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1.
Sun Y  Luo X  Wu J  Mo L  Chen S  Zhang Q  Zou F  Mai B 《Chemosphere》2012,89(4):445-451
Little data is available on the bioaccumulation of Dechlorane Plus (DP) in terrestrial organisms. Three terrestrial passerine bird species, light-vented bulbul, long-tailed shrike, and oriental magpie-robin, were collected from rural and urban sites in the Pearl River Delta to analyze for the presence of DP and its dechlorinated products in muscle and liver tissues. The relationships between trophic level and concentration and isomeric composition of DP in birds were also investigated based on stable nitrogen isotope analysis. DP levels had a wide range from 3.9 to 930 ng g−1 lipid weight (lw) in muscle and from 7.0 to 1300 ng g−1 lw in liver. Anti-Cl11-DP and syn-Cl11-DP, two dechlorinated products of DP, were also detected in bird samples with concentrations ranged between not detected (nd)-41 and nd-7.6 ng g−1 lw, respectively. DP preferentially accumulated in liver rather than in muscle for all three bird species. Birds had significantly higher concentrations of DP in urban sites than in rural sites (mean, 300 vs 73 ng g−1 lw). The fractions of anti-DP (fanti) were higher in birds collected in rural sites than in urban sites. Significant positive correlation between DP levels and δ15N values but significant negative correlation between fanti and δ15N values were found for birds in both urban and rural sites, indicating that trophic level of birds play an important role in determining DP level and isomeric profile.  相似文献   

2.
Since the 1980s, the eel population has been decreasing dangerously. Persistent Organic Pollutants (POPs) such as Polychlorinated Biphenyls (PCBs) are one of the suspected causes of this decline. A preliminary study of PCB contamination carried out on different fish from the Gironde estuary (southwest of France, Europe) has shown a relatively high level of contamination of eel muscles. In order to characterize the contamination level of PCBs and PBDEs (PolyBrominated Diphenyl-Ethers) in eels from this estuary more than 240 eels were collected during the years 2004-2005 in the Gironde estuarine system, from glass eels to silver eels. Individual European eels were grouped according to length and localization sites. The results have shown a low contamination level of glass eels: respectively 28 ± 11 ng g−1 dw for PCBs and 5 ± 3 ng g−1 dw for PBDEs. The contamination level in eels (expressed in ng g−1 dw) increases from glass eels to silver eels up to 3399 ng g−1 dw of PCBs for the most contaminated silver eel. Such levels of PCBs similar to those observed in Northern Europe, could raise sanitary problems connected with the World Health Organization (WHO) recommendations. These results are worrying for the local people who regularly eat eels caught in the Gironde estuary.  相似文献   

3.
To interpret the distribution of hexabromocyclododecanes (HBCDs) in various organisms, we measured the concentrations and diastereomer and enantiomer profiles of HBCDs in 21 different species of limnic and marine cohorts from Tianjin, China. The concentration ranges of HBCDs in limnic and marine organisms were 64.3–1111 ng g−1 lw and 85.5–989 ng g−1 lw, respectively. Living habitat and feeding habits had important impacts on HBCD diastereomer distribution. Most of the species appeared to preferentially select (+)-α-, (−)-β- and (−)-γ-HBCD. There is a tendency that the total and α-HBCDs were magnified as trophic level increased with trophic magnification factors (TMFs) around 2. The concentrations of HBCDs in the limnic and marine fishes were highest in the liver, followed by the gill, skin, and muscle. In terrestrial plants, the highest concentrations of HBCDs were observed in the leaf, followed by the root and the rhizosphere soil. Plants showed enantioselectivity for HBCD enantiomers, which varied with plant species and organs (leaf vs. root) of the same plant. Higher estimated daily intakes (EDIs) of HBCDs were observed from fish than from wheat.  相似文献   

