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1.
Sci Total Environ ; 921: 170495, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38296070

RESUMEN

Polycyclic aromatic hydrocarbons (PAHs) and their oxygenated and nitrated derivatives, OPAHs and NPAHs, are semivolatile air pollutants which are distributed and cycling regionally. Subsequent to atmospheric deposition to and accumulation in soils they may re-volatilise, a secondary source which is understudied. We studied the direction of air-soil mass exchange fluxes of 12 OPAHs, 17 NPAHs, 25 PAHs and one alkylated PAH in two rural environments being influenced by the pollutant concentrations in soil and air, by season, and by land cover. The OPAHs and NPAHs in samples of topsoil, of ambient air particulate and gas phases and in the gas-phase equilibrated with soil were analysed by GC-APCI-MS/MS. The pollutants soil burdens show a pronounced seasonality, a winter maximum for NPAHs and PAHs and a summer maximum for OPAHs. One order of magnitude more OPAH and parent PAH are found stored in forest soil than in nearby grassland soil. Among a number of 3-4 ring PAHs, the OPAHs benzanthrone and 6H-benzo(c,d)pyren-6-one, and the NPAHs 1- and 2-nitronaphthalene, 9-nitrophenanthrene and 7-nitrobenz(a)anthracene are found to re-volatilise from soils at a rural background site in central Europe in summer. At a receptor site in northern Europe, net deposition of polycyclic aromatic compounds (PACs) prevails and re-volatilisation occurs only sporadic. Re-volatilisation of a number of PACs, including strong mutagens, from soils in summer and even in winter indicates that long-range atmospheric transport of primary PAC emissions from central Europe to receptor areas might be enhanced by secondary emissions from soils.

2.
Environ Pollut ; 338: 122707, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-37816403

RESUMEN

The production and use of intentionally-produced polychlorinated biphenyls (PCBs) in China have a short history compared with countries of North America and Europe, where technical PCB mixtures were manufactured in large amounts for decades before being banned. Unintentionally-produced PCB emissions increased dramatically in China, leading to unique profiles of PCB burdens. This study first time evaluated 208 individual PCB congeners at 94 sites from surface sediments of the East China Marginal Seas (ECMSs) and explored their sources. Non-technical PCBs transported from atmospheric transport and river discharge played a dominant role in most areas of the ECMSs, while historical residuals of technical PCBs occupied the fine-grained sediments in muddy areas of the central Yellow Sea (YS), regarding to the low sedimentation rate in the central YS. Furthermore, emissions from Taizhou located on the coast of the East China Sea (ECS), which is an important electronic waste dismantling site in East China, contributed additional technical PCBs to the inner shelf of the ECS. Our results indicate that non-technical PCBs have become the dominant PCB species in the ECMSs, and emphasize the synergistic effects of large riverine input, long-range atmospheric transport, and muddy shelf deposition on PCB source and sink of in marginal seas.


Asunto(s)
Bifenilos Policlorados , Contaminantes Químicos del Agua , Bifenilos Policlorados/análisis , Sedimentos Geológicos , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente/métodos , Océanos y Mares , China
3.
Environ Sci Technol ; 57(42): 15999-16005, 2023 10 24.
Artículo en Inglés | MEDLINE | ID: mdl-37831888

RESUMEN

Endosulfan is a persistent organochlorine pesticide that was globally distributed before it was banned and continues to cycle in the Earth system. The chemical kinetics of the gas-phase reaction of α-endosulfan with the hydroxyl radical (OH) was studied by means of pulsed vacuum UV flash photolysis and time-resolved resonance fluorescence (FP-RF) as a function of temperature in the range of 348-395 K and led to a second-order rate coefficient kOH = 5.8 × 10-11 exp(-1960K/T) cm3 s-1 with an uncertainty range of 7 × 10-12 exp(-1210K/T) to 4 × 10-10 exp(-2710K/T) cm3 s-1. This corresponds to an estimated photochemical atmospheric half-life in the range of 3-12 months, which is much longer than previously assumed (days to weeks). Comparing the atmospheric concentrations observed after the global ban of endosulfan with environmental multimedia model predictions, we find that photochemical degradation in the atmosphere is slower than the model-estimated biodegradation in soil or water and that the latter limits the total environmental lifetime of endosulfan. We conclude that the lifetimes typically assumed for soil and aquatic systems are likely underestimated and should be revisited, in particular, for temperate and warm climates.


