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BackgroundFetal exposure to endocrine disrupting chemicals may increase the risk for adverse health effects at birth or later in life.ObjectivesThe objective of this study is to analyze the combined effect of xenoestrogens on reproductive and perinatal growth outcomes (child birthweight, early rapid growth and body mass index (BMI) at 14 months) using the biomarker total effective xenoestrogen burden (TEXB).Methods490 placentas were randomly collected in the Spanish prospective birth cohort Environment and Childhood (INMA) project. TEXB was used to assess the estrogenicity of placental samples in two fractions: that largely attributable to environmental organohalogenated xenoestrogens (TEXB-alpha), and that mostly due to endogenous estrogens (TEXB-beta), both expressed in estrogen equivalent units (Eeq) per gram of tissue. Linear or logistic regression models were performed adjusting for cohort and confounders. Sex interactions were investigated.ResultsThe median TEXB-alpha level was 0.76 pM Eeq/g (interquartile range (iqr): 1.14). In multivariate models, higher TEXB-alpha levels (third tertile, > 1.22 pM Eeq/g; iqr: 1.73) were associated with increased birthweight in boys but not in girls (β = 148.2 g, 95% CI: 14.01, 282.53, pint = 0.057). Additionally, higher TEXB-alpha values in boys were related with a lower risk of early rapid growth (OR = 0.37; 95% CI: 0.15, 0.88) and with a non significant association with larger BMI z-scores at 14 months of age (β = 0.29; 95% CI: − 0.11, 0.69).ConclusionsThese findings suggest that prenatal exposure to xenoestrogens may increase birthweight in boys, which might have an impact on child obesity and other later health outcomes.  相似文献   

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In this study we have examined the effect of exposure to different congeners of PCBs and their role in oxidative stress response. A metabolically competent human liver cell line (HepG2) was exposed with two prototype congeners of PCBs: coplanar PCB-77 and non-coplanar PCB-153. After the predetermined times of exposure (0–24 h) at 70 μM concentration, the HepG2 cells showed significant apoptotic changes by fluorescent microscopy after 12 h of exposure. Gene set enrichment analysis (GSEA) identified oxidative stress as the predominant enrichment. Further, paraquat assay showed that PCB congeners lead to oxidative stress to different extents, PCB-77 being more toxic. This study, with emphasis on all recommended microarray quality control steps, showed that apoptosis was one of the most significant cellular processes as a result of oxidative stress, but each of these congeners had a unique signature gene expression, which was further validated by Taqman real time PCR and immunoblotting. The pathways involved leading to the common apoptotic effect were completely different. Further in-silico analysis showed that PCB-153 most likely acted through the TNF receptor, leading to oxidative stress involving metallothionein gene families, and causing apoptosis mainly by the Fas receptor signaling pathway. In contrast, PCB-77 acted through the aryl hydrocarbon receptor. It induced oxidative stress through the involvement of cytochrome P450 (CYP1A1) leading to apoptosis through AHR/ARNT pathway.  相似文献   

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Carbon-14 is a particularly interesting radionuclide from the perspective of dose estimation because it mixes readily with stable CO2, and hence enters the food-chain as fundamental biomolecules. A model was developed for the situation of 14C releases to surface waters, where there are distinct changes in the water 14C activity concentrations throughout the year. The model computes the specific activity in water, phytoplankton, fish, crops, meat, milk and air, following a typical irrigation-based food-chain scenario. This paper describes the derivation of the required 14C-specific parameter values. Many of the key parameters are not commonly measured, at least not in the context of dose assessment. Thus, inference from other sources of data was required, and this is the scientific contribution described in this paper. The best estimates and appropriate measures of statistical dispersion are provided. This required consideration of both the temporal and spatial averaging domains to ensure they were correct for parameters as defined in the model. The model coupled with these parameter values represents several new developments for modelling 14C transfers.  相似文献   

