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1.
Mar Pollut Bull ; 206: 116777, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39083910

RESUMEN

This study evaluates the performance of three typical convolutional neural network based deep learning algorithms for oil spill detection using medium-resolution optical satellite imagery from Sentinel-2 MSI, Landsat-8 OLI, and Landsat-9 OLI2. Oil slick training and validation dataset were created through a semi-automatic labeling approach, based on chronic and accidental oil spill cases reported worldwide. The research enhances UNet, BiSeNetV2, and DeepLabV3+ architectures by integrating attention mechanisms including the Squeeze-and-Excitation module (SE), Convolutional Block Attention Module (CBAM), and a Simple, parameter-free Attention Module (SimAM), analyzing the optimal model for oil spill detection. Notably, UNet integrated with CBAM, especially with sun glint as a feature, significantly outperformed others, achieving a micro-average F1 score of 88.8 %. This research highlights deep learning's potential in optical remote sensing for oil spill detection, stressing its escalating relevance with the growing deployment of medium- to high-resolution optical satellites.


Asunto(s)
Aprendizaje Profundo , Monitoreo del Ambiente , Contaminación por Petróleo , Imágenes Satelitales , Monitoreo del Ambiente/métodos , Algoritmos , Redes Neurales de la Computación , Tecnología de Sensores Remotos
2.
Phytomedicine ; 129: 155619, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38723524

RESUMEN

BACKGROUND: As a common complication of diabetes, diabetic cardiomyopathy (DCM) often leads to further damage to the heart muscle. Curcumin has been proven to have a variety of cardioprotective effects, however, the protective effect against DCM has not been systematically reviewed. PURPOSE: In this study, we aimed to analyze the preclinical (animal model) evidence of curcumin's therapeutic effects in DCM. METHODS: Eight databases and two registry systems were searched from the time of library construction to 1 November 2023. We performed rigorous data extraction and quality assessment. The included studies' methodological quality was appraised using the SYRCLE RoB tool, statistical analyses were carried out using RevMan 5.4 software, and Funnel plots and Egger's test were performed using Stata 17.0 software to assess publication bias. RESULTS: This study included 32 trials with a total of 681 animals. Meta-analysis showed that curcumin significantly improved cardiac function indices (LVEF, LVFS, and LVSd) (p < 0.01), decreased markers of myocardial injury, HW/BW ratio, and randomized blood glucose compared to the control group, in addition to showing beneficial effects on mechanistic indices of myocardial oxidation, inflammation, apoptosis, and autophagy (p < 0.05). CONCLUSIONS: Curcumin may exert cardioprotective effects in DCM through its antioxidant, anti-inflammatory, autophagy-enhancing, and anti-apoptotic effects. Its protective effect is proportional to the dose, and the efficacy may be further increased at a concentration of more than 200 mg/kg, and further validation is needed.


Asunto(s)
Cardiotónicos , Curcumina , Cardiomiopatías Diabéticas , Curcumina/farmacología , Curcumina/uso terapéutico , Cardiomiopatías Diabéticas/tratamiento farmacológico , Cardiomiopatías Diabéticas/prevención & control , Animales , Cardiotónicos/farmacología , Cardiotónicos/uso terapéutico , Apoptosis/efectos de los fármacos
3.
Gene ; 833: 146572, 2022 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-35609799

