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 15 毫秒
1.
Concentrations of 18 trace elements (V, Cr, Mn, Co, Cu, Zn, Se, Rb, Sr, Zr, Mo, Ag, Cd, Sb, Cs, Hg, Tl and Pb) were determined in liver, kidney, muscle and hair of Baikal seals, Caspian seals and northern fur seals. All the three species showed the highest concentrations of Hg, V, Mn, Se and Ag in liver, Cd, Co and Tl in kidney, and Cs in muscle among the soft tissues examined. The highest burdens of Zn, Rb and Cs were observed in muscle, Mo and Ag in liver, and Sb and Pb in hair in all the three species. Concentrations of non-essential elements, Rb, Cd, Cs and Hg, showed significant positive correlations among liver, kidney and muscle, whereas correlation coefficients for essential elements, Mn, Co, Cu, Zn and Se, between the three tissues were generally low for all the species, suggesting that homeostasis controls the concentrations of essential elements but not the non-essential elements in the tissues of these animals. Significant age-dependent increase was found in the concentrations of V, Se and Ag in liver and Hg in liver and kidney of all the three species. Hair concentrations showed significant positive correlations with Zn levels in liver and kidney and Hg in muscle for Caspian seals, Hg in liver and kidney for Baikal seals, and Pb in liver for northern fur seals. Furthermore, regression analysis using the data in the present study and in the literature showed significant positive correlations between Hg levels in hair, and liver, kidney and muscle for various species of pinnipeds. These results indicate the possibility of using hair samples for monitoring these trace elements in pinnipeds.  相似文献   

2.
Effects of pollution on humic substances   总被引:1,自引:0,他引:1  
To assess effects of industrial and environmental pollution on analytical characteristics of humic substances, we isolated humic acids (HA's) and fulvic acids (FA's) from unpolluted and polluted soils and sediments. Following purification, the HA's and FA's were characterized by elemental (C, H, O, N, S) and functional group (CO2H, phenolic OH, total acidity) analyses, infrared (IR) spectrophotometry, differential thermal analysis (DTA) and by metal (Fe, Al, Cu, Mn, Pb, Ni, Co, Zn, Cr, Cd, Hg, Ca and Mg) analyses. Si was also determined in all samples. Polluted HA's and FA's contained more N and S but less O and were richer in all metals and Si than were unpolluted ones. IR spectra showed that polluted humic materials were enriched in COO- groups, secondary non-cyclic amides and possible also in SO3H groups. DTA curves indicated that polluted HA's and FA's were more thermostable than unpolluted HA's and FA's. Unusually high N, S, Cu, Cr, Zn and Hg contents of humic materials appear to be useful indicators of soil and sediment pollution.  相似文献   

3.
Liu X  Zhao S  Sun L  Yin X  Xie Z  Honghao L  Wang Y 《Chemosphere》2006,65(4):707-715
Concentrations of P and trace metals Zn, Cu, Cd, Pb and Hg in the faeces, bones, eggshells and feathers of seabirds and in the plants, soils and sediments with and without seabird influence on Dongdao Island, South China Sea, were determined and analyzed. Among the seabird biomaterials, the levels of P, Zn, Cu and Cd are the highest in the droppings and several times those in other materials; the Hg concentration is the highest in the feathers; and the Pb content is comparable among these biomaterials. These marked differences indicate different intake-bioaccumulation-elimination pathways for different trace metals. The levels of P, Zn, Cu, Cd and Hg in the plant, soil and sediment samples with the influence of seabird droppings are significantly higher than those in the samples without, and they are significantly correlated with each other. Thus, P, Zn, Cu, Cd and Hg are very likely to have a common source-predominantly bird guano-and the faeces of red-footed booby is an important vector for the flux of nutrient phosphorus and trace metals Zn, Cu, Cd and Hg from marine to island ecosystems on Dongdao Island.  相似文献   

