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351.
兰州市西固区蔬菜重金属污染现状及健康风险评价研究 总被引:1,自引:0,他引:1
针对西北地区典型的工业区-兰州市西固工业区内种植的蔬菜进行重金属含量状况调查分析,对购自当地市场的8种蔬菜中Cu、Cd、Pb、Zn 4种重金属元素的含量进行分析,通过污染指数法和经蔬菜途径重金属暴露接触对人体的健康风险进行了系统评价.结果表明,蔬菜中均不含有Pb元素或Pb元素在蔬菜中的含量比较少,低于分析方法检测限;Cu元素含量最高的是茄子为0.067 mg/kg,含量最低的是菜花为0.015 mg/kg;Cd元素含量最高的是芹菜为0.067 mg/kg,含量最低的是白菜为0.023 mg/kg;Zn元素含量最高的是菠菜为1.001 mg/kg,含量最低的是辣椒为0.274 mg/kg.美国环境健康风险评估方法评价所得THQ值均小于1,表明实验所采集的大多数蔬菜样品的重金属含量符合农产品安全质量要求. 相似文献
352.
An evaluation of the link between climate and population dynamics requires understanding of climate effects both within and across generations. In ectothermic vertebrates, demographic responses to climate changes should crucially depend on balancing needs for heat and water. Here, we studied how temperature and rainfall regimes experienced before and during adulthood influenced reproductive performances (litter size, offspring size, and survival) in a natural population of the live-bearing common lizard, Lacerta vivipara, monitored continuously from 1989 to 2004. Rainfall regime, but not temperature, had both immediate and delayed effects on these reproductive performances. Rainfall during the first month of life was positively correlated with juvenile survival. Females experiencing more rainfall during gestation produced smaller neonates that showed greater survival when controlling for the positive effect of body size on survival. Furthermore, females that experienced heavier rainfall when in utero produced fewer but longer neonates during adulthood. These demographic effects of rainfall on adult reproductive traits may come from maternal effects of climate conditions and/or from delayed effects of rainfall on the environment experienced early in life. Irrespective of the precise mechanism, however, this study provides evidence of intergenerational climate effects in natural populations of an ectothermic vertebrate. 相似文献
353.
Li Yafei Zhou Can Wang Shizhong Lin Qingqi Ni Zhuobiao Qiu Hao Morel Jean Louis Qiu Rongliang 《Environmental science and pollution research international》2019,26(25):25985-25999
Environmental Science and Pollution Research - The large-scale use of quaternary ammonium compounds (QACs) in medicines or disinfectants can lead to their release into the environment, posing a... 相似文献
354.
Jean Pierre Temga Jean Pierre Nguetnkam Daniela Palazzini Robert Ndjouenkeu Francesco Vitali 《International Journal of Sustainable Engineering》2014,7(3):222-234
Deforestation is one of the most dramatic threats to environmental equilibrium and food safety in many regions of the world, and particularly in sub-Saharan Africa. It is enhanced by many kinds of human activities, among which is the earth brick-firing process that needs large amounts of wood for attaining and maintaining temperatures required during this process. In order to reduce deforestation, the present study investigated from different points of view the potential of crude earth to be used as building material, taking as a case study the Logone Valley located at the border between Chad and Cameroon. First, an on-site investigation was made to verify the state-of-the-art of brick production technologies and to evaluate their impact on the environment. Subsequently, morphological and geotechnical analyses on soil samples collected from different sites of the Logone Valley were carried out, to evaluate their suitability to brick production. Finally, a pilot plant for crude earthen brick production was set, particularly based on a new press designed for this purpose. 相似文献
355.
