首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 23 毫秒
1.
电子垃圾拆解区土壤中典型手性PCBs分布及对映体特征   总被引:1,自引:0,他引:1  
朱帅  刘世东 《环境化学》2021,40(3):671-677
龙塘镇位于广东省清远市,是国内最大的进口电子垃圾集中处理处置地之一.通过对龙塘镇土壤中7种手性PCBs对映体浓度和对映体百分数(enantiomer fractions,EF)值的测定,发现龙塘镇土壤样品除PCB45和PCB174外,其余5种手性PCBs在土壤中均有不同程度的检出.土壤中5种目标手性PCBs(PCB91...  相似文献   

2.
A comparison of PCB congener profiles and limited biological effects was made between direct exposure to PCB-contaminated soil and vapor phase PCBs from that soil to determine congener patterns useful for identifying exposure sources in humans and wildlife. Weanling female Sprague–Dawley rats were exposed to either control or PCB-contaminated soil (from a landfill in Southern Illinois) for 1 and 2 weeks. The exposures were via direct contact with the soil or via airborne exposure with the rats isolated from the soil by a wire screen. Total PCB of 25% contaminated soil used in the study was 13?500?ppm. No PCBs were detectable in control rats. In direct-exposed rats, total PCB residues in fat pad, ear skin, serum, liver, and inguinal lymph nodes after the 1-week exposure were 6256, 185, 3.2, 149, and 41?ppm, respectively, but decreased to 465, 72, 1.7, 106, and 32.4?ppm after the 2-week exposure. In airborne-exposed rats, total PCB residues were 7.8, 1.6, 0.03, 0.2, and 0.6 in the same manner and slightly increased in fat pad and ear skin to 11.6 and 2.14, respectively. Decreases in both the concentrations and percentages of “episodic” PCBs (those congeners rapidly metabolized) in the fat pad were apparent following the 2-week exposure compared to the 1-week exposure by both routes. Both EROD and BROD activities were significantly increased in the direct-exposed rats, whereas only BROD activity increased in airborne-exposed rats. Serum T 4 levels were depleted in the direct-exposed rats regardless of time of exposure but were increased insignificantly after 1-week and significantly after 2 weeks in the airborne-exposed rats. No significant changes in serum insulin levels were apparent in any of the treated groups. The results suggested that exposure of animals to PCBs via different routes could result in different PCB profiles, which could cause different biological effects.  相似文献   

3.
The concentrations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were determined in amniotic fluid of 200 pregnant women from the Cukurova region of Turkey. The concentrations of OCPs [hexachlorocyclohexane (HCH), hexachlorobenzene (HCB), dichlorodiphenyl trichloroethane (p,p-DDT), and various metabolites], and different PCB congeners (28, 52, 101, 118, 138, 153, 180) were determined by gas chromatography with electron capture detection as follows: HCB 6.6 ± 4.7, ΣHCH 21.6 ± 14.2, ΣDDT 12.5 ± 7.5, and ΣPCBs 74.0 ± 54 ng mL?1. Correlations of maternal or gestational age and levels of OCPs and PCBs were not significant. The levels of these organochlorine compounds (OCs) were below detection limit for 5% of the samples, 80% contained more than one OC. This study illustrates that prenatal exposure of a fetus to OCs is prevalent in the Cukurova region.  相似文献   