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Pesticides have been associated with Parkinson's disease (PD), and protective gloves and workplace hygiene can reduce pesticide exposure. We assessed whether use of gloves and workplace hygiene modified associations between pesticides and PD. The Farming and Movement Evaluation (FAME) study is a nested case–control study within the Agricultural Health Study. Use of protective gloves, other PPE, and hygiene practices were determined by questionnaire (69 cases and 237 controls were included). We considered interactions of gloves and hygiene with ever-use of pesticides for all pesticides with ≥ 5 exposed and unexposed cases and controls in each glove-use stratum (paraquat, permethrin, rotenone, and trifluralin). 61% of respondents consistently used protective gloves and 87% consistently used ≥ 2 hygiene practices. Protective glove use modified the associations of paraquat and permethrin with PD: neither pesticide was associated with PD among protective glove users, while both pesticides were associated with PD among non-users (paraquat OR 3.9 [95% CI 1.3, 11.7], interaction p = 0.15; permethrin OR 4.3 [95% CI 1.2, 15.6] interaction p = 0.05). Rotenone was associated with PD regardless of glove use. Trifluralin was associated with PD among participants who used < 2 hygiene practices (OR 5.5 [95% CI 1.1, 27.1]) but was not associated with PD among participants who used 2 or more practices (interaction p = 0.02). Although sample size was limited in the FAME study, protective glove use and hygiene practices appeared to be important modifiers of the association between pesticides and PD and may reduce risk of PD associated with certain pesticides.  相似文献   

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Fallout (137)Cs and stable Cs in soils were separated with two extractants (1M CH(3)COONH(4) solution and 0.8M CH(3)COONH(4) in 5% HNO(3) solution after H(2)O(2) oxidization). The residue remaining after removal of the oxidizable organic-bound fraction was separated into the particle-size fractions including clay, silt, fine sand and coarse sand with a sieving and sedimentation method. Then, the concentrations of (137)Cs and stable Cs in the extracted fractions and the particle-size fractions were determined. The (137)Cs contents in the exchangeable and organic-bound fractions in the soil were approximately 10 and 20%, respectively. The (137)Cs content in the strongly bound fraction was about 70%, and the concentration of (137)Cs in the clay was the richest among the particle-size fractions. The specific activity of (137)Cs (concentration ratio of fallout (137)Cs/stable Cs) decreased in the order exchangeable, organic-bound and strongly bound fractions. The data suggest that equilibrium between (137)Cs and stable Cs was not reached among those fractions, even though most of the (137)Cs that had been deposited on the soil was derived from fallout weapons tests that occurred several decades ago. The concentration of (137)Cs among the particle-size fractions in each soil was different, whereas the specific activity of (137)Cs in the particle-size fractions had a relatively similar value.  相似文献   

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Regional Environmental Change - The numerous Mediterranean islands (&gt;10,000) are very important from a biodiversity point of view, both in term of plant species (numerous endemics, presence...  相似文献   

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Carbon-14 is a particularly interesting radionuclide from the perspective of dose estimation. Many nuclear facilities, including power reactors, release 14C into the environment, and much of this is as 14CO2. This mixes readily with stable CO2, and hence enters the food chain as fundamental biomolecules. This isotopic mixing is often used as the basis for dose assessment models. The present model was developed for the situation of 14C releases to surface waters, where there are distinct changes in the water 14C activity concentrations throughout the year. Complete isotopic mixing (equilibrium) cannot be assumed. The model computes the specific activity (activity of 14C per mass of total C) in water, phytoplankton, fish, crops, meat, milk and air, following a typical irrigation-based food-chain scenario. For most of the biotic compartments, the specific activity is a function of the specific activity in the previous time step, the specific activity of the substrate media, and the C turnover rate in the tissue. The turnover rate is taken to include biochemical turnover, growth dilution and mortality, recognizing that it is turnover of C in the population, not a tissue or an individual, that is relevant. Attention is paid to the incorporation of 14C into the surface water biota and the loss of any remaining 14CO2 from the surface water-air interface under its own activity concentration gradient. For certain pathways, variants in the conceptual model are presented, in order to fully discuss the possibilities. As an example, a new model of the soil-to-plant specific activity relationship is proposed, where the degassing of both 14C and stable C from the soil is considered. Selection of parameter values to represent the turnover rates as modeled is important, and is dealt with in a companion paper.  相似文献   