4.
The Fresno Supersite intends to 1) evaluate non-routine monitoring methods, establishing their comparability with existing methods and their applicability to air quality planning, exposure assessment, and health effects studies; 2) provide a better understanding of aerosol characteristics, behavior, and sources to assist regulatory agencies in developing standards and strategies that protect public health; and 3) support studies that evaluate relationships between aerosol properties, co-factors, and observed health end-points. Supersite observables include in-situ, continuous, short-duration measurements of 1) PM2.5, PM10, and coarse (PM10 minus PM2.5) mass; 2) PM2.5 SO4(-2), NO3-, carbon, light absorption, and light extinction; 3) numbers of particles in discrete size bins ranging from 0.01 to approximately 10 microns; 4) criteria pollutant gases (O3, CO, NOx); 5) reactive gases (NO2, NOy, HNO3, peroxyacetyl nitrate [PAN], NH3); and 6) single particle characterization by time-of-flight mass spectrometry. Field sampling and laboratory analysis are applied for gaseous and particulate organic compounds (light hydrocarbons, heavy hydrocarbons, carbonyls, polycyclic aromatic hydrocarbons [PAH], and other semi-volatiles), and PM2.5 mass, elements, ions, and carbon. Observables common to other Supersites are 1) daily PM2.5 24-hr average mass with Federal Reference Method (FRM) samplers; 2) continuous hourly and 5-min average PM2.5 and PM10 mass with beta attenuation monitors (BAM) and tapered element oscillating microbalances (TEOM); 3) PM2.5 chemical speciation with a U.S. Environmental Protection Agency (EPA) speciation monitor and protocol; 4) coarse particle mass by dichotomous sampler and difference between PM10 and PM2.5 BAM and TEOM measurements; 5) coarse particle chemical composition; and 6) high sensitivity and time resolution scalar and vector wind speed, wind direction, temperature, relative humidity, barometric pressure, and solar radiation. The Fresno Supersite is coordinated with health and toxicological studies that will use these data in establishing relationships with asthma, other respiratory disease, and cardiovascular changes in human and animal subjects.  相似文献   

5.
Yang N  Matsuda M  Kawano M  Wakimoto T 《Chemosphere》2006,63(8):1342-1352
A wide variety of fish and shellfish were collected from local supermarkets of Dalian, Tianjin and Shanghai in China and analyzed for the concentrations of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) such as hexachlorobenzene (HCB), hexachlorocyclohexane isomers (HCHs), chlordane compounds (CHLs, including trans-chlordane, cis-chlordane, trans-nonachlor and cis-nonachlor) and dichlorodiphenyltrichloroethane (DDT) and its metabolites (DDTs, including o,p'-DDE, p,p'-DDE, o,p'-DDD, p,p'-DDD, o,p'-DDT and p,p'-DDT). Concentrations of PCBs in samples collected from Dalian, Tianjin and Shanghai ranged from 1.11 to 8.04 ng/g, 1.26 to 5.60 ng/g and 0.83 to 11.4 ng/g on wet weight basis, respectively. The concentrations were lower compared to those in developed countries such as Japan and Italy. Average concentrations of HCB, HCHs, CHLs and DDTs were 0.38, 0.92, 0.47 and 28.9 ng/g on wet weight basis, respectively. The daily intake of PCBs and organochlorine pesticides ingested by people living in these cities in China through fish and shellfish was estimated and compared with those observed in other areas.  相似文献   