4.
Polybrominated diphenyl ethers (PBDEs), commonly used flame retardants, have been reported as potential endocrine disruptor and neurodevelopmental toxicants, thus giving rise to the public health concern. The goal of this study was to investigate the relationship between umbilical cord blood, maternal blood, and breast milk concentrations of PBDEs in South Korean. We assessed PBDE levels in paired samples of umbilical cord blood, maternal blood, and breast milk. The levels of seven PBDE congeners were measured in 21 paired samples collected from the Cheil Woman’s Hospital (Seoul, Korea) in 2008. We also measured thyroid hormones levels in maternal and cord blood to assess the association between PBDEs exposure and thyroid hormone levels. However, there was no correlation between serum thyroxin (T4) and total PBDEs concentrations. The total PBDEs concentrations in the umbilical cord blood, maternal blood, and breast milk were 10.7 ± 5.1 ng g−1 lipid, 7.7 ± 4.2 ng g−1 lipid, and 3.0 ± 1.8 ng g−1 lipid, respectively. The ranges of total PBDE concentrations observed were 2.28-30.94 ng g−1 lipid in umbilical cord blood, 1.8-17.66 ng g−1 lipid in maternal blood, and 1.08-8.66 ng g−1 lipid in breast milk. BDE-47 (45-73% of total PBDEs) was observed to be present dominantly in all samples, followed by BDE-153. A strong correlation was found for major BDE-congeners between breast milk and cord blood or maternal blood and cord blood samples. The measurement of PBDEs concentrations in maternal blood or breast milk may help to determine the concentration of PBDEs in infant.  相似文献   

5.
In this study, an analytical methodology was developed for the determination of psycho-active drugs in the treated effluent of the University Hospital at the Federal University of Santa Maria, RS – Brazil. Samples were collected from point A (Emergency) and point B (General effluent). The adopted methodology included a pre-concentration procedure involving the use of solid phase extraction and determination by liquid chromatography coupled to mass spectrometry. The limit of detection for bromazepam and lorazepam was 4.9 ± 1.0 ng L−1 and, for carbamazepine, clonazepam and diazepam was 6.1 ± 1.5 ng L−1. The limit of quantification was 30.0 ± 1.1 ng L−1, for bromazepam, clonazepam and lorazepam; for carbamazepine was 50.0 ± 1.8 ng L−1 and was 40.0 ± 1.0 ng L−1 for diazepam. The mean concentrations in the Emergency and General effluent treated currents were as follows: for bromazepam, 195 ± 6 ng L−1 and 137 ± 7 ng L−1; for carbamazepine, 590 ± 6 ng L−1 and 461 ± 10 ng L−1; for diazepam, 645 ± 1 ng L−1 and 571 ± 10 ng L−1; for lorazepam, 96 ± 7 ng L−1 and 42 ± 4 ng L−1; and for clonazepam, 134 ± 10 ng L−1 and 57 ± 10 ng L−1. A preliminary risk assessment was conducted: carbamazepine and diazepam require considerable attention owing to their environmental toxicity. The occurrence of these psychoactive-drugs and the environmental risks that they pose demonstrated the need for a more efficient treatment system. As far we are aware, there have been no comparable studies to this on the hazards of hospital effluents in Brazil, and very few that have carried out a risk assessment of psycho-active drugs in hospital effluent in general.  相似文献   