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A method for determining the specific alpha activity of thick sources using a large area ZnS(Ag) scintillation detector is presented. In this method a quadratic relationship between the detector response and window thickness is assumed. This method provides a quick estimation of alpha activity in the sample, so it is an indicative method. The aim of this experimental work is to approve theoretical assumption and to develop a standard routine method for absolute alpha measurements of thick contaminated environmental sources. For this purpose reference material U(3)O(8) and spiked standards of soil were used. Measurements of contaminated soil samples from south Serbia showed the practical application of this method.  相似文献   

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Climate change-related risks encompass an intensification of extreme weather events, such as fluvial and pluvial flooding, droughts, storms, and heat stress. A transparent and comprehensive division of responsibilities is a necessary—but not the only—precondition for being prepared for climate change. In this paper, we present, and preliminarily test, a method for the ex-ante assessment of the division of public and private responsibilities for climate adaptation in terms of comprehensiveness, transparency, legitimacy, and effectiveness. This method proofs particularly suited for the assessment of adaptation responsibilities in combination with a sectoral approach. It helps identifying a number of shortcomings in divisions of responsibilities for climate adaptation. We conclude that this method is useful as a diagnostic tool for identifying the expected climate change preparedness level, and recommend to combine this with ex-post analyses of real-life cases of extreme events in order to assess the actual preparedness for climate change. Besides the scientific purpose of providing a generally applicable assessment method, with this method, we also intend to assist policy-makers in developing and implementing adaptation plans at various levels.  相似文献   

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ObjectiveA systematic review of observational studies was performed to address the strength of evidence for an association between actual and perceived exposure to electromagnetic fields (EMF) and non-specific physical symptoms (NSPS) in the general population. To gain more insight into the magnitude of a possible association, meta-analyses were conducted.MethodsLiterature databases Medline, Embase, SciSearch, PsychInfo, Psyndex and Biosis and additional bibliographic sources such as reference sections of key publications were searched for the detection of studies published between January 2000 and April 2011.ResultsTwenty-two studies met our inclusion criteria. Qualitative assessment of the epidemiological evidence showed either no association between symptoms and higher EMF exposure or contradictory results. To strengthen our conclusions, random effects meta-analyses were performed, which produced the following results for the association with actual EMF; for symptom severity: Headache odds ratio (OR) = 1.65; 95% confidence interval (CI) = 0.88–3.08, concentration problems OR = 1.28; 95% CI = 0.56–2.94, fatigue-related problems OR = 1.15; 95% CI = 0.59–2.27, dizziness-related problems OR = 1.38; 95% CI = 0.92–2.07. For symptom frequency: headache OR = 1.01; 95% CI = 0.66–1.53, fatigue OR = 1.12; 95% CI = 0.60–2.07 and sleep problems OR = 1.18; 95% CI = 0.80–1.74. Associations between perceived exposure and NSPS were more consistently observed but a meta-analysis was not performed due to considerable heterogeneity between the studies.ConclusionsThis systematic review and meta-analysis finds no evidence for a direct association between frequency and severity of NSPS and higher levels of EMF exposure. An association with perceived exposure seems to exist, but evidence is still limited because of differences in conceptualization and assessment methods.  相似文献   