4.
For monitoring and risk assessment, levels and distributions of Σ29 PCBs in paddy soil samples collected from Gwangyang (10 sites) and Ulsan (20 sites), heavily industrialized cities in Korea, were investigated using high-resolution gas chromatography/high-resolution mass spectrometry. Overall, total concentrations of Σ29 PCBs in Gwangyang (216.4–978.6 pg g?1 dw) and Ulsan (273.8–1824.1 pg g?1 dw) were higher than those (106.6–222.6 pg g?1 dw) in agricultural soil from Anseong in Korea. The TEQ (toxic equivalency) values from Gwangyang (0.06–0.40 ng TEQ kg?1 dw) and Ulsan (0.06–0.22 ng TEQ kg?1 dw) were higher than those (0.04–0.11 ng TEQ kg?1 dw) in Anseong but lower than the WHO threshold level (20 ng TEQ kg?1). However, one of the most toxic congeners, PCB 126, gave the highest concentration, possibly posing a risk to the biota. Seven indicator PCB congeners contributed to 50–80% of the total concentration of Σ29 PCBs, indicating the 7 PCBs can be used as valuable indicators for monitoring. The principal component analysis and cluster analysis for the homologue profiles of PCBs indicated that all the samples from both cities had the similar PCB contamination patterns, and the major sources of the PCB contamination were most likely from the usage of Aroclor 1254 than those of Aroclors 1242 and 1260. These PCB technical mixtures were possibly significantly used by various industries including iron and steel industries in Gwangyang and petrochemical and shipbuilding industries in Ulsan.  相似文献   

5.
Polychlorinated biphenyl (PCB) congener concentrations and their distributions were determined for the first time in 12 major rivers of eastern China. It was found that the PCB contamination level in those rivers was relatively low compared to the levels reported in most developing countries. Total amount of PCBs in the river sediments ranged from 10 to 22 ng/g dry weight and dichlorodiphenyldichloroethene (DDE) ranged from 0.89 to 7.62 ng/g. The PCB concentrations were basically homogeneous in different rivers; however, they consistently changed with the percent of total organic carbon (TOC). The PCB concentrations and compositions found in the 12 river sediments were very similar, with the tetra‐ and penta‐ groups as the dominants. Given that distributions and contaminant levels in sediments reflect the number of PCBs, the contamination of the 12 major rivers in eastern China is probably due to atmospheric deposition rather than the point source contamination.  相似文献   

6.
The emerging issue of electronic wastes (e-waste) and the associated environmental problems has gained considerable attention from the scientific community in recent decades. In the present study, the levels of polybrominated diphenyl ethers (PBDEs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the surface soil obtained from the Taizhou e-waste recycling area of China were investigated. Also the correlation among these chemicals and previously published data of heavy metals, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls was analysed. We determined that the pollution levels of eight PBDEs congeners were serious, ranging from 27.9 to 3128.4 μg/kg. The concentration of PCDD/Fs was in the range of 218.3–3122.2 pg/g with a mean value of 659.5 pg/g. The PBDEs were not well-correlated with organic pollutants (PAHs and PCBs) in soil, whereas PCDD/Fs exhibited a significant positive correlation with the PCBs. The higher levels of persistent organic pollutants may pose potential adverse effects to soil quality and human beings and needs to be properly managed and remediated.  相似文献   

7.
The purpose of this study was to evaluate polychlorinated biphenyls (PCBs) contamination levels in roe and red deer from north-western Poland and to assess environmental pollution in this area. A quantitative analysis was conducted using a capillary gas chromatography/mass spectrometry method. The mean concentrations of ΣPCBs (sum of PCBs: 28, 52, 101, 138, 153, 180) in liver samples were 30.24±12.35 ng·g?1 of lipid weight (l.w.) in roe deer and 60.13±14.23 ng·g?1 l.w. in red deer, compared with 24.21±10.02 and 45.22±9.77 ng·g?1 in the lungs of roe and red deer, respectively. PCBs 138, 153 and 180 were the dominant congeners in the liver samples of the analysed animals, whereas PCB 138 and 153 in the lungs. TEQs levels calculated for only dioxin-like PCBs were low: 0.32 and 0.29 pg WHO-PCB-TEQ·g?1 fat in liver of red deer and roe deer, respectively. The mean PCB concentrations obtained in our study for organs of roe deer and red deer were several times lower than those reported elsewhere. These findings show that the investigated roe and red deer originated from an area with low levels of PCB contamination.  相似文献   