6.
Cadmium, lead, mercury, copper, nickel, zinc, and arsenic were analyzed in suspended particulate matter (SPM), zebra mussels, and bream sampled yearly under the program of the German Environmental Specimen Bank (ESB) in the rivers Rhine, Elbe, Danube, Saar, Mulde, and Saale and in Lake Belau. Temporal and spatial trends were analyzed, correlations between metal levels in different specimen types assessed, and sampling sites ranked according to their metal levels by calculating a Multi-Metal Index (MMI) for every specimen type and site. SPM: Highest metal loads were detected in Mulde, Saale, and Elbe right downstream of the Saale confluence. In the Elbe, metal loads in SPM were mostly highest in the upper and middle section of the river while in Rhine and Saar concentrations increased downstream. Temporal trends since 2005 were detected only at three sites. Zebra mussel: MMIs were highest in the tidal section of the Elbe and the lower Rhine and lowest in Lake Belau and the upper Danube. Different temporal trends were detected since the early 1990s depending on site and metal. Bream: As, Pb, Cu, and Hg were analyzed in muscle tissue and Pb, Cd, Cu, and Zn in liver. For both tissues, MMIs were highest in Mulde and Saale and the lower and middle Elbe. Since the early 1990s, Hg, Pb, and Cu decreased in bream muscle at many sites while As increased at 6 of the 17 sites. The findings indicate that Hg, Pb, and Cu have obviously decreased in many freshwater ecosystems in recent years, whereas As and Ni levels have increased at several sites. Metal levels and temporal trends mostly differed between the specimen types under investigation and only few correlations between specimen types were detected. This underlines the importance of including different components of an ecosystem when assessing its environmental quality.  相似文献   

7.
PBDEs and PBBs in the adipose tissue of women from Spain   总被引:1,自引:0,他引:1  
Polybromodiphenyl ethers (PBDEs) and polybromobiphenyls (PBBs) were investigated in adipose tissue of women living in Southeastern Spain. Mean Sigma PBDE (BDE 28, 75, 71, 47, 66, 77, 100, 119, 99, 85, 154, 153, 138, and 183) and Sigma PBB (PBB 18, 29, 31, 22, 38, 37, 53, 52, 49, 75, 80, 56, 77, 103, 101, 155, 154, 153, and 169) levels were 3.85 and 0.36 ng/g of lipid, respectively. Among PBDEs, congeners 153, 47, 183, 99, and 100 were the most frequent and abundant and together constituted 96% of the total amount of PBDEs in adipose tissue. Concentrations of PBDEs in this population were similar to those reported in other parts of Spain and in Swedish and Belgium populations but lower than those found in other Western countries. Among PBB congeners studied, PBB 153 presented the highest concentrations and contributed 79% of all PBBs. There are no published data on PBB congeners in adipose tissues of the Spanish population for comparison, but the levels found were similar to those described in other European countries. Further research is needed to determine trends in human exposure to PBDEs and PBBs and to explore putative effects on human health.  相似文献   

8.
Taiwan's industrial heavy metal pollution threatens terrestrial biota   总被引:15,自引:0,他引:15  
The bioconcentration levels of essential (Cu, Fe, Mg, Mn, and Zn) and non-essential (As, Cd, Hg, Pb, and Sn) elements have been investigated in different terrestrial biota such as fungi, plant, earthworm, snail, crab, insect, amphibian, lizard, snake, and bat including the associated soil, to investigate the ecosystem health status in Kenting National Park, Taiwan. High bioconcentrations of Cd, Hg, and Sn in snail, earthworm, crab, lizard, snake, and bat indicated a contaminated terrestrial ecosystem. High concentrations of Cd, Hg, and Sn in plant species, effective bioaccumulation of Cd by earthworm, snail, crab and bat, as well as very high levels of Hg found in invertebrates, amphibians, and reptiles revealed a strong influence from industrial pollution on the biotic community. This study for the first time presents data on the impact of heavy metal pollution on various terrestrial organisms in Taiwan.  相似文献   