Asunto(s)
Endosulfano , Plaguicidas , Radical Hidroxilo , Temperatura , Suelo , Cinética
4.
Nat Commun ; 14(1): 3740, 2023 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-37349341

RESUMEN

Polyhalogenated carbazoles (PHCZs) are emerging global pollutants found in environmental matrices, e.g., 3000 tonnes of PHCZs have been detected in the sediments of the Great Lakes. Recognition of PHCZ emissions from ongoing industrial activities worldwide is still lacking. Here, we identify and quantify PHCZ emissions from 13 large-scale industries, 12 of which previously have no data. Congener profiles of PHCZs from investigated industrial sources are clarified, which enables apportioning of PHCZ sources. Annual PHCZ emissions from major industries are estimated on the basis of derived emission factors and then mapped globally. Coke production is a prime PHCZ emitter of 9229 g/yr, followed by iron ore sintering with a PHCZ emission of 3237 g/yr. China, Australia, Japan, India, USA, and Russia are found to be significant emitters through these industrial activities. PHCZ pollution is potentially a global human health and environmental issue.


Asunto(s)
Carbazoles , Contaminantes Químicos del Agua , Humanos , Contaminantes Químicos del Agua/análisis , China , Contaminación Ambiental , Monitoreo del Ambiente
5.
Environ Pollut ; 330: 121648, 2023 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-37088251

RESUMEN

Polybrominated diphenyl ethers (PBDEs) have been used as flame retardants in building materials, electronics, furnishings, vehicles, airplanes, plastics, polyurethane foams, and textiles for many years. Currently, the primary commercial mixtures, penta-, octa-, and deca-BDE, are globally restricted. Still, products containing PBDEs are expected to impact waste management and the environment for many years. In January 2016, an open fire in the Santa Marta landfill close to Santiago de Chile affected the city and surroundings. The fire caused several acute health effects and an increase in emergency hospitalizations. We measured PBDE levels in the areas affected by the fire in the air (gaseous and particulate) and soil, and PBDE emissions were estimated using a dispersion model. The results showed an increase in PBDE concentrations by a factor of 2-4 one day after the start of the fire. However, PBDE concentrations measured after the fire in PM10 and the gas phase were considered low compared to other regions. Interestingly, PBDEs' patterns differed across the sites; however, BDE209 was the dominant congener for all environmental matrices. A preliminary risk assessment was conducted using the daily exposure dose (DED) by air inhalation estimation. The results showed low DED values for adults and children and suggested no direct health risk due to PBDE exposure. This study brings new data useful for future solid waste management initiatives in the country.


Asunto(s)
Retardadores de Llama , Éteres Difenilos Halogenados , Niño , Adulto , Humanos , Éteres Difenilos Halogenados/análisis , Monitoreo del Ambiente/métodos , Chile , Retardadores de Llama/análisis , Medición de Riesgo , Instalaciones de Eliminación de Residuos
6.
Environ Sci Pollut Res Int ; 30(6): 16749-16755, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36550248

RESUMEN

Redox-active substances in fine particulate matter (PM) contribute to inhalation health risks through their potential to generate reactive oxygen species in epithelial lung lining fluid (ELF). The ELF's air-liquid interface (ALI) can play an important role in the phase transfer and multi-phase reactions of redox-active PM constituents. We investigated the influence of interfacial processes and properties by scrubbing of coated nano-particles with simulated ELF in a nebulizing mist chamber. Weakly water-soluble redox-active organics abundant in ambient fine PM were reproducibly loaded into ELF via ALI mixing. The resulting oxidative potential (OP) of selected quinones and other PAH derivatives were found to exceed the OP resulting from bulk mixing of the same amounts of redox-active substances and ELF. Our results indicate that the OP of PM components depends not only on the PM substance properties but also on the ELF interface properties and uptake mechanisms. OP measurements based on bulk mixing of phases may not represent the effective OP in the human lung.


