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1.
Concentrations of polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs), such as dichlorodiphenyltrichloroethane (DDT) and analogs, hexachlorocyclohexanes (HCHs) and hexachlorobenzene (HCB), were determined in 8 fish species collected during October and November 2007 from the largest Iranian wetland, the Shadegan Marshes. Fishes were selected on the basis of their importance in the local diet and feeding behavior. In all samples, OCPs were found in higher concentrations than PCBs. Common carp (Cyprinus carpio) had the highest OCs (1680 ng/g lipid wt.), with DDTs being most prevalent and p,p′-DDE contributing by 53-88% to the total DDTs. In all samples, OCs were found in order of DDTs>HCHs>PCBs>HCB. The highest concentration of HCHs was found in common carp (410±180 ng/g lipid wt.) and α-HCH was the predominant compound among HCH isomers (range 70-90%, mean 82%) in all species. All samples contained PCBs and CB 28 (37%) and CB 52 (26%) were the most frequently occurring congeners. common barbel (Barbus barbulus) (70±17 ng/g lipid wt.) exhibited the highest concentrations of HCB. OC levels in fish were relatively low, but the levels of several OCs in some of our specimens exceed the guidelines for food safety issued by the European Union (EU) and US Food and Drug Administration (FDA).  相似文献   

2.
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   

3.
Persistent organochlorines such as DDT and its metabolites (DDTs), hexachlorocyclohexane isomers (HCHs), chlordane compounds (CHLs), hexachlorobenzene (HCB), and polychlorinated biphenyls (PCBs) were determined in whole-body homogenates of resident and migratory birds collected from South India. Organochlorine contamination pattern in birds varied depending on their migratory behaviour. Resident birds contained relatively greater concentrations of HCHs (14–8,800 ng/g wet wt) than DDTs and PCBs concentrations. In contrast, migrants exhibited elevated concentrations of PCBs (20–4,400 ng/g wet wt). The sex differences in concentrations and burdens of organochlorines in birds were pronounced, with females containing lower levels than males. Inland piscivores and scavengers accumulated greater concentrations of HCHs and DDTs while coastal piscivores contained comparable or greater amounts of PCBs. Global comparison of organochlorine concentrations indicated that resident birds in India had the highest residues of HCHs and moderate to high residues of DDTs. It is, therefore, proposed that migratory birds wintering in India acquire considerable amounts of HCHs and DDTs. Estimates of hazards associated with organochlorine levels in resident and migratory birds in India suggested that Pond Heron, Little Ringed Plover, and Terek Sandpiper may be at risk from exposure to DDTs. Received: 22 May 1997/Accepted: 7 October 1997  相似文献   

4.
Concentrations of organochlorine pesticides (OCPs) were measured in blood plasma of 13 species of birds collected from Ahmedabad, India. Among the various OCPs determined, HCHs and its isomers had higher contribution to the total OCPs. Concentration of ∑HCHs varied from 11.4 ng/mL in White ibis Threskiornis melanocephalus to 286 ng/mL in Sarus Crane Grus antigone, while ∑DDT ranged between 19 ng/mL in Black Ibis Pseudibis papillosa and 147 ng/mL in Painted Stork Mycteria leucocephala. p,p′-DDE was accounted for more than 50% of total DDT in many of the samples analysed. However, a p,p′-DDT to p,p′-DDE ratio higher than one obtained for many species of birds indicates the recent use of DDT in this study region. The concentrations of cyclodiene insecticides, heptachlor epoxide, dieldrin and total endosulfan ranged from 15.8 to 296.2 ng/mL, below detectable level to 15 and 41.1–153.2 ng/mL, respectively. The pattern of total OCP load generally occurred in the following order: granivores < insectivores < omnivores < piscivores < carnivores. Although, the organochlorine residues detected in blood plasma of birds are not indicative of toxicity, the presence of residues in birds over the years (2005–2007) indicates continued exposure to organochlorine compounds. However, continuous monitoring is recommended to facilitate the early identification of risks to the survival of a species.  相似文献   