9.
The development and application of an analytical methodology for the pretreatment and determination of 253 multiclass pesticides, in lake sediment samples, using liquid chromatography coupled with mass spectrometry (LC-MS/MS) are described in this work. Sediments of lakes Volvi, Doirani, and Kerkini, located in northern Greece, were collected in two-time periods (fall/winter 2010 and spring/summer 2011) and analyzed, applying the developed analytical methodology. Microwave-assisted extraction (MAE) was applied to extract the pesticide residues from lake sediment samples. Analytical results were stored, categorized, and visualized using geographical information systems, in order to assess and observe spatial and temporal variations of the pollution. Main pesticides that were detected included the following: amitrole, tebuconazole, phoxim, diniconazole, sethoxydim, temephos, tetrachlorvinphos, pendimethalin, boscalid, disulfoton sulfone, lenacil, propiconazole, cycloxydim, pyridaben, and terbuthylazine. Amitrole, diniconazole, and tebuconazole were found to be common in all three lakes. Lakes Kerkini and Doirani exhibited increased concentrations during the first sampling period (winter 2010) with predominant pesticide classes, triazines/triazoles and organophosphates. Pollution is mainly located near the populated villages of the lakes and the nearby cultivations. During the second sampling period, pesticide concentrations appear lower and located in sediments near the center of the lake. Lake Volvi exhibits increased pesticide concentrations during the second sampling period, temporal and spatial variations and different pesticide profile pattern. Increased pollution occurs near the center of the lake during the first sampling period, mainly comprised by triazines/triazoles and organophosphates. During the second sampling period, the majority of the sediment samples demonstrated a different pesticide profile dominated by unclassified pesticides and triazines/triazoles. Mineralogical analysis of the samples demonstrates that sediments are mainly composed of clay, mud, and sand particles, and they present spatial variations. Near the center of the lakes, sediments appear to be more fine-grained with higher clay content and are more likely to adsorb pesticides.  相似文献   

10.
During the period 1978-1989, samples of liver, kidney and subcutaneous fat from 24 polar bears, Ursus maritimus, from Svalbard were analysed for mercury, cadmium, lead, copper, zinc, selenium, arsenic, HCB, DDE, PCBs (as Aroclor 1260 or Phenoclor DP6). In a selected number of liver (seven) and fat (three) samples, the composition of individual PCB congeners was studied by comparison with 23 individual PCB congeners (IUPAC nos 28, 52, 74, 101, 99, 110, 149, 118, 114, 105, 153, 141, 138, 187, 128, 183, 156, 157, 180, 170, 194, 206 and 209). In the seven liver samples, the concentrations of o,p'- and p,p'-isomers of DDT, TDE, DDE, alpha-, beta- and gamma-HCH, oxychlordane, heptachlor, heptachlorepoxide, aldrin and dieldrin were also determined. The hepatic concentrations of mercury, cadmium and lead in animals of all ages were 0.4-6.0, <0.1-1.2, and <0.5-1.6 microg g(-1), respectively. This indicates a moderate exposure. Concentrations of mercury and selenium were correlated (r=0.80). The levels of copper and zinc represented normal physiological concentrations. The concentrations of HCB, DDE and PCBs in fat were <0.05-1.5, <0.1-3.4 and 2.9-90 microg g(-1), respectively. The corresponding results for liver were <0.01-0.11, <0.1-0.5 and 0.1-78 microg g(-1), respectively. Six PCB congeners, PCB-99, -153, -138, -180, -170, and, -194 accounted for about 99 and 87% of the total PCB content (sum of the 12 congeners, nos. 28, 99, 153, 138, 128 + 187, 156, 157, 180, 170, 194, 206 and 209) in liver and fat, respectively. PCB-153 represented 37+/-3 30+/-16% of the sum PCB (sum of 12 congeners) in liver and fat, respectively. The range of the hepatic concentration of oxychlordane was 5-19 microg g(-1). Quantifiable concentrations of heptachlor, heptachlorepoxide, beta-HCH and dieldrin were also found in all the liver samples analysed. Low concentrations of p,p'- and o,p'-DDT were found in two of seven liver and two of two fat samples. Comparisons are made with investigations from Canada and Greenland. Possible effects of PCBs, especially on reproduction, cannot be excluded. Ringed seal, Foca hispida, and to some extent bearded seal, Erignathus barbatus, are the main food of the polar bear. It is therefore likely that the exposure to environmental pollutants occurs via the consumption of these two species.  相似文献   