Asunto(s)
Contaminantes Atmosféricos , Material Particulado , Humanos , Material Particulado/análisis , Contaminantes Atmosféricos/análisis , Especies Reactivas de Oxígeno , Oxidación-Reducción , Estrés Oxidativo
8.
Mar Pollut Bull ; 177: 113518, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35299147

RESUMEN

Air-sea exchange of POPs and PAHs was assessed in Concepción Bay during January, summer 2015. Results showed low levels, in air and water, for POPs (1-20 pg m-3, and 6-50 pg L-1, respectively) and for ΣPAHs (1-2 ng m-3 and 1-2 ng L-1, respectively). The highest levels were found for PBDEs (200-20,000 pg L-1) in the water samples (3-fold times higher than PCBs and OCP) and PBDE209 accounted for 90% of total ΣPBDEs. Air-sea exchange fluxes (ng m-2 d-1) were low in general, with exception of PBDEs showing values up to 40,000 ng m-2 d-1. Net deposition was found for PAHs, HCB and some PBDEs; while, BDE99, and BDE100 showed net volatilization. These findings contribute with new data of diffusive air-sea exchange on the southern hemisphere Pacific coast.


Asunto(s)
Contaminantes Atmosféricos , Contaminantes Químicos del Agua , Contaminantes Atmosféricos/análisis , Bahías , Chile , Monitoreo del Ambiente , Contaminantes Químicos del Agua/análisis
9.
Mar Pollut Bull ; 174: 113144, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-35090286

RESUMEN

Persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs) were determined in abiotic samples from Concepción Bay in Central Chile. Samples were soxhlet extracted and injected in gas chromatography-mass spectrometry (GCMS). Polybrominated diphenyl ethers (PBDEs) showed the highest levels in air (3-1100 pg m-3), in water (2-64 pg L-1), in sediment, and soil (1-78 ng g-1 (dw)). PAHs were also high in the air (1-6 ng m-3), in water (1-7 ng L-1), in sediment (90-300 ng g-1 (dw)), and in soil (15-2300 ng g-1 (dw)). The polychlorinated biphenyls (PCBs) and chlorinated pesticides were generally low and did not show clear trends along the water column, with exception of PAHs. New data are presented in this work to assess the health status of a relevant coastal area in central Chile.


Asunto(s)
Contaminantes Ambientales , Hidrocarburos Policíclicos Aromáticos , Bahías , Chile , Monitoreo del Ambiente , Hidrocarburos Policíclicos Aromáticos/análisis , Tsunamis
11.
Sci Total Environ ; 793: 148528, 2021 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-34328964