RESUMEN

Paris L. genus has been a precious traditional herb for more than 2000 years in China. However, due to overexploitation and habitat destruction, Paris is threatened by extinction. Similar morphological features cause the classification of Paris species in dispute. The chloroplast (cp) genome approach has been used to investigate the evolution of Paris. However, some studies confirm that the cp genome may result in misleading relationships because of the length variation, gaps/indels deletion, and incorrect models of sequence evolution in concatenated datasets. Therefore, there is a high demand for a reconstructed phylogenetic relationship and developed genetic markers to conserve these species. Recent studies have demonstrated that the protein-coding genes could provide a better phylogenetic relationship in the phylogenetic investigation. In this study, the complete cp genomes of five species were characterized, and the length of five cp genomes ranges from 162,927 bp to 165,267 bp, covering 89 protein-coding genes, 38 tRNA, and eight rRNA. The analysis of the repeat sequences, codon usage, RNA-editing sites, and comparison of cp genomes shared a high degree of conservation. Based on the protein-coding genes, the phylogenetic tree confirmed Paris's position in the order Melanthiaceae, providing maximum support for a sister relationship of the subgenera Paris sensu strict (Paris s.s.) with the Daiswa and Trillium. In addition, the molecular clock showed that subgenus Paris was inferred to have occurred at about 52.81 Mya, whereas subgenus Daiswa has originated at 24.56 Mya, which was consistent with the phylogenetic investigation. This study provided a valuable insight into the evolutionary dynamics of cp genome structure in the family Melanthiaceae, and it also contributes to the bioprospecting and conservation of Paris species.


Asunto(s)
Genoma del Cloroplasto , Animales , Especies en Peligro de Extinción , Filogenia , Edición de ARN , Secuencias Repetitivas de Ácidos Nucleicos
4.
Biomed Chromatogr ; 36(4): e5320, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34984722

RESUMEN

Polygonati Rhizoma (Huangjing) is traditional medicine in China, which can only be used as medicine after being processed. However, there is a limited theoretical basis for analyzing the changes in chemical components after traditional processing. In this study, analytical techniques including Fourier transform infrared spectroscopy, high-performance gel permeation chromatography-evaporative light scattering detection, and HPLC-diode array detection were proposed to perform multiple fingerprint analyses of the changes in the processed materials; the total sugar was also determined. Moreover, the chemometric studies, including hierarchical cluster analysis and principal component analysis, were used to visualize the discrimination of raw and processed materials. The results revealed that the chemical constituents had been profoundly changed following sample processing. In conclusion, these methods could be successfully used to compare raw and processed materials of Polygonatum kingianum, which could be used to elaborate the rationality of processing from the perspective of chemical composition.


Asunto(s)
Medicamentos Herbarios Chinos , Polygonatum , China , Cromatografía Líquida de Alta Presión , Medicamentos Herbarios Chinos/química , Polygonatum/química , Análisis de Componente Principal , Rizoma
5.
Ecotoxicol Environ Saf ; 225: 112747, 2021 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-34488146

RESUMEN

Understanding the metal pollution can help governments and estuary management groups manage metal inputs. Here, we comprehensively analyzed the behaviors of seven metals Cd, Zn, Cu, As, Pb, Cr, and Hg in water and the responses of these metals to hydrological connectivity in the Pearl River Estuary. The analyses were based on the field measurements of August-2016 in the estuary and January-2016 in the upper river mouth. We also assessed the ecosystem health of these metals. Overall, this estuary had an overall moderate pollution level, with occasional severe perturbations. The mean concentration of individual metal was in the order of Zn > As > Cu > Cr > Pb > Cd > Hg. The eastern estuary was more heavily polluted by metals (notably, Zn, Cd, and Cu) than the western estuary; this condition was attributable to sewage and industrial effluent discharges from the eastern urban cities of Dongguan and Shenzhen. Longitudinally, high levels of Cd and Zn appeared in the upper estuary, while elevated levels of Cu, As, Pb, Cr, and Hg were found in the middle and lower estuaries. The riverine inputs and estuarine mixing significantly influenced the distribution and movement of trace metals in the estuary, and have contributed to phytoplankton productivity (chlorophyll-a > 10 µg/L). River inflow inhibited the vertical diffusion of metals, and tidal currents facilitated surface-to-bottom mixing. Cu and Cd posed ecological risks. We determined the source contributions and transport routes of the metals using principal component analysis combining with multiple linear regression. The results of this study suggest that the source apportionment of metals can help to manage the source input entering into the estuary. Further, identified hydrological connectivity of metals can inform water quality managers in the highly anthropogenically influenced estuary.


