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 437 毫秒
1.
采用气相色谱法毛细管色谱柱分离、电子捕获检测器检测土壤中残留的六六六和滴滴涕含量。取风干过筛的土壤样品,用丙酮、石油醚(1:)浸泡,超声波提取,浸泡液经浓硫酸净化后进样测定。当土壤样品取样量为10g时,方法检测限α-六六六,γ-六六六为0.001mg/kg,β-六六六、δ-六六六、op'-DDT和pp'-DDT为0.004mg/kg,pp'-DDE,pp'-DDD为0.002mg/kg。加标回收率在77%-100%之间,相对标准偏差为2.5%-8.5%。方法简便、灵敏。  相似文献   

2.
The prevalence and distribution of soil and water samples contaminated with enteroparasites of humans and animals with zoonotic potential (EHAZP) in Apucaraninha Indigenous Land (AIL), southern Brazil, was evaluated. An environmental survey was conducted to evaluate the presence of parasitic forms in peridomiciliary soil and associated variables. Soil samples were collected from 40/293 domiciles (10 domiciles per season), from November 2010 to June 2011, and evaluated by modified methods of Faust et al. and Lutz. Analyses of water from seven consumption sites were also performed. The overall prevalence of soil samples contaminated by EHAZP was 23.8 %. The most prevalent parasitic forms were cyst of Entamoeba spp. and eggs of Ascaris spp. The highest prevalence of contaminated soil samples was observed in winter (31 %). The probability map obtained with geostatistical analyses showed an average of 47 % soil contamination at a distance of approximately 140 m. The parasitological analysis of water did not detect Giardia spp. or Cryptosporidium spp. and showed that all collection points were within the standards of the Brazilian law. However, the microbiological analysis showed the presence of Escherichia coli in 6/7 sampled points. Despite the low level of contamination by EHAZP in peridomiciliar soil and the absence of pathogenic protozoa in water, the AIL soil and water (due to the presence of fecal coliforms) are potential sources of infection for the population, indicating the need for improvements in sanitation and water treatment, in addition periodic treatment of the population with antiparasitic.  相似文献   

3.
We investigated chlorinated hydrocarbon contaminants in aquatic mustelid species on the Fraser and Columbia Rivers of northwestern North America. Carcasses of river otter (Lutra canadensis) (N=24) and mink (Mustela vison) (N=34) were obtained from commercial trappers during the winters of 1990–91 and 1991–92. Pooled liver samples were analyzed for organochlorine pesticides, polychlorinated biphenyls (PCBs), including non-ortho congeners, polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). Most samples contained detectable concentrations of DDE, PCBs, although there was substantial variability in patterns and trends among neighboring samples. Concentrations of DDE were in some mink and several otter samples from the lower Columbia River elevated (to 4700 g/kg wet weight); excluding one mink sample from the Wenatchee area, mean DDE levels generally decreased between 1978–79 and 1990–92. PCBs were present in all samples. PCB concentrations in otter livers collected from the lower Columbia were ten-fold lower than measured a decade previously; nevertheless, a sample taken near Portland had a mean concentration of 1500 g/kg, within a range of concentrations associated with reproductive effects in captive mink. Concentrations of 2,3,7,8-TCDD and TCDF were generally below detection limits, except for one otter collected near a pulp mill at Castlegar, on the upper Columbia, with 11 ng TCDD/kg in liver. Elevated concentrations of higher chlorinated PCDD/Fs, probably resulting from use of chlorophenolic wood preservatives, were found in both species; one otter sample from the lower Columbia had 2200 ng OCDD/kg. International TCDD toxic equivalent levels in mink (31 ng/kg) and otter (93 ng/kg) from the lower Columbia River approached toxicity thresholds for effects on reproduction in ranch mink.  相似文献   

