Source identification and global implications of black carbon

Blanco-Donado, Erika P.; Schneider, Ismael L.; Artaxo, Paulo; Lozano-Osorio, Jesus; Portz, Luana; Oliveira, Marcos L.S.

doi:10.1016/j.gsf.2021.101149

Cited by 30 publications

(18 citation statements)

References 99 publications

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“…However, we observed variability in the slope of the linear fit line across the MA300 units (0.73-1.01), highlighting the presence of unit-to-unit variability. The range of slopes estimated from this study is consistent with other reported slopes from MA-series instruments when compared against a reference monitor ( Kuula et al, 2020;Alas et al, 2020;Blanco-Donado et al, 2022). To assess the unit-to-unit variability of MA300s, we adapt the methodology from Müller et al (2011a), where instruments of the same make and type were evaluated against a reference instrument.…”

Section: Unit-to-unit Variability Of Ma300 Reported Ebcsupporting

confidence: 84%

Performance evaluation of portable dual-spot micro-aethalometers for source identification of Black Carbon aerosols: Application to wildfire smoke and traffic emissions in the Pacific Northwest

Chakraborty

Giang²,

Zimmerman³

2022

Preprint

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Abstract. Black Carbon (BC) is a component of particulate matter, emitted from the incomplete combustion of carbonaceous fuels. The presence of BC in the atmosphere can disrupt the atmospheric radiation budget, and exposure to BC can adversely affect human health. Multi-wavelength light absorption-based dual-spot aethalometers can be used to quantify the source and characteristics of BC from traffic or biomass burning-based sources. However, aethalometer measurements are affected by artifacts such as aerosol loading and light scattering; hence, they often need correction to reduce measurement uncertainty. This work assesses the performance of the recently developed portable aethalometer (MA300, AethLabs). Due to their portability and ease of usage, MA300s can be suitable for mobile and personal exposure monitoring. Here, we evaluate BC concentration and source apportionment accuracy of three MA300 units relative to a widely used aethalometer, the AE33 (Magee Scientific). Synchronous field measurements were performed at a major traffic intersection during regular and wildfire smoke-affected days in Vancouver, Canada. We find that MA300 reported BC mass concentrations were strongly correlated (Slope range between 0.73 and 1.01, with R2 = 0.9) compared to the reference instrument, yet there is visible instrumental variability (15 %) across three units. The mean absolute error of MA300 reported BC concentrations ranged between 0.44–0.98 ug m-3 with the highest deviations observed in wildfire smoke-affected polluted days. From the aerosol light absorption measurement perspective, MA300s tend to underestimate the absorption coefficients (babs) across the five wavelengths. UV channel light absorption results were subjected to the highest amount of noise, leading to systematic bias in source apportionment analysis. We investigated the application of the latest non-linear aethalometer correction protocols in the MA300 and found that flow fluctuations enhanced noise across all channels, compared to onboard instrument correction. We also identify that the UV (λ = 370 nm) channel absorption measurements are most sensitive to instrumental artifacts during the wildfire smoke-affected period. Hence, as an alternative to traditional UV and IR (λ = 880 nm)-based BC source apportionment methods, in this work, we tested the Blue (λ = 470 nm) and IR wavelengths for BC source apportionment calculation. By adopting Blue-IR based source apportionment technique in MA300, the apportioned BC components improves on average in the order of 10 % when compared against the reference monitor's results.

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Section: Unit-to-unit Variability Of Ma300 Reported Ebcsupporting

confidence: 84%

Performance evaluation of portable dual-spot micro-aethalometers for source identification of Black Carbon aerosols: Application to wildfire smoke and traffic emissions in the Pacific Northwest

Chakraborty

Giang²,

Zimmerman³

2022

Preprint

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“…BC was observed to have the largest effect estimates on mortality per 1 μg/m 3 change in exposure, although a 1 μg/m 3 increase is a much larger relative increase for BC than other components studied (e.g., OM and sulfate) as shown in Table . BC emissions mainly come from incomplete combustion of biomass and fossil fuel and traffic emission . We observed larger effect sizes using Exposure II data compared to Exposure I (Figure ).…”

Section: Discussionmentioning

confidence: 65%

“…BC emissions mainly come from incomplete combustion of biomass and fossil fuel and traffic emission. 33 We observed larger effect sizes using Exposure II data compared to Exposure I ( Figure 2 ). This discrepancy in the effect size for BC may be explained, in part, by the discrepancy in BC concentrations of the two exposure sets that relied on monitored data from different sources (i.e., thermal method vs optical method).…”

Section: Discussionmentioning

confidence: 73%

National Cohort Study of Long-Term Exposure to PM_2.5 Components and Mortality in Medicare American Older Adults

Hao

Wang

Zhu

et al. 2023

Environ. Sci. Technol.