Asunto(s)
Estuarios , Ríos , Ecosistema , Hidrología , Calidad del Agua
6.
Environ Pollut ; 290: 118126, 2021 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-34523508

RESUMEN

Sediment samples were collected to clarify the effect of changing sedimentary environment under long-term reclamation on heavy metals (Cr, Zn, Pb, Cu, Cd, and Ni) in a partially mixed estuary (Modaomen) of the Pearl River Delta. The ecological toxicity and source apportionment of these metals were discussed as well. The metal species during the 2010s (as 2015, 2018) was more enriched than that during the 2000s (as 2003) and 1990s (as 1991). This estuary overall suffered from a "moderate-to-high" pollution status. The element Cd was a major concern for the ecosystem's health because of its high toxicity. Sediment quality guidelines suggested that adverse biological effects were likely to be caused by Cu and Cd in the early adjustment stage, while the threats to marine organisms caused by the elements of Cu, Cr, Zn, and Ni were elevated during the 2010s. Two receptor models of PCA-MLR and PMF quantified the source types and contributions of these heavy metals. Strong intensity of industrial activities coupling with agricultural applications and import of adjacent seas were responsible for the enriched accumulation of heavy metals in sediments. Metal source apportionment would help to control the metal input into the estuary; identifying the role of sedimentary environment on heavy metals can inform the sediment quality management in the estuary.


Asunto(s)
Metales Pesados , Contaminantes Químicos del Agua , China , Ecosistema , Monitoreo del Ambiente , Estuarios , Sedimentos Geológicos , Metales Pesados/análisis , Metales Pesados/toxicidad , Medición de Riesgo , Ríos , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad
7.
Mitochondrial DNA B Resour ; 6(9): 2503-2504, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34377807

RESUMEN

Paris polyphylla var. alba is a medicinal plant commonly used in the southwest of China. This study characterized the complete chloroplast (cp) genome sequence of P. polyphylla var. alba to investigate its phylogenetic relationship in Melanthiaceae. The cp genome of P. polyphylla var. alba is 165,079 base pairs (bp) in length with 36.96% G + C content. The cp genome is divided into (a) large single copy (LSC) (84,393 bp), (b) small single copy (SSC) (16,066 bp), and (c) two inverted regions (32,310 bp). The cp genome contains 135 genes, including 89 protein-coding genes, 38 tRNA genes, and 8 rRNA genes. Phylogenetic analysis indicated that P. polyphylla var. alba is closest to P. polyphylla var. emeiensis, and Paris had a close relationship with Trillium in Melanthiaceae.

8.
Mitochondrial DNA B Resour ; 6(2): 346-348, 2021 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-33659673

RESUMEN

Paris liiana sp. nov is a species of flowering herb of the genus Paris and widely distributed in the southwest of China. In this study, we sequenced the complete chloroplast (cp) genome of P. liiana sp. nov to investigate its phylogenetic relationship in genus Paris. The cp genome of P. liiana sp. nov was 163,860 bp in length, containing a large single-copy (LSC) region of 84,415 bp, a small single-copy (SSC) region of 12,947 bp, and a pair of inverted repeats (IRs) region of 33,249 bp. The overall GC content was 37.0%. The genome comprises of 135 genes, including 91 protein-coding genes, 37 tRNA genes, and 4 rRNA genes. Phylogenetic relationship analysis based on complete cp genome sequences exhibited that P. liiana sp. nov was most related to P. polyphylla var. yunnanensis.

