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Mehdi Adjeroud Marine J. Briand Mohsen Kayal Pascal Dumas 《Environmental monitoring and assessment》2013,185(7):5763-5773
Coral reefs in Tonga have been confronted by multiple threats of various origins, including large-scale disturbances and human-induced stressors. These reef communities have been poorly studied, and efficient conservation actions are urgently needed. The aim of this study was to: (1) examine the spatial distribution of coral assemblages in the lagoon of Tongatapu; (2) determine the degree to which spatial heterogeneity of adult corals is influenced by recruitment processes; and (3) examine the implications of these results in terms of conservation actions. We recorded a total of 37 adult and 28 juvenile coral genera, a mean density of 11.6 adult and 5.5 juvenile colonies m?2, and a dominance of Montipora, Acropora, and Porites. For seven of the 10 dominant genera, spatial patterns of adults were linked to the short-term recruitment pattern history. Despite a reduced diversity and abundance of adult corals in some areas, the lagoon of Tongatapu retains the potential for replenishment through recruitment of young corals. Consequently, we suggest that conservation actions should focus on reducing factors causing coral mortality and maintain suitable conditions for the establishment and growth of juvenile corals, thus increasing the probability that they will reach maturity and participate to the maintenance of local populations. Rather than establishing a large marine protected area, which will almost certainly suffer from a lack of control and poor enforcement, alternative conservation measures could be successfully implemented through the establishment of several small village-based marine reserves, as has been undertaken in other South Pacific islands with promising results. 相似文献
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C. Dumas D. Aubert X. Durrieu de Madron W. Ludwig S. Heussner N. Delsaut C. Menniti C. Sotin R. Buscail 《Environmental geochemistry and health》2014,36(5):995-1014
In order to calculate budgets of particulate matter and sediment-bound contaminants leaving the continental shelf of the Gulf of Lion (GoL), settling particles were collected in March 2011 during a major storm, using sediment traps. The collecting devices were deployed in the Cap de Creus submarine canyon, which represents the main export route. Particulate matter samples were analyzed to obtain mass fluxes and contents in organic carbon, Al, Cr, Co, Ni, Cu, Zn, Cd, Pb and La, Nd and Sm. The natural or anthropogenic origin of trace metals was assessed using enrichment factors (EFs). Results are that Zn, Cu and Pb appeared to be of anthropogenic origin, whereas Ni, Co and Cr appeared to be strictly natural. The anthropogenic contribution of all elements (except Cd) was refined by acid-leaching (HCl 1 N) techniques, confirming that Zn, Cu and Pb are the elements that are the most enriched. However, although those elements are highly labile (59–77 %), they do not reflect severe enrichment (EFs <4). Most particles originate from the Rhone River. This has been confirmed by two different tracing procedures using rare earth elements ratios and concentrations of acid-leaching residual trace metals. Our results hence indicate that even in this western extremity of the GoL, storm events mainly export Rhone-derived particles via the Cap de Creus submarine canyons to the deep-sea environments. This export of material is significant as it represents about a third of the annual PTM input from the Rhone River. 相似文献
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BACKGROUND: NO production (NOex) in the airway epithelium is increased in asthmatic patients and is potently inhibited by anti-inflammatory treatments. The study was designed to compare the: (i) levels of NOex in two groups of asthmatic children residing in different environments (one in a national park in the mountains and the other in a large city) and (ii) the influence of glucocorticoids on levels of NOex between the children and those without treatment. METHODS: The measurements were performed during the same period in the two locations, 100 km apart. NOex was measured using a chemiluminescence analyzer in controls and two comparable groups of asthmatic children. The first group included 63 children (10+/-3 years) recruited from a specialized institution for asthmatic children, and the second group consisted of 46 asthmatic children (9+/-3 years) living in an urban area. A reference group of 17 healthy children residing in the same city was also studied. MEASUREMENTS AND RESULTS: The concentrations of NOex in children in the specialized institution were significantly lower (P<.001) than those in asthmatic children living in the city (5.1+/-2.4 vs. 13.8+/-9.3 ppb) and comparable to those in healthy controls (5.3+/-4.0 ppb). In the urban area, NOex levels increased when atmospheric pollution recorded on the previous day had increased. In contrast to that observed in the urban children, glucocorticoids had little influence on the levels of NOex in the children living in the specialized institution. CONCLUSIONS: Although these relationships need to be confirmed, our findings show that for the determination of NOex, specifying the quality of the environment, in particular, the purity of the air respired by asthmatic children, not only at the time of measurement but also over the previous days, is important. 相似文献
4.
