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2.
4.
Environ Monit Assess ; 192(2): 71, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31894417

RESUMO

The aim of this study is to investigate the relationship between bioclimatic comfort and land use in Trabzon by using geographical information systems and remote sensing technologies. We aimed to evaluate the relationship between the bioclimatic conditions of the years 1985, 1994, 2005, and 2018 with the use of land in the same years in the province of Trabzon in seasonal and annual periods. Physiological equivalent temperature (PET) index, which takes into consideration the physiological characteristics of humans, was used when determining bioclimatic comfort zones. The meteorological parameters used in the calculation of this index are as follows: daily average temperature values reduced to sea level, daily average relative humidity, and wind speed. The inverse distance weighting (IDW) method was preferred in the calculation of the spatial distribution of the obtained values at sea level. Using DEM data, height-dependent PET values were obtained and bioclimatic comfort maps were generated. According to the years of the bioclimatic comfort maps produced, land use maps were created by using CORINE land cover data. Then, the relationship between bioclimatic comfort zones and land use was examined.


Assuntos
Clima , Monitoramento Ambiental , Sistemas de Informação Geográfica , Humanos , Temperatura Ambiente , Vento
5.
Ying Yong Sheng Tai Xue Bao ; 31(1): 219-229, 2020 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-31957399

RESUMO

Using Landsat 5/TM and Landsat 8/OLI images in 2000 and 2017, based on remote sensing ecological index (RSEI) model, combined with meteorological observation data and socio-economic data in Nanjing from 2000 to 2017, we analyzed and evaluated the ecological environment changes and the characteristic ecological areas in Nanjing. The results showed that the average RSEI of Nanjing decreased from 0.626 to 0.618 during 2000-2017. The RSEI values could be divided into five grades: bad, poor, fair, good and excellent. The proportion of area above good grade decreased from 61.0% to 57.1%, while that below poor grade increased slightly. Compared with 2000, the proportion of areas with improved ecological environment quality was 34.5%, 34.7% area had deteriorated, and 30.8% area remained unchanged in 2017. Among them, the ecological quality of main urban area had significantly improved, and the area with improved ecological quality exceeded that of deterioration. The ecological quality of new urban area and suburbs had deteriorated. The area with poor ecological environment exceeded the area of improvement. Among the three ecological protection areas, the ecological quality of Zijin Mountain was significantly better than that of Laoshan Mountain and Jiangxinzhou. The urbanization rate was negatively correlated with RSEI, with a correlation coefficient of -0.91. The urbanization process would have negative impacts on the ecological environment in general. However, strict protection and management measures could maintain the good ecological environment even improve it.


Assuntos
Ecossistema , Urbanização , China , Monitoramento Ambiental , Tecnologia de Sensoriamento Remoto
6.
Chemosphere ; 240: 124909, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31550590

RESUMO

Environmental pollution and human health issues due to unrestricted electronic waste (e-waste) recycling activities have been reported at a number of locations. Among different e-waste recycling techniques, open burning of e-waste releases diverse metal(loid)s into the environment, which has aroused concern worldwide. In human health risk assessments (HHRAs), oral ingestion of soil can be a major route of exposure to many immobile soil contaminants. In vitro assays are currently being developed and validated to avoid overestimation of pollutants absorbed by the human body when calculating total pollutant concentrations in HHRAs. In this study, Cu, As, Cd, Sb, and Pb bioaccessibility in polluted soils (n = 10) from e-waste open burning sites at Agbogbloshie in Accra, Ghana, was assessed using an in vitro assay, the physiologically based extraction test. A bioaccessibility-corrected HHRA was then conducted to estimate the potential health risks to local inhabitants. The in vitro results (%) varied greatly among the different metal(loid)s (Cu: 1.3-60, As: 1.3-40, Cd: 4.2-67, Sb: 0.7-85, Pb: 4.1-57), and also showed marked variance between the gastric phase and small intestinal phase. The particle sizes of soil samples and chemical forms of metal(loid)s also influenced bioaccessibility values. Using these bioaccessibility values, both the hazard index and carcinogenic risk were calculated. The hazard index was above the threshold value (>1) for 5/10 samples, indicating a potential health risk to local inhabitants.