9.
Mar Pollut Bull ; 162: 111831, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33229004

RESUMEN

Understanding the transportation of polycyclic aromatic hydrocarbons (PAHs) across the water-sediment interface can help researchers to partition their sources while being particularly important for managing PAH input. This study fully explored the PAH dynamics between water and sediment in a tide-dominated estuary. The monthly concentration of ΣPAHs in sediments ranged from 325.47 to 1098.49 ng/g (dry weight), while that in water varied from 154.00 to 725.80 ng/L. The PAH levels found in the present study were relatively high in comparison with other estuarine systems worldwide. The high-molecular-weight PAHs were more readily redissolved from sediment to water, while the low-molecular-weight PAHs were mostly in an unsaturated state with diffusion occurring from water to sediment. The seasonal differences of ΣPAHs were significant and were largely controlled by the changes in sediment properties, marine currents, and water temperature. The diagnostic ratios revealed that predominant sources of PAHs were pyrogenic processes and petrogenic inputs.


Asunto(s)
Hidrocarburos Policíclicos Aromáticos , Contaminantes Químicos del Agua , China , Monitoreo del Ambiente , Estuarios , Sedimentos Geológicos , Hidrocarburos Policíclicos Aromáticos/análisis , Ríos , Estaciones del Año , Agua , Contaminantes Químicos del Agua/análisis
10.
Environ Sci Pollut Res Int ; 27(10): 10925-10938, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31953768

RESUMEN

Based on a monthly field survey in 2011 of the Pearl River Estuary, the dynamics of polycyclic aromatic hydrocarbons (PAHs) in surface sediments (depth < 5 cm) were explored. The seasonal variations in PAH level and composition were investigated in this study, as well as their environmental behaviors, the role of particles, and source apportionment. The concentration of the sum of 16 priority PAHs (defined as ∑16PAHs) ranged from 0.32 to 1.10 µg/g, while that of the sum of 62 PAHs (defined as ∑tPAHs) varied from 0.83 to 2.75 µg/g. The levels of both the ∑16PAHs and ∑tPAHs peaked in February, although the minimum levels appeared in different months-December and August, respectively. The seasonal difference in the ∑tPAHs was significant (flood season, 7.69 µg/g; dry season, 10.51 µg/g). The 5-ring PAH compound (e.g., perylene) was the most abundant and was responsible for 35% of the total, which implied a terrestrial input source via the Pearl River. Sediment particles were predominantly composed of clayed sand, and sediment PAHs showed a greater tendency to be adsorbed onto the large-sized particles rather than the fine fractions. Total organic carbon (TOC) could considerably facilitate the sediment PAHs. Principal component analysis revealed that vehicle emission sources, petroleum sources, and combustion sources were the major anthropogenic contamination sources. The diagnostic ratios of various individual PAHs were also explored. These findings are particularly useful for understanding the geochemistry of organic pollutants in the complex estuarine environment.


Asunto(s)
Hidrocarburos Policíclicos Aromáticos/análisis , Contaminantes Químicos del Agua/análisis , China , Monitoreo del Ambiente , Estuarios , Sedimentos Geológicos , Ríos
11.
Mar Pollut Bull ; 131(Pt A): 276-283, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29886948

RESUMEN

To examine the impacts of estuarine mixing on the dispersion of polycyclic aromatic hydrocarbons (PAHs), seasonal variations in the vertical distribution of dissolved PAHs in the Humen River mouth of the Pearl River Estuary, which is a tide-dominated estuary, were thoroughly examined. An analysis of the vertical distribution of the concentration, composition and sources of PAHs indicates enhanced mixing of PAHs in January relative to June, which is strongly related to seasonal variations in the magnitude of estuarine mixing. Furthermore, the vertical distribution of PAHs initially indicated an increase and then a decrease from the surface layer to the bottom layer. In general, estuarine mixing promotes the vertical dispersion of PAHs, causing a more even PAHs distribution, while salinity stratification can trap PAHs, resulting in higher PAHs concentrations. Our study indicates that salinity variability stimulates significant dynamic effects regarding the dispersion of PAHs within estuarine environments.


