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 31 毫秒
1.
In this study, residual level and enantiomeric composition of typical organochlorine pesticides (OCPs) were surveyed in urban soils of Yinchuan, China. The median levels of ∑HCHs and ∑DDTs were 0.852 and 2.24 ng/g, respectively, which suggested little risk for ecological environment and human health in the study area. Both chiral α-HCH and o,p′-DDT displayed the non-racemic signatures in all samples. The isomer ratios of ∑HCHs and ∑DDTs combined with enantiomer fractions (EFs) of α-HCH and o,p′-DDT, suggested that contamination source of HCHs derived from historical HCHs (including technical HCHs and Lindane) and that of DDTs originated from old source with the usage of mixed technical DDTs and dicofol.  相似文献   

2.
This study provides information on the current status of contamination by organochlorine pesticides (OCPs) in eggs and tissues of House Sparrow, Passer domesticus, in Tamil Nadu, India. The mean concentration of total hexachlorocyclohexane (∑HCH) and total dichloro-diphenyl-trichloroethane (∑DDT) in eggs ranged from 0.01 to 1.81 μg/g and 0.02 to 1.29 μg/g, respectively. Concentration of 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p′-DDE) ranged from below detectable limit (BDL) to 0.64 μg/g, representing more than 60% of the ∑DDTs. About 28% of samples had p,p′-DDE levels above the critical concentration associated with reproductive impairment. However, the mean concentrations of cyclodiene insecticides were less than 0.5 μg/g. Although OCPs levels detected in tissues are not indicative of toxicity, continuous monitoring is recommended.  相似文献   

3.
Residual levels, distribution and possible sources of organochlorine pesticides (OCPs) in nine water column and suspended particulate matter (SPM) samples collected from Xiangshan Bay, East China Sea were investigated. Total OCPs concentrations in water column and SPM ranges from 2.88 to 34.72 ng/L and 2.47 to 29.94 ng/L, respectively, which exceed the US Environmental Protection Agency regulatory limits. Moreover, low ratio of α-HCH/γ-HCH and high ratios β- and γ-HCH suggested the cocktail input pattern of fresh and weathered HCHs. Meanwhile, low ratio of (DDE + DDD)/DDT and high ratios p,p′- and o,p′-DDT reflected a “dicofol type DDT pollution” pattern.  相似文献   

4.
Organochlorine pesticides (OCPs), such as hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT), are ubiquitous anthropogenic environmental contaminants. They are persistent, broad-spectrum toxicants that accumulate in the food web with potential risks to the ecosystem and human health. HCHs were the predominant contaminants in Baiyangdian Lake, North China. Concentrations of HCHs and DDTs ranged from 58 to 563 ng/g lipid weight (lw) and 21 to 401 ng/g lw, respectively, for aquatic biota samples. The highest levels of HCHs and DDTs were observed in muscles of yellow catfish. The mean concentrations of OCPs were 4.6 ng/L for water, 95 ng/g dry weight (dw) for aquatic plants, and 14 ng/g dw for sediments. Among the isomers and metabolites, α-HCH and p,p′-1,1-di(p-chlorophenyl)-2,2-dichloroethylene (p,p′-DDE) were the predominant congeners in biota samples. Correlations between log lipid-normalized concentrations of HCHs and DDTs and trophic levels (TLs) based on analysis of stable isotopes of nitrogen confirmed that persistent organic pollutants were magnified in the Baiyangdian Lake food web. Significant positive relationships were found for α-HCH and p,p′-DDT and their trophic magnification factors, which were 1.6 and 1.7, respectively. These results provide evidence of biomagnification of persistent organic pollutants (POPs) in freshwater food webs.  相似文献   