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Eradicating poverty, reducing environmental degradation and achieving sustainable economic growth are some of the major macroeconomic goals of Pakistan. There are, however, serious interlinkages among these issues. The present paper investigates these linkages and the existing evidence for Pakistan and other countries. The aim of the paper is to examine and test some hypotheses and answer some questions regarding poverty-environment-nexus in Pakistan. The paper uses secondary data and information to probe into these linkages. The paper finds that poverty leads to environmental degradation is a common belief but it is not clearly supported by evidence. What is more strongly supported by evidence is the fact that environmental degradation hurts more the poor. There is a need of studies that deal with the social and environmental impacts of specific factors, and a need of a better understanding of institutional dynamics. More understanding on how levels and changes in poverty relate to changes in environmental quality is needed. There is a need to understand how the levels and rates of change vary with poverty. There is a need to know how and where the changes are taking place. More research is needed on the effects of changes in the population and the dynamics of institutional development. It has been showed that low income groups are the most affected when environmental degradation occur, but not enough information available in Pakistan on the mechanisms. There is a need of empirical studies regarding effect on poor relative to non-poor. More understanding on how poor people depend on, interact with and use their environment in rural and urban areas is needed. Ideally, in Pakistan, we would need to relate data gathered in an area with socio-economic data from the same area, answering this way to questions such as, to what extent are different income groups affected by resource degradation? And, by pollution? Finally, Pakistan should apply open minded and innovative policies in order to take advantage of the many existing opportunities. Some suggestions are eco-labeling schemes, organic practices, fair trade and so forth. Very little research has been conducted in developing countries, especially in Pakistan on the issues involving poverty, environment and development. The present study is an attempt in this regard. The results of the study are expected to assume pivotal importance for policy makers, academics and other researchers. It may help policy makers how to design policy to ensure poverty alleviation vis-à-vis environmental conservation. It may also help academicians to understand the complex poverty-environment-growth nexus. It will also open new avenues for further research in this area.  相似文献   

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A cohort of low income, city dwelling, pregnant African American Women (delivered from 1994–1999) was assembled to identify factors related to organochlorine exposure through consumption of Great Lakes resources. The cohort is known as the Great Lakes Cohort of Pregnant African American Women (GLCPAAW). Pregnant women from metropolitan Chicago, IL area clinics were administered a questionnaire on diet, demographics, and health history. Weight, height, and serum lipids were measured at delivery along with serum organochlorines such as PCBs and DDE. Congener specific concentrations of PCBs and p,p'-DDE found in the maternal serum are reported. Dominant PCB congeners found in the serum of the pregnant women at delivery included PCB 101, 118, 138, 153, and 180. The high prevalence and magnitude of PCB 101 (greater than the limit of detection in > 80% of the women in the cohort) are unique characteristics of this cohort.Great Lakes fish has been identified as a source of exposure to organochlorines in several studies. Spearman correlations and robust regression models were utilized to identify the impact of Great Lakes fish ingestion on cohort serum organochlorine concentrations. Several potential confounders of the relationship between serum organochlorines and Great Lakes fish consumption were identified. Covariates related to organochlorines in correlations as well as regression models included age, body surface area, fish ingestion, lipids, parity, race and smoking. Lower chlorinated PCB congeners do not follow the same trends as the higher chlorinated congeners and DDE. The higher chlorinated PCB congeners (PCB 138, 153, and 180) and DDE were correlated with age while the lower chlorinated congeners were not. PCB 153 and 180 regression models included age as a significant covariate. None of the higher chlorinated congeners correlated to race, while both lower chlorinated congeners were correlated to race. Race was also significant in both lower chlorinated congeners' regression models. PCB 101, a lower chlorinated congener seldom found in human serum, is readily found in the cohort. Airborne PCB exposure as well as diminished metabolism of PCB 101 in African Americans may explain the increased presence of PCB 101 and it's correlation with race.High end sport fish consumers (≥ 1meal per week) carried elevated levels of DDE and higher chlorinated PCB congeners (138, 153, and 180) compared to non-sport fish eaters. Unexpectedly, DDE was correlated more consistently with fish ingestion and age (a marker of bioaccumulation) in comparison to PCBs. Small correlations were found between serum PCBs and fish ingestion (Spearman correlation = 0.19 for total PCBs and fish meals per year). Additionally, Serum PCBs in low end Great Lakes sport fish consumers were not higher than non-consumers. These findings suggest the women of the cohort are being exposed to PCBs through other routes in addition to Great lakes sport fish. One major route of exposure may be Chicago air. The observed trends amongst individual PCB congeners has important ramifications because lower chlorinated congeners or their metabolites may be mediators of toxicity. Organochlorine exposure through Great Lakes fish ingestion was clearly identified in high end fish consumers while associations with race, metabolism, and possible airborne exposures pose new questions.  相似文献   

