Modelling the influence of environmental and weather factors on the density of the invasive polychaete Boccardia proboscidea

The inter‐tidal zone around sewage discharges in a Southwest Atlantic shore (Mar del Plata, Argentina) is currently colonized by extensive inter‐tidal reefs of the invasive spionid Boccardia proboscidea. Understanding the links between both human and natural disturbances and the massive development of non‐indigenous species will help prevent marine bioinvasions, which are already favoured by global oceanic trade. We present herein predictive models for variations in the density of B. proboscidea around sewage discharges of Mar del Plata, using environmental (pH, turbidity, temperature, salinity and total organic matter content), weather (wind direction and storm records), spatial (sites) and temporal (season and year) variables. Density variations were modelled by generalized linear models, and model averaging (multimodel inference) was used to obtain predicted values. The highest predicted values of B. proboscidea density occurred at sites to the south of the sewage effluent in spring. These sites are more affected by urban effluent discharges and they showed increased B. proboscidea density when the north wind was predominant. In addition, B. proboscidea density values were higher in sites with 20–22 °C (seawater temperature), high total organic matter content in sediments and low salinity. The averaged model was only a good ‘predictive model’ for sites to the north of the outfall, but was useful as an ‘explanatory model’ in all sites. Such predictions may help to back up conservation and management policies and decisions.     

Immigration,mobility, and environmental injustice: A comparative study of Hispanic people’s residential decision-making and exposure to hazardous air pollutants in Greater Houston,Texas

The themes of immigration and mobility have not been adequately examined by environmental justice (EJ) scholars. This study addresses that gap by clarifying factors shaping Hispanic people’s residential decision-making and their associated exposures to cancer risks from Hazardous Air Pollutants (HAPs) in Greater Houston, Texas. In-depth semi-structured interviews were conducted with 29 Hispanic householders who had previously completed a structured survey, which was representative of Greater Houston’s population. Our research design enabled data collection from immigrant and United States (US)-born Hispanics living at high and low risk to HAPs. By using a comparative qualitative analysis approach to examine divergent experiences of Hispanic subgroups, we advance from the monolithic treatment of the US Hispanic population reflected in the extant EJ literature. Our findings reveal that key determinants of high HAP risks included economic constraint on residential locational options for both US-born and immigrant Hispanics, and attraction to sociocultural benefits in co-ethnic enclaves among immigrants in particular. In contrast, protective factors differed entirely between US-born and immigrant Hispanics. For US-born participants, the experience of upward-and-outward sociospatial mobility – coupled with detachment from the Hispanic community – generated lower HAP risks, while the experience of living in social isolation within a less-than-ideal rental unit was protective for immigrants. The pernicious, multiscalar nature of environmental injustice experienced by Greater Houston’s Hispanic immigrants is encapsulated by the fact that their pursuit of affordable and comfortable residential settings at the household level contributes to the reproduction of their collectively disproportionate HAP exposures.     

How does carbon dioxide emission change with the economic development? Statistical experiences from 132 countries

Issues concerning what measures should be adopted to achieve a sustainable world with less carbon dioxide emission and in what magnitude should we reduce our emission have been on agenda in both international negotiations and countries’ policy making aimed at coping with potential global climate change. These issues cannot be easily addressed unless comprehensive understanding about the countries’ status quo as well as historical relationship between economic development and carbon dioxide emission are gained. In this paper, we examine the historical relationship between economic development and carbon dioxide emission; the ex ante restrictions on function forms and the poorly handled robustness issues rife in economics literature are synthetically addressed. Evidence from recent four decades indicates that per capita carbon dioxide emission first significantly and monotonously increase at low income level and flattens after per capita income reaches at about 22,000 $ (2005 constant price). We perform various robustness checks by employing different data sources, different model specifications and different econometric estimates. The captured development–emission relationship is robust. Our empirical results indicate factors such as urbanization, population density, trade, energy mix and economic environment impact the absolute level of carbon dioxide emission not the overall income elasticity structure of carbon dioxide emission.     

Implication of environmental flows in river basin management

Consideration of environmental flows in river basin management poses great challenges. Environmental flows are interpreted as the natural or regulated releases of water needed in a river to maintain specified valued features of the river ecosystems. This has never been considered explicitly in water resources management of a river basin. An attempt is, therefore, made here to reflect the perception and implications of environmental flows in water resources management. Assessment approaches are reviewed in the context of flow characteristics of a river system and recommendations are put forward on what is to be done to adopt this new concept in practice.     

New Strategy to Reduce the Harmful Effects of Smoking: Reducing the Level of N‐nitrosamines in Mainstream Smoke by NaA Zeolite and In vitro and In vivo Investigations

A new effort to control the pollution caused by smoking by use of zeolite sieving the N‐nitrosamines in smoke is depicted and assessed in this paper, which is a first preliminary approach to demonstrate the performance characteristics of zeolite for the reduction of the concentration of N‐nitrosamines in the cigarette smoke. Smoking causes global pollution and is difficult to control because smoke is a complex system containing thousands of components. A new strategy is presented here for the reduction of the harmful effects of smoking through dispersion of zeolite into the tobacco rod of cigarettes to eliminate the N‐nitrosamines once they form in the smoke, and both in vitro and in vivo tests were employed to check the efficiency of this strategy. The impact of zeolite on the combustion of tobacco and the total toxicity of smoke are evaluated for the first time. Lower mutagenic activity and higher CHO cell livability were found for the test cigarette containing zeolite in comparison with the control, and no significant damage was detected in 30‐day animal experiments when exposed to the cigarette smoke. This confirms the feasibility of the new strategy and promotes the potential application of zeolite for protecting public health.     