5.
Residues of hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) and their environmental risks in surface sediments collected from the rivers and lakes in Yangtze River Catchment of Wuhan, China, are investigated in this paper. Based on dry weight (dw), the concentrations of ΣHCH (α-, β-, and γ-HCH) and ΣDDT (p p′-DDT, o p′-DDT, p p′-DDE, p p′-DDD) in sediments ranged from 0.10 to 21.10 ng g−1 (mean, 4.03 ng g−1 dw) and 0.79 to 35.61 ng g−1 dw (average, 6.93 ng g−1 dw), respectively. Compared with some published guideline values of organochlorine pesticides (OCPs) in sediments, the concentrations of HCHs were at safe levels while the DDT residues would pose adverse biological effects in this studied catchment. The distribution of OCPs in sediments indicated that the input of tributaries was an important factor for OCP residues in the mainstream of the Yangtze River. Levels of OCPs in the sediments were influenced by total organic carbon contents, clay contents, water contents, and pH values of sediments. The present study suggested that historical usage of technical HCH and DDT was the main reason for OCP residues in the sediments from both rivers and lakes. Furthermore, the composition of OCPs reflected additional sources of the holding usage of lindane and fresh inputs of dicofol mixture in this region.  相似文献   

6.
We report concentrations of several classes of organochlorines (OCs) in the blubber of California sea lions (Zalophus californianus) from the Gulf of California. Summed OC levels measured in 34 wild-ranging animals were, in general, lower than those previously reported in sea lions from the eastern Pacific. The rank order of OCs was ΣDDTs (mean = 3400 ng g−1 lipid weight [lw]) > ΣPCBs (1400 ng g−1 lw) > ΣHCHs (50 ng g−1 lw) ≥ ΣCHLORs (46 ng g−1 lw). The most abundant OC measured was the DDT metabolite, p,p′-DDE. No significant differences in OC profiles were found between genders or rookeries. Although the mean concentrations of OCs measured in adult males and females were similar, only adult females had significantly higher (p < 0.05) mean blubber concentrations of ∑DDTs and ∑HCHs than pups.  相似文献   

7.
In this study, organochlorine pesticides (OCPs) and polychlorinated biphenyles (PCBs) levels were determined in 100 human milk samples from the city of Antalya. The levels of seven major PCB congeners; 28, 52, 101, 118, 138, 153, 180 and nine OCPs, α-HCH, β-HCH, γ-HCH, HCB, heptachlor epoxide, p.p-DDT, p,p-DDE, endosulfan-α and endosulfan-β were determined by gas chromatography with ECD detection. The levels of analyzed compounds were as follows: ΣPCBs 27.46 ± 11.58, ΣDDT 1,407 ± 123, and ΣBHC 160 ± 490 ng/g lipid wt.basis. PCB 153 and p,p-DDE were the dominant contaminants. The results have been discussed and compared with similar studies from other regions of Turkey.  相似文献   

8.
The concentrations of persistent organic pollutants, such as DDT and its metabolites (DDTs), hexachlorocyclohexane isomers (HCHs), cyclodienes (Cycls), and polychlorinated biphenyls (PCBs), were measured in livers and subcutaneous fat tissues of six Accipitridae and four Falconidae bird species from different areas in Greece. This is the first report of persistent organochlorine (OC) pollutants in birds of prey tissues presented for Greece and the Eastern Mediterranean region. Accumulation patterns of OCs found in birds suggested that the predominant contaminants were p,p′-dichlorodiphenyldichloro-1,1-ethylene (DDE) and PCBs, whereas Cycls and HCHs occurred at low concentrations only. Concentration values of p,p′-DDE ranged from nondetected to 19,518.72 ng/g wet wt in livers and from nondetected to 2679.19 ng/g wet wt in fat. Total PCB levels ranged from 1.01 to 7419.43 ng/g and from 3.25 to 490.10 ng/g wet weight for liver and fat samples, respectively. Higher-chlorinated PCBs such as 118, 138, 153, and 180 predominated in both the liver and subcutaneous fat samples, a pattern comparable to that observed in birds from other European countries. No significant differences in mean concentrations of OCs are detected between species. Hepatic concentrations were in general higher than the fat concentrations showing depleted fat stores in most birds. Concentration ranges were also found in lower or similar levels to those reported for birds in other regions. Variation of OCs levels in bird tissues could be due to different causes of death, with a subsequent effect on body lipid levels, and different feeding and migration habits. The liver PCB levels reported in this study are below the concentrations currently believed to exert mortality or ecotoxicological effects. On the contrary, in some cases p,p′-DDE concentrations were higher than the reported effect values for birds of the same families and could be associated with sublethal effects.  相似文献   

