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1.
We report on the comparative bioaccumulation, biotransformation and/or biomagnification from East Greenland ringed seal (Pusa hispida) blubber to polar bear (Ursus maritimus) tissues (adipose, liver and brain) of various classes and congeners of persistent chlorinated and brominated contaminants and metabolic by-products: polychlorinated biphenyls (PCBs), chlordanes (CHLs), hydroxyl (OH-) and methylsulfonyl (MeSO2-) PCBs, polybrominated biphenyls (PBBs), OH-PBBs, polybrominated diphenyl ether (PBDE) and hexabromocyclododecane (HBCD) flame retardants and OH- and methoxyl (MeO-) PBDEs, 2,2-dichloro-bis(4-chlorophenyl)ethene (p,p′-DDE), 3-MeSO2-p,p′-DDE, pentachlorophenol (PCP) and 4-OH-heptachlorostyrene (4-OH-HpCS). We detected all of the investigated contaminants in ringed seal blubber with high frequency, the main diet of East Greenland bears, with the exception of OH-PCBs and 4-OH-HpCS, which indicated that these phenolic contaminants were likely of metabolic origin and formed in the bears from accumulated PCBs and octachlorostyrene (OCS), respectively, rather than being bioaccumulated from a seal blubber diet. For all of the detectable sum of classes or individual organohalogens, in general, the ringed seal to polar bear mean BMFs for ΣPCBs, p,p′-DDE, ΣCHLs, ΣMeSO2-PCBs, 3-MeSO2-p,p′-DDE, PCP, ΣPBDEs, total-(α)-HBCD, ΣOH-PBDEs, ΣMeO-PBDEs and ΣOH-PBBs indicated that these organohalogens bioaccumulate, and in some cases there was tissue-specific biomagnification, e.g., BMFs for bear adipose and liver ranged from 2 to 570. The blood-brain barrier appeared to be effective in minimizing brain accumulation as BMFs were ≤ 1 in the brain, with the exception of ΣOH-PBBs (mean BMF = 93 ± 54). Unlike OH-PCB metabolites, OH-PBDEs in the bear tissues appeared to be mainly accumulated from the seal blubber rather than being metabolic formed from PBDEs in the bears. In vitro PBDE depletion assays using polar bear hepatic microsomes, wherein the rate of oxidative metabolism of PBDE congeners was very slow, supported the probability that accumulation from seals is the main source of OH-PBDEs in the bear tissues. Our findings demonstrated from ringed seal to polar bears that organohalogen biotransformation, bioaccumulation and/or biomagnification varied widely and depended on the contaminant in question. Our results show the increasing complexity of bioaccumulated and in some cases biomagnified, chlorinated and brominated contaminants and/or metabolites from the diet may be a contributing stress factor in the health of East Greenland polar bears.  相似文献   

2.
The identification of characteristics of noise-susceptible (S) or noise-resistant (R) individuals is necessary for the development of noise-susceptibility risk profiles. Fifty-six naval aviators, categorized as having either incurred a hearing loss, i.e., hearing threshold levels (HTLs) > 40 dB at 4–8 kHz or retained normal hearing, i.e., HTLs ≤ 25 dB at 125 Hz-8 kHz, after thousands of flight hours were compared along several auditory and non-auditory dimensions. A number of variables occurred differentially in the two groups: Minimal Auditory Intensity Differential (MAID) scores at 2 kHz (p < 0.01) and 4 kHz (p < 0.001); iris pigmentation (blue eyes were over-represented in the S group; p < 0.05); systolic blood pressure (sitting; S group was higher; p < 0.05); calcium, albumin, and LDH levels (higher in the R group; p < 0.05); and present tobacco usage (more S aviators were currently smokers; p < 0.05). The S population also tended (p < 0.10) to exhibit elevated cholesterol and triglyceride levels as well as higher contralateral acoustic reflexes, and to have fewer individuals who had never smoked. Although no classic profile of the S or R individual definitely emerged, results suggested that at least one measurement device (MAID test) may serve as an “early warning” of imminent noise-induced damage. Further research, however, is required to test this possibility.  相似文献   