大亚湾澳头海域硅藻、甲藻的数量变动及其与环境因子的关系

于1997年7月-1998年6月采集大亚湾澳头海域水样,根据《海洋监测规范》分析调查方法,研究了硅藻和甲藻的数量变动及其与环境因子之间的关系,共鉴定出浮游植物198种,其中硅藻98种,甲藻83种。结果表明,大亚湾浮游植物细胞密度较高,年平均细胞密度为424．7cells／ml,最高细胞密度为6689．8cells／ml,硅藻为浮游植物的主要类群。调查期间共发生藻类水华7次,硅藻可在全年各季节发生水华,而甲藻水华仅在春季发生。硅藻水华的消退与N的大量消耗有关,而甲藻水华对P消耗较大。结果表明,大亚湾合适的温度、盐度、气象条件、丰富的硅酸盐含量及N、P等营养盐的及时补充是大亚湾浮游植物数量高和水华频繁发生的主要原因,同时风、流等物理因素对藻类的聚积作用对水华的发生也有一定的促进作用。     

辽东湾鲅鱼圈赤潮与环境因子分析

赤潮的发生是一个复杂的生态变化过程,赤潮藻的快速增殖不仅需要丰富的营养物质基础,适宜的物理环境条件亦是不可或缺的,是诸如水文、气象、物理、化学和生物因子综合作用的结果。辽东湾为我国北方海域赤潮最频繁海域。本文就1998年～2003年5月间发生在辽东湾的赤潮过程,从天气形势、水文气象环境动力因子的角度对赤潮的暴发进行分析研究与统计,得出了赤潮暴发的相似天气形势及水文气象环境动力因子的变化规律,试图探索其预报的可能性。并就2001年北海分局在鲅鱼圈监测到的赤潮水文、气象、物理、化学等环境因子数据,运用正交分析、聚类分析多元统计分析方法,分析了赤潮发生过程中环境因子的变化规律,试图寻找影响赤潮的主导因子与重要因子。     

战略环境评价指标体系框架构建研究

从SEA指标体系研究的意义出发,以SEA的目标——环境可持续发展为基础,通过分析SEA指标体系,将其功能确定为准确反映战略实施后环境-人口-资源系统的外在状态、内部协调程度和变化趋势,并建立了SEA指标体系的框架,将SEA指标体系确定为基于驱使力-状态-响应模型(DSR)的层次性指标体系,依据指标作用的不同,将SEA指标分为核心指标和外围指标,并以建立科学、实用和可操作的指标体系为目标对SEA指标的选取原则进行了探讨。     

圆弧破坏边坡反演设计的ANN方法与ANFIS方法的比较研究

圆弧破坏边坡反演设计方法,是根据边坡的岩土力学参数及边坡高度,在确保安全系数满足要求的前提下,对圆弧破坏边坡的边坡角进行设计的一种新方法。建立圆弧破坏边坡反演设计方法的关键,就是要对大量稳定圆弧破坏边坡实例加以集成,以建立从{ , c, , H, F}到 的映射。文中收集了大量稳定圆弧破坏边坡实例,采用ANN和ANFIS对其进行了集成,分别建立了圆弧破坏边坡反演设计的ANN方法和ANFIS方法,进而又采用圆弧破坏边坡实例对两者的反演结果进行了比较。结果表明,ANFIS更适合于用来建立圆弧破坏边坡反演设计方法。     

Mineralogy and speciation of Zn and As in Fe-oxide-clay aggregates in the mining waste at the MVT Zn–Pb deposits near Olkusz,Poland

Oxidation zones of ore deposits offer valuable insights into the long-term fate of many metals and metalloids. In this work, we have studied a paleo-acid rock drainage (ARD) system – the oxidation zone of Mississippi-valley type Zn–Pb deposits near Olkusz in southern Poland. The ARD systems exhausted their acid-generating capacity and have come almost to the conclusion of the mineral and geochemical transformations. Primary pyrite, marcasite, galena and sphalerite have been decomposed but the acidity was neutralized by the abundant carbonate host rocks. Zinc is stored in smithsonite, hemimorphite, and Zn-rich sheet aluminosilicates. Some of these minerals formed simultaneously with the oxidation zone but some precipitated in the soils in situ, thus documenting the mobility of Zn, Al, and Si in the soils. Iron oxides are represented mostly by goethite, either well-crystalline or nanocrystalline, as determined by a combination of powder X-ray diffraction, micro-X-ray diffraction, and Mössbauer spectroscopy. Iron oxides bind a substantial amount of arsenic, to a lesser extent also zinc, lead, and cadmium, as shown by electron microprobe analyses and sequential extractions. The X-ray absorption spectroscopy data of the local environment of arsenic in goethite suggest the existence of bidentate mononuclear complex, in addition to the more common bidentate binuclear complex. These results suggest that arsenic is incorporated in the crystal structure of goethite, in addition to adsorbed to the surface of the particles or occluded in the voids and pores. Zinc is bound in goethite as a mixture of tetrahedrally and octahedrally coordinated cations. This study shows that the mature system binds the metals from the primary sulfides relatively strongly. Yet, some release of the metals was observed in this study, either in the laboratory (by sequential extractions) and in nature (e.g., neoformed Zn phyllosilicates). The physical conditions in the oxidation zone and on the surface are largely similar but the metals, to a certain extent, are still mobile in the soils. We may speculate that their mobility near the surface, in the mining waste, may be enhanced by a higher water/rock ratio than in the oxidation zone. This result implies that although the studied material is relatively benign, it still has a potential to cause local environmental problems.