Assuntos
Resíduo Eletrônico , Metaloides/análise , Medição de Risco , Poluentes do Solo/farmacocinética , Disponibilidade Biológica , Exposição Dietética/efeitos adversos , Exposição Dietética/análise , Exposição Ambiental/efeitos adversos , Exposição Ambiental/análise , Monitoramento Ambiental , Gana , Humanos , Concentração de Íons de Hidrogênio , Metaloides/farmacocinética , Metaloides/toxicidade , Metais/análise , Metais/farmacocinética , Metais/toxicidade , Tamanho da Partícula , Reciclagem , Solo/química , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
7.
Chemosphere ; 240: 124910, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31561159

RESUMO

The micronucleus test has been applied for more than three decades in tadpoles, generating an early warning of environmental quality. In this study, we reviewed 48 articles on the micronucleus test in tadpoles, published between 1987 and 2018. The findings reveal that pesticides have been the main topic discussed in the induction of micronucleus and other nuclear abnormalities in anuran larvae to the detriment of the widespread use of compounds used in agriculture. In addition to pesticides, a number of other xenobiotic agents have been targeted for genotoxic damage, such as heavy metals, radiation and wastewater. An appeal is reported to environmental contaminants, which when released naturally into the environment or because of human activities may contaminate aquatic habitats, threatening populations of tadpoles that depend on these environments for their survival. Larvae can bioaccumulate these contaminants that cause progressive impacts, ranging from DNA damage to metamorphosis delays, as well as malformations. We found that Argentina is the main driving force for the application of this test in anuran larvae along with Brazil. Different erythrocyte malformations have been reported for the erythrocyte nuclear abnormalities test, binucleated cells, nuclear buds, notched, lobed, reniform, nuclear bebbled, anucleated, picnotic and apoptotic cells are the most cited. In summary, the presence of chemical or physical agents, along with other disturbances of the habitat, can have a significant impact on the life history of the species, contributing to the decline of anuran populations.


Assuntos
Anuros/genética , Ecotoxicologia/tendências , Eritrócitos/efeitos dos fármacos , Larva/efeitos dos fármacos , Larva/genética , Testes para Micronúcleos , Agricultura , Animais , Argentina , Brasil , Dano ao DNA , Ecossistema , Monitoramento Ambiental/métodos , Poluição Ambiental , Eritrócitos/patologia , Eritrócitos/fisiologia , Metais Pesados/toxicidade , Metamorfose Biológica/efeitos dos fármacos , Publicações Seriadas , Poluentes Químicos da Água/toxicidade
8.
Chemosphere ; 239: 124614, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31505444

RESUMO

Studies are carried out in two wet scrubbing systems (WSSs) subordinated to two similar full-scale (30 t h-1) municipal solid waste (MSW) incinerators to explore the influence factors and mass balance of memory effect on polychlorinated-ρ-dibenzodioxins and dibenzofurans (PCDD/Fs) emissions. The results show that the memory effect on two WSSs notably increases the TEQ concentrations by 13.6 and 3 times, respectively, through increase in the total mass concentration and the proportions of low-chlorinated PCDD/Fs, directly resulting in the PCDD/F emissions of 1# MSW incinerator over the national standard. PCDD/F adsorption/desorption in WSSs is the reasonable acting mechanisms of memory effect. In addition, memory effect mainly influences gaseous PCDD/F emissions by elevating the percentage of PCDFs, while slightly affects PCDD/Fs in residuals. A mass balance of PCDD/Fs is established to further analyze the influence factors of memory effect on WSSs, indicating filling as the largest potential source discharging PCDD/Fs into outlet flue gas. The results pave the way for further industrial optimization of WSSs design, such as the filling materials with less adsorption capacity on PCDD/Fs and more reasonable operation.