8.
This paper presents a first result of an investigation of the presence of anthropogenic pollutants named polychlorinated biphenyls (PCBs, sum of 25 congeners) in snow samples in the Aconcagua Mountains in the Andean Range, along an altitudinal gradient. Samples were taken during an expedition in 2003 and analysed by using a specific technique of thermodesorption and GC-MS adapted to small amount of sample. Mountain ecosystems could be efficient natural trap of persistent organic pollutants (POPs) transported by the atmosphere, and it is shown in this note that PCBs are also present in snow samples but at low concentrations, levels ranged from 0.02 to 0.190 ng/L. The detected congeners were those more persistent (PCB 138, PCB180) and compared to other mountain and cold areas around the world, detected levels are in the low range indicating that pollution levels are lower in the southern hemisphere. This results points out the need of investigating with some more detail the role of mountains in the trapping of POPs and the associated risks including the climate change.  相似文献   

9.
We evaluated the use of Talitrus saltator as biomonitor of polychlorinated byphenyls (PCBs) contamination of the supralittoral zone of Mediterranean sandy shores, an area not yet investigated about the presence of these pollutants. Twenty of 22 PCB congeners analysed were detected and quantified in sand and sandhoppers' samples collected in 6 different sites along the Tyrrhenian coast of Central Italy. Among the congeners analysed, PCB 153 and PCB 138 were the most abundant both in amphipods and sand samples and, regarding the congener pattern analysis, hexa-, hepta- and penta-PCBs were the most abundant congeners in sandhoppers. Though hydrophobic compounds, such as PCBs, bind strongly to sand and sediments, PCB concentrations were higher in T. saltator than in the sand revealing a good ability of this species to accumulate this class of contaminants. The concentration of each PCB congener recorded in tissues of sandhoppers showed significant differences among sampling sites revealing a good ability of these species to accumulate PCBs at different concentrations depending on the contamination levels of the sampling site. Therefore, our results suggest the possible utilisation of T. saltator as a biomonitor of PCB contamination of the supralittoral zone of Mediterranean sandy shores.  相似文献   

10.
Spatial distribution, seasonal variation and potential inhalation risks of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) were investigated in the atmosphere of Beijing, using passive air samplers equipped with polyurethane foam disks. Concentrations of ΣPCDD/Fs, ΣPCBs and ΣPBDEs ranged from 8.4 to 179 fg WHO2005-TEQ/m3, 38.6–139 and 1.5–176 pg/m3, respectively. PCDFs showed higher air concentrations than those of PCDDs, indicating the influence of industrial activities and other combustion processes. The non-Aroclor congener, PCB-11, was detected in air (12.3–99.4 pg/m3) and dominated the PCB congener profiles (61.7–71.5% to ∑PCBs). The congener patterns of PBDEs showed signatures from both penta-BDE and octa-BDE products. Levels of PCDD/Fs, PCBs and PBDEs at the industrial and residential sites were higher than those at rural site, indicating human activities in urban area as potential sources. Higher air concentrations of PCDD/Fs, PCBs and PBDEs were observed in summer, which could be associated with atmospheric deposition process, re-volatilization from soil surface and volatilization from use of technical products, respectively. Results of inhalation exposure and cancer risk showed that atmospheric PCDD/Fs, dioxin-like PCBs and PBDEs did not cause high risks to the local residents of Beijing. This study provides further aid in evaluating emission sources, influencing factors and potential inhalation risks of the persistent organic pollutants to human health in mega-cities of China.  相似文献   

11.
Polychlorinated biphenyls (PCBs) are documented endocrine-disrupting chemicals. This study examined the bioaccumulation of PCBs and the utility of the chorioallantoic membrane (CAM) as a non-lethal sampling technique for PCB analysis in the northern diamondback terrapin (Malaclemys terrapin terrapin), a species endemic to US East Coast salt marshes. To determine the viability of the CAM as a surrogate for PCB burdens within this species, maternal transfer of PCBs to CAM and egg samples was studied. Egg and CAM samples were collected from populations in Cape May County, NJ and Jamaica Bay, NY; liver samples were collected only from NJ terrapins. PCB congeners were detected in all sample types, but less-chlorinated congeners preferentially partitioned in the CAM. Liver and egg sample PCB concentrations were strongly correlated (p=0.002, r s=0.883), but PCB concentrations of CAM were not strongly correlated to liver (p=0.035, r s=0.733) and egg samples (p=0.036, r s=0.484). Examination of homologue groups indicated a strong correlation between penta- and hexachlorinated biphenyls for all sample types. This study shows that maternal transfer of PCB contaminants occurs with selective partitioning of congeners into the CAM, and that analysis of the CAM alone may not reflect total PCB body burdens in this species.  相似文献   

