High time-resolution and time-integrated measurements of particulate metals and elements in an environmental justice community within the Los Angeles Basin: Spatio-temporal trends and source apportionment

Impact of 4th of July Fireworks on Spatiotemporal PM2.5 Concentrations in California Based on the PurpleAir Sensor Network: Implications for Policy and Environmental Justice

“…Our results were consistent with state-average daily trace metal concentrations and real-time hourly measurements as reported by the South Coast Air Quality Management District (SCAQMD), which showed elevated ambient concentrations of major toxic trace metals on the 4th of July 2019 based on an intensive field campaign in Compton, California [42]. In the present study, PM 2.5 concentrations spiked dramatically during the 4th of July period, reaching levels that were ten-times above background levels in some areas.…”

“…In the present study, PM 2.5 concentrations spiked dramatically during the 4th of July period, reaching levels that were ten-times above background levels in some areas. Such findings reinforce evidence that fireworks are the dominant contributors to ambient PM 2.5 pollution during the 4th of July holiday [ 6 , 42 ]. After PM 2.5 concentrations peaked on July 4th and 5th, concentrations returned to the baseline levels of mid-June and mid-July within 3–4 days in northern California and 5–6 days in southern California, which is most likely attributable to the topography of Los Angeles County, which effectively traps air pollution for extended periods.…”

“…In California, while local news reports documented a statewide increase in the use of illegal fireworks leading up to the 4th of July 2020 [ 39 , 40 , 41 ], the impact on regional PM 2.5 levels appeared more pronounced in southern California [ 48 , 49 ]. On average, concentrations of PM 2.5 in the South Coast Air Basin were 70% higher on the 4th of July 2020 than the average of previous recent years (i.e., 2017–2019) [ 42 , 43 ]. This finding is reinforced by SCAQMD, which reported that, despite the cancelation of public firework shows due to COVID-19, there was extensive use of personal fireworks that produced a “nonstop barrage of aerial bursts and explosions” across southern California for hours [ 50 ].…”

“…This finding is reinforced by SCAQMD, which reported that, despite the cancelation of public firework shows due to COVID-19, there was extensive use of personal fireworks that produced a “nonstop barrage of aerial bursts and explosions” across southern California for hours [ 50 ]. In addition to extensive use of at-home fireworks in southern California, the dry and stagnant air reported during the night of July 4th 2020 is also likely to have exacerbated the problem by trapping air pollution near the surface [ 42 ].…”

Dynamic Ni/V Ratio in the Ship-Emitted Particles Driven by Multiphase Fuel Oil Regulations in Coastal China

“…Ambient concentrations of V and Ni together with the ratios between them related to ship emissions in coastal regions have been reported in a number of studies, and most of the earlier ones relied on manual filter samples for periodic observation in which the intervals were at least 12–24 h. − Several online measurement technologies such as particle-induced Streaker sampling with particle-induced X-ray emission spectrometry (PIXE) analysis and rotating drum impactor sampling with synchrotron radiation induced X-ray fluorescence (SR-XRF) have been developed and applied to observe metal compositions in particles including V and Ni. Recently, a highly time-resolved Xact method based on nondestructive energy dispersive XRF (ED-XRF) analysis has been developed and applied in the measurements in America, Europe, and Asia including coastal regions of China. − It is feasible to capture the signal of ship emissions using the Xact method.…”