4.
Grebe and seaduck species were collected during late winter at industrial and reference sites along coastal British Columbia, and during spring migration in the Yukon Territory, from 1988 to 1993. Liver and/or breast muscle were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), organochlorine (OC) pesticides, and chlorophenol-related compounds. Piscivorous species, including western grebes (Aechmophorus occidentalis) and common mergansers (Mergus merganser), contained highest levels of all contaminants. DDE and PCBs were detectable in all species analyzed, but were at low levels (<50 and 100 g/kg [sum PCBs] wet weight, respectively) in all but some grebe and merganser samples. Highest DDE concentration (229 g/kg) was in liver of common mergansers collected at Port Alberni in 1989, and that of PCB (2300 g/kg) in breast muscle of western grebes collected in 1992 from the same site. The interspecific PCDD/PCDF pattern was similar to that of the OC pesticides and PCBs, with the fish-eating species containing highest concentrations. The only congener detected in all samples was 2,3,7,8-TCDF, although 2,3,7,8-TCDD was regularly present. Generally, of all samples collected in 1989, those from the bleached-kraft pulp mill (BKPM) site at Port Alberni were the most contaminated with PCDDs and PCDFs. Of the chlorophenolic compounds measured, only pentachlorophenol was routinely detected, typically at levels below 5 g/kg. Traces of 3,4,5,6-tetrachloroguaiacol, 5-chloroguaiacol and 4,5-dichloroguaiacol were also detected in a few samples, mainly from a BKPM site at Prince Rupert. By 1992, after changes to pulp mill bleaching processes and restrictions in chlorophenolic anti-sapstain use, PCDD and PCDF concentrations were substantially lower compared to 1989 in all species sampled and no longer posed a concern for human consumers. International TCDD-toxic equivalents (I-TEQs) in some western grebe samples were within the range of concentrations associated with sublethal effects in waterbird species (200–400 ng/kg).  相似文献   

5.
The ocelot (Felis pardalis) isan endangered neotropical cat distributed within asmall range in the Lower Rio Grande Valley (LRGV), inTexas, U.S.A. Studies of the impacts of environmentalcontaminants in wild cats are few. Approximately onefourth of the estimated population (about 100) ofocelots in the LRGV was sampled to evaluate theimpacts of chlorinated pesticides, polychlorinatedbiphenyls, and trace elements on the population. Hairwas collected from 32 ocelots trapped between 1986–1992,and blood was collected from 20 ocelots trappedbetween 1993–1997. A few blood samples were obtainedfrom individuals recaptured two or three times. Tissue samples from 4 road-killed ocelots were alsoanalyzed. DDE, PCBs, and Hg were some of the mostcommon contaminants detected in hair and blood. MeanHg levels in hair ranged from 0.5 to 1.25 g g-1 dw,Se from 1.5 to 3.48 g g-1 dw, and Pb from 0.56 to26.8 g g-1 dw. Mean DDE concentrations in plasma ranged from 0.005 g g-1 ww to 0.153 g g-1 ww, and PCBs ranged from 0.006 g g-1 ww to 0.092 g g-1 ww. Mean Hg levels in red blood cells rangedfrom 0.056 g g-1 dw to 0.25 g g-1 dw. Concentrations of DDE, PCBs, or Hg, did not increasesignificantly with age, although the highestconcentrations of DDE and Hg were found in olderanimals. Overall, concentrations of DDE, PCBs, and Hgwere low and at levels that currently do not pose anythreat to health or survival of the ocelot. This isfurther supported by good reproduction of the ocelotin the LRGV, where adult females averaged about 1.5kittens/litter. Thus, it seems that the current majorthreat to recovery of the ocelot in the LRGV may behabitat loss, although potential impacts of newgeneration pesticides, such as organophosphorus andcarbamate insecticides need further study.  相似文献   

6.
Persistent organic pollutants (POPs) such as chlorinated pesticides are of global concern due to their widespread occurrence, persistence, bioaccumulation and toxicity to animals and human. This paper summarises recent research on 18 chlorinated pesticides in an important catchment in China, by determining their concentrations and behaviour in water, sediment, soil and plants. The concentrations of the total pesticides were in the ranges 187-893 ng l(-1) in river water, 8.53-210 ng g(-1) dry weight in soil, 2.66-13.45 ng g(-1) dry weight in river sediment, and 651-2823 ng g(-1) dry weight in plants. The predominance of beta-HCH as the major isomer of HCHs in all water, soil, sediment and plant samples was clearly observed, due to beta-HCH's resistance to biodegradation. On average beta-HCH accounted for 44%, 53%, 50%, and 46% of the total HCH concentration in water, soil, sediment and plant, respectively. Of the DDTs, DDE accounted for 48%, 43%, 53%, 55% of the total DDT, which suggested that DDT had been transformed to its metabolites, DDE and DDD, of which DDE was the more stable. The chlorinated pesticide levels in the River Wuchuan were generally below the guideline values in China, but some sites displayed levels in excess of EC Environmental Quality Standards for HCHs and DDTs. The results therefore provide important information on the current contamination status of a key agricultural watershed in China, and point to the need for urgent actions to evaluate the long-term fate and toxicity of such persistent compounds and an appropriate remediation strategy.  相似文献   