5.
Previous ecotoxicological studies have documented relationships between residues of various organochlorines (OCs) and immune status, carotenoid colors, and wing feather growth in different bird species. In this study, the density of white blood cells (WBC), carotenoid colors, and length of the same feathers on each wing were measured in breeding great black-backed gulls (Larus marinus) on the coast of northern Norway, and related to the blood residues of five OCs, including HCB (hexachlorobenzene), β-HCH (β-hexachlorocyclohexane), p,p′-DDE (p, p′-dichlorodiphenyldichloroethylene), oxychlordane, and polychlorinated biphenyl (PCB), in addition to ΣOC. Neither, WBC density nor carotenoid colors were significantly related to blood residues of any of the OCs, suggesting that OC levels may have been too low to significantly affect these outcome parameters. However, in the colony where the OC concentrations were highest, there was a weak but significantly positive relationship between the probability of having different length of feathers on each wing and levels of PCB and ΣOC, in males. Thus varying length of the wing primaries may reflect adverse impacts of OCs in great black-backed gulls. However, in gulls with moderate levels of OCs, it is probably not a sensitive indicator of progressing ecological impacts of OCs, since such adverse ecological relationships were found in the breeding colonies where there were no relationships between differences in wing feather lengths and OCs.  相似文献   

6.
This paper presents the first comprehensive report of the organochlorine pesticide residues (OCs) such as hexachlorocyclohexane isomers (HCHs), dichlorodiphenyltrichloroethane and its six metabolites (DDTs), and hexachlorobenzene (HCB) in core sediments (<63-μm particle size) from the Indian Sunderban wetland. The pooled mean values of the mass fraction of ΣHCHs, HCB, and ΣDDTs in the sediments were 0.05–12, 0.05–1.4, and 0.05–11.5 ng g−1 dry weight, respectively. The vertical distribution of pesticides reveals an erratic pattern. The concentration of four isomers of HCHs reveals a heterogenic distribution where γ-HCH (lindane) and β-HCH shared the dominant part. The mass fraction of HCB did not show any sharp spatial variation. The prevailing sequence of DDT metabolites indicates an active degradation of the parent compound in the sediments and/or inputs of already degraded pp’DDT to the region. Peak concentrations of HCH isomers and DDT metabolites have the potential to induce ecotoxicological impact as per the sediment quality guidelines.  相似文献   

7.
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   

8.
Twenty-two organochlorine pesticides (OCPs) were investigated in Anhui reach of Huaihe river, China. Seventeen out of 22 OCPs were detected by GC-MS. The mean concentrations of OCPs followed the order: HCHs?>?DDTs?>?HCB?>?chlordanes?>?endosulfans. Levels of total HCHs and total DDTs ranged from 2.54 to 13.91 ng g?1 (mean?=?7.52 ng g?1) and 0.016 to 2.54 ng g?1 (mean?=?0.45 ng g?1), respectively. The concentrations of DDTs were lower than those of HCHs. Compared with the other rivers in China, DDTs and HCHs were relatively lower or similar. Statistical analysis indicated that the OCPs concentration differences were not insignificant between upstream, midstream and downstream. The compound compositions suggested that historical usage of lindane and fresh DDT were the main sources. The regression analysis indicated that TOC has influence on the levels of HCHs and little influence on the levels of DDTs in the sediments.  相似文献   