3.
The main focus of this study was to evaluate long term effects of cadmium on forearm bone mineral density after stopping ingestion of cadmium-polluted rice for 10 years in a Chinese population. A total of 532 persons (338 women and 194 men), living in control, moderately and heavily polluted areas, were included in this study. The residents living in the polluted area ceased ingesting cadmium-polluted rice in 1996. All participants were require to answer a questionnaire and the bone mineral density (BMD) was measured by dual energy X-ray absorptiometry (DXA) at the proximal radius and ulna. Samples of urine and blood were collected for determination of cadmium in urine (UCd) and blood (BCd).The BMD of subjects living in the heavily polluted area was significantly lower than that of those living in control area in both men and women (p < 0.01). For the people living in the moderately polluted area, only the women's BMD was greatly lower compared to that in the control area (p < 0.05). The BMD declined with the increasing BCd and UCd in both sexes, especially in the highest level (BCd > 5 µg/L, UCd > 10 µg/g crea) groups (p < 0.01). It was found that there were significant differences in the prevalence of osteoporosis among the different areas (χ2 = 13.046, p = 0.0003) and different UCd groups (χ2 = 4.511, p = 0.0337) in women, but not in men (χ2 = 0.962, p = 0.3268; χ2 = 1.906, p = 0.1675). But a significant difference exists in the prevalence of osteoporosis among different BCd groups in both genders (χ2 = 9.304, p = 0.00229, in women; χ2 = 4603, p = 0.0319, in men). This study suggested that cadmium could play a long-term role on bone and more attention should be paid to cadmium effects on bone metabolism after reduction of exposure.  相似文献   

4.
Kragujevac, as an important industrial and economic center of the region, is now placed on the top of the list of environmentally endangered cities in our country. The aim of this biomonitoring study was to evaluate cytogenetic damage in a sample of newborns from Kragujevac after contamination of the environment entailed by the intensive bombing of the industrial zone of this city in the spring of 1999. The frequency of micronuclei (MN) in peripheral blood lymphocytes in a total of 61 phenotypically healthy newborns was analyzed before and after the NATO bombing. Analysis of micronuclei has been performed using the cytokinesis-block technique (CB MN test). Average MN frequency in lymphocytes of newborns before the bombing (N = 25) was 5.77 ± 0.85/1000 analyzed cells. After the bombing (N = 36), the average frequency of MN increased by a factor of 1.4 (8.11 ± 0.85), compared to the control frequency before the bombing. Statistical difference (p < 0.05) was established by Student's t-test. Our data suggest that such changes in genetic material were a direct consequence of contamination of the living environment.  相似文献   

5.
Human breast milk samples collected in 2007–2008 from four countries, Vietnam (Hanoi), China (Beijing), Korea (Seoul) and Japan (Sendai, Kyoto and Takayama), were analyzed for persistent organic pollutants (POPs) such as dichlorodiphenyltrichloroethane and its metabolites (DDTs), chlordane-related compounds (CHLs), hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). Comparing with previous surveys, the present study indicates that the DDTs in breast milk from China and Vietnam had gradually decreased during the last decade, but were still 5–10 times higher than those in other nations. The ratios of p,p′-DDE/p,p′-DDT and o,p′-DDT/p,p′-DDT were higher in Beijing than in the other countries, suggesting that there is less fresh intake of commercial DDT products and a possible exposure to dicofol in China. CHL and PCB levels were relatively higher in mothers from Japan, whereas β-HCH and HCB were more common in Chinese women. In Japan, it is suspected that mothers in the urban/coastal area (Sendai) were more continuously exposed to organochlorine pesticides (OCPs) than mothers in the rural/inland area (Takayama). In addition, OCP levels in primiparae were significantly higher than those in multiparae from Japan and Korea. These indicate that both parity and regional factors are major determinants of the levels of OCPs and PCBs in human milk. On the other hand, higher concentrations of PBDEs were observed in mothers' milk from Korea. The congener was dominated by BDE-47 (43–54%), followed by BDE-153 (23–33%) in all regions except for Beijing where BDE-28 (23%) was relatively abundant. In Japanese breast milk, regional and parity-dependent distributions were not observed for PBDEs. Among PBDE congeners, age-dependency was observed for BDE-153, which was negatively correlated (p < 0.05) to the age of mothers in Kyoto (17 participants were housewives), while it increased with age in Sendai (10 participants were clerks). No such correlation was seen for BDE-47, indicating that BDE-47 was ingested and assimilated via different kinetics or routes from BDE-153 in Japan.  相似文献   

