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231.
This paper explores a finding that emerged in the early phases of a multidisciplinary project applying population health and psychology to issues of social progress and sustainability. Across 180 countries and half a century of data, the levels of carbon emissions per capita that maximise life expectancy fall within a tight band averaging only 6.6 tonnes—considerably less than wealthier countries emit per person. Various tests fail to break down the curves and, although the authors remain cautious, the stability since 1960 offers implications for the carbon budget leading up to 2050. This is the first time these curves have been contextualised against established climate science, with timely implications for international negotiations on sustainability and development.  相似文献   
232.
233.
Radioxenon isotopes play a major role in confirming whether or not an underground explosion was nuclear in nature. It is then of key importance to understand the sources of environmental radioxenon to be able to distinguish them from those of a nuclear explosion.  相似文献   
234.
A simple modeling concept was previously applied to study air-foliage exchange of both polybrominated diphenyl ethers (PBDEs) and polycyclic aromatic hydrocarbons (PAHs) using field measurements. In this paper, the predictive capabilities of this framework were tested using an independent set of data collected at the same sampling location for a different time period. Firstly, atmospheric (particle-bound and gaseous phase) PBDE and PAH concentrations were used to predict their accumulation in spruce needles. Conversely, we used PBDE and PAH concentrations in vegetation to predict their atmospheric concentrations. In both cases, calculated and measured values showed good agreement, providing evidence that the developed framework and our derived deposition velocities can be used as a predictive tool for these two different classes of semi-volatile organic compounds.  相似文献   
235.
Between the tenth and twentieth century the population of Paris city increased from a few thousand to near 10 million inhabitants. In response to the growing urban demand during this period, the agrarian systems of the surrounding rural areas tremendously increased their potential for commercial export of agricultural products, made possible by a surplus of agricultural production over local consumption by humans and livestock in these areas. Expressed in terms of nitrogen, the potential for export increased from about 60 kg N/km2/year of rural territory in the Middle Ages, to more than 5,000 kg N/km2/year from modern agriculture. As a result of the balance between urban population growth and rural productivity, the rural area required to supply Paris (i.e. its food-print) did not change substantially for several centuries, remaining at the size of the Seine watershed surrounding the city (around 60,000 km2). The theoretical estimate of the size of the supplying hinterland at the end of the eighteenth century is confirmed by the figures deduced from the analysis of the historical city toll data (octroi). During the second half of the twentieth century, the ‘food-print’ of Paris reduced in size, owing to an unprecedented increase in the potential for commercial export associated with modern agricultural systems based on chemical N fertilization. We argue that analysing the capacity of territories to satisfy the demand for nitrogen-containing food products of local or distant urban population and markets might provide new and useful insights when assessing world food resource allocation in the context of increasing population and urbanization.  相似文献   
236.
Measurements of estrogenic and androgenic activities in total plasma with Chemically Activated LUciferase gene eXpression (CALUX?) bioassays could provide biologically relevant measures for exposure to endocrine disruptors in epidemiologic studies. The objective of this study was to explore the effects of a variety of sources of potential endocrine disruptors on estrogenic and androgenic activities in total plasma measured by CALUX?. Plasma samples and interview data on sources of potential endocrine disruptors were collected from 108 men with different exposures profiles. CALUX? measurements (BioDetection Services) involved human U2-OS cell lines controlled by the estrogen receptor alpha and the androgen receptor. Mean differences (beta) in 17β-estradiol equivalents (EEQs) and dihydrotestosterone equivalents (AEQs) between exposure groups were estimated using general linear models. Mean plasma AEQs and EEQs were 9.1×10(-1)ng/ml and 12.0pg/ml, respectively. Elevated AEQs were found in smokers (beta 1.9 (95%CI 0.1-3.6)×10(-1)ng/ml) and heavy drinkers (1.4 (0.2-3.1)×10(-1)ng/ml), and in men occupationally exposed to disinfectants (1.6 (0.3-3.5)×10(-1)ng/ml) or welding/soldering fumes (1.4 (-0.2-2.9)×10(-1)ng/ml). Occupational exposure to pesticides, disinfectants, and exhaust fumes seemed to be associated with increased plasma EEQs: 1.5 (-0.2-3.2)pg/ml, 2.1 (0.2-3.9)pg/ml, and 2.9 (0.6-5.2)pg/ml, respectively. Moderate to high plasma dioxin levels, measured in a subgroup by the dioxin-responsive CALUX?, were accompanied by a 20% increase in AEQs. This is the first study in which CALUX? was used to assess hormone activities in total plasma. Although the results are not yet readily interpretable, they indicate that these measurements can be valuable for epidemiologic studies on endocrine disruptors and give direction for further research.  相似文献   
237.
Geology has been highlighted by a number of authors as a key factor in high indoor radon levels. In the light of this, this study examines the application of seasonal correction factors to indoor radon concentrations in the UK. This practice is based on an extensive database gathered by the National Radiological Protection Board over the years (small-scale surveys began in 1976 and continued with a larger scale survey in 1988) and reflects well known seasonal variations observed in indoor radon levels. However, due to the complexity of underlying geology (the UK arguably has the world's most complex solid and surficial geology over the shortest distances) and considerable variations in permeability of underlying materials it is clear that there are a significant number of occurrences where the application of a seasonal correction factor may give rise to over-estimated or under-estimated radon levels. Therefore, the practice of applying a seasonal correction should be one that is undertaken with caution, or not at all. This work is based on case studies taken from the Northamptonshire region and comparisons made to other permeable geologies in the UK.  相似文献   
238.