6.
Within the framework of the MYTITURK project, heavy metals and organic compounds contaminations were assessed in transplanted mussels in eight different bays from the Eastern Aegean coast. Izmir Bay, Canakkale Strait entrance, Saros and Candarli Bay were defined low pollution extent according to Principal Component Analysis taking into metal accumulation. PAHs (Polycyclic Aromatic Hydrocarbons) levels in the range of 29.4–64.2 ng g−1 (dry weight) indicated that PAH contamination level classified as low along the Aegean coast. Concentrations of Aroclor1254 and 1260 were higher in transplanted mussels from Canakkale Strait Outlet due to industrial activities was originated from Marmara Sea. The organochlorinated pesticides such as heptachlor (<0.4 ng g−1), aldrin (<0.30 ng g−1), dieldrin (<0.75 ng g−1), endrin (<2.3 ng g−1) concentrations were homogeneous however, HCB (Hexachlorobenzene) and lindane concentrations were found undetectable level along the coast. DDE/DDT ratio in the caged mussels form Gulluk and Gokova Bay indicated recent DDT (Dikloro difenil trikloroethan) usage in these areas. The residues of organochlorinated compounds in transplanted mussels confirm the long persistence of DDTs. According to world health authorities, the concentration of heavy metals in mussels for the study area can generally be considered not to be at levels posing a health risk except Zn. The levels of POPs indicated that transplanted mussels have a lack of risk for the human health.  相似文献   

7.
We investigated the PCBs, PBDEs and HBCDs contamination in sludge, sediments and fish from various locations including raw leachate pond, leachate treatment plans (LTPs), control wells and reference site at open landfill of municipal dumpsite, Surabaya City, Indonesia. 62 PCBs and 14 PBDEs congeners, and 3 HBCDs isomers were identified and quantified using GC–MS and LC–MS/MS, respectively. Concentration ranges and median (value in parentheses) of PCBs, PBDEs and HBCDs were from not detected (ND) to 60 (3.9) ng g−1 dw, 0.0075 to 45 (4.5) ng g−1 dw and ND to 2.8 (0.052) ng g−1 dw in sludge and sediments, respectively. While in two polled of fish samples were 30–55 ng g−1 lw, 6.6–11 ng g−1 lw and 1.6–3.3 ng g−1 lw, respectively. Among the sampling sites, the highest level of PCBs and PBDEs were detected in sludge from raw leachate pond. However, PCBs and PBDEs levels were showing decreased in LTP-1 that could be due to the bacterial degradation but not in LTP-2, HBCDs were more stable in both LTPs. Levels of PCBs and BFRs in sludge at the present study were lower than those reported in sewage sludge reported from some other countries. PCBs profiles were mainly composed in that order by CB-138, -153, -180, -101, -118 and -28, while by BDE-47, -99, -100, -153, -154 and -28 for PBDEs in sludge, sediments and fish. Profiles of HBCDs were predominantly composed by γ- and α-isomers in sludge and fish, respectively. Debromination, dechlorination, commercial formulations used and congener-specific accumulation of those contaminants are the factors influenced the profiles.  相似文献   

8.
The residual levels of polycyclic aromatic hydrocarbons (PAHs) in the atmosphere and in dissolved phase from Lake Chaohu were measured by (GC–MS). The composition and seasonal variation were investigated. The diffusive air–water exchange flux was estimated by a two-film model, and the uncertainty in the flux calculations and the sensitivity of the parameters were evaluated. The following results were obtained: (1) the average residual levels of all PAHs (PAH16) in the atmosphere from Lake Chaohu were 60.85 ± 46.17 ng m−3 in the gaseous phase and 14.32 ± 23.82 ng m−3 in the particulate phase. The dissolved PAH16 level was 173.46 ± 132.89 ng L−1. (2) The seasonal variation of average PAH16 contents ranged from 43.09 ± 33.20 ng m−3 (summer) to 137.47 ± 41.69 ng m−3 (winter) in gaseous phase, from 6.62 ± 2.72 ng m−3 (summer) to 56.13 ± 22.99 ng m−3 (winter) in particulate phase, and 142.68 ± 74.68 ng L−1 (winter) to 360.00 ± 176.60 ng L−1 (summer) in water samples. Obvious seasonal trends of PAH16 concentrations were found in the atmosphere and water. The values of PAH16 for both the atmosphere and the water were significantly correlated with temperature. (3) The monthly diffusive air–water exchange flux of total PAH16 ranged from −1.77 × 104 ng m−2 d−1 to 1.11 × 105 ng m−2 d−1, with an average value of 3.45 × 104 ng m−2 d−1. (4) The results of a Monte Carlo simulation showed that the monthly average PAH fluxes ranged from −3.4 × 103 ng m−2 d−1 to 1.6 × 104 ng m−2 d−1 throughout the year, and the uncertainties for individual PAHs were compared. (5) According to the sensitivity analysis, the concentrations of dissolved and gaseous phase PAHs were the two most important factors affecting the results of the flux calculations.  相似文献   