6.
The types, frequency, and intensity of human interference with forests markedly affect the vegetation dynamics. Assessment of the impact of anthropogenic disturbances on forest diversity and structure is one of the central issues related to human behaviour and forest ecosystems and management. Both species diversity and density are very sensitive to local anthropogenic disturbance, which can be reduced depending on land-use systems. We used 10 line transects of 500 × 10 m to record and measure all plants ≥10 cm girth in some of the remaining forests surrounding villages in Tripura, Northeast India. To predict the effects of anthropogenic pressure on species richness and forest structure, we recorded and scored all ongoing disturbances in all transects of the forests. Although our study did not show any significant effects on the mean number of species, all diversity indices were significantly affected by disturbance. Total stem density (F = 128.60, p < 0.0001) and basal area (F = 65.30, p < 0.0001) of the forest stands were significantly affected by disturbance. Disturbance significantly (F = 84.81, p < 0.0001) impacts the abundance of mature voluminous trees removed by extensive illegal logging. Further, stem density at the middle (F = 10.01, p < 0.05) and upper (F = 131.70, p < 0.0001) canopy stories was also reduced by high disturbance intensity. The present analysis will be useful to policy-makers and planners for implementation of sustainable forest management at both the local and regional scale.  相似文献   

7.
Galicia (NW Spain) is a radon-prone area in the Iberian Peninsula. Measurements were carried out at a rural dwelling, with an annual average of radon concentration over 4000 Bq m−3 and a maximum of 9000 Bq m−3, found during a radon screening campaign held in the Autonomous Community of Galicia. We performed a detailed study to identify the main contamination source and the behaviour of the radon concentration, in which a linear dependence with temperature was verified, once corrected for relative humidity. We used different passive methods (charcoal canisters and two types of etched track detectors) as well as a radon concentration monitor that provided continuous measurement. Subsequent to this characterization, and in order to reduce the high radon concentration, a remedial action was developed using different passive and forced ventilation methods. A modified subslab depressurization technique was found to be the most effective remedy, providing a radon concentration reduction of around 96%. This method also has the advantages of being inexpensive and reliable over time.  相似文献   

8.
Measurements of the variation of the carbon dioxide partial pressure in water were performed up to pCO2 and CO2 using 6.000 ppm. The consistent data so far obtained were compared with calculated pCO2 using the Lynan constants. A plot of the experimental and calculated data evidences that comparisons are only possible by using varying carbonate alkalinity.  相似文献   

9.
10.
Distillery effluents, a major by-product of distilleries are a major environmental hazard as they are rich in organic matter, micro- and macroelements. Management of this enormous amount of nutrient-rich effluent and its effective utilization is a major challenge. These effluents can be used as a source of nutrient by C4 crops like sugarcane and subsequent ratoon crops under fertigation system. Impact of fertigation in sugarcane-ratoon cropping system on soil microbial biomass is important as the microbial population plays an important role in the nutrient and biogeochemical recycling. Keeping this in mind, a field experiment was carried out in the sandy loam soil of semi-arid to humid sub-tropical climate of Gajraula (28.85°N, 78.23°E) region, India with different doses of diluted and undiluted effluent for fertigation of sugarcane crop in presence and absence of 50 % recommended dose of fertilizers with suitable replicates. Two post-sown irrigations with four times diluted effluent gave the maximum yield in case of sugarcane crop. Taking into consideration the yield and the culturable microbial population sizes, it can be concluded that one to two post-sown irrigations with diluted effluent can be used to enhance soil fertility in terms of microbial population and to enhance sugarcane and ratoon crop productivity. This package is economically viable and can also take care of distillery waste management and reduction in consumption of chemical fertilizers by 50 %, a key for sustainable agricultural development.  相似文献   