11.
The present study was under taken to demonstrate the effect of some commonly used insecticides on the activity of cytochrome P450 system including cytochrome b5, aryl hydrocarbon [benzo(a)pyrene] hydroxylase (AHH), N-nirosodimethylamine N-demethylase I [NDMA-dI] and NADPH-cytochrome c reductase as phase I of drug oxidation. In addition, the activity of glutathione S-transferase (GST), glutathione reductase (GR), and the level of glutathione (GSH) were determined in the liver of male mice after oral administration of sumithion, dursban, chlordane, methoxychlor, heptachlor epoxide, and lindane as single (24h) or as repeated doses for six consecutive days. Oral administration of sumithion, dursban, chlordane, methoxychlore, and heptachlor epoxide as repeated doses decreased: (i) the hepatic content of cytochrome P450 by 36, 37, 47, 37, and 67%, respectively, (ii) AHH activity by 28, 29, 70, 31, and 79%, respectively, (iii) NDMA-dI activity by 43, 44, 32, 27, and 31, respectively. On the other hand, sumithion, chlordane, and methoxychlore induced the activity of NADPH-cytochrome c reductase by 45, 62, and 43 respectively after repeated dose treatments. In addition, single and repeated-dose treatments of mice with lindane induced: (i) cytochrome P450 by 23 and 65%, respectively, (ii) cytochrome b5 by 49 and 131%, respectively, (iii) AHH activity by 64 and 50%, respectively. Repeated-dose treatments of mice with chlordane, methoxychlore, and heptachlor epoxide decreased the GSH level by 42, 38, and 68%, respectively and GST activity by 44, 44, and 55% respectively. Moreover, single- and repeated-dose treatments of mice with lindane decreased the GSH levels by 40 and 54%, respectively, and induced GST activity by 25 and 41%, respectively. Interestingly, single-dose treatments with chlordane, methoxychlore, and heptachlor epoxide decreased the activity of GR by 32, 38, and 31, respectively whereas repeated doses of these compounds induced such activity by 83, 50, and 64%, respectively. It is concluded that modifications in cytochrome P450 system by pesticides could potentiate the toxicity and carcinogenicity of environmental carcinogens such as polycyclic aromatic hydrocarbon and N-nirosodimethylamine (NDMA).  相似文献   

12.
Concentration of ten metals (Cd, Cr, Co, Cu, Fe, Li, Mn, Ni, Pb and Zn) were analyzed in the egg contents, prey and soil samples of little egret (Egretta garzetta) and cattle egret (Bubulcus ibis) from two Headworks to determine habitat and species-specific differences; to assess the importance of prey and habitat contamination as an exposure source for heavy metals. Concentration of Cu, Mn, Cr and Pb in egg contents, Fe, Co, Cu, Mn, Zn in prey and Fe, Co, Cu, Ni, Li in surface soils were significantly different (P < 0.05). Mean metal concentrations of Cr, Pb and Cd were relatively higher in little egret whereas Cu and Mn were higher in the egg contents of cattle egret. The mean concentrations of Cu, Mn and Zn were higher in prey samples of cattle egrets and Cr, Cd and Pb in prey samples of little egrets. In soil samples collected from little egret heronries metal concentrations were higher except Cu and Ni. Correlation Analysis and Hierarchical Agglomerative Cluster Analysis (HACA) identified relatively similar associations of metals and their source identification. Metals such as Fe, Cu, Mn, and Li were related with geochemical origin from parent rock material as well as anthropogenic input whereas Cr, Cd, Pb, Ni, Co and Zn were associated mostly with anthropogenic activities. The study suggested that eggs are useful bio-monitor of local heavy metal contamination.  相似文献   