9.
Concentrations of organochlorine persistent pollutants were investigated in tissues of the European hedgehog (Erinaceus europaeus). Road kills and carcasses from wildlife rescue centers were used to characterize organochlorine compound tissue distribution and tissue profile dissimilarities (hair, liver, kidney, muscle, and adipose tissue). The most important contaminants were polychlorinated biphenyls (PCBs), chlordanes (CHLs), and DDTs, with median concentrations of 75, 5.1, and 1.4 ng/g liver wet weight, respectively. Median levels for the remaining compounds-hexachlorobenzene (HCB), hexachlorocyclohexanes (HCHs), and octachlorostyrene-were less than 0.5 ng/g liver wet weight. Compared to results with other mammalian wildlife, the present results indicate that hedgehogs may accumulate considerable concentrations of organochlorine compounds. Polychlorinated biphenyls and HCB preferably accumulated in liver and muscle tissue. Concentrations of DDTs and HCHs were highest in muscle tissue and hair, respectively. Octachlorostyrene and CHL levels were predominant in liver. The observed positive relationships between concentrations in hair and internal tissues for PCBs, DDTs, HCB, HCHs, and CHLs (0.49 < r < 0.91) and for several individual PCB, DDT, and CHL compounds (0.31 < r < 0.76) indicate the usefulness of hair as a biomonitoring tool of organochlorine compounds. Multivariate profile analyses revealed a higher dominance of less-persistent compounds (p,p'-DDT, alpha-HCH, and PCBs 95, 101, and 149) in hair compared to internal tissues. The present study demonstrates the suitability of hedgehog hair as a nondestructive biomonitoring tool regarding pollution with organochlorine compounds and the promising role of the hedgehog as a mammalian indicator species of pollution in terrestrial environments.  相似文献   

10.
The concentrations of dichlorodiphenytrichloroethane and its metabolites (DDTs), hexachlorobenzene (HCB), hexachlorocyclohexane isomers (HCHs), dieldrin, and 20 polychlorinated biphenyls (PCBs) were determined in 237 human breast milk samples collected from 12 locations in Tunisia. Gas chromatography with electron capture detector (GC-ECD) was used to identify and quantify residue levels on a lipid basis of organochlorine compounds (OCs). The predominant OCs in human breast milk were PCBs, p,p′-DDE, p,p′-DDT, HCHs, and HCB. Concentrations of DDTs in human breast milk from rural areas were significantly higher than those from urban locations (p<0.05). With regard to PCBs, we observed the predominance of mid-chlorinated congeners due to the presence of PCBs with high Kow such as PCB 153, 138, and 180. Positive correlations were found between concentrations of OCs in human breast milk and age of mothers and number of parities, suggesting the influence of such factors on OC burdens in lactating mothers. The comparison of daily intakes of PCBs, DDTs, HCHs, and HCB to infants through human breast milk with guidelines proposed by WHO and Health Canada shows that some individuals accumulated OCs in breast milk close to or higher than these guidelines.  相似文献   

11.
Feather and muscle of 10 avian species (n = 46), were analyzed for polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs). Muscle contained significantly higher PCB and OCP than liver and feather. Mean muscle and feather PCB was 408.5 ± 134.5 and 32 ± 4.5 ng/g wet weight. Highly chlorinated PCBs were found in muscle and liver while feather had PCBs with less chlorination. Gulls had highest levels of both pollutants. Gull feather PCB and OCP were strongly correlated with their levels in the liver and muscle tissues (0.6 < r < 0.9, p < 0.01). Analysis of gull feather can be used as a non-invasive method for monitoring organic pollutants.  相似文献   

12.
Organochlorine (OC) bioaccumulation and biomagnification were studied in a marine food web at a pristine site in Iceland. The species studied were the gastropod and grazer chink shell (Lacuna vincta), the filter feeding bivalve blue mussel (Mytilus edulis), the predators butterfish (Pholis gunnellus), and the seabird black guillemot (Cepphus grylle), all sampled and analysed in 1996–1997. Individual OC levels were generally low in chink shell and blue mussels, somewhat elevated in the fish, and an order of a magnitude higher in the top predator black guillemot, except for ΣHCH (hexachlorocyclohexane isomers) and Σchlordane levels, which were similar in all organisms, ranging from 10 to 36 ng/g lipid weight (lw). In the molluscs and fish, mean concentrations of ΣPCB (polychlorinated biphenyl) ranged from 111 to 377 ng/g lw, ΣDDT (dichlorodiphenyltrichloroethane) ranged from 19 to 65 ng/g lw, and HCB (hexachlorobenzene) ranged from 21 to 30 ng/g lw. The levels of same OCs in the black guillemot were on average 2352, 361, and 283 ng/g lw, respectively. The OC tissue concentrations in blue mussel and black guillemot are comparable to levels in Arctic and sub-Arctic regions, but OC levels in blue mussel tissue were an order of magnitude lower than found in the North Sea and the Baltic Sea. The relative composition of OCs were generally similar among species with the PCB congeners emerging as the most abundant compounds with levels an order of magnitude higher than the other compounds in all species. Food web magnification factors (FWMFs) were determined for the OCs by using trophic levels determined from δ15N. FWMFs >1, indicating biomagnification, were found for ΣPCB, penta- or higher chlorinated PCBs (e.g., PCB 101, 118, 138, 153, 180), β-HCH, HCB, ΣDDT, p,p-DDE, and transnonachlor. The highest FWMF was observed for PCB 180 at FWMF = 5.8.  相似文献   