7.
Only organochlorine (OC) residues were monitored by gas chromatographyin water, sediment and shrimp samples collected everymonth between July 1982 and August 1983 from therivers of Rio Cobre basin. In samples collected everyfour months during 1989–1990, and seven times duringJuly 1995–March 1996, OC and OP (organophosphates)residues were monitored. Carbamate and pyrethroidresidues were not monitored. The detection ofresidues in 1982–1983 was 54 to 100% in water andsediment, and 83 to 100% in shrimp samples fromvarious sampling stations in the four rivers. In otheryears, it ranged from about 40 to 100% in the threetypes of samples.In 1982–1983, DDE and dieldrin residues were found tobe much higher than those of lindane and - and-endosulfan in Black River, Rio Pedro, ThomasRiver and Rio Cobre in the watershed. The ranges ofmeans of each residue in water (g L-1), sediment(ng g-1) and shrimp (ng g-1) samples, respectively, were:DDE, 0.059–102.0, 3.44–13.97, 0.344–14.57;dieldrin, 0.026–173.6, 1.21–2.75, 0.427–5.59;-endosulfan, bdl, 1.75–4.00, bdl;-endosulfan, bdl (below detectable limits), 2.51–9.48, bdl;and lindane, (bdl), 0.110–0.319, 2.90.In 1989–1990 and 1995–1996, residues of six OCs and two OPs were detected quite regularly. DDE, dieldrinand Chlorpyrifos residues were much higher than thoseof the other insecticides. The range of their meansin water (g L-1), sediment and shrimp (ng g-1),respectively, were: DDE, 1.66–19.76, 0.941–5.84,1.11–8.32; dieldrin, 0.077–7.22, 0.425–3.31,0.385–1.59; -endosulfan, 0.034–1.25, 0.021–1.22, 0.032–3.62; -endosulfan, 0.665–1.23,0.008–3.60, 0.005–3.97; endosulfan sulphate, 0.959–1.34, 0.035–3.08, 0.012–1.80; lindane, bdl,0.005–0.82, 1.19–1.56; chlorpyrifos, 0.702–4.06,0.005–1.51, 0.156–7.04; and diazinon, bdl, 0–0.150, 0.001–0.006. At the mouth of the river, whereit discharges into the sea, the levels of almost allthe residues were higher than upstream.  相似文献   

8.
Organochlorinated Compounds in Waters of the Pearl River Delta Region   总被引:4,自引:0,他引:4  
Samples of river water and sewage water were analysed for ten PCB congeners, chlorobenzenes and chlorinated pesticides (BHCs and DDT) in three cities (Guangzhou, Shenzhen and Zhaoqing) in the Pearl River Delta, The results showed that the sewage water in Shengzhen had the highest concentration of total PCBs at about 10ng/L, and Dasha River (Shengzhen), the lowest at about 1.0ng/L. In general, the sewage waters in the three cities had higher concentrations of PCBs than river waters. Chlorobenzenes were investigated in the water samples. The total concentrations of chlorobenzenes ranged from 0.02~0.13g/L, the Dasha River had the highest level of chlorobenzenes, and the sewage water in the city of Zhaoqing had the next highest. The result may be related to the discharges from paper production factories nearby the sampling sections of the Dasha River (Shenzhen) and sewage water in Zhaoqing. The concentrations of organochlorinated pesticides (-BHC, -BHC, -BHC, DDT and DDE) changed little in all water samples except for the sewage water in Guangzhou. It seemed that these pesticides are more a residual signal than a direct discharge from point sources.  相似文献   

9.
In a baseline study, muscle and liver from important commercial fish belonging to different trophic levels were analysed for organochlorines. Samples of sole, sardine and hake were collected from seven locations off the Continental coast and greater forkbeard and horse mackerel off two Azores islands. Residues of ppDDT, ppDDE and PCBs were present in all muscle and liver samples. ppDDD occurred in all liver samples and in most muscle samples, except in sole where it occurred in 29% of the samples. Dieldrin was detected less frequently and did not occur in samples from the Azores. The residue levels were generally similar to those detected in related species from the North Sea, except for samples of sole collected between the Tagus and Sado estuaries where much higher residues were obtained. In view of the low consumption of insecticides in the Azores, it is proposed that long-range transport of organochlorines by winds and/or marine currents is responsible for their presence in this area. The organochlorine residues found in these fish showed no relationship with their position in the food chain but the values did increase with the quantity of lipids present. An unknown compound analysed by GC-MS interfered with DDE quantification in one sample of greater forkbeard.  相似文献   