Assuntos
Poluentes Atmosféricos/análise , Benzofuranos/análise , Dibenzofuranos Policlorados/análise , Incineração/métodos , Dibenzodioxinas Policloradas/análise , Resíduos Sólidos/análise , China , Monitoramento Ambiental/métodos , Gases
9.
Chemosphere ; 239: 124644, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31514004

RESUMO

Per- and polyfluoroalkyl substances (PFASs) are a group of anthropogenic organic fluorinated compounds that have been detected widely. To discover unknown PFASs, previous researchers have applied high-resolution mass spectrometer using fragmentation flagging approach with common fragment ion at the same retention time as the flags. However, it was difficult to search for their molecular ion from co-eluting peaks in the full-scan spectrum at a specific retention time. Here, we attempted to utilize drift time acquired by ion mobility spectrometry for making linkages between fragment ions and their molecular ions. For validating the process, standard solution spiked with PFASs were analyzed by liquid chromatography/ion mobility - quadrupole time-of-flight mass spectrometry (LC/IM-QTOF-MS). Fluorinated fragment ions (fragmentation flags) were categorized into three classes: Class 1 (120 types of [CxFy]-), Class 2 (123 types of [CxFyO]-), Class 3 (131 types of [CxFyO3S]-) and all overlapping fragmentation flags detected at an identical retention time were bundled together as a "flag set". Injecting standard mixed solution of 20 types of PFASs resulted in picking up 20 flag sets by fragmentation flagging. All the fragmentation flags were detected within a designated range of drift time, and their molecular ion was confirmed as a PFAS spiked in the standard solution even when co-eluting compounds were found at almost same retention time. This method was applied to a household fire extinguisher liquid, resulting in finding out nine molecular ions. Therefore, the new linking method achieved rapid searching for the prospective molecular ions using LC/IM-QTOF-MS.


Assuntos
Monitoramento Ambiental/métodos , Fluorcarbonetos/análise , Espectrometria de Mobilidade Iônica/métodos , Cromatografia Líquida/métodos , Halogenação , Íons/análise , Estudos Prospectivos , Espectrometria de Massas em Tandem/métodos
10.
Chemosphere ; 239: 124642, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31521936

RESUMO

The occurrence of 24 pharmaceuticals (including 15 antibiotics, three analgesic/anti-inflammatory drugs, three anti-epileptic/antidepressant drugs, two beta blockers, and one lipid regulator) was investigated in 75 water samples collected from four bays in the Ugandan part of Lake Victoria. In addition, the potential environmental risk of the target pharmaceutical compounds to aquatic organisms in the aquatic ecosystem of Lake Victoria was assessed. Water samples were extracted using solid phase extraction and analyzed for pharmaceuticals using high-performance liquid chromatography coupled with triple quadrupole mass spectrometry (LC/MS/MS). Eighteen of the 24 pharmaceuticals occurred at quantifiable concentrations. Sulfamethoxazole (1-5600 ng L-1), trimethoprim (1-89 ng L-1), tetracycline (3-70 ng L-1), sulfacetamide (1-13 ng L-1), and ibuprofen (6-780 ng L-1) occurred at quantifiable concentrations in all water samples. Sulfamethazine (2-50 ng L-1), erythromycin (10-66 ng L-1), diclofenac (2-160 ng L-1), and carbamazepine (5-72 ng L-1) were only quantifiable in water samples from Murchison Bay. The highest concentrations of pharmaceuticals were found in Murchison Bay, the main recipient of sewage effluents, industrial and municipal waste from Kampala city via the Nakivubo channel. Ecotoxicological risk assessment showed that sulfamethoxazole, oxytetracycline, erythromycin, and diclofenac pose a high toxic risk to aquatic organisms in the lake, while ciprofloxacin, norfloxacin, and ibuprofen pose a medium risk. This study is the first of its kind to report the levels and ecotoxic risks of pharmaceutical compounds in Lake Victoria waters, of Uganda, and East Africa as a whole.