12.
13.
The spatial and seasonal variation of polychlorinated biphenyls (PCBs) were investigated in water and sediment samples collected from Songhua River, China, from 2007 to 2008. The total concentration of PCB congeners ranged from 1.1 to 14 ng/l in water and 0.26–9.7 ng/g dry weight (dw) in sediment. The results of seasonal variation may suggest an impact to PCB concentration in water from its atmospheric input, the dilution to PCBs concentrations of high stream in summer, and a general trend towards increased volatilization in warmer conditions. From PCBs concentrations comparison between upstream and downstream of industrial urban cities, it was obvious that industrial urban cities reflect an important pollutant source for PCBs in our study, also with the evidences of high concentrations of PCBs occurring in high development industry and residential areas. Meanwhile, the homologue profile of PCBs in Songhua was analyzed, whose comparison with published data indicates that the sources of PCBs accumulated in the sediment may also came from the residue of PCBs production in China. Total five dioxin-like PCBs (CB-77, 81, 105, 114, and 126) and nine (CB-77, 81, 105, 114, 118, 123, 126, 156, and 167) were found in Songhua water and sediment.  相似文献   

14.

Background

In the past, cases of PCDD/F and PCB contamination exceeding limits in food from animal origin (eggs, meat or milk) were mainly caused by industrially produced feed. But in the last decade, exceedances of EU limit values were discovered more frequently for PCDD/Fs or dioxin-like(dl)-PCBs from free range chicken, sheep, and beef, often in the absence of any known contamination source.

Results

The German Environment Agency initiated a project to elucidate the entry of PCBs and PCDD/Fs in food related to environmental contamination. This paper summarizes the most important findings. Food products from farm animals sensitive to dioxin/PCB exposure—suckling calves and laying hens housed outdoor—can exceed EU maximum levels at soil concentrations that have previously been considered as safe. Maximum permitted levels can already be exceeded in beef/veal when soil is contaminated around 5 ng PCB-TEQ/kg dry matter (dm). For eggs/broiler, this can occur at a concentration of PCDD/Fs in soil below 5 ng PCDD/F–PCB-TEQ/kg dm. Egg consumers—especially young children—can easily exceed health-based guidance values (TDI). The soil–chicken egg exposure pathway is probably the most sensitive route for human exposure to both dl-PCBs and PCDD/Fs from soil and needs to be considered for soil guidelines. The study also found that calves from suckler cow herds are most prone to the impacts of dl-PCB contamination due to the excretion/accumulation via milk. PCB (and PCDD/F) intake for free-range cattle stems from feed and soil. Daily dl-PCB intake for suckler cow herds must in average be less than 2 ng PCB-TEQ/day. This translates to a maximum concentration in grass of 0.2 ng PCB-TEQ/kg dm which is less than 1/6 of the current EU maximum permitted level. This review compiles sources for PCDD/Fs and PCBs relevant to environmental contamination in respect to food safety. It also includes considerations on assessment of emerging POPs.

Conclusions

The major sources of PCDD/F and dl-PCB contamination of food of animal origin in Germany are (1) soils contaminated from past PCB and PCDD/F releases; (2) PCBs emitted from buildings and constructions; (3) PCBs present at farms. Impacted areas need to be assessed with respect to potential contamination of food-producing animals. Livestock management techniques can reduce exposure to PCDD/Fs and PCBs. Further research and regulatory action are needed to overcome gaps. Control and reduction measures are recommended for emission sources and new listed and emerging POPs to ensure food safety.
  相似文献   