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There is increasing evidence linking long-term fine particulate matter (PM 2.5 ) exposure to negative health effects. However, the relative influence of each component of PM 2.5 on health risk is poorly understood. In a cohort study in the contiguous United States between 2000 and 2017, we examined the effect of long-term exposure to PM 2.5 main components and allcause mortality in older adults who had to be at least 65 years old and enrolled in Medicare. We estimated the yearly mean concentrations of six key PM 2.5 compounds, including black carbon (BC), organic matter (OM), soil dust (DUST), nitrate (NO 3 − ), sulfate (SO 4 2−), and ammonium (NH 4 + ), using two independently sourced well-validated prediction models. We applied Cox proportional hazard models to evaluate the hazard ratios for mortality and penalized splines for assessing potential nonlinear concentration−response associations. Results suggested that increased exposure to PM 2.5 mass and its six main constituents were significantly linked to elevated all-cause mortality. All components showed linear concentration−response relationships in the low exposure concentration ranges. Our research indicates that long-term exposure to PM 2.5 mass and its essential compounds are strongly connected to increased mortality risk. Reductions of fossil fuel burning may yield significant air quality and public health benefit.

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“…The eBC/elemental carbon (EC) ratios were 2.8 for eBC AE33 /EC, 2.2 ± 0.2 for eBC AE51 /EC. No comparison of AE33 and MA200 were possible; however, a recent instrument comparison showed a 9% lower eBC yield for MA200 compared to AE33 (Blanco-Donado et al 2021 ).…”

Section: Methodsmentioning

confidence: 99%

Underground emissions and miners’ personal exposure to diesel and renewable diesel exhaust in a Swedish iron ore mine

Gren

Krais

Assarsson

et al. 2022

Int Arch Occup Environ Health

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Purpose Underground diesel exhaust exposure is an occupational health risk. It is not known how recent intensified emission legislation and use of renewable fuels have reduced or altered occupational exposures. We characterized these effects on multipollutant personal exposure to diesel exhaust and underground ambient air concentrations in an underground iron ore mine. Methods Full-shift personal sampling (12 workers) of elemental carbon (EC), nitrogen dioxide (NO2), polycyclic aromatic hydrocarbons (PAHs), and equivalent black carbon (eBC) was performed. The study used and validated eBC as an online proxy for occupational exposure to EC. Ambient air sampling of these pollutants and particle number size distribution and concentration were performed in the vicinity of the workers. Urine samples (27 workers) were collected after 8 h exposure and analyzed for PAH metabolites and effect biomarkers (8-oxodG for DNA oxidative damage, 4-HNE-MA for lipid peroxidation, 3-HPMA for acrolein). Results The personal exposures (geometric mean; GM) of the participating miners were 7 µg EC m−3 and 153 µg NO2 m−3, which are below the EU occupational exposure limits. However, exposures up to 94 µg EC m−3 and 1200 µg NO2 m−3 were observed. There was a tendency that the operators of vehicles complying with sharpened emission legislation had lower exposure of EC. eBC and NO2 correlated with EC, R = 0.94 and R = 0.66, respectively. No correlation was found between EC and the sum of 16 priority PAHs (GM 1790 ng m−3). Ratios between personal exposures and ambient concentrations were similar and close to 1 for EC and NO2, but significantly higher for PAHs. Semi-volatile PAHs may not be effectively reduced by the aftertreatment systems, and ambient area sampling did not predict the personal airborne PAHs exposure well, neither did the slightly elevated concentration of urinary PAH metabolites correlate with airborne PAH exposure. Conclusion Miners’ exposures to EC and NO2 were lower than those in older studies indicating the effect of sharpened emission legislation and new technologies. Using modern vehicles with diesel particulate filter (DPF) may have contributed to the lower ambient underground PM concentration and exposures. The semi-volatile behavior of the PAHs might have led to inefficient removal in the engines aftertreatment systems and delayed removal by the workplace ventilation system due to partitioning to indoor surfaces. The results indicate that secondary emissions can be an important source of gaseous PAH exposure in the mine.

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Source identification and global implications of black carbon

Cited by 30 publications

References 99 publications

Performance evaluation of portable dual-spot micro-aethalometers for source identification of Black Carbon aerosols: Application to wildfire smoke and traffic emissions in the Pacific Northwest

Performance evaluation of portable dual-spot micro-aethalometers for source identification of Black Carbon aerosols: Application to wildfire smoke and traffic emissions in the Pacific Northwest

National Cohort Study of Long-Term Exposure to PM_2.5 Components and Mortality in Medicare American Older Adults

Underground emissions and miners’ personal exposure to diesel and renewable diesel exhaust in a Swedish iron ore mine

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Source identification and global implications of black carbon

Cited by 30 publications

References 99 publications

Performance evaluation of portable dual-spot micro-aethalometers for source identification of Black Carbon aerosols: Application to wildfire smoke and traffic emissions in the Pacific Northwest

Performance evaluation of portable dual-spot micro-aethalometers for source identification of Black Carbon aerosols: Application to wildfire smoke and traffic emissions in the Pacific Northwest

National Cohort Study of Long-Term Exposure to PM2.5 Components and Mortality in Medicare American Older Adults

Underground emissions and miners’ personal exposure to diesel and renewable diesel exhaust in a Swedish iron ore mine

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Product

Resources

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National Cohort Study of Long-Term Exposure to PM_2.5 Components and Mortality in Medicare American Older Adults