13.
Cao X  Chen Y  Wang X  Deng X 《Chemosphere》2001,44(4):655-661
Equilibrium release experiments were conducted under three different pH values of 3.5, 5.5 and 7.5 as well as three redox potentials of 400, 0 and -100 Mv to investigate the influence of redox potential and pH value on the La, Ce, Gd and Y release of from the simulated-REEs-accumulation (SRA) soil. Oxygen and nitrogen were allowed to flow into soil suspension to adjust redox potential to a preset value, and 1 mol/l HCl or 1 mol/l NaOH solutions were added into the soil suspension to keep pH at a preset value. Results indicated that La, Ce, Gd and Y release increased gradually with the decrease of pH value or Eh, and the influence of redox potential on Ce was more remarkable than on La, Gd and Y. At the same time. It was observed that La, Ce, Gd and Y releases were positively correlated with the release of Fe and Mn, indicating that La, Ce, Gd and Y releases might originate from dissolution of Fe-Mn oxyhydroxides under reduction and low pH conditions. Moreover, it was found that alteration of pH value and redox potential might affect the change of La, Ce, Gd and Y species in the soil. The contents of La, Ce, Gd and Y in exchangeable fraction and Fe-Mn oxide fraction in the solid phase from soil suspension separation decreased with the decline of pH value and redox potential. Multiple stepwise regression analysis showed that exchangeable fraction and Fe-Mn oxide fraction predominately contributed to the La, Ce, Gd and Y release. Low pH value and redox potential were more favorable to La, Ce, Gd and Y releases following the change of their species. The La, Ce, Gd and Y contents in exchangeable fraction and Fe-Mn oxide fraction are the main contributors to their release.  相似文献   

14.
The past 50 years have seen rapid development of new building materials, furnishings, and consumer products and a corresponding explosion in new chemicals in the built environment. While exposure levels are largely undocumented, they are likely to have increased as a wider variety of chemicals came into use, people began spending more time indoors, and air exchange rates decreased to improve energy efficiency. As a result of weak regulatory requirements for chemical safety testing, only limited toxicity data are available for these chemicals. Over the past 15 years, some chemical classes commonly used in building materials, furnishings, and consumer products have been shown to be endocrine disrupting chemicals – that is they interfere with the action of endogenous hormones. These include PCBs, used in electrical equipment, caulking, paints and surface coatings; chlorinated and brominated flame retardants, used in electronics, furniture, and textiles; pesticides, used to control insects, weeds, and other pests in agriculture, lawn maintenance, and the built environment; phthalates, used in vinyl, plastics, fragrances, and other products; alkylphenols, used in detergents, pesticide formulations, and polystyrene plastics; and parabens, used to preserve products like lotions and sunscreens. This paper summarizes reported indoor and outdoor air concentrations, chemical use and sources, and toxicity data for each of these chemical classes. While industrial and transportation-related pollutants have been shown to migrate indoors from outdoor sources, it is expected that indoor sources predominate for these consumer product chemicals; and some studies have identified indoor sources as the predominant factor influencing outdoor ambient air concentrations in densely populated areas. Mechanisms of action, adverse effects, and dose–response relationships for many of these chemicals are poorly understood and no systematic screening of common chemicals for endocrine disrupting effects is currently underway, so questions remain as to the health impacts of these exposures.  相似文献   

15.
16.
An in situ toxicity and bioaccumulation assessment approach is described to assess stressor exposure and effects in surface waters (low and high flow), the sediment-water interface, surficial sediments and pore waters (including groundwater upwellings). This approach can be used for exposing species, representing major functional and taxonomic groups. Pimephales promelas, Daphnia magna, Ceriodaphnia dubia, Hyalella azteca, Hyalella sp., Chironomus tentans, Lumbriculus variegatus, Hydra attenuatta, Hexagenia sp. and Baetis tibialis were successfully used to measure effects on survival, growth, feeding, and/or uptake. Stressors identified included chemical toxicants, suspended solids, photo-induced toxicity, indigenous predators, and flow. Responses varied between laboratory and in situ exposures in many cases and were attributed to differing exposure dynamics and sample-processing artifacts. These in situ exposure approaches provide unique assessment information that is complementary to traditional laboratory-based toxicity and bioaccumulation testing and reduce the uncertainties of extrapolating from the laboratory to field responses.  相似文献   