Assuntos
Monitoramento Ambiental/métodos , Lagos/química , Preparações Farmacêuticas/análise , Esgotos/química , Poluentes Químicos da Água/análise , Antagonistas Adrenérgicos beta/análise , Antibacterianos/análise , Anti-Inflamatórios não Esteroides/análise , Organismos Aquáticos/efeitos dos fármacos , Cromatografia Líquida , Cidades , Diclofenaco/análise , Ecossistema , Ecotoxicologia , Medição de Risco , Extração em Fase Sólida , Espectrometria de Massas em Tandem , Uganda
11.
Chemosphere ; 240: 124923, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31726605

RESUMO

The purpose of this study is to deepen the knowledge of the various emission phenomena present in aerated tanks, widely used systems for municipal and industrial wastewater treatment. In order to investigate the emission mechanism, a specific model was developed. The theoretical model proposes to consider three different contributions to the emission of organic compounds from aerated wastewater tanks: the convection due to the sweep air flow rate, the rising bubbles stripping and the aerosol formation and successive evaporation. To compare the modeled results, an experimental campaign was conducted with two different solutes, acetone and butanol. The sampling was carried out with a Wind Tunnel system and the outflow gas samples were analysed with gas chromatographic technique. Moreover, this study investigates the dependence of the concentration in the gaseous phase from the speed of the air on the surface (1-5 cm/s) and from the flow of air diffused inside the liquid body (50-200 L/h). The empirical data were compared with theoretical curves. The results confirm two facts: the gas solute concentration decreases as the air velocity increases and, instead, increases with the air flow diffused through the tank.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Modelos Teóricos , Compostos Orgânicos/análise , Aerossóis/análise , Veículos Automotores , Águas Residuárias/análise
12.
Chemosphere ; 240: 124757, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31726607

RESUMO

In this study, in order to determine atmospheric PAH concentrations in Inegol/Turkey, ambient air samples were collected from two different sites representing industrial and uncontrolled furniture manufacturers regions. Sampling campaign took place between December 2017 and November 2018. Air samples were collected using high volume air samplers (HVAS) and PAH concentrations were determined in both gas and particulate phases. The mean of the atmospheric PAH concentrations obtained in the gas phase in the furniture workshops (FW) and industrial district (ID) regions were 697.82 ±â€¯637 ng/m3 and 772.92 ±â€¯864.23 ng/m3, respectively. The concentrations in the particulate phase in the regions were 413.52 ±â€¯430.23 ng/m3 and 342.40 ±â€¯527.48 ng/m3, respectively. The average total (gas + particlulate phases) concentration of ∑16PAH determined in the site of FW was 1111.34 ±â€¯1045.24 ng/m3 while that was 772.92 ±â€¯864.23 ng/m3 in ID. These values are over the ambient levels reported for urban sites wherein big industries exist around the world. Additionally, the average of particle phase percentage was 30% because of nearby combustion sources. The determination of possible sources of PAHs in the regions was performed using principal component analysis (PCA). PCA results showed that the main sources of pollutants of the regions are intertwined (combustion, traffic, industries). However, the most effective source is thought to be uncontrolled combustion of furniture wastes as fuel for residential heating. Health risks for the citizens were calculated for both regions and were found not to be at high-class risk.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Indústrias , Material Particulado/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Cidades , Carvão Mineral/análise , Análise de Componente Principal , Estações do Ano , Turquia
13.
Chemosphere ; 240: 124933, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31726611

RESUMO

The occurrence, air-sea exchange, and gas-particle partitioning of polybrominated diphenyl ethers (PBDEs) were analyzed during a 2015 research expedition from the East China Sea (ECS) to the open Northwest Pacific Ocean (NWP). The sum of 13 PBDEs (Σ13PBDEs) in air and surface seawater varied in the range of 0.54-14.5. pg m-3 and 0.60-13.5 pg L-1, respectively, with the highest concentrations observed in the ECS. The Clausius-Clapeyron approach and air mass origin analysis indicated that continued primary emissions of PBDEs, particularly BDE-209, from East Asian sources governed the spatial variability of air PBDEs over the NWP through long-range atmospheric transport (LRAT). Net air-to-seawater gas deposition of PBDEs was evidenced based on the fugacity calculation with sum fluxes of seven selected PBDEs ranging from -45 to -582 pg m-2 d-1. Following the substantial advection of aerosol phase BDE-209 over the ECS, dry particle deposition dominated the input pathway of PBDEs into the ECS, whereas in the open NWP, relatively free from the influence of the land emissions, fluxes in PBDE absorption and in dry particle deposition were comparable. This suggests an impact of continental outflow on the fate of atmospheric PBDEs over the NWP. Regarding gas-particle partitioning, PBDEs over the NWP were obviously absorbed into continental organic aerosols during atmospheric transport, except for BDE-209, which tended to remain within the steady state.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Éteres Difenil Halogenados/análise , Aerossóis/análise , Ásia , Atmosfera/química , China , Extremo Oriente , Oceano Pacífico , Água do Mar
14.
Chemosphere ; 238: 124569, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31442777