13.
The aim was to evaluate the extent of pollution of the Svratka River with organochlorinated pollutants using the chub (Leuciscus cephalus) as a suitable bioindicator of the river contamination. The sum of 7 PCB congeners was found in range of 7.6–93.8 ng/g (with median of 31.7 ng/g) wet weight (ww), DDTs of 2.9–93.8 (29.9) ng/g ww, HCHs isomers of 0.1–5.3 (1.0) ng/g ww, HCB of 0.3–8.4 (2.2) ng/g ww and OCS of <0.1-0.5 (0.1) ng/g ww. Our results confirm predominance of metabolite DDE and higher-chlorinated PCB congeners and are comparable with similar studies and findings within the Czech Republic.  相似文献   

14.
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   

15.
Organic Contaminants in the Marine Environment of Manila Bay,Philippines   总被引:1,自引:0,他引:1  
Organochlorine pesticides (OCs) and polychlorobiphenyls (PCBs) were determined in sediments and oysters’ soft tissues (Cassostrea gigas) collected in selected sites of Manila Bay. Overall, the concentration levels were very low. In sediments, PCBs were the compounds present in higher concentrations, with Σ13PCB congeners averaging 0.69 ± 0.46 ng/g (dry weight), followed by ΣDDT averaging 0.53 ± 0.28 ng/g and Σchlordane with 0.26 ± 0.28 ng/g. Concentrations measured in oysters averaged 20 ± 17 ng/g (dry weight) for Σ13PCB and were higher than ΣDDT, with 9.5 ± 2.4 ng/g, and Σchlordane, with 3.8 ± 3.1 ng/g. No dissolved residues of polar compounds, such as herbicides, and organophosphorous and organochlorine pesticides were found in the bay water. In general, results showed that concentrations of organochlorine pesticide residues, such as DDT, hexachlorocyclohexane, chlordane, lindane, endosulfan, and heptachlor in sediments and oysters were low in comparison with other coastal areas in Asia, although PCB concentrations in oysters were relatively high in some zones of Manila Bay and indicative of loose control of industrial chemical waste discharges into the bay. Nevertheless, current concentrations of persistent organochlorine contaminants in sediments were under threshold effect levels (TELs) and chronic toxic effects are, thus, unlikely to generate impairment of marine biota in Manila Bay.  相似文献   

16.
Persistent organochlorine residues such as hexachlorobenzene (HCB), hexachlorocyclohexane isomers (HCHs), chlorocyclodienes, and the DDT group (DDTs) were determined in fat and muscle samples of resident red-legged partridges (Alectoris rufa) hunted in Spain. Chlorinated contamination pattern varied largely depending on geographical distribution. Birds collected from the northern part of Spain contained greater concentrations of lindane (34.4 ng/g fat basis) than those from central or southern Spain. In contrast, red-legged partridges collected in southern locations exhibited elevated levels of p,p′-DDE (62.3 ng/g fat basis) as compared with central (31.2 ng/g fat basis) and northern areas (5.6 ng/g fat basis). The only cyclodiene detected, dieldrin, showed higher amounts (3.4 ng/g fat basis) in partridges collected in central Spain. The sex differences in pollutant occurrence and concentrations were negligible. One-year-old birds accumulated greater concentrations of β-HCH, and dieldrin than older birds. Global comparison of organochlorine concentrations indicated that northern partridges are more contaminated by compounds of industrial origin, whereas southern birds contained greater amounts of agricultural chemicals. Estimates of hazards associated with organochlorine levels in resident red-legged partridges in Spain suggested that southern birds may be at risk from exposure to DDTs, and northern birds may be affected by excessive concentrations of lindane. The use of red-legged partridge as bioindicator for OCP contamination is discussed. Received: 4 January 1999/Accepted: 7 June 1999  相似文献   