9.
Geens T  Neels H  Covaci A 《Chemosphere》2012,87(7):796-802
In this study, an analytical method was optimized for the determination of bisphenol-A (BPA), triclosan (TCS) and 4-n-nonylphenol (4n-NP), environmental contaminants with potential endocrine disruptive activities, in human tissues. The method consisted of a liquid extraction step, derivatization with pentafluorobenzoylchloride followed by a clean-up on acidified silica and detection with gas chromatography coupled with mass spectrometry (GC-ECNI/MS). Recoveries ranged between 92% and 102% with a precision below 5%. Limits of quantification ranged between 0.3-0.4 ng g−1, 0.045-0.06 ng g−1 and 0.003-0.004 ng g−1 for BPA, TCS and 4n-NP in different tissues, respectively. The method was applied for the determination of BPA, TCS and 4n-NP in paired adipose tissue, liver and brain samples from 11 individuals. BPA could be detected in almost all tissues, with the highest concentrations found in adipose tissue (mean 3.78 ng g−1), followed by liver (1.48 ng g−1) and brain (0.91 ng g−1). TCS showed the highest concentrations in liver (3.14 ng g−1), followed by adipose tissue (0.61 ng g−1), while it could be detected in only one brain sample. Levels of 4n-NP were much lower, mostly undetected, and therefore 4n-NP is considered of minor importance for human exposure. Despite the measurable concentrations in adipose tissue, these compounds seem to have a low bioaccumulation potential. The reported concentrations of free BPA in the various tissues are slight disagreement with pharmacokinetic models in humans and rats and therefore the possibility of external contamination with BPA during sample collection/storage cannot be ruled out.  相似文献   

10.
In this study, the presence of bisphenol A (BPA) in human placental and fetal liver samples collected from 1998 to 2008 was investigated to provide a more detailed analysis of the transfer of BPA across the placenta and fetal exposure to BPA. The average concentrations in placental samples were 12.6 ng g−1 for free BPA, 17.2 ng g−1 for BPA-glu, and 30.2 ng g−1 for total BPA. The highest concentrations in placental samples were 165 ng g−1 for free BPA, 178 ng g−1 for BPA-glu, and 280 ng g−1 for total BPA. Samples with higher levels of BPA-glu had higher levels of free BPA in general. Fetal age was observed to have a significant effect on BPA-glu levels in placental samples, but not on free or total BPA. The percentages of free BPA relative to total BPA for the placental samples varied considerably from 4.2% to 100%, suggesting that the ability of maternal liver and/or the placenta to conjugate BPA is highly variable during early to mid-gestation. The average concentrations in fetal liver samples were 9.02 ng g−1 for free BPA, 19.1 ng g−1 for BPA-glu, and 25.8 ng g−1 for total BPA. The highest concentrations in fetal liver samples were 37.7 ng g−1 for free BPA, 93.9 ng g−1 for BPA-glu, and 123 ng g−1 for total BPA. The percentages of free BPA level relative to total BPA for all fetal liver samples varied from 12.4% to 99.1%, indicating extensive variability in the ability of the human feto-placental unit to glucuronidate BPA.  相似文献   