RESUMO

Point pollution sources may differently impact lakes littoral, possibly leading to local ecological risks. The concomitant chemical analysis of littoral-benthic organisms and sediment can provide insights into the bioavailability and thus the ecological risk of contaminants. In this study, the autochthonous Corbicula fluminea was used to assess the sources and transfer of six trace metals (TMs) and fourteen Polycyclic Aromatic Hydrocarbons (PAHs) to the littoral-benthic biota of a large lake. The contaminant concentrations spatially varied with a value scale from 1 to 280 000 times along the lake littoral in both the sediment and clams. Multiple linear regressions were performed to explain the spatial variability of Corbicula fluminea contamination by considering both watershed and in-lake sources. The concentration of the sum of PAHs in clams was significantly correlated with sediment contamination, suggesting that PAHs contamination of the benthic biota mainly occur from the sediment. Most of the internal TM concentrations of clams were significantly correlated with stormwater drainage areas in the lake watershed, highlighting the importance of stormwater runoffs in the littoral biota contamination. The transfer of TMs and PAHs was assessed through the bioconcentration factor defined as the ratio of internal and sediment concentrations. As, Cd, Cu, Zn and light molecular weight PAHs were more bioconcentrated in C. fluminea than Pb, Sn and heavy molecular weight PAHs, suggesting differences in their bioavailability. This study underlines the relevance of using autochthonous organisms as bioindicators of lake littoral biota contamination concomitantly with sediment matrices, and illustrates the challenge of tracking pollution sources in lakes.


Assuntos
Corbicula/química , Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Hidrocarbonetos Policíclicos Aromáticos/análise , Oligoelementos/análise , Poluentes Químicos da Água/análise , Animais , Biota , Biomarcadores Ambientais , Lagos/química , Metais Pesados/análise , Alimentos Marinhos/análise
15.
Chemosphere ; 238: 124566, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31446272

RESUMO

How far-reaching is the influence of the urban area over the mineral composition of the Russula cyanoxantha mushroom? We studied the metal uptake behavior of this fungus relying on the soil properties. We sampled mushroom and soil from six forests according to an urbanization gradient, and two city parks in Cluj-Napoca (Romania). The elements were quantified using inductively coupled plasma - optical emission spectroscopy (ICP-OES). The concentrations of some elements differed significantly (p < 0.05) in the samples from the city (0.39 ±â€¯0.35 mg kg-1 for cadmium (Cd), 0.40 ±â€¯0.19 mg kg-1 for chromium (Cr), 69.1 ±â€¯29.9 mg kg-1 for iron (Fe), 10.9 ±â€¯1.3 mg kg-1 for manganese (Mn), 0.76 ±â€¯0.45 mg kg-1 for titanium (Ti) compared with the samples from the forests (3.15-14.1 mg kg-1 Cd, < 0.18 mg kg-1 for Cr, 22.6-34.5 mg kg-1 for Fe, 15.9-19.1 mg kg-1 for Mn, 0.19-0.36 mg kg-1 for Ti). We observed a definite negative trend in the mineral accumulation potential of this fungus along the urbanization gradient. The fungus turned from a cadmium-accumulator to a cadmium-excluder. This highlights a positive environmental influence of the urbanization over the toxic metal uptake of R. cyanoxantha. The hypothesis, that the urban soil pollution would increase the metal content of the mushroom was disproved. The possible explanation might be the elevated carbonate content of the urban soil, which is known to immobilize the metals in the soil.