Asunto(s)
Estuarios , Hidrocarburos Policíclicos Aromáticos/análisis , Contaminantes Químicos del Agua/análisis , China , Monitoreo del Ambiente/métodos , Ríos , Salinidad , Estaciones del Año
12.
Mar Pollut Bull ; 117(1-2): 255-263, 2017 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-28187969

RESUMEN

The behaviours of PAHs (containing 2-6 aromatic rings) in the Pearl River estuary were examined each month in 2011. This study was designed to investigate the abundance of 16 priority PAHs and their response to the seasonal dynamics of anthropogenic activities and hydrological cycles. Monthly mean concentrations of ∑16PAHs in water and suspended particulate matter (SPM) were 88.31ng/L and 252.31ng/L respectively, with higher concentrations in the wet season (April to September). Heavy precipitation in the wet season resulted in relatively increased PAH input via riverine discharges and atmospheric deposition. Seasonal variations in suspended sediment concentration (SSC), temperature and salinity have considerably affected the PAH phase association. Higher SSC in the wet season contributed to higher concentration of the PAHs in SPM, and higher temperature and lower salinity facilitated desorption from SPM. The PAH sources were largely attributed to vehicular emissions, coal combustion and coke ovens.


Asunto(s)
Monitoreo del Ambiente , Estuarios , Hidrocarburos Policíclicos Aromáticos/análisis , Estaciones del Año , Contaminantes Químicos del Agua/análisis , China , Sedimentos Geológicos , Hidrología , Ríos
13.
Environ Pollut ; 199: 66-72, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25618368

RESUMEN

Distributions of 31 parent polycyclic aromatic hydrocarbons (PAHs) and 29 alkyl PAHs in surface sediments of the Pearl River Estuary (PRE), Daya Bay (DYB) and northern South China Sea (SCS) were examined to study the influence of riverine input. It was found that the contributions of riverine input to sediment PAHs in PRE was much higher than other areas. However, higher proportion of alkyl PAHs and low molecular weight PAHs in DYB and the northern SCS was observed, indicating their different sources. Nevertheless, the sediment PAHs in PRE were heterogeneous and affected by the hydrodynamic conditions. The high molecular weight PAHs were dominant in PRE and enriched in the depositional area of suspended particular matter (SPM). Moreover, the concentration of PAHs in SPM was similar to those in surface sediments and dominated in water columns. Therefore, SPM played a very important role in transportation and distribution of PAHs in PRE.


Asunto(s)
Monitoreo del Ambiente , Estuarios , Hidrocarburos Policíclicos Aromáticos/análisis , Ríos/química , Contaminantes Químicos del Agua/análisis , Bahías/química , China , Sedimentos Geológicos/química
14.
Mar Pollut Bull ; 84(1-2): 401-10, 2014 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-24837319

RESUMEN

Five different water samples were collected from the surface to the bottom layers at the Humen river mouth in the Pearl River delta during the flood and ebb tides in August 2011, respectively. Changes in the distribution and characteristics of polycyclic aromatic hydrocarbons (PAHs) were examined to explore their transportation process. More than 62 types of PAHs were detected in the water columns. The mean concentration of the total PAHs ranged from 849.33 to 1370.53 ng/l and from 629.21 to 2019.91 ng/l during the flood and ebb tides, respectively. Furthermore, 2-ring PAHs were the most abundant species, followed by 3-ring PAHs. There were different composition patterns of the PAHs during the flood and ebb tides. And the transportation process of PAHs was influenced by their sources and different estuarine hydrodynamics. Analysis of the sources of the PAHs indicated that the PAHs were derived from primarily petroleum and coal combustion sources.


