Paired PM₁₀ and fine particulate matter (PM_2.5) samples were collected indoor and outdoor at a fully mechanically ventilated high school in the ultraindustrialized ship channel region of Houston, Texas over a two-month period. The primary foci of this research are to measure the elemental composition of ambient outdoor and indoor coarse particulate matter (PM_10-2.5), characterize aerosol infiltration/ventilation, and obtain clues to their origins. Several metallic hazardous air pollutants were detected inside the school but at concentrations lower than even the most rigorous indoor air quality benchmarks. Only chromium may have potentially posed a hazard based on indoor air quality standards set by the California Environmental Protection Agency. Indoor-to-outdoor (I/O) mass abundance ratios for some metals (Li, Be, Si, Ti, Cr, Co, Ni, Zn, As, Se, Zr, Cd, Sn, Sb, Hf, and Pb) were significantly greater than 1 in PM_10-2.5, suggesting corresponding indoor sources in the PM_10-2.5 size range. Some other metals (Al, K, Ca, V, Mn, Fe, Cu, Ga, Rb, Sr, Y, Mo, Ce, Pr, Nd, Sm, Gd, Dy, Yb, and U) in PM_10-2.5 had I/O ratios close to one suggesting they had predominantly outdoor origins. Enrichment factors of several metals including light rare earths (e.g. Cu, Sb, Pb, Mo, Cd, La, Ce, Pr, Nd, and Sm) with respect to local soil were overall the highest both indoors and outdoors, illustrating their anthropogenic origins. Several lines of evidence including light lanthanoid ratios, simultaneous La–Ce-Sm variations (ternary diagrams), and correlations with cracking catalysts indicated that petroleum refineries are principally responsible for the elevated lanthanoid concentrations. Rare earth element analysis revealed shifts between transient catalyst releases from petroleum refining operations and windblown soil resuspension as their dominant sources.

对 PM ₁₀和细颗粒物 (PM _2.5 ) 样本在德克萨斯州休斯顿超工业化航道地区的一所完全机械通风的高中在室内和室外收集了两个月的时间。本研究的主要重点是测量环境室外和室内粗颗粒物（PM _10-2.5)，表征气溶胶渗透/通风，并获得其起源的线索。在学校内检测到几种金属有害空气污染物，但浓度甚至低于最严格的室内空气质量基准。根据加州环境保护局制定的室内空气质量标准，只有铬可能会造成危害。某些金属（Li、Be、Si、Ti、Cr、Co、Ni、Zn、As、Se、Zr、Cd、Sn、Sb、Hf 和 Pb）的室内外 (I/O) 质量丰度比在 PM _10-2.5中显着大于 1 ，表明 PM _10-2.5大小范围内的相应室内源。PM _{10-2.5 中的}其他一些金属（Al、K、Ca、V、Mn、Fe、Cu、Ga、Rb、Sr、Y、Mo、Ce、Pr、Nd、Sm、Gd、Dy、Yb 和 U）I/O 比率接近 1，表明它们主要来自户外。包括轻稀土在内的几种金属（如 Cu、Sb、Pb、Mo、Cd、La、Ce、Pr、Nd 和 Sm）相对于当地土壤的富集因子在室内和室外总体上最高，说明了它们的人为来源. 包括轻镧系元素比率、同时发生的 La​​-Ce-Sm 变化（三元图）以及与裂化催化剂的相关性在内的几条证据表明，石油精炼厂是造成镧系元素浓度升高的主要原因。稀土元素分析揭示了石油精炼操作的瞬时催化剂释放和风吹土壤再悬浮作为其主要来源之间的转变。