10.
A microwave-assisted solvent extraction (MASE) technique was developed for the quantitative extraction of gasoline- and diesel-range petroleum hydrocarbons (PHs) from soil and marine sediment samples. The influence of different extracting solvents, extraction temperature and duration of extraction on the recoveries of PHs was evaluated using a two-level orthogonal array design (OAD) with a OA8(27) matrix. Gas chromatographic-mass spectrometry (GC-MS) in multiple selective ion monitoring (MSIM) mode was used for the analysis of the PHs in environmental samples. The spiking range of the PHs in the environmental samples was between 1 to 1000 g/g. Good recoveries (>80%) could be obtained for most of the PHs using the optimum MASE conditions. The limit of detection (LOD) achieved by the GC-MS-MSIM was 0.02 g/g. A preliminary survey for the levels of PHs in marine sediment and soil samples from different parts of Singapore was carried out using the method.  相似文献   

11.
Mercury contamination in the water bodies of developing countries is a serious concern due to its toxicity, persistence, and bioaccumulation. Vembanad, a tropical backwater lake situated at the southwest coast of India, is the largest Ramsar site in southern India. The lake supports thousands of people directly and indirectly through its resources and ecosystem services. It is highly polluted with toxic pollutants such as heavy metals, as it receives effluent discharges from Kerala’s major industrial zone. In the present study, water, pore water, sediment, and fish samples collected from Vembanad Lake were analysed for total mercury (THg) and methyl mercury (MHg) contents. The maximum concentrations of THg and MHg in surface water samples were31.8 and 0.21 ng/L, respectively, and those in bottom water samples were 206 and 1.22 ng/L, respectively. Maximum concentration of THg in surface sediment was observed during monsoon season (2850 ng/g) followed by that in the pre-monsoon season (2730 ng/g) and the post-monsoon season (2140 ng/g). The highest sediment concentration of MHg (202.02 ng/g) was obtained during monsoon season. The spatial variation in the mercury contamination clearly indicates that the industrial discharge into the Periyar River is a major reason for pollution in the lake. The mercury pollution was found to be much higher in Vembanad Lake than in other wetlands in India. The bioaccumulation was high in carnivorous fishes, followed by benthic carnivores. The THg limit in fish for human consumption (0.5 mg/kg dry wt.) was exceeded for all fish species, except for Glossogobius guiris and Synaptura orientalis. The concentration of THg was five times higher in Megalops cyprinoides and four times higher in Gazza minuta. Significant variation was observed among species with different habits and habitats. Overall, risk assessment factors showed that the mercury levels in the edible fishes of Vembanad Lake can pose serious health impacts to the human population.  相似文献   

12.
Organochlorine pesticides (OCPs) in sediment, water and biota samples from the coastal marine environment of Mumbai were analysed to elucidate their distribution in various environmental compartments. HCH isomers, dichlorodiphenyltrichloroethane (DDT) and its metabolites were the predominantly identified compounds in all the samples. High ratios of DDT to dichlorodiphenyldichloroethylene (DDE) were found in seawater samples. This indicates the presence of a significant source of DDT in this region. In sediment samples, the gamma-isomer contributed almost 55% to the total HCH, indicating a high affinity of the gamma-isomer towards the sediment. The levels of organochlorines in fish obtained from this region were found to be lower than the levels of organochlorines in fish in temperate regions.  相似文献   

13.
A study was conducted to determine the levels of heavy metals Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn along with physico-chemical parameters in ground waters of Aligarh city, U.P. (India). Twenty seven samples of hand pump water and twenty three samples of municipal water supply were collected from different localities of the Aligarh city, five times during the period of two months at intervals of 12 days. The samples were analysed for physico-chemical characteristics (pH, electrical conductivity, chlorides, sulphates, total hardness, total alkalinity, nitrate-nitrogen, fluoride, calcium and magnesium) and heavy metal contents. The concentrations of heavy metals in the hand pump water samples were found in the ranges of Cd (ND-5.00); Cr (ND-30.00); Cu (ND-82.50); Fe (16.80–460.00); Mn (ND-425.00); Ni (ND-25.00); Pb (ND-25.00) and Zn (28.60–775.00) g l–1. The heavy metal concentrations in the municipal water supply samples were found to be Cd (ND-5.00); Cr (ND-25.00); Cu (ND-37.50); Fe (8.00–37.50); Mn (ND-320.00); Ni (ND-25.00); Pb (ND-25.00) and Zn (2.00–271.87) g l–1.It appears from the results of these studies the concentrations of Cd, Cr, Cu, Ni, Pb, and Zn in the ground waters of the Aligarh City were found to be lower than the prescribed limits of World Health Organisation (1984), whereas the values of Fe and Mn were found above the prescribed limits in some localities. The chloride total hardness and nitrate-nitrogen were comparatively higher in the hand pump water than the municipal supply water. The reason of higher values of these parameters may be ascribed to the surface disposal of sewage wastes, wastes from metal processing industries and other house hold refuses.  相似文献   