RESUMEN

Derivatives of polycyclic aromatic hydrocarbons (PAHs) such as nitrated- and oxygenated-PAHs (NPAHs and OPAHs) could be even more toxic and harmful for the environment and humans than PAHs. We assessed the spatial and seasonal variations of NPAHs and OPAHs atmospheric levels, their cancer risks and their gas-to-particle partitioning. To this end, about 250 samples of fine particulate matter (PM2.5) and 50 gaseous samples were collected in 2017 in central Europe in the cities of Brno and Ljubljana (two traffic and two urban background sites) as well as one rural site. The average particulate concentrations were ranging from below limit of quantification to 593 pg m-3 for Σ9NPAHs and from 1.64 to 4330 pg m-3 for Σ11OPAHs, with significantly higher concentrations in winter compared to summer. In winter, the particulate levels of NPAHs and OPAHs were higher at the traffic site compared to the urban background site in Brno while the opposite was found in Ljubljana. NPAHs and OPAHs particulate levels were influenced by the meteorological parameters and co-varied with several air pollutants. The significance of secondary formation on the occurrence of some NPAHs and OPAHs is indicated. In winter, 27-47% of samples collected at all sites were above the acceptable lifetime carcinogenic risk. The gas-particle partitioning of NPAHs and OPAHs was influenced by their physico-chemical properties, the season and the site-specific aerosol composition. Three NPAHs and five OPAHs had higher particulate mass fractions at the traffic site, suggesting they could be primarily emitted as particles from vehicle traffic and subsequently partitioning to the gas phase along air transport. This study underlines the importance of inclusion of the gas phase in addition to the particulate phase when assessing the atmospheric fate of polycyclic aromatic compounds and also when assessing the related health risk.


Asunto(s)
Contaminantes Atmosféricos , Neoplasias , Hidrocarburos Policíclicos Aromáticos , Contaminantes Atmosféricos/análisis , Ciudades , Monitoreo del Ambiente , Humanos , Neoplasias/epidemiología , Material Particulado/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Estaciones del Año
12.
Environ Sci Pollut Res Int ; 28(43): 61360-61368, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34173951

RESUMEN

Chlorinated and brominated polycyclic aromatic hydrocarbons (ClPAHs and BrPAHs) are persistent organic pollutants that are ubiquitous in the atmospheric environment. The sources, fate, and sinks in the atmosphere of these substances are largely unknown. One of the reasons is the lack of widely accessible analytical instrumentation. In this study, a new analytical method for ClPAHs and BrPAHs using gas-chromatography coupled with triple quadrupole mass spectrometry is presented. The method was applied to determine ClPAHs and BrPAHs in total deposition samples collected at two sites in central Europe. Deposition fluxes of ClPAHs and BrPAHs ranged 580 (272-962) and 494 (161-936) pg m-2 day-1, respectively, at a regional background site, Kosetice, and 547 (351-724) and 449 (202-758) pg m-2 day-1, respectively, at a semi-urban site, Praha-Libus. These fluxes are similar to those of PCBs and more than 2 orders of magnitude lower than those of the parent PAHs in the region. Seasonal variations of the deposition fluxes of these halogenated PAHs were found with maxima in summer and autumn, and minima in winter at Kosetice, but vice versa at Praha-Libus. The distribution of ClPAHs and BrPAHs between the particulate and dissolved phases in deposition samples suggests higher degradability of particulate BrFlt/Pyr and BrBaA than of the corresponding ClPAHs. A number of congeners were detected for the first time in the atmospheric environment.


Asunto(s)
Contaminantes Atmosféricos , Hidrocarburos Clorados , Bifenilos Policlorados , Hidrocarburos Policíclicos Aromáticos , Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente , Europa (Continente) , Cromatografía de Gases y Espectrometría de Masas , Hidrocarburos Clorados/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Espectrometría de Masas en Tándem
13.
Mar Pollut Bull ; 168: 112375, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33895394

RESUMEN

Mapping of hydrophobic organic compounds (HOCs) in surface seawater on an east-to-west transect of the South Atlantic Ocean (SAO) and across the Black Sea (BS) in 2016 was performed by a dynamic passive sampling device containing silicone-based passive samplers. In SAO as well as in BS the measurements confirmed freely dissolved concentrations of polychlorinated biphenyls, DDT and its metabolites, chlorobenzenes, cyclodiene pesticides, and brominated flame retardants in the range of units to low hundreds of pg per litre. The findings indicate that the spatial distribution of HOCs and emerging pollutants in the SAO and the BS is influenced by riverine inputs, ocean currents and atmospheric deposition from continental plumes. Observed concentration gradients indicate that eastern SAO receives DDT from sources in South Africa, whereas the emissions of endosulfan originate in South America. Elevated HOC concentrations in the northwestern BS are related to their discharge by rivers from the European continent.