9.
Organochlorine pesticides (OCPs) concentrations in sediments and sediment trap fluxes of particulate organic carbon and OCPs were measured from October 2006 to May 2008 in the urban reach of Haihe River, Tianjin, China, in order to investigate vertical fluxes and accumulation of OCPs in sediments. The concentrations of OCPs in sediments (dry weight basis) were in the range of 2.08–10.07 ng/g (mean 4.70 ng/g) for HCHs (α-, β-, γ-, δ-HCH), 5.82–43.39 ng/g (mean 17.43 ng/g) for DDTs (p,p′-DDE, p,p′-DDD, o,p′-DDT, p,p′-DDT). Compared with data reported in Haihe River 2003, the levels of OCPs showed a significant decrease between 2003 and 2008. This is mainly attributed to significant decrease of production and usage of HCHs and DDTs and biodegradation of HCHs and DDTs in sediment. Concentrations of HCHs and DDTs in sediments were well correlated with sediment organic carbon contents. Concentrations of OCPs in settling particles (dry weight basis) ranged from 21.2 to 138.4 ng/g (mean 52.6 ng/g) for HCHs, 30.0–245.7 ng/g (mean 87.1 ng/g) for DDTs, which were 2.2–48.2-fold higher than those associated with sediments. β-HCH was the dominant HCH isomer in both sediments and settling particles. Among DDTs, p,p′-DDE was found to be dominant in sediments, while p,p′-DDT was the predominant form in settling particles. This suggests that further biodegradation of OCPs occurred during the course of sedimentation and burial. The annual sediment trap flux of OCPs in Haihe River in the urban area of Tianjin was 177–211 μg/m2 yr for HCHs and 213–341 μg/m2 yr for DDTs, respectively.  相似文献   

10.
The origin and occurrence of organochlorine pesticides [OCPs; hexachlorocyclohexanes (HCHs) and 1,1,1-trichloro-2,2- bis(p-chlorophenyl) ethane (DDTs)] in the surface and profile of soils from former OCPs production areas were compared with those of agricultural plots in Beijing, China in order to identify their characteristics, assess the eco-toxicological risk, and provide management suggestions. The comparison indicated heavier contamination caused by the production, storage, and waste disposal than the application of OCPs. Concentrations of HCHs and DDTs in topsoils varied by several orders of magnitude among different land-use groups. The concentrations (ng/g dry soil, geometric means) of HCHs (1958.2) and DDTs (3998.2) in the topsoils of former OCPs production factories were significantly higher than those in agricultural soils. The residue of DDTs and HCHs accumulated only on the surface of agricultural soil, but at depths ranging from 0 to 400 cm for the OCPs plant and warehouse. β-HCH and p,p’-DDE dominated in the agricultural soils, whereas β-HCH, γ-HCH, p,p’-DDT, and p,p’-DDE were dominant in the industrial soils. The risk of examined OCPs in soils on human health was assessed in light of the Dutch and Canadian soil quality criteria, and the results indicated a high risk in the OCPs production factory area and the agricultural lands with large application. The results point to the need for urgent actions to evaluate long-term toxicity and preassessment for OCPs-related land-use management.  相似文献   

11.
Persistent organochlorine pesticides (OCPs), such as dichlorodiphenyltrichloroethane (DDT) and its metabolites, hexachlorobenzene (HCB), α-, β-, and γ-hexachlorocyclohexane (HCH) isomers, together with polychlorinated biphenyl (PCB) congeners (IUPAC Nos. 28, 52, 101, 138, 153, and 180) were determined in tail feathers from 35 birds belonging to 15 species, all originating from the southwest of Iran (Khuzestan, coast of the Persian Gulf) and kept in museum collections. The patterns of organochlorine contaminants (OCs) in birds varied depending on their migratory behavior. Resident birds contained higher median PCB concentrations (<LOQ-151 ng/g feather) than HCHs, DDTs, and HCB. Locally migrating birds had higher median concentrations of HCHs (19–83 ng/g feather). In contrast, long-distance migrants had lower concentrations of HCB and HCHs. A positive correlation was observed among OCs in these birds, suggesting that trophic level, feeding strategy, and taxonomic group are influencing factors for the OC concentrations in bird feathers. An estimate of the risk associated suggests that levels of OCPs and PCBs were lower or close to the threshold reported to affect reproduction in 1990s.  相似文献   