Analysis of HO-PCBs and PCP in blood plasma from individuals with high PCB exposure living on the Chukotka Peninsula in the Russian Arctic 总被引:1,自引:0,他引:1
Sandanger TM Dumas P Berger U Burkow IC 《Journal of environmental monitoring : JEM》2004,6(9):758-765
A trace analytical method is presented for the analysis of hydroxylated polychlorinated biphenyl metabolites (HO-PCBs) and pentachlorophenol (PCP) in human plasma. The described methodology is a modification of a previously validated method used for PCB and organochlorine pesticide analysis. The modified method enables the combined analysis of phenolic and neutral halogenated compounds. A tandem Florisil column is used for separating the HO-PCBs and PCP from the neutral fraction, instead of the more common chemical partitioning. In the same step the neutral fraction is purified for GC analysis. The extraction of the HO-PCBs and PCP was found to be highly dependent on sufficient acidification of the sample and the polarity of the extracting solvent. Analysis of plasma samples gave recovery rates for (13)C(6)-PCP and (13)C(12)-4-HO-CB 187 of 64 and 72%, respectively. The limit of detection ranged between 2-20 pg g(-1) plasma for the HO-PCBs and 5 pg g(-1) plasma for PCP. No matrix interferences were observed in the chromatograms. In plasma samples (n = 15) from the native Chukchi people in Uelen (Russian Arctic), a population with high PCB exposure, the median ratio of sum HO-PCBs to sum PCBs was as high as 0.4 and the sum HO-PCBs and PCBs were significantly correlated (r(2) > 0.7, p < 0.01). The median sum HO-PCBs (10 congeners) was 5920 pg g(-1) plasma with 4-HO-CB 107 as the dominating congener (median: 1670 pg g(-1) plasma). The median PCP level was measured at 642 pg g(-1) plasma. 相似文献
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Edouard Kauffmann Horatiu Roman Georges Barau Hervé Dumas Annick Laffitte Alain Fourmaintraux Marc Bintner Hanitra Randrianaivo 《黑龙江环境通报》2003,23(2):163-165
The Jarcho–Levin syndrome is a specific form of spondylocostal/spondylothoracic dysostosis. There have been various classifications of this syndrome. We present the case of a severe prenatal Jarcho–Levin syndrome, diagnosed by ultrasound examination during the first trimester of pregnancy in a family with no previous medical history of an affected child. X-ray exploration, high-resolution spiral computed tomography and autopsy confirmed the diagnosis. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
7.
Kenneth W. Harrison Robert D. Dumas Subba R. Nishtala 《Journal of the Air & Waste Management Association (1995)》2013,63(6):993-1003
ABSTRACT Evaluation of alternate strategies for municipal solid waste (MSW) management requires models to calculate environmental emissions as a function of both waste quantity and composition. A methodology to calculate waste component-specific emissions associated with MSW combustion is presented here. The methodology considers emissions at a combustion facility as well as those avoided at an electrical energy facility because of energy recovered from waste combustion. Emission factors, in units of kg pollutant per metric ton MSW entering the combustion facility, are calculated for CO2-biomass, CO2-fossil, SOx , HCl, NOx , dioxins/furans, PM, CO, and 11 metals. Water emissions associated with electrical energy offsets are also considered. Reductions in environmental emissions for a 500-metric-ton-per-day combustion facility that recovers energy are calculated. 相似文献
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Philippe Ambrosi Jean-Charles Hourcade Stéphane Hallegatte Franck Lecocq Patrice Dumas Minh Ha Duong 《Environmental Modeling and Assessment》2003,8(3):133-147
This paper examines the consequences of various attitudes towards climate damages through a family of stochastic optimal control models (RESPONSE): cost-efficiency for a given temperature ceiling; cost-benefit analysis with a pure preference for current climate regime and full cost-benefit analysis. The choice of a given proxy of climate change risks is actually more than a technical option. It is essentially motivated by the degree of distrust regarding the legitimacy of an assessment of climate damages and the possibility of providing in due time reliable and non controversial estimates. Our results demonstrate that (a) for early decades abatement, the difference between various decision-making frameworks appears to matter less than the difference between stochastic and non stochastic approach given the cascade of uncertainty from emissions to damages; (b) in a stochastic approach, the possibility of non-catastrophic singularities in the damage function is sufficient to significantly increase earlier optimal abatements; (c) a window of opportunity for action exists up to 2040: abatements further delayed may induce significant regret in case of bad news about climate response or singularities in damages. 相似文献
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Harrison KW Dumas RD Barlaz MA Nishtala SR 《Journal of the Air & Waste Management Association (1995)》2000,50(6):993-1003
Evaluation of alternate strategies for municipal solid waste (MSW) management requires models to calculate environmental emissions as a function of both waste quantity and composition. A methodology to calculate waste component-specific emissions associated with MSW combustion is presented here. The methodology considers emissions at a combustion facility as well as those avoided at an electrical energy facility because of energy recovered from waste combustion. Emission factors, in units of kg pollutant per metric ton MSW entering the combustion facility, are calculated for CO2-biomass, CO2-fossil, SOx, HCl, NOx, dioxins/furans, PM, CO, and 11 metals. Water emissions associated with electrical energy offsets are also considered. Reductions in environmental emissions for a 500-metric-ton-per-day combustion facility that recovers energy are calculated. 相似文献