Asunto(s)
Plaguicidas , Bifenilos Policlorados , Océano Atlántico , Mar Negro , Monitoreo del Ambiente , Éteres Difenilos Halogenados/análisis , Plaguicidas/análisis , Bifenilos Policlorados/análisis , Agua de Mar , Sudáfrica , América del Sur
14.
Environ Sci Technol ; 55(14): 9434-9443, 2021 07 20.
Artículo en Inglés | MEDLINE | ID: mdl-33475343

RESUMEN

As a result of its unique location, Turkey receives air masses from Europe, Russia, Middle East, and Africa, making it an important place in terms of long-range atmospheric transport (LRT) of contaminants. Atmospheric levels of 22 organochlorine pesticides (OCPs), 45 polychlorinated biphenyls (PCBs), and 14 polybrominated diphenyl ethers (PBDEs) were measured in two metropolitan cities, Istanbul and Izmir, on a weekly basis from May 2014 to May 2015. Dichlorodiphenyltrichloroethane (DDT) and its derivatives were dominant OCP species, followed by isomers of hexachlorocyclohexane (HCH) at both sites. The annual mean concentration of ∑DDX (sum of o,p'-DDT, p,p'-DDT, o,p'-DDD, p,p'-DDD, o,p'-DDE, and p,p'-DDE) was 82 pg/m3 for Istanbul and 89 pg/m3 for Izmir, while these levels were about 46 pg/m3 for ∑HCHs (sum of α-, ß-, γ-, and δ-HCH) at both of the sites. At both stations, tri- and tetra-PCBs and tetra- and penta-PBDEs were dominant congeners. The temperature dependence indicates that both LRT and local contaminated areas contribute to the elevated levels. A Lagrangian particle dispersion model (FLEXPART) showed a few potential source regions in northern Africa and Middle East, southern-southwestern and eastern Europe including Russia, as well as from local domestic metropolitan areas.


Asunto(s)
Contaminantes Atmosféricos , Hidrocarburos Clorados , Plaguicidas , Bifenilos Policlorados , Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente , Hidrocarburos Clorados/análisis , Contaminantes Orgánicos Persistentes , Plaguicidas/análisis , Bifenilos Policlorados/análisis , Turquía
15.
J Hazard Mater ; 405: 124141, 2021 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-33087285

RESUMEN

The occurrence and bioaccumulation of new and legacy persistent organic pollutants (POPs), organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), hexabromocyclododecanes (HBCDs), and Dechlorane Plus (DPs) and their related compounds (Dechloranes) in an ecosystem on King George Island, Antarctica are investigated. The new and legacy POPs were widely detected in the animal samples collected from Antarctica, which included Limpet, Antarctic cod, Amphipods, Antarctic icefish, Gentoo and Chinstrap penguins, Kelp gull, and South polar skua. The trophic magnification factors indicated that the levels of PCNs and HBCDs, as well as the legacy POPs, were magnified through the food web, whereas DPs might be diluted through the trophic levels contradicting the classification of Dechloranes as POPs. This is one of the first extensive surveys on PCNs, HBCDs, and Dechloranes, which provides unique information on the distribution and trophic biomagnification potential of the new and legacy POPs in the Antarctic region.