Marie Revel Christophe Colin Stefano Bernasconi Nathalie Combourieu-Nebout Emmanuelle Ducassou Francis E. Grousset Yann Rolland Sebastien Migeon Delphine Bosch Pierre Brunet Yulong Zhao Jean Mascle 《Regional Environmental Change》2014,14(5):1685-1696
The Nile delta sedimentation constitutes a continuous high-resolution record of Ethiopian African monsoon (EAM) regime intensity. Multi-proxy analyses performed on hemipelagic sediments deposited on the Nile deep-sea fan allow the quantification of the Saharan aeolian dust and the Blue/White Nile River suspended matter frequency fluctuations during the last 21,000 years. The radiogenic strontium and neodymium isotopes, clay mineralogy, elemental composition and preliminary palynological analyses reveal large changes in source components, oscillating between a dominant aeolian Saharan contribution during the Last Glacial Maximum (LGM) and the late Holocene (~4,000–2,000 years), a dominant Blue/Atbara Nile River contribution during the early Holocene (15,000–8,000 years) and a probable White Nile River contribution during the middle Holocene (8,000–4,000 years). The following main features are highlighted: (1) The rapid shift from the LGM arid conditions to the African Humid Period (AHP) started at about 15,000 years. The AHP extends until 8,000 years, and we suggest that the EAM maximum between 15,000 and 8,000 years is responsible for a larger Blue/Atbara Nile sediment load and freshwater input into the eastern Mediterranean Sea. (2) The transition between the AHP and the arid late Holocene is gradual and occurs in two main phases between 8,400–6,500 years and 6,500–3,200 years. We suggest that the main rain belt shifted southward from 8,000 to ~4,000 years and was responsible for progressively reduced sediment load and freshwater input into the eastern Mediterranean Sea. (3) The aridification along the Nile catchments occurred from ~4,000 to 2,000 years. This dry period, which culminates at 3,200 year, seems to coincide with a re-establishment of increased oceanic primary productivity in the western Mediterranean Sea. Such a pattern imposes a large and rapid northward shift of the rain belt over the Ethiopian highlands (5–15°N) since 15,000 years. Precipitation over Ethiopia increased from 15,000 to 8,000 years. It was followed by a gradual southward shift of the rain belt over the equator from 8,000 to 4,000 years and finally a large shift of the rain belt south the equator between 4,000 and 2,000 years inducing North African aridification. We postulate that the decrease in thermohaline water Mediterranean circulation could be part of a response to huge volumes of freshwater delivered principally by the Nile River from 15,000 to 8,000 years in the eastern Mediterranean. 相似文献
356.
Michelle Peppina Covi Donna Jean Kain 《Environmental Communication: A Journal of Nature and Culture》2016,10(5):612-633
We present the results of a study using a document-based evaluation method to better understand how residents in vulnerable coastal areas respond to risk communications about sea-level rise (SLR) and to determine whether communications localized for specific populations improve reception. Similar to climate change communication, SLR risk communication presents challenges involving complex science, uncertainty, invisibility, and politicization. To be comprehensible and persuasive, risk messages must be appropriately framed and visually compelling and must take into account risk perceptions and diverse viewpoints. Our approach involves assessing people's encounters with actual risk messages to determine their reactions and responses. Participants in this study had difficulty understanding information and expressed attitudes including fear, fatalism, skepticism, and loss. SLR risks were also perceived as both temporally and spatially distant, creating a challenge for communicators trying to convey a sense of urgency. We conclude by considering the implications of audience-focused research for SLR risk communication. 相似文献
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359.
Expert Perceptions of Approaches to Protecting Isolated Wetlands in the Northeastern United States 下载免费PDF全文
Kristin Floress Mary Beth Kolozsvary Jean Mangun 《Journal of the American Water Resources Association》2017,53(5):1048-1061
In this article, we describe how protecting vernal pools was discussed by experts in the northeastern United States (U.S) within the context of a theoretical policy framework. We offer insight about characteristics of feasible vernal pool policy solutions, and identify gaps in our understanding, particularly regarding conditions in states currently lacking specific vernal pool protections. Vernal pools are geographically isolated, intermittent wetlands that provide important habitat for a variety of plants and animals. Many may not be federally protected as a result of judicial decisions over the past two decades, and the rule intended to clarify what qualifies for federal protection is currently being reviewed by the courts. Thus, state or local policy approaches may be alternatives to conserving vernal pools. We interviewed vernal pool experts in the northeastern U.S. regarding approaches to vernal pool protection and analyzed their perceptions through the lens of Kingdon's ( 2011 ) multiple streams policy development framework. The framework denotes 13 characteristics of three processes associated with policy development: problem identification, policy solution development, and the impacts of politics. While analyzed for all 13 components, we found participants most often discussed feasibility of policy formulation and implementation, particularly with regard to protecting vernal pools of high value while also remaining within the bounds of what public opinion supports. 相似文献
360.
Adama Ndao Balasubramanian Sellamuthu Jean R. Gnepe Rajeshwar D. Tyagi Jose R. Valero 《Journal of environmental science and health. Part. B》2017,52(9):623-630
Pilot-scale Bacillus thuringiensis based biopesticide production (2000 L bioreactor) was conducted using starch industry wastewater (SIW) as a raw material using optimized operational parameters obtained in 15 L and 150 L fermenters. In pilot scale fermentation process the oxygen transfer rate is a major limiting factor for high product yield. Thus, the volumetric mass transfer coefficient (KLa) remains a tool to determine the oxygen transfer capacity [oxygen utilization rate (OUR) and oxygen transfer rate (OTR)] to obtain better bacterial growth rate and entomotoxicity in new bioreactor process optimization and scale-up. This study results demonstrated that the oxygen transfer rate in 2000 L bioreactor was better than 15 L and 150 L fermenters. The better oxygen transfer in 2000 L bioreactor augmented the bacterial growth [total cell (TC) and viable spore count (SC)] and delta-endotoxin yield. Prepared a stable biopesticide formulation for field use and its entomotoxicity was also evaluated. This study result corroborates the feasibility of industrial scale operation of biopesticide production using starch industry wastewater as raw material. 相似文献