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We have evaluated the levels and specific profiles of several organohalogenated contaminants, including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and flame retardants (FRs), such as polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDs), novel brominated FRs (NBFRs), and organophosphate FRs (OPFRs), in 47 indoor dust samples collected in 2010 from urban locations from Iasi, Eastern Romania. The dominant contaminants found in the samples were OPFRs (median sum OPFRs 7890 ng/g). Surprisingly, OCPs were also measured at high levels (median 1300 ng/g). Except for BDE 209 (median 275 ng/g), PBDEs were present in dust samples at relatively low levels (median sum PBDEs 8 ng/g). PCBs were also measured at low levels (median sum PCBs 35 ng/g), while NBFRs were only occasionally detected, showing a low usage in goods present on the Romanian market. The results of the present study evidence the existence of a multitude of chemical formulations in indoor dust. FRs are usually associated to human exposure via ingestion of dust, but other chemicals, such as OCPs, are not commonly reported in such matrix. Although OCPs were found at comparable levels with OPFRs in Romanian dust, OCPs possess a higher risk to human health due to their considerably lower reference dose (RfD) values. Indeed, the OCP exposure calculated for various intake scenarios was only 2-fold lower than the corresponding RfD. Therefore, the inclusion of OCPs as target chemicals in the indoor environment becomes important for countries where elevated levels in other environmental compartments have been previously shown.  相似文献   

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The specific activity of (226)Ra, (232)Th and (40)K in 52 Turkish pumice samples collected from 11 geographical areas located in Central Anatolia, Eastern Anatolia, Mediterranean and Aegean regions was determined by gamma-ray spectrometry with a high-purity germanium (HPGe) detector. The specific activity of (226)Ra, (232)Th and (40)K ranged from 12.7+/-0.5 to 256.2+/-9.1Bqkg(-1) with a mean of 89.1+/-65.2Bqkg(-1), 12.3+/-1.0 to 237.9+/-12.2Bqkg(-1) with a mean of 87.0+/-61.4Bqkg(-1) and 300.1+/-5.5 to 1899.0+/-30.8Bqkg(-1) with a mean of 1211.9+/-419.8Bqkg(-1), respectively. Elemental concentrations were determined for U (from 1.0 to 20.7ppm with a mean of 7.2+/-5.3ppm), Th (from 3.0 to 58.6ppm with a mean of 21.4+/-15.1ppm) and K (from 1.0 to 6.1% with a mean of 3.9+/-1.3%). The radium equivalent activity (Ra(eq)), the activity index, the emanation coefficient, the (222)Rn mass exhalation rate, the indoor absorbed dose rate and the effective dose rate were estimated for the radiation hazard of the natural radioactivity in all samples. The calculated mean Ra(eq) value was 306.6+/-177.7Bqkg(-1) (54.6+/-5.5 to 737.6+/-49.0Bqkg(-1)) for all pumice samples. This value is lower than the recommended limit value of 370Bqkg(-1) for building raws and products. The emanation coefficient and the (222)Rn mass exhalation rate of all samples ranged from 29.4 to 42.9% with a mean of 36.2% and from 11.0 to 196.4muBqkg(-1)s(-1) with a mean of 73.5muBqkg(-1)s(-1), respectively. The mean indoor absorbed dose rate and the corresponding mean effective dose rate were 274.6+/-153.6nGyh(-1) (50.4-644.6nGyh(-1)) and 1.35+/-0.75mSvy(-1) (0.24-3.16mSvy(-1)), respectively. For all pumice samples the mean indoor absorbed dose rate is about three times higher than the population-weighted average of 84nGyh(-1), while the mean effective dose rate values except for PUM 05, PUM 06, PUM 10 and PUM 15 exceed the dose criterion of 1mSvy(-1).  相似文献   