12.
A gas chromatography/ion trap mass spectrometry method was developed for analysis of organochlorine pesticides (OCPs) in coral samples, which were extracted with accelerated solvent extraction (ASE) and cleaned up on a sulfuric acid-modified silica gel column. The optimal ASE conditions were found to be 100°C and 2000 psi, with a mixture of acetone and methylene chloride (1:1, v/v). The target analytes include hexachlorocyclohexanes (HCHs, specifically, α-, β-, γ-, and δ-HCH isomers), heptachlor, and hexachlorobenzene (HCB), o,p′-, p,p′-dichlorodiphenyltrichloroethane (o,p′-, p,p′-DDT), o,p′-, p,p′-dichlorodiphenyl-dichloroethylene (o,p′-, p,p′-DDE), and o,p′-, p,p′-dichlorodiphenyldichloroethane (o,p′-, p,p′-DDD). Standard sand samples were used as an alternative matrix spiked with OCP standards to determine the method precision and accuracy. Average recoveries of OCPs ranged from 82% to 102%, with relative standard deviations (RSDs) of 3%–6%, at a level of 10 ng/g and from 50% to 68%, with RSDs of 13%–19% at a level of 2 ng/g. The developed method was applied for analysis of OCPs in coral samples collected from Tern Island and Bikini Atoll in the Pacific Ocean. The concentrations of HCB were 7–26 pg/g dry weight in the samples from Bikini Atoll and 3–45 pg/g in those from Tern Island, and heptachlor concentrations were 208–2200 and 44–104 pg/g in the coral samples from Bikini Atoll and Tern Island, respectively. ∑HCH (sum of α-, β-, γ-, and δ-HCH) were 8–82 pg/g in Bikini Atoll coral and 86–629 pg/g in Tern island coral, and ∑DDT (sum of o,p′-, p,p′-DDD, o,p′-, p,p′-DDE, and o,p′- p,p′-DDT) were 80–212 pg/g in Bikini Atoll coral and 593–3165 pg/g in Tern Island coral. The results suggest that coral is a viable indicator species for pollution monitoring, which pollutants and their concentrations may be related to dated carbonate layers.  相似文献   

13.
On a global scale tropical regions in developing countries are thought to be significant source areas of organochlorine pesticides (OCPs), owing to a long history of widespread use and only a recent production ban or restriction on the application of these pesticides. In the present study, 32 soil samples were collected in 2004 from agriculture lands around the urban area of Guangzhou, in southern China, and analyzed for residues of OCPs including p,p’-DDT, p,p’-DDE, p,p’-DDD, and α-, β-, γ-, and δ-HCH. The dry weight concentrations of ΣHCH (ΣHCH = α-HCH + β-HCH + γ-HCH + δ-HCH) ranged from 0.2 to 103.9 ng/g, with a median of 4.4 ng/g. Residues of ΣDDT (ΣDDT = p,p’-DDT + p,p’-DDE + p,p’-DDD) ranged from 7.6 to 662.9 ng/g, with a median of 67.3 ng/g. The predominance of β-HCH among HCHs in most soil samples suggested that they were from historical contamination rather than recent input. The mean HCH α/γ-ratio of 2.72 was lower than that of technical HCHs, possibly due to more loss of α-HCH via evaporation from soil with time, conversion of γ-HCH to α-HCH or recent application of lindane in the region. The mean ratio of (DDE + DDD)/ΣDDT was 0.54, indicating that quite a portion of DDT in soils was degraded since its official ban in 1983. Higher DDT concentrations with lower (DDE + DDD)/ΣDDT ratios at a few sites suggested possible local DDT sources via the application of Dicofol. A positive but weak correlation (r = 0.449, p < 0.01) between DDT residues and TOC contents implied that soil organic matter might enhance adsorption of DDT in soils in the tropical regions. Hierarchical cluster analysis and principal component analysis were also performed to study the distribution and compositional patterns of OCPs as well as their sources and environemtal fates within the study area.  相似文献   