11.
Variation of bilateral leaf structures in Middle Ural cenopopulations of the weeping birch (Betula pendula Roth.) growing in gradients of industrial pollution was studied to test the efficiency of a new method of population and individual phenogenetic monitoring allowing an indirect assessment of developmental destabilization by segregating the variance of total asymmetry (TA R 2) into its additive components, the variances of fluctuating asymmetry (FA R 2) and directional asymmetry (DA R 2). The method was tested in the impact zones of two copper-smelting plants in the Middle Urals. The degree of impact was characterized by the index of technogenic pollution (ITP) reflecting the average total contents of 15 water-soluble pollutants in snow samples. The level of asymmetry was estimated from the numbers of denticles with incoming veins (dentovenal elements) on the left and right leaf margins. Spearman’s coefficient of rank correlation between the group values of variance in fluctuating asymmetry (FA R 2) and corresponding ITP values reached r S = 0.914 (p < 0.001), providing evidence that the method is highly appropriate for ecological indication of the phenogenetic response of trees to environmental pollution.  相似文献   

12.
The use of a previously untried biosorbent, barley husk, for dye removal is compared to corncob. The effectiveness of adsorption as a means of dye removal has made it an ideal alternative to other more costly treatments. This paper deals with two low-cost, renewable biosorbents, which are agroindustrial by-products, for textile dye removal. Experiments at total dye concentrations of 10, 20, 30, 40, 50, 100, 150, and 200 mg l(-1) were carried out with an artificial effluent consisting of an equal mixture of five textile dyes. The effects of initial dye concentration, biosorbent particle size, dose of biosorbent, effective adsorbance, and dye removal kinetics were examined. One gram (per 100 ml) of < or = 600 microm corncob was found to be effective in removing a high percentage of dyes at a rapid rate (92% in 48 h). One gram of I x 4 mm barley husk was found to be the most effective weight and particle size combination for the removal of dyes (92% in 48 h). The results illustrate how barley husk and corncob are effective biosorbents concerning the removal of textile dyes from effluent.  相似文献   

13.
The ruthenium sawhorse has proven effective in the conversion of trans-cinnamic acid, and substituted trans-cinnamic acids, giving an effective source of biobased styrene and styrene analogues. The reaction is especially versatile, as it achieves product without utilising co-reagents. However, the optimum conditions and substrate scope of the reaction remain unexplored. This report covers the decarboxylation of a series of cinnamates with different structures. Apparent activation energies ranging from 66 to 142 kJ mol?1 were uncovered.  相似文献   

14.
To appreciate the sustainabilty of these plantations of Eucalyptus, it is necessary to make a comparative study of energy, carbon, mineral and water balances of two ecosystems, i.e. the original savannah ecosystem, and the man-made ecosystem the Eucalyptus plantations that have succeeded it. The aim of this work is to study the water balance of the two ecosystems and more particularly their actual evapo-transpiration. Throughfall, net interception during the rainy seasons (1996–99) were 867. mm and 112 mm for the Eucalyptus plantation and 878 mm and 101 mm for the savannah, respectively. The mean total annual actual evapo-transpiration respectively 1127. mm for a plantation and 821 mm for a savannah. During the year transpiration/potential evapotranspiration ratio (T/E p ) is related to the soil-water depletion: The T/E p ratio of 0.79 was not reduced from field capacity until 65% of R FC , and then it decreased quickly to near zero at wilting point. The drainage out of rooting depths of savannah during the rainy season was of 827. mm, a total over 3 years; while the drainage out of rooting depths of Eucalyptus plantation was of 470 mm, a difference in drainage between two ecosystems of 357. mm a total over these three years. The Eucalyptus plantation is manmade ecosystem which takes up and transpires every day throughout the year and uses all available water. The succession of several rain-deficient years will reduce the wood production of the plantation but, knowing that between 1949 and 1998 four successive rain-deficient years have only occured once while the length of rotation is seven years; this dry episode does not compromise the survival of the plantation, although it reduces its wood production. The savannah has a cycle of vegetation such that at the end of the dry season the water remaining in the rooting depths of savannah is sufficient for three successive rain-deficient years to have no impact on its production.  相似文献   