14.
Multiple residues of organochlorine insecticides were monitored in the agricultural fields near Farrukhabad in the vicinity of the River Ganga in northern India for one year (1991–1992). Almost all soil samples were found to be contaminated with residues of hexachlorocylohexane (HCH) and dichlorodiphenyl-trichloroethane (DDT). Residues of aldrin and endosulfan were also detected in a large number of samples. Heptachlor residues were scarcely detected. Alpha-HCH, pp-DDT and alpha-endosulfan were found to dominate over the other isomers/metabolites of HCH, DDT and endosulfan, respectively. The average concentration of dieldrin was more than that of aldrin. The concentrations of residues progressively increased up to a depth of 1 m.  相似文献   

15.
Qiantang River is a typical river used for drinking water source, flowing through agricultural area in east China. Surface water samples at 45 sampling sites from the river were collected and analyzed for 13 organochlorine pesticides (OCPs) during six surveys in 2 years of 2005–2006. Sediments, soils, farmland runoff water and dry/wet deposition of this region were also measured for their OCPs residue in order to know possible source of OCPs contamination. The total OCPs concentrations in surface water were 7.68–615.2 ng/l. β-HCH, δ-HCH, Aldrin, Heptachlor, Heptachlor epoxide are the major OCPs in water. The maximum levels of OCPs in water were found in July, while significantly lower OCP concentrations were measured in January. Significant linear correlation was found between the concentration of HCH and that of total 13 OCPs in water. The measured OCP concentrations in sediments, soils, farmland runoff water and dry/wet deposition are discussed in relation to concentrations and patterns found in the surface water. Comparison of OCP levels in sediments and soils led to conclusion that erosion of soil contribute significantly to the contamination of water. The OCPs dry and wet deposition to water body was estimated to 0.49 and 0.86 ton/year, respectively. The ratio of α/γ-HCH and (DDE+DDD)/∑DDT in environmental matrix indicated there probably existed new OCPs input of lindane and dicofol into the river.  相似文献   

16.
Starlings were collected from 129 sites throughout the contiguous United States in the fall of 1982 and analyzed for organochlorine compounds as part of a nationwide monitoring program. Residues of 14 organochlorine compounds were found. Only DDE, polychlorobiphenyls (PCB), dieldrin, and heptachlor epoxide occurred in more than 50% of the 10-starling pools. Geographical variation in the occurrence of seven organochlorine compounds was noted. Mean DDE levels were higher in the southwestern United States. Mean PCB levels were higher in the eastern United States. The occurrence frequency of most organochlorines in 1982 was similar to that which was reported in the previous nationwide study in 1979. A slight increase in occurrence was noted for trans-nonachlor. Mean DDE level in 1982 was similar to that of 1979. Mean PCB level in 1982 was lower than the 1979 mean, but this change may not reflect a decrease in environmental PCB levels.  相似文献   