14.
Selected organochlorine pesticides (p,p′-DDT, p,p′-DDE, p,p′-DDD, α,β,γ,δ-HCH) were analyzed in the surface soils of Bacninh, Viet Nam. Forty representative soil samples were collected from Bacninh town and three surrounding districts. ΣDDT concentrations ranged from <0.02 to 160.86 ng g−1 dry weight, whereas ΣHCH concentrations ranged from <0.05 to 9.54 ng g−1 dry weight. The half-life times of ΣDDT and ΣHCH are 6.7 and 4.9 years, respectively. The decreasing trends of ΣDDT and ΣHCH levels during the period from 1992 to 2006 are observed. There is no recent input of DDT and HCH in the study area.  相似文献   

15.
The objective of this study was to determine the levels of organochlorine pesticides HCB, α-β-γ-HCH, p,p′-DDE, o,p′-DDT and p,p′-DDT in 150 adipose tissue of inhabitants of Tabasco, Mexico. The following pesticides were detected: p,p′-DDE in 100 % of samples at mean 1.034 mg/kg; p,p′-DDT in 96.7 % at mean 0.116 mg/kg; o,p′-DDT in 78.7 % at mean 0.022 mg/kg and β-HCH in 58.0 % at mean 0.049 mg/kg. The pooled sample was divided according to sex of donors (75 female and 75 male). Significantly higher levels of all organochlorine pesticides in females were found. The sample was divided into three age’s ranges (15–28, 29–45 and 46–84 years). The mean and median levels of β-HCH, p,p’-DDE and Σ-DDT increase significantly (p < 0.05) from the first to the second and third group. The presence of organochlorine pesticide residues in Tabasco inhabitants is still observed, indicating sources of exposure to the pesticides.  相似文献   

16.
This work describes concentrations of organochlorine pesticides in bottled drinking water (BDW) in Mexico City. The results of 36 samples (1.5 and 19 L presentations, 18 samples, respectively) showed the presence of seven pesticides (HCH isomers, heptachlor, aldrin, and p,p′-DDE) in bottled water compared with the drinking water standards set by NOM-127-SSA1-1994, EPA, and World Health Organization. The concentrations of the majority of organochlorine pesticides were within drinking water standards (0.01 ng/mL) except for β-HCH of BW 3, 5, and 6 samples with values of 0.121, 0.136, and 0.192 ng/mL, respectively. It is important monitoring drinking bottled water for protecting human health.  相似文献   

17.
The objective of the present study was to determine levels and calculate ratios of copartition coefficients among organochlorine pesticides β-HCH, pp′DDE, op′DDT and pp′DDT in maternal adipose tissue, maternal blood serum and umbilical blood serum of mother-infant pairs from Veracruz, Mexico. Organochlorine pesticides were analyzed in 70 binomials: maternal adipose tissue, maternal serum and umbilical cord serum samples, using gas chromatography with electron capture detection (GC-ECD). The results were expressed as mg/kg on fat basis. p,p′-DDE was the major organochlorine component, detected in every maternal adipose tissue (0.770 mg/kg), maternal serum sample (5.8 mg/kg on fat basis) and umbilical cord blood sample (6.9 mg/kg on fat basis). p,p′-DDT was detected at 0.101 mg/kg, 2.2 mg/kg and 5.9 mg/kg respectively, according to the order given above. β-HCH was detected at 0.027 mg/kg, 4.2 mg/kg and 28.0 mg/kg respectively. op′DDT was detected only in maternal adipose tissue at 0.011 mg/kg. The copartition coefficients among samples identify significant increases in concentrations from adipose tissue to maternal blood serum and to umbilical blood serum. The increase indicated that maternal adipose tissue released organochlorine pesticides to blood serum and that they are carried over to umbilical cord blood.  相似文献   

