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In the present study, the risk to humans by consuming European sea bass (Dicentrarchus labrax), captured at three sites along a Hg contamination gradient, was evaluated by comparing muscle and kidney total Hg (T-Hg) levels with the European regulations for marketed fish. Moreover, T-Hg and organic Hg (O-Hg) levels in muscle were compared with the Provisional Tolerable Weekly Intake (PTWI) and the Reference Dose (RfD). Although T-Hg levels in muscle were below the European value allowable for marketed fish, kidney’s levels were higher than the set value, stressing the importance of redefining the concept of edible tissue and which tissues should be considered. Mercury weekly ingestion in the contaminated areas was higher than the PTWI, and O-Hg daily ingestion rates were higher than the RfD in all sampling sites. Thus, populations consuming sea bass from the contaminated sites may be at risk, with particular relevance for children and pregnant women.  相似文献   
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利用微波辐射计、探空气球、天气雷达和地面雨量等资料,对2020年1-3月长沙国家站5次降水过程的微波辐射计和探空温度廓线、水汽密度进行检验的基础上,分析了 5次降水过程中微波辐射计反演的水汽含量、液态水含量与雷达资料、降水量的变化特征.结果表明,微波辐射计反演的大气温度、水汽密度廓线精度较高,其反演的大气水汽资料可以作...  相似文献   
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Environmental pollution in the Gulf of Guinea (GOG) coastal zone has caused eutrophication and oxygen depletion in the lagoon systems, particularly around the urban centres, resulting in decreased fish (reproduction) levels and waterborne diseases. A pollution sources assessment was undertaken by six countries in the region as a first step in defining a region-wide Environmental Management Plan. Results show that households produce 90% of solid waste. Industry, however, is responsible for substantial amounts of hazardous waste, specifically the Nigerian petroleum industry. The latter is also responsible for the spilling of large amounts of oil. BOD load from industrial effluents is slightly larger than domestic loads in the industrialised coastal zone. Wastewater treatment systems are either absent or inadequate. Apart from large-scale gas flaring in Nigeria, air pollution, in terms of COx, HC, NOx and SO2 emissions, is contributed mainly by traffic. Particulates, originate mainly from industries and domestic biomass burning.  相似文献   
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本文的对比结果是通过电子经伟仪和光学经伟仪及电磁波测距仪测定而得来的。以及在设计和在非常简单的水平控制测量中立标桩,都必须应用导线网的基本测量知识。  相似文献   
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Naphthalene (NAP) and phenanthrene (PHE) effects on Salminus brasiliensis, a carnivorous freshwater fish, were investigated using behavioral tests. Larval stages of S. brasiliensis were exposed to water concentrations of 0, 0.04 mg/l, 0.20mg/l and 0.50mg/l for naphthalene and 0, 0.01 mg/l, 0.05 mg/l and 0.1mg/l for phenanthrene during two developmental phases. The prey fish Prochilodus lineatus were not exposed. Visual acuity was measured at the end of phase 2 in individual S. brasiliensis, which were also tested at the end of each phase for number of attacks on prey, number of prey captured, prey capture efficiency, and distance swam. Vision was impaired by PHE exposure, as acuity angles increased in exposed fish. At Stage I 2.3+/-1.2 prey were captured with 46% efficiency in controls compared to 0.4+/-0.3 prey captured with 13.4% efficiency in fish exposed to 0.05 mg PHEl(-1), the LOEL for both endpoints. At Stage II 4.0+/-1.1 preys were captured in controls compared to 2.5+/-0.9 preys captured in fish exposed to 0.01 mg PHEl(-1), the LOEL. Stage II control fish captured prey with 70% efficiency compared to 30% efficiency at Stage II fish exposed to 0.05 mg PHEl(-1), the LOEL. Distance swam was not affected by either NAP or PHE exposure. The exposure of larval stages of S. brasiliensis to realistic water concentrations of PHE impairs foraging skills and could affect recruitment of the species.  相似文献   
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Petroleum pollution is a problem for seabirds along the Southwest Atlantic coast. Twenty-five groups from Salvador, Brazil (12 degrees 58'S) to San Antonio Oeste, Argentina (40 degrees 43'S) survey or rehabilitate sick or oiled seabirds. Four groups, one each in Brazil and Uruguay, and two in Argentina, kept counts of birds found alive and in need of rehabilitation. An average of 63.7% of the seabirds found were Magellanic penguins (Spheniscus magellanicus), with 3869 reported since 1987. Mainly adult penguins were found in Argentina (1605 of 2102 penguins of known age class) and Uruguay (158 of 197). Juveniles were most common in Brazil (234 of 325). Oil fouling was the most frequent cause of injury or sickness. The number of oiled penguins reported in their wintering range has greatly increased since the early 1990s and is strongly correlated with petroleum exports from Argentina. Our results show that chronic petroleum pollution is a problem for wildlife from Southern Brazil through Northern Argentina, and regulations and enforcement are failing to protect living resources.  相似文献   
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