17.
The integrated pest management (IPM) modules of pesticide schedule on Basmati rice were validated at field experiments conducted in Northern India for consecutive 3 years (2005–2008). The pesticide residues were found below the detectable limit (<0.01–0.001 mg/kg) in soil and irrigation water samples of Kaithal region. In Dehra Dun region of Uttrakhand, the residues of carbendazim in rice grains and soil were detected below <0.01 mg/kg level. In second year experiments (2006–2007), only four non-IPM soil samples indicated the presence of chlorpyrifos and endosulfan in the range of ND <0.001 to 0.07 mg/kg, out of 45 samples analyzed. Carbendazim applied as seed treatment at Dehradun and Kaithal field trials was found below detectable limit in both IPM and non-IPM rice grains (<0.01 mg/kg) and irrigation water (0.01 μl/ml). Chlorpyrifos was detected in five water samples from Kaithal and one from Pant Nagar in the range of 0.003–0.006 μl/L, α- and β-isomer of endosulfan in the range of 0.005–0.03, and 0.005–0.02 μl/ml, respectively, in one sample from Pant Nagar and two from Kaithal, out of a total of 22 samples. In the region of Uttrakhand and Uttar Pradesh during 2007–2008, four non-IPM samples of soil indicated trace levels of endosulfan, out of 16 samples analyzed. The residues were detected below detection limit for carbendazim (<0.01 mg/kg) in soil samples of Dehradun IPM fields and for endosulfan and carbendazim (0.001–0.01 μl/L) in water samples each from IPM and non-IPM fields of Uttar Pradesh. The results of 3-year trials of IPM module indicated basmati rice as safe and economical with pesticide residue-free rice grains.  相似文献   

18.
Fluoride Deposition in Central India   总被引:1,自引:0,他引:1  
Fluoride is a volatile element emitted from natural and anthropogenic sources into the atmoshere and scavenged from the atmosphere by rain water. We collected 444 rain water and 36 dust samples on an event basis at 13 sites and on the bulk basis (monthly) at 3 sites, respectively, in central India (extending over 17°N to 24°N latitude and 80° 17 to 84°11E longitude). The level of F- in the atmospheric samples was determined by automating the conventional Zr(IV)-SPADNS [Sodium 2- (parasulfophenylazo)-1, 8-dihydroxy-3, 6-naphthalene disulfonate] method in the presence of surfactant, i.e. TX–100 [Triton x- 100]. The detection limit of the method is 10.0 ppb F- with a sample throughput of 70 samples/h. The F- deposited with rain water (in 13 sites) and with dust (three sites) were ranged between 54.8 to 483.0, and 105.0 to 503.3 kg/km2/year, respectively. The level of F- in atmospheric samples, seasonal and spatial variation in deposition and sources of F- are discussed.  相似文献   

19.
Environmental occurrence of CECs poses a great threat to both aquatic life and human health. The aim of this study was to optimize and validate SPE/LC-(ESI)MS-MS method for simultaneous quantitative monitoring of two sub-classes of CECs (pharmaceuticals and hormones) and to estimate the concentrations of select CECs in environmental water samples. For all the tested analytes, recoveries in laboratory reagent water were greater than 81%. Average percent (relative standard deviation) RSD of the analytes in recovery, repeatability, and reproducibility experiments were ≤?10%. Determination coefficients (r2) of primidone, diclofenac, testosterone, and progesterone were estimated to be 0.9979, 0.9972, 0.9968, and 0.9962, respectively. Limits of detection (LOD) for primidone, diclofenac, testosterone, and progesterone were 4.63 ng/L, 5.36 ng/L, 0.55 ng/L, and 0.88 ng/L, respectively. Limits of quantification (LOQ) for primidone, diclofenac, testosterone, and progesterone were 14.72 ng/L, 17.06 ng/L, 1.766 ng/L, and 2.813 ng/L, respectively. Average recoveries in environmental water and wastewater samples were greater than 74% and RSD were ≤?7%. Trace levels (68.33–125.70 ng/L) of primidone were detected in four environmental water samples, whereas diclofenac was not detected in any of the tested sample. Trace levels of progesterone were observed in two environmental samples (16.64 –203.73 ng/L), whereas testosterone was detected in STP inlet sample (178.16 ng/L).  相似文献   

20.
The residues of organochlorine pesticides (OCPs) in 19 surface sediments of Bohai Sea Bay were determined in this study. Total OCP concentration in surface sediment ranged from 9.01 to 18.04 ng/g dry weight, with a mean concentration of 12.50 ng/g. These findings are in the mid-range of pesticide concentrations compared to those reported in other regions worldwide. DDTs and HCHs were the predominant species. The α-HCH/β-HCH ratios and the predominant γ-HCH indicate that the technical HCH contamination was due mainly to historical usage, although there appeared to be a fresh input of lindane. The results from \(\left( {\mbox{DDD}\,\mbox{+}\,\mbox{DDE}} \right)\mbox{/}\sum {\mbox{DDTs}} \) and DDD/DDE calculations suggest that the usage of DDT in agricultural activities was not terminated, and the historical/fresh inputs of DDT in these areas could be more easily degraded into DDD under an anoxic condition. PCA implies that the recent usage of DDT could serve as important fresh input sources for OCPs.  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