The levels of 1,1,1-trichloro-bis-2,2'-(4-chlorophenyl) ethane (p,p'-DDT) and its metabolites, hexachlorobenzene (HCB), hexachlorocyclohexane isomers (HCHs), chlordanes (trans- and cis-chlordane, oxychlordane and trans-nonachlor), 11 polychlorinated biphenyl (PCB) congeners, and 7 polybrominated diphenyl ether (PBDE) congeners were measured in 37 individual human milk samples from Kahramanmara? region, Turkey. Organochlorine pesticides were the major contaminants in the milk samples. p,p'-DDE and p,p'-DDT were detected in all samples, while beta-HCH had a detection frequency of 97%. The sum of the DDTs in human milk samples varied between 0.52 and 315.8 ng/g wet weight (ww) with a mean ratio between p,p'-DDE and p,p'-DDT equal to 31.1. p,p'-DDD could be measured only in six samples. beta-HCH was the most prevalent HCH isomer with a mean value of 2.08 ng/g ww. The mean concentration of gamma-HCH was 0.38 ng/g ww, while alpha-HCH was not detected in any sample. HCB is found in 95% of the milk samples with a mean concentration of 0.30 ng/g ww. The mean value for the sum of chlordanes was 0.39 ng/g ww, with oxychlordane and trans-nonachlor being the principal contributors. PCBs could be measured only in 8 out of 37 samples and their concentration ranged between <0.15 and 1.92 ng/g ww for the sum of PCBs. PCB profiles were dominated by congeners 153, 180 and 138. PBDEs were detected only in 3 out of 37 samples, with the highest value being 0.014 ng/g ww (0.40 ng/g lipid weight) and BDE 47 was the dominant congener. Although the number of samples is relatively low and they are not representative for the whole Turkish population, the results of the present study are important to provide additional data on the concentrations of persistent organochlorinated pollutants in Turkey and show as first the PBDE levels in Turkish population.  相似文献   
239.
Dietary PBDE intake: a market-basket study in Belgium   总被引:1,自引:0,他引:1  
A food market-basket, representative for the general Belgian population, containing various meat, fish and dairy food products, was assembled and analysed for its polybrominated diphenyl ether (PBDE) content. Additionally, fast food samples were also investigated. Based on the measured PBDE levels, an average daily dietary intake estimate of PBDEs was calculated. Of all foods analysed, fish had the highest average sum of PBDE levels (BDEs 28, 47, 99, 100, 153, 154, and 183; 460 pg/g ww), followed by dairy products and eggs (260 pg/g ww), fast food (86 pg/g ww) and meat products (70 pg/g ww). One fresh salmon filet had the highest total concentration of PBDEs (2360 pg/g ww), whereas levels in steak and chicken breast were the lowest of all foods analysed. BDE 209 was never found above LOQ in any food. PBDE intake calculations were based on the average daily food consumption in Belgium and were estimated between 23 and 48 ng/day of total PBDEs (lower and upper bound). This value is in accordance with what was previously reported for diets from geographical distinct areas, such as Canada, Finland, Spain, Sweden and the UK. Although it is only a minor constituent of the Belgian diet, fish is the major contributor to the total daily PBDE-intake (around 40%) due to the high PBDE levels in this type of food. Although low contaminated, meat products account for around 30% of the total dietary intake of PBDEs. Dairy products and eggs contribute to a lesser degree (less than 30%).  相似文献   
240.
Polybrominated diphenyl ether in the East Asian environment: a critical review   总被引:20,自引:0,他引:20  
Polybrominated diphenyl ethers (PBDEs) have been extensively used as flame retardants in consumer goods. Sufficient evidence shows that PBDEs have been rapidly accumulating in the environment worldwide. In Asia, deca-bromodiphenyl ether has been produced and used in large quantities, while penta-BDE has largely ceased in the mid-1990s. This paper summarizes and critically reviews the status of PBDE pollution in East Asia, with emphases on the comparisons with Europe and North America and the interpretation of the differences. In general, the concentrations of PBDEs in atmosphere, sludge, human and biological samples of East Asia are comparable to or lower than those in Europe and North America. However, in the sediments of waters near densely populated and heavily industrialized areas, PBDE levels are among the highest ever reported in the literature. In Japan and China, concentrations of PBDEs in sediment cores showed an increasing trend for the past 20-30 years. Also, PBDEs levels in human breast milk in Japan increased about 10-fold in the past 20 years. The presence of PBDEs in fur seal has increased about 150-fold in 1994 than that in 1972. Regional and inter-continental transport cannot be confirmed due to insufficient information. However, the detection of a number of PBDE congeners in a pristine lake on the Qinghai-Tibet Plateau may be an evidence of their long-range transport.  相似文献   
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