15.
We studied distribution of heavy metals [lead (Pb), copper (Cu) and zinc (Zn)] in surface soil at an electronic-waste (e-waste) recycling workshop near Metro Manila in the Philippines to evaluate the pollution size (spot size, small area or the entire workshop), as well as to assess heavy metal transport into the surrounding soil environment. On-site length-of-stride-scale (~70 cm) measurements were performed at each surface soil point using field-portable X-ray fluorescence (FP-XRF). The surface soil at the e-waste recycling workshop was polluted with Cu, Zn and Pb, which were distributed discretely in surface soil. The site was divided into five areas based on the distance from an entrance gate (y-axis) of the e-waste recycling workshop. The three heavy metals showed similar concentration gradients in the y-axis direction. Zn, Pb and Cu concentrations were estimated to decrease to half of their maximum concentrations at ~3, 7 and 7 m from the pollution spot, respectively, inside the informal e-waste recycling workshop. Distance from an entrance may play an important role in heavy metal transport at the soil surface. Using on-site FP-XRF, we evaluated the metal ratio to characterise pollution features of the solid surface. Variability analysis of heavy metals revealed vanishing surficial autocorrelation over metre ranges. Also, the possibility of concentration prediction at unmeasured points using geostatistical kriging was evaluated, and heavy metals had a relative “small” pollution scales and remained inside the original workshop compared with toxic organohalogen compounds. Thus, exposure to heavy metals may directly influence the health of e-waste workers at the original site rather than the surrounding habitat and environmental media.  相似文献   

16.
The purpose of this study was to determine concentrations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in Nile tilapia (Oreochromis niloticus) and Bouri fish (Mugil cephalus) from Lake Qarun, a protected area of Egypt, and evaluate the relative ecological risk of these compounds. Different tissues of the fish species were analyzed for 26 chlorinated pesticides and 29 PCB congeners. Total concentrations (µg/kg wet weight, ww) of OCPs ranged between 1487 and 6217 (mean: 3260) and of PCBs between 9.0 and 61 (mean: 34). The trend of detected organochlorine pollutants was: endrin aldehyde > dieldrin > hexachlorobenzene > PCBs > endrin > 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethanes (DDTs). Heptachlor epoxide; oxy-, cis-, and trans-chlordane; trans-nonachlor; β-hexachlorocyclohexane; δ-hexachlorocyclohexane; and endosulfan I and endosulfan sulfate levels were below the detection limit. The ratios of (1,1-dichloro-2,2-bis(p-chlorophenyl)ethylenes [DDEs] + 1,1-dichloro-2,2-bis(p-chlorophenyl)ethanes [DDDs])/ΣDDTs in fish tissues indicated no recent DDT exposure. Concentrations of DDTs and PCBs were generally comparable or higher than those found in studies of similar species worldwide. The concentrations of hexachlorobenzene, dieldrin, and endrin aldehyde in fish muscles exceeded the maximum residue level recommended by various organizations.  相似文献   

17.
《Ecological modelling》2004,179(3):405-416
The fate of persistent organic pollutants (POPs) in aquatic ecosystems is intimately linked to the cycling of organic matter. In this paper, we present a model of the effect of organic matter decomposition on the distribution of persistent organic pollutants in sediments. The model predicts a diagenetic (sediment-ageing) magnification of chemical concentrations in sediments enriched with labile organic matter. We predict two- to four-fold diagenetic magnification across a wide range of realistic parameter values, and higher levels (up to 20-fold) for labile organic matter in systems with low burial rates (i.e., residence times on the order of years). As an illustration, we apply our model to understand the fate of waste organic matter and associated PCBs discharged by marine fish farms. The available data support both the spatial pattern (as a function of burial rate) and the range of sediment PCB concentrations predicted by our model. This model explains why equilibrium models fail to predict the very high sediment-water partitioning coefficients often observed in the field. Effectively, diagenetic processes impose an additional biomagnification step at the bottom of the detritus-based food web, increasing the exposure to POPs of organisms at higher trophic levels.  相似文献   