Assuntos
Agaricales/química , Monitoramento Ambiental/métodos , Metais Pesados/análise , Poluentes do Solo/análise , Solo/química , Cádmio/análise , Cromo/análise , Cidades , Ferro/análise , Manganês/análise , Romênia , Urbanização
16.
Chemosphere ; 238: 124593, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31446275

RESUMO

This paper presents the abundance, concentration and variability of microplastics (MP) in an urban wastewater treatment plant (WWTP), according to different water parameters and environmental factors, their possible sources and removal efficiency. A total of 352.6 L of wastewater from four stages of the treatment process were processed following a standardized extraction protocol by density separation, trinocular microscopic identification and polymeric analysis by Fourier transform infrared spectroscopy. MP comprised a 46.6% of total microlitter, with a statistically significant removal of 90.3% in the final effluent of the WWTP. Five different shapes were isolated; i.e. fragment, film, bead, fiber, and foam. The most prominent MP forms in the final effluent were fragments and fibers, with the most common size class being 400-600 µm. Seventeen different polymer families were identified, with low-density polyethylene being the most prevalent one (52.4%) in a film form (27.7%), mostly from agriculture greenhouses near the sewage plant and single plastic bags (it is noted that only a year ago consumers are charged for them in Spain). Influent wastewater with high concentrations of suspended solids proved to have a low MP burden with a larger MP size, possibly due to a hetero-aggregation with particulate matter. Agglomeration of polystyrene and polyethylene terephthalate with organic material is also suggested, both with surface energies higher than 25 mN m-1 enough for a high biofouling rate. The sewage plant cushions sharp-point microplastic concentrations during the warm season, allowing a stable performance of the WWTP.


Assuntos
Monitoramento Ambiental/métodos , Esgotos/química , Poluentes Químicos da Água/análise , Purificação da Água , Incrustação Biológica , Polietilenotereftalatos/análise , Poliestirenos/análise , Espanha , Espectroscopia de Infravermelho com Transformada de Fourier
17.
Chemosphere ; 238: 124577, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31450111

RESUMO

Biota samples from the Vancouver municipal landfill located in Delta, BC, Canada, have some of the highest polybrominated diphenyl ether (PBDE) levels reported from North America. We followed a population of European starlings (Sturnus vulgaris) breeding in a remediated area in the landfill to identify exposure routes and bioaccumulation of PBDEs in a simple terrestrial food chain. This population was compared to a reference farm site located 40 km east in Glen Valley. We analyzed samples of European starling eggs and nestling livers as well as invertebrate prey species consumed by starlings for PBDE concentrations. We also collected soil samples from starling foraging areas. All samples from the Delta landfill had higher PBDE congener concentrations compared to the Glen Valley reference site and were dominated by BDE-99 and BDE-47. Stable nitrogen (δ N15) and carbon (δ C13) isotope analysis of starling blood samples and provisioned invertebrates revealed that stable δC13 signatures differed between the sites indicating that the diet of starlings in the Delta landfill included a component of human refuse. Biota-soil accumulation factors (BSAFs) > 1 demonstrated that PBDEs were bioaccumulating in soil invertebrates, particularly earthworms, which were readily accessible to foraging starlings in the landfill. Biomagnification factors (BMFs) calculated from foraged food items and starling egg and liver samples were >1, indicating that a diet of soil invertebrates and refuse contributed substantially to the PBDE exposure of local starlings.


Assuntos
Bioacumulação/efeitos dos fármacos , Éteres Difenil Halogenados/análise , Oligoquetos/química , Estorninhos/metabolismo , Animais , Canadá , Exposição Ambiental , Monitoramento Ambiental , Cadeia Alimentar , Humanos , Solo/química , Instalações de Eliminação de Resíduos
18.
Chemosphere ; 238: 124564, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31472348

RESUMO

Microplastics pose a worldwide risk for the environment. Microplastic fibers, which are released during the household washing of synthetic fabrics, are a substantial percentage of microplastics in rivers and in oceans. A novel quantification and simultaneous identification of fiber polymers via Micro-FTIR (Fourier Transform Infrared Spectroscopy) was developed. Washing simulations with commercially available household products were performed and effluents were filtered either on GF/F filters (0.7 µm) or on Anodisc filter (0.2 µm), to gather even the smallest fibers. Furthermore, a novel purification procedure of effluents was developed. Subsequently, filters were analyzed also with the scanning electronic microscope (SEM) to confirm the width and length of fibers. This novel method is robust and replicable and it allows better quantification of fibers released and identification of fiber polymers with optimal matches (averagely 80%).