11.
Accumulation of organochlorine compounds is well studied in aquatic food chains whereas little information is available from terrestrial food chains. This study presents data of organochlorine levels in tissue and plasma samples of 15 critically endangered Iberian lynx (Lynx pardinus) and other 55 wild carnivores belonging to five species from three natural areas of Spain (Doñana National Park, Sierra Morena and Lozoya River) and explores their relationship with species diet. The Iberian lynx, with a diet based on the consumption of rabbit, had lower PCB levels (geometric means, plasma: <0.01 ng mL−1, liver: 0.4 ng g−1 wet weight, fat: 87 ng g−1 lipid weight) than other carnivores with more anthropic and opportunistic foraging behavior, such as the red fox (Vulpes vulpes; plasma: 1.11 ng mL−1, liver: 459 ng g−1, fat: 1984 ng g−1), or with diets including reptiles at higher proportion, such as the Egyptian mongoose (Herpestes ichneumon; plasma: 7.15 ng mL−1, liver: 216 ng g−1, fat: 540 ng g−1), or the common genet (Genetta genetta; liver: 466 ng g−1, fat: 3854 ng g−1). Chlorinated pesticides showed interspecific variations similar to PCBs. Organochlorine levels have declined since the 80s in carnivores from Doñana National Park, but PCB levels are still of concern in Eurasian otters (Lutra lutra; liver: 3873-5426 ng g−1) from the industrialized region of Madrid.  相似文献   

12.
The first attempt to systematically investigate the atmospheric mercury (Hg) in the MBL of the Augusta basin (SE Sicily, Italy) has been undertaken. In the past the basin was the receptor for Hg from an intense industrial activity which contaminated the bottom sediments of the Bay, making this area a potential source of pollution for the surrounding Mediterranean. Three oceanographic cruises have been thus performed in the basin during the winter and summer 2011/2012, where we estimated averaged Hgatm concentrations of about 1.5 ± 0.4 (range 0.9–3.1) and 2.1 ± 0.98 (range 1.1–3.1) ng m−3 for the two seasons, respectively. These data are somewhat higher than the background Hgatm value measured over the land (range 1.1 ± 0.3 ng m−3) at downtown Augusta, while are similar to those detected in other polluted regions elsewhere. Hg evasion fluxes estimated at the sea/air interface over the Bay range from 3.6 ± 0.3 (unpolluted site) to 72 ± 0.1 (polluted site of the basin) ng m−2 h−1. By extending these measurements to the entire area of the Augusta basin (∼23.5 km2), we calculated a total sea–air Hg evasion flux of about 9.7 ± 0.1 g d−1 (∼0.004 t yr−1), accounting for ∼0.0002% of the global Hg oceanic evasion (2000 t yr−1). The new proposed data set offers a unique and original study on the potential outflow of Hg from the sea–air interface at the basin, and it represents an important step for a better comprehension of the processes occurring in the marine biogeochemical cycle of this element.  相似文献   

13.
The non-dioxin-like polychlorinated biphenyls (NDL-PCBs) highly contribute to the PCB dietary intake of total PCBs. Most of the NDL-PCBs are assumed through ingestion of contaminated fish and fishery products. Therefore, it is important to quantify their presence in aquatic organisms to evaluate human risks associated with fish consumption. The European catfish is a top food-chain predator and is considered a reliable bio-monitoring tool reflecting the state of the environmental organic pollution. From 2006 to 2009, 54 European catfish were captured in four sites covering the area of the Po River (North Italy), and their muscles were analysed to determine the levels of 18 PCBs congeners. All samples presented detectable levels of 18 congeners and, on average, results showed an important presence of NDL-PCBs. The sum of the six congeners (28, 52, 101, 138, 153, 180 IUPAC) was used as indicator of the total PCBs concentration. The 33% of the samples analysed exceeded the maximum levels of 125 ng g−1 set by European regulations in fish. The values measured ranged from 19.7 to 1015.4 ng g−1 (mean 135.6 ± 149.8 ng g−1).  相似文献   

