdoor PNC was found to be the most important predictor of indoor PNC at all meteorological conditions [30,35], but the residents' preferences and activities may dominate the IOR when considerable indoor activities prevail, e.g., smoking, stir and fry cooking, vacuum cleaning, dusting, etc. While smoking and cooking tend to elevate the fine PNC, house holding activities affect to a larger extent the coarse fraction [20,36].Information about the indoor-to-outdoor ratio (IOR) of particle concentrations in different regions and seasons may help epidemiologists and policy makers understand the health effects of ambient air pollution and correct their exposure assessments with a measure that represents indoor exposure as well.…”

Characterization of urinary concentrations of heavy metals among socioeconomically disadvantaged black pregnant women

“…Metals that loaded on Factor 2 (Al, V, Cr, and Co) might be associated with either industrial or natural sources. Although Al, V, and Cr from crustal materials are naturally present in soil, these elements are also emitted from petrochemical plants and refineries, from burning heavy oil for shipping vessels, and from other metal-related industrial facilities (Moreno et al 2010;Bozlaker et al 2017;Han et al 2017), which are abundant in the greater Houston area (US EPA 2019). Factor 3 (Ni, Cu, Zn, and Se) consisted of metals that may be associated with traffic sources such as vehicular and railroad emissions (e.g., break wear) (Harrison et al 2012;Ha et al 2014).…”