15.
Climate-related changes that occurred in the Ary-Mas larch forests (the world’s northernmost forest range) in the last three decades of the 20th century have been analyzed. An analysis of remote-sensing images made by Landsat satellites in 1973 and 2000 has provided evidence for an increase in the closeness of larch forest canopy (by 65%) and the expansion of larch to the tundra (for 3–10 m per year) and to areas relatively poorly protected from wind due to topographic features (elevation, azimuth, and slope). It has also been shown that the radial tree increment correlates with summer temperatures (r = 0.65, τ = 0.39) and the amounts of precipitation in summer (r = ?0.51, τ = 0–41) and winter (r = ?0.70, τ = ?0.48), decreases with an increase in the closeness of forest canopy (r = ?0.52, p > 0.8; τ = ?0.48, p > 0.95), and increases with an increase in the depth of soil thawing (r = 0.63, p > 0.9; τ = 0.46, p > 0.9). The density of undergrowth depends on temperatures in winter (τ = 0.53, p > 0.8) and summer (r = 0.98, p > 0.99, τ = 0.9, p > 0.99) and the date of the onset of the growing period (r = ?0.60, p > 0.99; τ = ?0.4, p > 0.99) and negatively correlates with the amount of precipitation in summer (r = ?0.56, p > 0.99, τ = ?0.38, p > 0.99).  相似文献   

16.
Twelve fishponds each measuring 1,000 m2 stocked with 2,000 fish consisting of 85% Oreochromis niloticus, 14% Cyprinus carpio and 1% Ophicephalus striatus were used to determine the level of fecal coliforms in the pondwater and fish flesh and the presence of Salmonella in the pondwater. Water samples for coliforms were collected at weekly intervals while those for Salmonella were done biweekly from three pond sites. Fish were randomly sampled by seining the pond over a three-month period. Both water and fish samples were analyzed for coliforms with the multiple-tube fermentation technique and for Salmonella using the swab technique. Results showed coliform counts with mean concentrations varying from 29,700/L of water in the middle of the pond to 18,100/L farthest from the manure dumping site. Differences in concentration between collection sites were not significant (P > 0.05) but mean values obtained weekly differed significantly (P < 0.05). Tilapia had coliform counts of 1.7 while carp had 1.1/g flesh. Differences among fish samples of the same species were not significant (P > 0.05) but were significant between species (P < 0.05). Biochemical tests revealed the presence of E. coli and Klebsiella sp. and more commonly S. cholerasuis.  相似文献   

17.
Background Sustainable development (SD) is a common concept. Knowledge and attitudes are essential in the SD process. This study assesses the knowledge, attitudes, and practices (KAP) of local people about SD. Aim To study the factors that influence the understanding of the concept, contents, and indicators of different aspects affecting the health and environmental issues. Methods A cross-sectional study was carried out from June to July 2007 among 546 households in the Quang Tri province. Data were gathered on basis of socio-demographic variables, namely age, gender, education, occupation, income, and region. Chi square tests and multivariate analysis were performed on the obtained data. The data were cleaned and analysed using SPSS 15.0 for windows. Results Occupation is related to knowledge, attitude, or practice. Income is related to knowledge or practice. Gender related to only attitude. Lastly, region is related to attitude or practice. The proportion of wrong understanding about SD is 2.0 times (95% CI: 1.3; 3.1, p < 0.001) higher than that of the people who have good understanding about it. The rate of willingness to do any related SD programmes of the people who understanding is 2.1 times (95% CI: 1.4; 3.2, p < 0.001) higher than that of the people who have bad one. Conclusions This study shows that knowledge on sustainability of the local communities is low. Occupation and income influence understanding of SD more than region, age, gender, and education. Most of the local people who do not understand SD in general, do not want to participate or act in SD programmes.  相似文献   