14.
Plastic debris were collected from eight beaches around San Diego County, California. Debris collected include: pre-production pellets and post-consumer plastics including fragments, polystyrene (PS) foam, and rubber. A total of n = 2453 pieces were collected ranging from <5 mm to 50 mm in size. The plastic pieces were separated by type, location, and appearance and analyzed for polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT) and its breakdown products, and chlordanes. PAH concentrations ranged from 30 ng g−1 to 1900 ng g−1, PCBs from non-detect to 47 ng g−1, chlordanes from 1.8 ng g−1 to 60 ng g−1, and DDTs from non-detect to 76 ng g−1. Consistently higher PAH concentrations found in PS foam samples (300-1900 ng g−1) led us to examine unexposed PS foam packaging materials and PS virgin pellets. Unexposed PS foam contained higher concentrations of PAHs (240-1700 ng g−1) than PS virgin pellets (12-15 ng g−1), suggesting that PAHs may be produced during manufacturing. Temporal trends of debris were investigated at one site, Ocean Beach, where storm events and beach maintenance were found to be important variables influencing debris present at a given time.  相似文献   

15.
Mercury pollution is caused by artisanal and small-scale gold mining (ASGM) operations along the Cikaniki River (West Java, Indonesia). The atmosphere is one of the primary media through which mercury can disperse. In this study, atmospheric mercury levels are estimated using the native epiphytic fern Asplenium nidus complex (A. nidus) as a biomonitor; these estimates shed light on the atmospheric dispersion of mercury released during mining.Samples were collected from 8 sites along the Cikaniki Basin during September-November, 2008 and September-November, 2009.The A. nidus fronds that were attached to tree trunks 1-3 m above the ground were collected and measured for total mercury concentration using cold vapor atomic absorption spectrometry (CVAAS) after acid-digestion. The atmospheric mercury was collected using porous gold collectors, and the concentrations were determined using double-amalgam CVAAS.The highest atmospheric mercury concentration, 1.8 × 103 ± 1.6 × 103 ng m−3, was observed at the mining hot spot, and the lowest concentration of mercury, 5.6 ± 2.0 ng m−3, was observed at the remote site from the Cikaniki River in 2009. The mercury concentrations in A. nidus were higher at the mining village (5.4 × 103 ± 1.6 × 103 ng g−1) than at the remote site (70 ± 30 ng g−1). The distribution of mercury in A. nidus was similar to that in the atmosphere; a significant correlation was observed between the mercury concentrations in the air and in A. nidus (r = 0.895, P < 0.001, n = 14). The mercury levels in the atmosphere can be estimated from the mercury concentration in A. nidus using a regression equation: log (HgA.nidu/ng g−1) = 0.740 log (HgAir/ng m−3) − 1.324.  相似文献   