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There is a growing wealth of data capturing the direct-use values of the environment and recognition of forests and wild resources as representing “the poor manȁ9s overcoat”. This focus has however resulted in an emphasis on the utilitarian values of wild resources for rural livelihoods and has for the most part overlooked their cultural values. In tangent to these developments within the field of anthropology there has been increased attention directed towards the relationship between biodiversity and human diversity over the past decade. This has resulted in the recognition of what the Declaration of Belem calls an ȁ8inextricable linkȁ9 between biological and cultural diversity. The term bio-cultural diversity has been introduced as a concept denoting this link. Consequently there is a need for more elaborate assessments of the various ways in which different groups of people find value in biodiversity. The aim of this paper is to demonstrate the cultural significance of wild harvested plant resources for the maintenance of two gender specific cultural artefacts for amaXhosa people in South Africa, to assess the persistence of these practices in rapidly modernizing communities. We demonstrate the endurance of these ancient cultural artefacts in present-day peri-urban communities and suggest that they point to the need for improved understanding of the significance of bio-cultural diversity. The findings of the study should not be interpreted as illustrating stagnation in the traditional past, but rather as pointing at the need for improved understanding of the significance of bio-cultural diversity in a dynamic sense.  相似文献   

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基于1987~2017年Landsat时序数据,提取汉江中下游河流消落区及水域面积和淹没频率逐年变化信息,分析消落区及水域时空变化过程及阶段性特征。结果表明:汉江消落区呈上游宽下游窄的特征分布,消落区面积最为集中的区域位于中游的宜城-钟山口段,相对较少的区域位于下游的仙桃-汉川段。在过去30年间,汉江中下游消落区平均面积在76到256 km~2之间波动,水域面积在183~550 km~2之间变化,水域及消落区面积均呈波动特征并存在较大时空差异。汉江中下游总体淹没频率在1987~2001年间呈减小特征,2002~2017年存在增加趋势。汉江中下游大型水利枢纽工程库区的水域面积、淹没频率在水库建成后大幅度增加,消落区面积波动幅度减小;而非水库地区的水域及消落区面积无明显增减趋势。  相似文献   

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夏季南亚高压对我国长江中下游旱涝分布有重要影响,为深入认识长江中下游夏季降水年代际演变规律和机理,提高其短期气候预测水平,利用1960~2015年NCEP/NCAR再分析资料和地面气象站降水资料,分析夏季南亚高压年代际变化及其对长江中下游降水的影响。结果表明:夏季南亚高压强度、面积、南界、东伸脊点、西伸脊点和脊线均存在显著的年代际变化,长江中下游夏季降水也有明显年代际转折,南亚高压脊线与长江中下游夏季降水相关最好,呈显著负相关。夏季南亚高压脊线年代际偏南期,南亚高压偏大偏强,长江中下游高层气流强,且形成发散;副高增强西伸,印度有稳定低压存在,长江中下游处于副高西北侧和西风槽前,盛行西南风,与北方来的偏西气流汇合;低层风场有明显切变和辐合,从孟湾、南海输送来的水汽在长江中下游辐合上升,导致降水偏多。1990s初至2000s初,夏季南亚高压年代际减弱西撤,副高减弱东撤,但由于两个高压减弱程度较小,长江中下游夏季降水仍偏多。  相似文献   

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