Selection of metric for indoor‐outdoor source apportionment of metals in PM 2.5 : mg/kg versus ng/m 3

• DOI: 10.1111/ina.12924
• Publication Date: 2021-08-21T19:24:57Z
• Authors: Pat E. Rasmussen; Christine Levesque; Owen Butler; Marc Chénier; H. David Gardner
• Keywords: Gravimetric analysis; Negative correlation; Positive correlation; Dilution

Trends in the elemental composition of fine particulate matter (PM2.5) collected from indoor, outdoor, and personal microenvironments were investigated using two metrics: ng/m3 mg/kg. Pearson correlations that positive one metric commonly disappeared or flipped to become negative when other was applied same dataset. For example, correlation between Mo S outdoor microenvironment (p < 0.05) but mg/kg 0.05). In general, concentrations (mg/kg) within PM2.5 decreased significantly as (µg/m3) increased—a dilution effect observed all seasons. An exception S: microenvironment, wt% winter 0.01) summer, whereas indoor this year-round Correlation analyses indicated associations may arise Fe-Mn oxyhydroxide sorption processes occur particles age, with without presence a common anthropogenic source. Application mass-normalized concentration metrics (mg/kg wt%), enabled by careful gravimetric analysis, revealed new evidence importance sources elements PM2.5.