18.
Residue concentrations of polybrominated diphenyl ethers (PBDEs) in different kinds of samples including consumer products, indoor dust, sediment and fish collected from two e-waste recycling sites, and some industrial, urban and suburban areas in Vietnam were determined to provide a comprehensive assessment of the contamination levels, accumulation pattern, emission potential and human exposure through dust ingestion and fish consumption. There was a large variation of PBDE levels in plastic parts of obsolete electronic equipment (from 1730 to 97,300 ng/g), which is a common result observed in consumer plastic products reported elsewhere. PBDE levels in indoor dust samples collected from e-waste recycling sites ranged from 250 to 8740 ng/g, which were markedly higher than those in industrial areas and household offices. Emission rate of PBDEs from plastic parts of disposed electronic equipment to dust was estimated to be in a range from 3.4 × 10?7 to 1.2 × 10?5 (year?1) for total PBDEs and from 2.9 × 10?7 to 7.2 × 10?6 (year?1) for BDE-209. Some fish species collected from ponds in e-waste recycling villages contained elevated levels of PBDEs, especially BDE-209, which were markedly higher than those in fish previously reported. Overall, levels and patterns of PBDE accumulation in different kinds of samples suggest significant emission from e-waste sites and that these areas are potential sources of PBDE contamination. Intakes of PBDEs via fish consumption were generally higher than those estimated through dust ingestion. Intake of BDE-99 and BDE-209 through dust ingestion contributes a large proportion due to higher concentrations in dust and fish. Body weight normalized daily intake through dust ingestion estimated for the e-waste recycling sites (0.10–3.46 ng/day/kg body wt.) were in a high range as compared to those reported in other countries. Our results highlight the potential releases of PBDEs from informal recycling activities and the high degree of human exposure and suggest the need for continuous investigations on environmental pollution and toxic impacts of e-waste-related hazardous chemicals.  相似文献   

19.
多溴联苯醚(PBDEs)和多氯联苯(PCBs)都是为人熟知的持久性有机污染物,也同为室内半挥发性有机物(SVOCs)。由于二者结构类似,通常认为PBDEs具有和PCBs相似的毒性。染毒剂BDE-209和PCB153分别是PBDEs和PCB家族的主要同系物,并且同时存在于环境和人体组织中。实验以DNA蛋白质交联(DPC)为生物标志物研究BDE-209和PCB153单独及联合染毒的遗传毒性。对大鼠肝细胞在37℃下染毒1h。浓度设置如下:BDE-209(0、1、6.5、12μg.mL-1);PCB153(0、1、6.5、12μg.mL-1);BDE-209(3.25μg.mL-1)+PCB153(3.25μg.mL-1)。实验结果显示:与溶剂对照相比,测得DPC水平随BDE-209(或PCB153)浓度增大而显著增高(p<0.01);PCB153比BDE-209引起更高水平的DPC(p<0.05或p<0.01);联合染毒组的DPC水平显著低于PCB153组(p<0.01),但稍高于BDE-209组(p>0.05)。从以上结果可知,BDE-209和PCB153之间存在拮抗作用;BDE-209和PCB153具有遗传毒性,并且就致DPC作用而言,二者之间可能存在拮抗作用。  相似文献   

20.
This study assesses the potential risk of Texcalac River and riparian area. The p,p′ DDT and ∑DDTs levels in agricultural soils (3.9–208.0?µg/kg) and in surface sediments (0.6–137?µg/kg) surpassing the guidelines for protection of aquatic life (75% > TEC). The ∑PCBs concentration oscillated from 135 to 93941?µg/kg; the half of sediments exceeded the international guidelines (PEL, PEC), as well as two soils (SQGE?=?500?µg/kg). The TEQ concentration of four PCB-DL varied between 0.1 and 24.9?µg TEQ/kg, chiefly affected by PCB 169. Five sediments were lethal for E. foetida, two resulted to be cytotoxic and the 58% produced genotoxicity higher than negative control (A?=?0.28?±?0.05; DICA?=?72.5?±?16.9 au). Likewise, 31.6% of samples increased the micronuclei frequency in V. faba in comparison with negative control. The analytical data and the bioassays results suggest a significant and immediate risk to exposed biota of this region, highlighting a specific area in Texcalac River and other one in Sambrano Ravine. It is necessity assess the dispersion of pollutants and perform biomonitoring studies that display the exposure levels in biota with the goal to characterise the ecotoxicological risk.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号