16.
Guéguen F  Stille P  Millet M 《Chemosphere》2011,85(2):195-202
Tree barks were used as biomonitors to evaluate past atmospheric pollution within and around the industrial zones of Strasbourg (France) and Kehl (Germany) in the Rhine Valley. The here estimated residence time for trace metals, PCBs and PCDD/Fs in tree bark is >10 years. Thus, all pollution observed by tree bark biomonitoring can be older than 10 years. The PCB baseline concentration (sum of seven PCB indicators (Σ7PCBind)) determined on tree barks from a remote area in the Vosges mountains is 4 ng g−1 and corresponds to 0.36 × 10−3 ng toxic equivalent (TEQ) g−1 for the dioxin-like PCBs (DL-PCBs). The northern Rhine harbor suffered especially from steel plant, waste incinerator and thermal power plant emissions. The polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/Fs) concentrations analyzed in tree barks from this industrial area range between 392 and 1420 ng kg−1 dry-weight (dw) corresponding to 3.9 ng TEQPCDD/Fs kg−1 to 17.8 ng TEQPCDD/Fs kg−1, respectively. Highest PCDD/F values of 7.2 ng TEQ kg−1 to 17.8 ng TEQ kg−1 have been observed close to and at a distance of <2 km southwest of the chemical waste incinerator. However, very close to this incinerator lowest TEQ dioxin-like PCB (TEQDL-PCB) values of 0.006 ng TEQ g−1 have been found. On the other hand close to and southwest and northeast of the steel plant the values are comparatively higher and range between 0.011 ng TEQ g−1 and 0.026 ng TEQ g−1. However, even stronger Σ7PCBind enrichments have been observed at a few places in the city center of Kehl, where ΣDL-PCB values of up to 0.11 ng TEQ g−1 have been detected. These enrichments, however, are the result of ancient pollutions since recent long-term measurements at the same sites indicate that the atmospheric PCB concentrations are close to baseline. Emissions from an old landfill of waste and/or great fires might have been the reasons of these PCB enrichments. Other urban environments of the cities of Kehl and Strasbourg show significantly lower Σ7PCBind concentrations. They suffer especially from road and river traffic and have typically Σ7PCBind concentrations ranging from 11 ng g−1 to 29 ng g−1. The PCB concentration of 29 ng g−1 has been found in tree bark close to the railway station of Strasbourg. Nevertheless, the corresponding TEQDL-PCB are low and range between 0.2 × 10−3 ng TEQ g−1 and 7 × 10−3 ng TEQ g−1. Samples collected near road traffic are enriched in Fe, Sb, Sn and Pb. Cd enrichments were found close to almost all types of industries. Rural environments not far from industrial sites suffered from organic and inorganic pollution. In this case, TEQDL-PCB values may reach up to 58 × 10−3 ng TEQ g−1 and the corresponding V, Cr, Co, Ni, and Cd concentrations are comparatively high.  相似文献   

17.
Liu S  Xia X  Zhai Y  Wang R  Liu T  Zhang S 《Chemosphere》2011,82(2):223-228
The concentrations of black carbon (BC), total organic carbon (TOC) and polycyclic aromatic hydrocarbons (PAHs) have been determined in soils from urban and rural areas of Beijing. The rural area can be divided into plain and mountainous areas which are close to and relatively far from the urban area, respectively. Concentration of BC (5.83 ± 3.05 mg g−1) and BC/TOC concentration ratio (0.37 ± 0.15) in Beijing’s urban soil are high compared with that in world background soils and rural soils of Beijing, suggesting the urban environment to be an essential source and sink of BC. Concentration of BC in the urban area decreases from the inner city to exterior areas, which correlates with the urbanization history of Beijing and infers accumulation of BC in old urban soils. Black carbon in Beijing soils mainly comes from fossil fuel combustion, especially traffic emission. Median PAH concentration in the urban area (502 ng g−1) is one order of magnitude higher than that in the rural plain (148 ng g−1) and mountainous area (146 ng g−1) where PAHs are supposed to mainly come from atmospheric deposition from the urban area. Concentrations of BC correlate significantly with those of PAHs (p < 0.01, except naphthalene) in the urban area and with those of heavier 4-, 5- and 6- ring PAHs (p < 0.01) in the adjacent rural plain area, while there is no significant correlation with any PAH in the farther rural mountainous area.  相似文献   