Asunto(s)
Monitoreo del Ambiente/métodos , Hidrocarburos Policíclicos Aromáticos/química , Ríos/química , Contaminantes Químicos del Agua/química , China , Carbón Mineral/análisis , Petróleo/análisis
15.
J Sep Sci ; 35(8): 1017-26, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22589163

RESUMEN

A fully automated combination of solid-phase microextraction and on-fiber derivatization coupled with gas chromatography-mass spectrometry was developed to determine 17 chlorophenols in aqueous samples. Optimal parameters for the automated process, such as fiber coating (polyacrylate), derivatization reagent (N,O-bis(trimethylsilyl) trifluoroacetamide), extraction time (60 min), derivatization time (5 min), incubation temperature (35°C), sample pH (3), and ionic strength (300 g L(-1) of NaCl), as well as desorption time (5 min) and desorption temperature (270°C) were established. The whole procedure took only 90 min and was performed automatically. The shortcomings of silylation derivatives, like incompleteness and instability, were overcome by using solid-phase microextraction on-fiber silylation in this study. The results from both pure water and river water samples showed that the method had a good linearity (r(2) = 0.9993-1.0000), ranging from 0.01 to 100 µg L(-1). The related standard deviations were between 3.6 and 10.0%. The limits of detections and qualifications ranged from 0.03 to 3.11 ng L(-1) and 0.09 to 10.4 ng L(-1) for the CPs, respectively. The proposed method is superior to traditional solid phase extraction procedure.


Asunto(s)
Clorofenoles/análisis , Clorofenoles/aislamiento & purificación , Cromatografía de Gases y Espectrometría de Masas/métodos , Microextracción en Fase Sólida/métodos , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/aislamiento & purificación , Automatización , Ríos/química , Microextracción en Fase Sólida/instrumentación
16.
Environ Monit Assess ; 145(1-3): 427-36, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18080780

RESUMEN

Water samples were collected in the Pearl River Estuary in July 2002 and April 2003. The particulate and dissolved phase polycyclic aromatic hydrocarbons (PAHs) were determined. Total PAH concentrations in water samples were higher in April of 2003 (C (p): 4.0-39.1 ng/L or 445.1-1,089.9 ng/g; C (w): 15.9-184.2 ng/L) than in July of 2002 (C (p): 2.6-26.6 ng/L or 297.7-1,336.6 ng/g; C (w): 12.9-28.3 ng/L). It was found that 5, 6-ring PAHs enrich in the inner estuary samples and so did 3-ring PAHs in the July samples. Compositional differences in the suspended particulate matter (SPM) might be responsible for this observation. The partition coefficient (K (p)) increased with the increasing of the particular organic carbon content of suspended particles as well as the salinity of water, decreased with the increase of the total suspended particles content of samples. A linear correlation between logK (OC) and logK (OW) was found in two sampling periods. The observed values of logK (OC) exceed their predicted values derived form linear free energy relationship between logK (oc) and logK (ow), which could be attributed to the nonlinear sorption of soot-like carbons in suspended particles.


Asunto(s)
Compuestos Policíclicos/análisis , Contaminantes Químicos del Agua/análisis , China , Control de Calidad
17.
Chemosphere ; 63(4): 652-61, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16216309

RESUMEN

The occurrence of alkylphenols (APs) was investigated in surface water and sediments from the Pearl River Delta and adjacent northern South China Sea. Most of the water samples contained detectable amounts of APs, ranging up to 0.628 microg l(-1) for nonylphenol (NP) and 0.068 microg l(-1) for octylphenol (OP). APs were found in all of the sediment samples with concentrations ranging from 59 to 7808 microg kg(-1) for NP and from 1 to 93 microg kg(-1) for OP. The Zhujiang River showed the highest concentrations of APs in both water and sediments. Significant decrease of APs concentrations going from the Zhujiang River to the Shiziyang River was observed. The Xijiang River contained concentrations of APs slightly higher in water but relatively lower in sediments than the Lingding Bay, which might be attributed to their different hydrodynamic and sedimentary characteristics. There was a decreasing trend of APs in water from the rivers to the estuary and further to the sea on the whole. In the Lingding Bay and its outer waters, concentrations of APs in sediments increased to a maximum and then decrease seaward, which was consistent with the distribution trend of the sediment organic carbon contents. Linear regression analyses showed the concentrations of APs were markedly correlated with the sediment organic carbon contents, indicating that the sediment organic carbon is an important factor controlling the levels of APs in sediments.