Asunto(s)
Bifenilos Policlorados , Contaminantes Químicos del Agua , Animales , Regiones Antárticas , Bioacumulación , Ecosistema , Monitoreo del Ambiente , Contaminantes Orgánicos Persistentes , Bifenilos Policlorados/análisis , Contaminantes Químicos del Agua/análisis
16.
Environ Sci Pollut Res Int ; 28(42): 59317-59318, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32939650

RESUMEN

Recently, nearly 500 study programmes related to environmental disciplines were detected in Europe (Lammel et al, Environ Sci Pollut Res 21:7211-7218 2014). Following good practice from the 16th International Conference on Chemistry and the Environment (ICCE) in Oslo, during the 17th ICCE that took place in Thessaloniki, Greece, between 16 and 20 June 2019, a special Satellite Event dedicated to University Education in Environmental Sciences was organised. The session attracted students, teachers and experts from academia and industry/consulting. As conveners of the event, our aim was to provide an inspirative platform for presentation and discussion of curricula, present and future teaching methods and tools, and existing and new concepts of higher education of environmental topics.


Asunto(s)
Ciencia Ambiental , Universidades , Curriculum , Grecia , Humanos , Estudiantes
17.
Chemosphere ; 269: 128738, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33121801

RESUMEN

Nitrated and oxygenated polycyclic aromatic hydrocarbons (NPAHs, OPAHs) are abundant in the atmosphere and contribute significantly to the health risk associated with inhalation of polluted air. Despite the health hazard they pose, NPAHs and OPAHs were rarely included in monitoring. The aim of this study is to provide the first multi-year temporal trends of the concentrations, composition pattern and fate of NPAHs and OPAHs in air from a site representative of background air quality conditions in central Europe. Samples were collected every second week at a rural background site in the Czech Republic during 2015-2017. Concentrations ranged from 1.3 to 160 pg m-3 for Σ17NPAHs, from 32 to 2600 pg m-3 for Σ10OPAHs and from 5.1 to 4300 pg m-3 for Σ2O-heterocycles. The average particulate mass fraction (θ) ranged from 0.01 ± 0.02 (2-nitronaphthalene) to 0.83 ± 0.22 (1-nitropyrene) for individual NPAHs and from <0.01 ± 0.01 (dibenzofuran) to 0.96 ± 0.08 (6H-benzo (c,d)pyren-6-one) for individual OPAHs and O-heterocycles. The multiyear variations showed downward trends for a number of targeted compounds. This suggests that on-going emission reductions of PAHs are effective also for co-emitted NPAHs and OPAHs.


Asunto(s)
Contaminantes Atmosféricos , Hidrocarburos Policíclicos Aromáticos , Contaminantes Atmosféricos/análisis , República Checa , Monitoreo del Ambiente , Europa (Continente) , Humanos , Nitratos , Oxígeno/análisis , Material Particulado/análisis , Hidrocarburos Policíclicos Aromáticos/análisis
18.
Environ Sci Pollut Res Int ; 28(42): 59131-59140, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32529617

RESUMEN

Nitrated monoaromatic hydrocarbons (NMAHs) are ubiquitous in the environment and an important part of atmospheric humic-like substances (HULIS) and brown carbon. They are ecotoxic and with underresearched toxic potential for humans. NMAHs were determined in size-segregated ambient particulate matter collected at two urban sites in central Europe, Ostrava and Kladno, Czech Republic. The average sums of 12 NMAHs (Σ12NMAH) measured in winter PM10 samples from Ostrava and Kladno were 102 and 93 ng m-3, respectively, and 8.8 ng m-3 in summer PM10 samples from Ostrava. The concentrations in winter corresponded to 6.3-7.3% and 2.6-3.1% of HULIS-C and water-soluble organic carbon (WSOC), respectively. Nitrocatechols represented 67-93%, 61-73% and 28-96% of NMAHs in PM10 samples collected in winter and summer at Ostrava and in winter at Kladno, respectively. The mass size distribution of the targeted substance classes peaked in the submicrometre size fractions (PM1), often in the PM0.5 size fraction especially in summer. The bioaccessible fraction of NMAHs was determined by leaching PM3 samples in two simulated lung fluids, Gamble's solution and artificial lysosomal fluid (ALF). More than half of NMAH mass is found bioaccessible, almost complete for nitrosalicylic acids. The bioaccessible fraction was generally higher when using ALF (mimics the chemical environment created by macrophage activity, pH 4.5) than Gamble's solution (pH 7.4). Bioaccessibility may be negligible for lipophilic substances (i.e. log KOW > 4.5).