18.
The associations of 8 pesticides and pesticide metabolites with total diabetes (diagnosed and undiagnosed) and pre-diabetes (glycohemoglobin 5.7–6.4%) were evaluated using the National Health and Nutrition Examination Survey (NHANES), 1999–2004. Six of the pesticides were found to be associated with total diabetes in separate adjusted logistic regressions. These pesticides and pesticide metabolites were beta-hexachlorocyclohexane, p,p′-DDE, p,p′-DDT, oxychlordane, trans-nonachlor, and heptachlor epoxide. When the number of compounds elevated was tested, 4 or more, of the 6, elevated had an odds ratio of 4.99 (95% CI 1.97–12.61) compared to none elevated. When the 6 compounds were tested together in a single combined adjusted logistic regression only oxychlordane, a metabolite of chlordane, and heptachlor epoxide, a metabolite of heptachlor, were significantly associated with total diabetes. In the combined adjusted logistic regression, oxychlordane ≥ 14.5 ng/g lipid adjusted had an odds ratios of 1.90 (95% CI 1.09–3.32) compared to oxychlordane < 14.5 ng/g lipid adjusted, and heptachlor epoxide ≥ 14.6 ng/g lipid adjusted had an odds ratio of 1.70 (95% CI 1.16–2.49) compared to heptachlor epoxide < 14.6 ng/g lipid adjusted. Heptachlor epoxide and p,p′-DDT were significantly associated with pre-diabetes in separate adjusted logistic regressions. When these 2 compounds were tested together only heptachlor epoxide remained significantly associated with pre-diabetes. The evidence supporting the relationship between pesticides and pesticide metabolites, with diabetes, was strongest for heptachlor epoxide and oxychlordane, intermediate for p,p′-DDT, and least for beta-hexachlorocyclohexane, p,p′-DDE, and trans-nonachlor. Mirex and dieldrin were not associated with total diabetes or pre-diabetes.  相似文献   

19.
Pharmaceuticals for human use are consumed in significant quantities and their occurrence in aquatic systems has been reported by a number of authors. In the context of environmental risk assessment, there is an increasing interest in evaluating the discharge of pharmaceutical products to surface waters through sewage treatment plants (STP). This case study was carried out on a conventional biological treatment plant (Alès, France) and focused on a set of eleven drugs representing the main therapeutic classes. Measured environmental concentrations (MECs) range from the low ng L? 1 to 1.5 µg L? 1 in effluent and up to few hundred ng L? 1 in receiving surface waters. There is a good agreement between MEC and predicted environmental concentration (PEC) values for seven of the eleven investigated drugs in STP effluent. There is not such a good match between PEC and MEC values in surface waters, and this highlights the limits of this approach, at the local scale.  相似文献   

20.
This study was performed to investigate the concentration of PM10 and PM2.5 inside trains and platforms on subway lines 1, 2, 4 and 5 in Seoul, KOREA. PM10, PM2.5, carbon dioxide (CO2) and carbon monoxide (CO) were monitored using real-time monitoring instruments in the afternoons (between 13:00 and 16:00). The concentrations of PM10 and PM2.5 inside trains were significantly higher than those measured on platforms and in ambient air reported by the Korea Ministry of Environment (Korea MOE). This study found that PM10 levels inside subway lines 1, 2 and 4 exceeded the Korea indoor air quality (Korea IAQ) standard of 150 μg/m3. The average percentage that exceeded the PM10 standard was 83.3% on line 1, 37.9% on line 2 and 63.1% on line 4, respectively. PM2.5 concentration ranged from 77.7 μg/m3 to 158.2 μg/m3, which were found to be much higher than the ambient air PM2.5 standard promulgated by United States Environmental Protection Agency (US-EPA) (24 h arithmetic mean: 65 μg/m3). The reason for interior PM10 and PM2.5 being higher than those on platforms is due to subway trains in Korea not having mechanical ventilation systems to supply fresh air inside the train. This assumption was supported by the CO2 concentration results monitored in tube of subway that ranged from 1153 ppm to 3377 ppm. The percentage of PM2.5 in PM10 was 86.2% on platforms, 81.7% inside trains, 80.2% underground and 90.2% at ground track. These results indicated that fine particles (PM2.5) accounted for most of PM10 and polluted subway air. GLM statistical analysis indicated that two factors related to monitoring locations (underground and ground or inside trains and on platforms) significantly influence PM10 (p < 0.001, R2 = 0.230) and PM2.5 concentrations (p < 0.001, R2 = 0.172). Correlation analysis indicated that PM10, PM2.5, CO2 and CO were significantly correlated at p < 0.01 although correlation coefficients were different. The highest coefficient was 0.884 for the relationship between PM10 and PM2.5.  相似文献   

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