Emission Factors of Polycyclic Aromatic Hydrocarbons and Oxidative Potential of Fine Particles Emitted from Crop Residues Burning

Rosa, Naxieli Santiago-de la; Múgica-Álvarez, Violeta; González-Cardoso, Griselda; Vizcaya-Ruiz, Andrea De; Uribe-Ramírez, M.; Valle-Hernández, Brenda L.

doi:10.1080/10406638.2021.1924801

Cited by 3 publications

(1 citation statement)

References 85 publications

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“…Due to the complexity of OM in terms of sources and constitutions, the toxicity of some OM compounds has motivated greater scrutiny than other PM 2.5 compounds in health studies ( 36 ). OM includes highly toxic species such as PAHs (including products of atmospheric processing, such as oxy- and nitro-PAHs) and PCBs and contributes a large fraction of aerosol oxidative potential ( 37 , 38 ). Ultrafine particles from traffic sources also largely consist of carbonaceous species, including OM and BC ( 39 ).…”

Section: Discussionmentioning

confidence: 99%

Incident dementia and long-term exposure to constituents of fine particle air pollution: A national cohort study in the United States

Shi

Zhu

Wang

et al. 2022

Proc. Natl. Acad. Sci. U.S.A.

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Growing evidence suggests that fine particulate matter (PM 2.5 ) likely increases the risks of dementia, yet little is known about the relative contributions of different constituents. Here, we conducted a nationwide population-based cohort study (2000 to 2017) by integrating the Medicare Chronic Conditions Warehouse database and two independently sourced datasets of high-resolution PM 2.5 major chemical composition, including black carbon (BC), organic matter (OM), nitrate (NO 3 − ), sulfate (SO 4 2− ), ammonium (NH 4 + ), and soil dust (DUST). To investigate the impact of long-term exposure to PM 2.5 constituents on incident all-cause dementia and Alzheimer’s disease (AD), hazard ratios for dementia and AD were estimated using Cox proportional hazards models, and penalized splines were used to evaluate potential nonlinear concentration–response (C-R) relationships. Results using two exposure datasets consistently indicated higher rates of incident dementia and AD for an increased exposure to PM 2.5 and its major constituents. An interquartile range increase in PM 2.5 mass was associated with a 6 to 7% increase in dementia incidence and a 9% increase in AD incidence. For different PM 2.5 constituents, associations remained significant for BC, OM, SO 4 2− , and NH 4 + for both end points (even after adjustments of other constituents), among which BC and SO 4 2− showed the strongest associations. All constituents had largely linear C-R relationships in the low exposure range, but most tailed off at higher exposure concentrations. Our findings suggest that long-term exposure to PM 2.5 is significantly associated with higher rates of incident dementia and AD and that SO 4 2− , BC, and OM related to traffic and fossil fuel combustion might drive the observed associations.

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Section: Discussionmentioning

confidence: 99%

Incident dementia and long-term exposure to constituents of fine particle air pollution: A national cohort study in the United States

Shi

Zhu

Wang

et al. 2022

Proc. Natl. Acad. Sci. U.S.A.

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Increasing corn cultivation exacerbated crop residue burning in Northeast China in 21st century

Shang,

Pei,

et al. 2024

Geography and Sustainability

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Formation of Polycyclic Aromatic Hydrocarbons (PAHs) in Thermal Systems: A Comprehensive Mechanistic Review

Altarawneh,

Ali

2024

Energy Fuels

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Polycyclic aromatic hydrocarbons (PAHs) are formed invariably through oxidative and pyrolytic degradation of organic materials and fuels. Understanding the highly complex reaction mechanisms that dictate their synthesis in thermal systems has been given a great deal of focus. Such interest stems from two broad perspectives, namely, enhancing the efficiency of the combustion system, and energy recovery from fuels and protecting the environment. Health and environmental effects widely vary among PAHs where certain compounds exhibit carcinogenic tendencies. This critical review mainly aims to provide a general mechanistic view of the commonly discussed formation pathways of PAHs. The attained mechanistic knowledge often incorporates experimental measurements and kinetic modelings, as well as pathways mapped out by quantum chemical calculations. A chemical sampling of species is typically conducted via the molecular beam (MB)− mass spectroscopy (MS) technique connected to the reactor (flow reactor, jet-stirred reactor, or a shock tube). Generally, PAH precursors mainly encompass four categories of species (radicals and molecules): acetylenic compounds, alkyl radicals, phenyl radicals, and resonance-stabilized cyclic radicals. Overall, the relevance of a mechanism depends on the consistency between the proposed kinetic model that incorporates mechanism pathways, and the experimental profiles of products at the investigated conditions (i.e., temperatures, pressures, and distance from the burners). The effect of seeding common PAH precursors, with other precursors, has been explored by surveying pertinent experimental studies. Growth of higher PAHs, including the toxic pyrene, most likely involves a hydrogen abstraction acetylene addition (HACA)-like mechanism starting from anthracene and bimolecular reactions that involve benzyl radicals and indene molecules. A synergistic collaboration between different mechanisms is often suggested to account for the observed fast growth rate of PAHs. As experimentally shown, sequential mass growth by 15 u, 24 u, 26 u, and 74 u, indicate formation routes by the MAC, HACA, HAVA*, and PAC routes, respectively. Whether a physical or a chemical process is the initial step in the conversion of PAHs into soot (the inception step) is still debated in the literature. Recent experimental evidence underscores that the soot inception is likely to commence by creating PAH dimers through physical clustering under real flame conditions (i.e., 400− 1200 K). Formation of PAHs from degradation of synthetic and natural polymers ensues from condensation of their fragments as well as from structural arrangements of the polymeric structural entities, prior to their fragmentation. The surveyed and presented knowledge in this review will be useful for readers who aim to comprehend the highly complex chemistry underlying the synthesis of PAHs in thermal systems.

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Emission Factors of Polycyclic Aromatic Hydrocarbons and Oxidative Potential of Fine Particles Emitted from Crop Residues Burning

Cited by 3 publications

References 85 publications

Incident dementia and long-term exposure to constituents of fine particle air pollution: A national cohort study in the United States

Incident dementia and long-term exposure to constituents of fine particle air pollution: A national cohort study in the United States

Increasing corn cultivation exacerbated crop residue burning in Northeast China in 21st century

Formation of Polycyclic Aromatic Hydrocarbons (PAHs) in Thermal Systems: A Comprehensive Mechanistic Review

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