Emissions database development and dispersion model predictions of airborne particulate elements in the Canadian Athabasca oil sands region

This study developed an emission inventory for 29 elements in PM_2.5 and PM_2.5-10 covering an area of approximately 300 by 420 km² in the Athabasca Oil Sands Region in northern Alberta, Canada. Emission sources were aggregated into nine categories, of which the Oil Sands (OS) Sources emitted the most, followed by the Non-OS Dust sources for both fine and coarse elements over the study area. The top six fine particulate elements include Si, Ca, Al, Fe, S, and K (933, 442, 323, 269, 116, and 103 tonnes/year, respectively), the sum of which accounted for 20.5% of the total PM_2.5 emissions. The top five coarse elements include Si, Ca, Al, Fe, and K (3713, 1815, 1198, 1073, and 404 tonnes/year), and their sum accounted for 29% of the total PM_2.5-10 emissions. Using this emission inventory as input, the CALPUFF dispersion model simulated reasonable element concentrations in both PM_2.5 and PM_2.5-10 when compared to measurements collected at three sites during 2016-2017. Modeled PM₁₀ concentrations of all elements were very close to the measurements at an industrial site with the highest ambient concentration, overestimated by 65% at another industrial site with moderate ambient concentration, and underestimated by 27% at a remote site with very low ambient concentration. Model-measurement differences of annual average concentrations were within 20% for Si, Ca, Al, Fe, Ti, Mn, and Cu in PM_2.5, and were 20-50% for K, S, and Zn in PM_2.5 at two sites located within the OS surface mineable area. Model-measurement differences were larger, but still within a factor of two for elements in PM_2.5-10 at these two sites and for elements in both PM_2.5 and PM_2.5-10 at a background site.

Impacts of hazardous metals and PAHs in fine and coarse particles with long-range transports in Taipei City

This study assessed the impact on air quality and health risk by long-range transported (LRT) PM_2.5-10- and PM_2.5-bound metals and PAHs in Taipei City, Taiwan. Several methods with receptor aerosol measurements were used to quantify the effect of LRT. The hybrid single particle lagrangian integrated trajectory model (HYSPLIT) was used in conjunction with the potential source contribution function (PSCF) to distinguish the LRT aerosols. By using a general linear model (GLM) with a marginal mean and positive matrix fraction (PMF), this study also evaluated the annual increased level of LRT (AIR_LRT) for each source contribution to the concentration and the resultant health risk of particle-bound metals and polycyclic aromatic hydrocarbons (PAHs). The LRT influenced fine-sized metals and PAHs rather than coarse-sized ones. We found that the level of PM_2.5-bound toxic metals (Pb, Cd, and As) and PAHs (Benzo[a]pyrene and dibenzo[a,e]pyrene) could increase by 90% under the influence of LRT in 2014, while an AIR_LRT value of 25% for the PM_2.5 mass concentration was observed. Overall, the excess cancer risk (ECR) resulting from PM_2.5-bound metal and PAH exposures was 6.40 × 10^-5 in relation to coal combustions (20.7%), traffic-related emissions (59.7%) and re-suspended aerosols (19.6%). Among these contributors, LRT-related metals and PAHs in PM_2.5 accounted for 51% of the total ECR.