17.
Methylmercury exposure and health effects in humans: a worldwide concern   总被引:5,自引:0,他引:5  
The paper builds on existing literature, highlighting current understanding and identifying unresolved issues about MeHg exposure, health effects, and risk assessment, and concludes with a consensus statement. Methylmercury is a potent toxin, bioaccumulated and concentrated through the aquatic food chain, placing at risk people, throughout the globe and across the socioeconomic spectrum, who consume predatory fish or for whom fish is a dietary mainstay. Methylmercury developmental neurotoxicity has constituted the basis for risk assessments and public health policies. Despite gaps in our knowledge on new bioindicators of exposure, factors that influence MeHg uptake and toxicity, toxicokinetics, neurologic and cardiovascular effects in adult populations, and the nutritional benefits and risks from the large number of marine and freshwater fish and fish-eating species, the panel concluded that to preserve human health, all efforts need to be made to reduce and eliminate sources of exposure.  相似文献   

18.
Persistent organic pollutants have been shown to have immunomodulating effects in humans. However, epidemiological evidence regarding the relationships between organochlorine compound exposure and allergic disorders coming from studies of children has been limited and inconsistent. The current cross-sectional study examined the associations between the concentrations of β-hexachlorocyclohexane (HCH), hexachlorobenzene (HCB), p,p'-dichlorodiphenyldichloroethylene (DDE), and trans-nonachlordane in breast milk and the prevalence of allergic disorders in 124 adult Japanese women. The definition of wheeze and asthma was based on criteria from the European Community Respiratory Health Survey whereas that of eczema and rhinoconjunctivitis was based on criteria from the International Study of Asthma and Allergies in Childhood. Adjustment was made for age, smoking, family history of allergic disorders, and education. The prevalence values of wheeze, asthma, eczema, and rhinoconjunctivitis in the past 12 months were 9.7%, 4.8%, 13.7%, and 29.8%, respectively. The median concentrations of β-HCH, HCB, p,p'-DDE, and trans-nonachlordane in breast milk were 28.3, 7.0, 71.6, and 23.9 ng g(-1) lipid, respectively (range, 4.5-253, 2.1-14.5, 7.5-362, and 1.8-130 ng g(-1) lipid, respectively). When the exposures were treated as continuous variables, no significant associations were found between concentrations of HCB, β-HCH, p,p'-DDE, or trans-nonachlordane and the prevalence of wheeze, asthma, eczema, or rhinoconjunctivitis. Our results suggest that concentrations of β-HCH, HCB, p,p'-DDE, and trans-nonachlordane in breast milk are not evidently associated with the prevalence of wheeze, asthma, eczema, or rhinoconjunctivitis in young female Japanese adults.  相似文献   

19.
Techniques and applications of thin layer chromatography (planar chromatography) for the separation, detection, qualitative and quantitative determination, and preparative isolation of pesticides and their metabolites and other related compounds are reviewed for the period from November 1, 2008 to November 1, 2010. Analyses are described for a variety of samples types and pesticide classes. In addition to references on residue analysis, studies such as pesticide structure-retention relationships, identification and characterization of plant pesticides and synthesized pesticides, metabolism, degradation, mobility, identification of biomarkers for detection of herbicide effects in plants, and lipophilicity are covered.  相似文献   

20.
Abstract

To assess effects of industrial and environmental pollution on analytical characteristics of humic substances, we isolated humic acids (HA's) and fulvic acids (FA's) from unpolluted and polluted soils and sediments. Following purification, the HA's and FA's were characterized by elemental (C, H, O, N, S) and functional group (CO2H, phenolic OH, total acidity) analyses, infrared (IR) spectrophotometry, differential thermal analysis (DTA) and by metal (Fe, Al, Cu, Mn, Pb, Ni, Co, Zn, Cr, Cd, Hg, Ca and Mg) analyses. Si was also determined in all samples.

Polluted HA's and FA's contained more N and S but less 0 and were richer in all metals and Si than were unpolluted ones. IR spectra showed that polluted humic materials were enriched in COO groups, secondary non‐cyclic amides and possible also in SO3H groups. DTA curves indicated that polluted HA's and FA's were more thermostable than unpolluted HA's and FA's. Unusually high N, S, Cu, Cr, Zn and Hg contents of humic materials appear to be useful indicators of soil and sediment pollution.  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