18.
The present article attempts to use freshwater bivalves Anodonta woodiana for monitoring the pollution of hexachlorocyclohexane isomers (α-, β-, γ-, δ-HCH), dichlorodiphenyltrichloroethanes (o, p′, p, p′-DDT) and metabolites (p, p′-DDE, p, p′-DDD) in the Taihu Lake, China. A total of 36 bivalves were sampled from 4 sites of Huzhou city, Dapu of Yixing city, Xueyan of Changzhou city, and Wulihu of Wuxi city around the lake in August–October 2004. The organochlorines were detected in all bivalves, and the mean concentration of ΣDDTs (7.07 ng/g wet weight) was significantly higher than that of ΣHCHs (2.37 ng/g wet weight). Overall, ΣHCHs are at the highest concentrations in the bivalves from the Dapu and Huzhou site, whereas ΣDDTs are at highest concentrations in the bivalves from the Wulihu site. Compositions of ΣHCHs were predominated by α- and γ-HCH isomers in the bivalves from all four study sites. Among these sampling sites, p, p′-DDT exhibited the highest percentage in the bivalves from Huzhou site. Furthermore, significant regional variations in compositions of both ΣDDTs and ΣHCHs had been identified. The residue levels of ΣDDTs and ΣHCHs in the bivalves of the present study were much lower than the corresponding residue limits for aquatic products of Ministry of Agriculture of China, FDA, and FAO/WHO. These findings suggest that Anodonta woodiana could serve as a unique bioindicator to monitor the HCH and DDT pollutions in the freshwater environment.  相似文献   

19.
Levels of organochlorine pesticides (OCPs) were analyzed in mollusk samples collected from markets in Dalian, China. Among 14 OCPs screened, chlordane (Chls), dichlorodiphenyltrichloroethane (DDT) and 1,2,3,4,5,6-hexachlorocyclohexane (HCH) were dominant compounds with the medians of 30.2, 5.31 and 2.03 ng/g wet weight (ww), respectively. Source analysis showed that, much higher concentrations of Chls in mollusk samples were the result of usage of the chemical in the city, HCH in samples were mainly due to historical technical HCH usage, and a small amount of fresh use of DDT might exist, causing high portion of p,p′-DDT in samples. Cumulative distribution functions for the concentrations of the selected OCPs were compared to several threshold criteria, indicating that concentrations in most mollusk samples were lower than the safe lines. The concentration data of selected OCPs were used for risk assessment, and human exposure levels were compared to noncancer and cancer benchmarks.  相似文献   

20.
The objective of this study was to determine the levels of organochlorine pesticides HCB, α-β-γ-HCH, pp′DDE, op′DDT and pp′DDT in adipose tissue of females living in Puebla, Mexico. Organochlorine pesticides were analyzed in 75 abdominal adipose tissue samples taken during 2010 by autopsy at the Forensic Services of Puebla. The results were expressed as mg/kg on fat basis. In analyzed samples the following pesticides were detected: p,p’-DDE in 100% of samples at mean 1.464 mg/kg; p,p’-DDT in 96.0.% of samples at mean 0.105 mg/kg; op′DDT in 89.3% of monitored samples at mean 0.025 mg/kg and β-HCH in 94.7% of the samples at mean 0.108 mg/kg. To show if organochlorine pesticide levels in monitored female’s adipose tissues are age dependant, the group was divided in three ages ranges (13–26, 26–57 and 57–96 years). The mean and median levels of all organochlorine pesticides increase significantly (p < 0.05) from the first to second and from the first to third group. At the same time, the increase of mean and medians levels from the second to third group were not statistically significant (p > 0.05). The present results compared to previous ones from 2008 indicates an increase in the concentrations during the 2010 study, but only the differences for pp’DDE and op’DDT were statistically significant. The 2010 group of females was older compared to the 2008 group. The presence of organochlorine pesticide residues is still observed, indicating uniform and permanent exposure to the pesticides by Puebla inhabitants.  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