Asunto(s)
Contaminantes Atmosféricos , Material Particulado , Contaminantes Atmosféricos/análisis , Catecoles , Monitoreo del Ambiente , Humanos , Nitratos , Nitrocompuestos , Nitrofenoles , Material Particulado/análisis , Tolueno
19.
Environ Sci Technol ; 54(22): 14224-14234, 2020 11 17.
Artículo en Inglés | MEDLINE | ID: mdl-33112146

RESUMEN

Polycyclic aromatic hydrocarbons (PAHs) are common atmospheric pollutants and known to cause adverse health effects. Nitrated PAHs (NPAHs) are formed in combustion activities and by nitration of PAHs in the atmosphere and may be equally or more toxic, but their spatial and temporal distribution in the atmosphere is not well characterized. Using the global EMAC model with atmospheric chemistry and surface compartments coupled, we investigate the formation, abundance, and fate of two secondarily formed NPAHs, 2-nitrofluoranthene (2-NFLT) and 2-nitropyrene (2-NPYR). The default reactivity scenario, the model with the simplest interpretation of parameters from the literature, tends to overestimate both absolute concentrations and NPAH/PAH ratios at observational sites. Sensitivity scenarios indicate that NO2-dependent NPAH formation leads to better agreement between measured and predicted NPAH concentrations and that photodegradation is the most important loss process of 2-NFLT and 2-NPYR. The highest concentrations of 2-NFLT and 2-NPYR are found in regions with strong PAH emissions, but because of continued secondary formation from the PAH precursors, these two NPAHs are predicted to be spread across the globe.


Asunto(s)
Contaminantes Atmosféricos , Hidrocarburos Policíclicos Aromáticos , Contaminantes Atmosféricos/análisis , Atmósfera , Monitoreo del Ambiente , Fluorenos , Hidrocarburos Policíclicos Aromáticos/análisis , Pirenos
20.
Environ Pollut ; 265(Pt B): 114851, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32474357

RESUMEN

A total of 74 high volume air samples were collected at a background site in Czech Republic from 2012 to 2014 in which the concentrations of 20 per- and polyfluoroalkyl substances (PFASs) were investigated. The total concentrations (gas + particle phase) ranged from 0.03 to 2.08 pg m-3 (average 0.52 pg m-3) for the sum of perfluoroalkyl carboxylic acids (∑PFCAs), from 0.02 to 0.85 pg m-3 (average 0.28 pg m-3) for the sum of perfluoroalkyl sulfonates (ΣPFSAs) and from below detection to 0.18 pg m-3 (average 0.05 pg m-3) for the sum of perfluorooctane sulfonamides and sulfonamidoethanols (ΣFOSA/Es). The gas phase concentrations of most PFASs were not controlled by temperature dependent sources but rather by long-range atmospheric transport. Air mass backward trajectory analysis showed that the highest concentrations of PFASs were mainly originating from continental areas. The average particle fractions (θ) of ΣPFCAs (θ = 0.74 ± 0.26) and ΣPFSAs (θ = 0.78 ± 0.22) were higher compared to ΣFOSA/Es (θ = 0.31 ± 0.35). However, they may be subject to sampling artefacts. This is the first study ever reporting PFASs concentrations in air samples collected over consecutive years. Significant decreases in 2012-2014 for PFOA, MeFOSE, EtFOSE and ∑PFCAs were observed with apparent half-lives of 1.01, 0.86, 0.92 and 1.94 years, respectively.


Asunto(s)
Fluorocarburos/análisis , Ácidos Carboxílicos , República Checa , Monitoreo del Ambiente , Europa (Continente)
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