Asunto(s)
Fenoles/análisis , Contaminantes Químicos del Agua/análisis , China , Monitoreo del Ambiente , Sedimentos Geológicos , Fenoles/química , Ríos , Agua de Mar
18.
Environ Pollut ; 139(1): 9-20, 2006 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-15996803

RESUMEN

The spatial distribution, composition, and sources of polycyclic aromatic hydrocarbons (PAHs) in sediments and suspended particulate matter (SPM) from the Pearl River Estuary and adjacent coastal areas were examined. Total PAH concentrations varied from 189 to 637 ng/g in sediments and 422 to 1,850 ng/g in SPM. PAHs were dominated by 5,6-ring compounds in sediments and by 2,3-ring compounds in SPM samples. Assessment of PAH sources suggested that biomass and coal combustion is the major PAH source to the outer part of the estuary sediments and that petroleum combustion is the major PAH source to the inner part of estuary sediments. As for SPM samples, PAH isomer pair ratios indicated multiple (petroleum, petroleum combustion, and biomass and coal combustion) PAH sources, and significant temporal variations could exist for the sources of water column PAHs in the study area. The distribution of perylene in SPM samples indicated that the river was the dominant source of perylene in SPM and that perylene could be taken as an index to assess the contribution of river inflow to the total PAHs in SPM samples. The high concentration of perylene in the sediment was indicative of an in situ biogenic origin.


Asunto(s)
Sedimentos Geológicos/química , Hidrocarburos Policíclicos Aromáticos/análisis , Contaminantes Químicos del Agua/análisis , Biomasa , Carbono/análisis , China , Carbón Mineral , Residuos Industriales , Peso Molecular , Océanos y Mares , Perileno/análisis , Petróleo , Análisis de Componente Principal/métodos , Ríos/química , Contaminación Química del Agua
20.
Environ Sci Technol ; 39(10): 3521-7, 2005 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-15952354

RESUMEN

Spatial and temporal distributions of polybrominated diphenyl ethers (PBDEs) in sediments of the Pearl River Delta (PRD) and adjacent South China Sea (SCS) of southern China were examined. A total of 66 surface sediment samples were collected and analyzed to determine the concentrations of 10 PBDE congeners (BDE-28, -47, -66, -100, -99, -154, -153, -138, -183, and -209). The concentrations of BDE-209 and SigmaPBDEs (defined as the sum of all targeted PBDE congeners except for BDE-209) ranged from 0.4 to 7340 and from 0.04 to 94.7 ng/g, respectively. The SigmaPBDEs concentrations were mostly < 50 ng/g, within the range for riverine and coastal sediments around the world, whereas the BDE-209 concentrations at the most contaminated sites were at the high end of the worldwide figures. Congener compositions were dominated by BDE-209 (72.6 - 99.7%), with minor contributions from penta- and octa-BDEs. Slightly different PBDE compositions were observed among samples collected from different locations, attributable to possible decomposition of highly brominated congeners and/or redistribution between particles of various sizes during atmospheric or fluvial transportation. The PBDE patterns in the SCS and Pearl River Estuary sediments were similar to those in sediments of the Zhujiang and Dongjiang Rivers, reflecting the widespread influence from local inputs. Analyses of two short sediment cores collected from the Pearl River Estuary showed that concentrations of BDE-209 rapidly increased in the upper layers of both cores, coincident with the growth of the electronics manufacturing capacities in the PRD region. The major sources of PBDEs were probably waste discharges from the cities of Guangzhou, Dongguan, and Shenzhen, the three fastest growing urban centers in the PRD.


Asunto(s)
Sedimentos Geológicos/química , Éteres Fenílicos/análisis , Bifenilos Polibrominados/análisis , Contaminantes Químicos del Agua/análisis , China , Monitoreo del Ambiente , Retardadores de Llama/análisis , Océanos y Mares , Ríos , Agua de Mar
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