17.
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   

18.
Feathers as a nondestructive biomonitor for persistent organic pollutants   总被引:1,自引:0,他引:1  
Keratinous tissues of mammals and humans, such as hair, have been used to determine the exposure to polychlorinated biphenyls (PCBs) and organochlorine pesticides. In the present study, we investigated the accumulation of persistent organic pollutants (POPs; PCBs, p,p'-DDT, p,p'-dichlorodiphenyldichloroethane [DDD], p,p'-dichlorodiphenyldichloroethylene [DDE], hexachlorobenzene [HCB], oxychlordane, trans-nonachlor, polybrominated diphenyl ethers, and polybrominated biphenyls [PBBs]) in feathers of the great tit (Parus major). The accumulation of POPs in feathers and fat samples of 27 adult great tits collected in April 2000 and December 2002 was compared with regard to possible temporal and spatial differences. Polybrominated diphenyl ethers, PBBs, trans-nonachlor, and HCB could not be quantified in feathers. Most PCB congeners and DDTs (p,p'-DDE, p,p'-DDD, and p,p'-DDT) could be determined in feathers, although concentrations in feathers were markedly lower (sigmaPCB concentration range, 28.2-87.1 ng/g) than concentrations in fat (sigmaPCB concentration range, 1244-10074 ng/g). Feathers had relatively higher levels of low-chlorinated PCBs (tetra- and pentachlorinated biphenyls) and p,p'-DDD compared to levels in fat, presumably reflecting levels in blood. Persistent organic pollutant concentrations did not increase with the age of the feather, suggesting that exogenous or aerial depositions of POPs onto the feather surface had no, or only minimal, influence on levels in feathers. For almost all compounds studied, POPs in feathers and fat were significantly positively correlated in samples collected during the breeding season but not in samples collected during the winter. This temporal difference may have been caused by seasonal changes in lipid reserves. Although further research is required, feathers appear to be a promising new, nondestructive biomonitor for PCBs and DDTs in avian wildlife.  相似文献   

19.
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   

20.
This study of the body burden and serum concentrations of organochlorine compounds (OCs), represents a general population in a cohort from Menorca Island (birth 1997-1998) of children at birth and at 4 years of age; the study has shown that the concentrations of hexachlorobenzene (HCB), 4,4′-DDE, 4,4′-DDT, polychlorobiphenyl (PCB) congeners #153, #138 and #180 and total PCBs in sera collected at 4 years are much higher in breastfed children than in those fed with formula, e.g. HCB 0.48 vs 0.21 ng/ml, β-HCH 0.32 vs 0.24 ng/ml, total DDTs 2.2 vs 0.57 ng/ml and total PCBs 1.4 vs 0.52 ng/ml. Comparison of gender differences in 4 years old children shows higher concentrations of all examined OCs in females than in males with the exception of HCB and PeCB in breastfed children, which are higher in males than in females, e.g. β-HCH 0.34 vs 0.28 ng/ml, total DDTs 2.6 vs 1.7 ng/ml and total PCBs 1.6 vs 1.0 ng/ml for breastfed children and β-HCH 0.23 vs 0.19 ng/ml, total DDTs 0.59 vs 0.48 ng/ml and total PCBs 0.58 vs 0.45 ng/ml for formula fed children. Gender comparison of the body burden between children fed with breastmilk or formula also shows higher concentrations in females than in males, e.g. β-HCH 0.47 vs 0.35 μg, total DDTs 3.0 vs 1.8 μg and total PCBs 1.9 vs 1.2 μg for breastfed children, and β-HCH 0.39 vs 0.17 μg, total DDTs 0.48 vs 0.27 μg and total PCBs 0.66 vs 0.55 μg for formula fed children. The results may suggest a higher capacity in female children for the retention of OCs incorporated through breastfeeding. However, these results should be taken with caution because the differences of the gender averages have low statistically significance when evaluated with the Student test.  相似文献   

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