18.
Chicken eggs from five different production types (conventional, omega-3 enriched, free range, organic and free run) were collected, when available, from three regions (west, central and east) of Canada to determine persistent organic pollutant (POP) concentrations. Total polychlorinated biphenyl (PCB) concentrations (∑37 congeners) in yolks from the eggs ranged from 0.162 ng g−1 lipid to 24.8 ng g−1 lipid (median 1.25 ng g−1 lipid) while the concentration of the sum of the 6 indicator PCBs ranged from 0.100 ng g−1 lipid to 9.33 ng g−1 lipid (median 0.495 ng g−1 lipid). Total polychlorinated dibenzo-p-dioxin/dibenzofuran (PCDD/F) concentrations ranged from 2.37 pg g−1 lipid to 382 pg g−1 lipid (median 9.53 pg g−1 lipid). The 2005 WHO toxic equivalency (TEQ) ranged from 0.089 pg TEQPCDD/F+dioxin-like[DL]-PCB g−1 lipid to 12.8 pg TEQPCDD/F+DL-PCB g−1 lipid (median 0.342 pg TEQPCDD/F+DL-PCB g−1 lipid). PCB and PCDD/F concentrations were significantly different (p < 0.001) in egg yolks from different regions of collection. In contrast to observations in Europe, PCB and PCDD/F concentrations in Canadian egg yolks were not impacted solely by the production type (e.g., conventional, free range, organic, etc.) used to maintain the laying chickens. Additionally, only one Canadian free range yolk from western Canada (12.8 pg TEQPCDD/F+DL-PCB g−1 lipid) exceeded the European toxic equivalent concentration limits for eggs (5 pg TEQPCDD/F+DL-PCB g−1 lipid). This differs from observations in Europe where free range/home produced eggs frequently have higher POP concentrations than eggs from other production types. Median PCB dietary intake estimates based on consumption of eggs were less than 10 ng d−1 while median PCDD/F intakes were less than 45 pg d−1.  相似文献   

19.
Fish oils are one of the main sources of ω-3 fatty acids. However, they can present elevated levels of some lipophilic pollutants, such as hexabromocyclododecanes (HBCDs). Since data about HBCDs in fish oil samples are very limited, in this study, 25 samples of fish oil for feed and food have been analyzed. Total HBCDs, as well as, α-, β- and γ-diastereoisomers have been determined. Total HBCDs ranged from 0.09 to 26.8 ng g−1, with higher concentrations in fish oil for feed (average value of 9.69 ng g−1) than those for food (1.14 ng g−1). Concentrations of α-HBCD (average value of 4.12 ng g−1 in feed samples and 0.48 ng g−1 in food samples) and γ-HBCD (5.05 and 0.43 ng g−1 respectively) were higher than that of β-HBCD (0.52 and 0.19 ng g−1 respectively) in most of the samples. However, none of them was predominant in the samples. Concentrations of HBCDs were compared to concentrations of other pollutants and correlation between dioxin and dioxin-like PCBs levels and HBCDs levels were observed. Intake of HBCDs was calculated for fish oil with human consumption purposes and it ranged from 0.08 to 5.38 ng HBCDs d−1, which could contribute significantly to HBCDs total intake. Enantiomeric fractions were also determined. No clear enrichment was observed for γ-HBCD, while (−)-α-HBCD enrichment was detected in some samples.  相似文献   

20.
Organochlorine contamination in the Mediterranean coastal environment of Egypt was assessed based on 26 surface sediments samples collected from several locations on the Egyptian coast, including harbors, coastal lakes, bays, and estuaries. The distribution and potential ecological risk of contaminants is described. Organochlorine compounds (OCs) were widely distributed in the coastal environment of Egypt. Concentrations of PCBs, DDTs, and chloropyrifos ranged from 0.29 to 377 ng g−1 dw, 0.07 to 81.5 ng g−1 dw, and below the detection limit (DL) to 288 ng g−1 dw, respectively. Other organochlorinated pesticides (OCP) studied were 1–2 orders of magnitude lower. OCP and PCBs had higher concentrations at Burullus Lake, Abu Qir Bay, Alexandria Eastern Harbor, and El Max Bay compared to other sites. OCP and PCB contamination is higher in the vicinity of possible input sources such as shipping, industrial activities and urban areas. PCB congener profiles indicated they were derived from more than one commercially available mixture. The ratios of commercial chlordane and heptachlor metabolites indicate historical usage; however, DDT and HCHs inputs at several locations appear to be from recent usage. The concentrations of PCBs and DDTs are similar to those observed in sediments from coastal areas of the Mediterranean Sea. Ecotoxicological risk from DDTs and PCBs is greatest in Abu Qir Bay, Alexandria Harbor, and El-Max Bay.  相似文献   

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