Assuntos
Monitoramento Ambiental/métodos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Poluentes Químicos da Água/análise , Filtração , Produtos Domésticos/análise , Microscopia , Têxteis/análise
19.
Chemosphere ; 238: 124630, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31473530

RESUMO

Mercury (Hg) mining activities are an important anthropogenic source of atmospheric Hg. The Xunyang Hg mine located in Shaanxi Province is the largest active Hg producing centre in China. To understand the biogeochemical processes of atmospheric Hg through Hg mining activities, six groups of experimental pots were carefully designed to investigate the effect of Hg mining activities on Hg contamination from atmospheric deposition in the local surface soils. Based on the variations of Hg in the soil from the experimental pots, the deposition flux and loading of Hg in the Xunyang Hg mining district were investigated. The results showed that the average concentration of total gaseous mercury (TGM) as high as 193 ±â€¯122 ng m-3 was observed in the ambient air, which was orders of magnitude higher than that in remote areas. The average deposition flux and annual loading of atmospheric Hg were 72 mg m-2 y-1 and 10 t y-1, respectively. The dominant atmospheric Hg deposition is within a distance range of 6.0-12 km from the Hg retorting facility, accounting for approximately 85% of the total Hg loading. After 14 months of exposure, total mercury (THg) concentrations in the soil from the experimental pots increased 0.35-9.5 times, and the highest concentrations of methylmercury (MeHg) (3.7 ±â€¯2.9 µg kg-1) in soil were observed in February. Concentrations as high as 643 µg kg-1 THg and 13 µg kg-1 MeHg in rice were observed in the second experimental year. Elevated concentrations of both THg and MeHg in rice indicated that the newly deposited atmospheric Hg was bioavailable, readily methylated, and taken up by rice, suggesting that the ongoing Hg mining activities cause serious Hg contamination in the soil-rice ecosystem and posed a threat to local residents in the Xunyang Hg mining area.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Mercúrio/análise , Compostos de Metilmercúrio/análise , Oryza/química , Poluentes do Solo/análise , Atmosfera/química , China , Ecossistema , Mineração , Solo/química
20.
Chemosphere ; 238: 124578, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31524601

RESUMO

Twenty-four per- and polyfluoroalkyl substances (PFASs) were analyzed in water and sediment from the Jiulong Estuary-Xiamen Bay to study their seasonal variations, transport, partitioning behavior and ecological risks. The total concentration of PFASs in water ranged from 11 to 98 ng L-1 (average 45 ng L-1) during the dry season, 0.19-5.7 ng L-1 (average 1.5 ng L-1) during the wet season, and 3.0-5.4 ng g-1 dw (average 3.9 ng g-1 dw) in sediment. In water samples, short-chain PFASs were dominated by perfluorooctanoic acid (PFBA) in the dry season and perfluorobutane sulfonate (PFBS) in the wet season, while long chain PFASs, such as perfluorooctane sulfonate (PFOS), dominated in the sediment. The highest concentration of PFASs in water were found in the estuary; in contrast, the highest level of PFASs in sediment were found in Xiamen Bay. These spatial distributions of PFASs indicate that river discharge is the main source of PFASs in estuarine water, while the harbor, airport and wastewater treatment plant near Xiamen Bay may be responsible for the high PFBS and PFOS concentrations in water and sediment. The partition coefficients (log Kd) of PFASs between sediment and water (range from 1.64 to 4.14) increased with carbon chain length (R2 = 0.99) and also showed a positive relationship with salinity. A preliminary environmental risk assessment indicated that PFOS and perfluorooctanoic acid (PFOA) in water and sediment pose no significant ecological risk to organisms.


Assuntos
Ácidos Alcanossulfônicos/análise , Baías/química , Caprilatos/análise , Fluorcarbonetos/análise , Sedimentos Geológicos/química , Rios/química , Ácidos Sulfônicos/análise , Poluentes Químicos da Água/análise , China , Monitoramento Ambiental , Estuários , Salinidade , Estações do Ano
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