Long-term dynamics of radioactive <Superscript>90</Superscript>Sr and <Superscript>137</Superscript>Cs contamination of small mammals in the Chernobyl zone

Between 1986 and 1994, a decrease in nonalimentary ⁹⁰Sr and ¹³⁷Cs intake and changes in the accessibility of radionuclides in the soil-plant link of their cycle resulted in a 10-to 100-fold decrease in their specific activity (SA) in the bodies of small mammals inhabiting the Chernobyl zone, and a similar decrease was observed in the radionuclide transition factor (TF) in the soil-animal chain. Between 1995 and 2005, no consistent increase or decrease in SA or TF could be revealed against the background of a combined effect of different physicochemical and ecological factors. It is suggested that subsequent changes in the level of radioactive contamination of small mammals will generally reflect only the dynamics of physical ⁹⁰Sr and ¹³⁷Cs decay, but, nevertheless, seasonal and local variations in this level will be significant.     

Effects of Watershed Impervious Cover on Dissolved Silica Loading in Storm Flow1

Abstract: Dissolved silica (DSi) availability is a factor that affects the composition of algal populations in aquatic ecosystems. DSi cycling is tightly linked to the hydrological cycle, which is affected by human alterations of the landscape. Development activities that increase impervious cover change watershed hydrology and may increase the discharge of DSi‐poor rainwater and decrease the discharge of DSi‐rich ground water into aquatic ecosystems, possibly shifting algal community composition toward less desirable assemblages. In this study, DSi loadings from two adjacent coastal watersheds with different percent impervious cover were compared during four rain and five nonrain events. Loadings in the more impervious watershed contained a significantly larger proportion of surface runoff than base flow (ground‐water discharge) and had lower [DSi] water during rain events than the less impervious watershed. Application of the Soil Conservation Service Curve Number (CN) method showed that the minimum rainfall height necessary to yield runoff was significantly lower for the more impervious watershed, implying that runoff volumes increase with impervious cover as well as the frequency of runoff‐yielding events. Empirical data collected during this study and estimates derived from the CN method suggest that impervious cover may be responsible for both short‐term DSi limitation during rain events as well as long‐term reduction of DSi inputs into aquatic ecosystems.     

Characteristics of worker accidents on NYSDOT construction projects

INTRODUCTION: This paper aims at providing cost-effective safety measures to protect construction workers in highway work zones, based on real data. Two types of accidents that occur in work zones were: (a) construction work area accidents, and (b) traffic accidents involving construction worker(s). METHODOLOGY/RESULTS: A detailed analysis of work zone accidents involving 36 fatalities and 3,055 severe injuries to construction workers on New York State Department of Transportation (NYSDOT) construction projects from 1990 to 2001 established that five accident types: (a) Struck/Pinned by Large Equipment, (b) Trip or Fall (elevated), (c) Contact w/Electrical or Gas Utility, (d) Struck-by Moving/Falling Load, and (e) Crane/Lift Device Failure accounted for nearly 96% of the fatal accidents, nearly 63% of the hospital-level injury accidents, and nearly 91% of the total costs. These construction work area accidents had a total cost of $133.8 million. Traffic accidents that involve contractors' employees were also examined. Statistical analyses of the traffic accidents established that five traffic accident types: (a) Work Space Intrusion, (b) Worker Struck-by Vehicle Inside Work Space, (c) Flagger Struck-by Vehicle, (d) Worker Struck-by Vehicle Entering/Exiting Work Space, and (e) Construction Equipment Struck-by Vehicle Inside Work Space accounted for nearly 86% of the fatal, nearly 70% of the hospital-level injury and minor injury traffic accidents, and $45.4 million (79.4%) of the total traffic accident costs. CONCLUSIONS: The results of this paper provide real statistics on construction worker related accidents reported on construction work zones. Potential preventions based on real statistics have also been suggested. IMPACT ON INDUSTRY: The ranking of accident types, both within the work area as well as in traffic, will guide the heavy highway contractor and owner agencies in identifying the most cost effective safety preventions.     

海岸带城市环境-经济系统的协调发展评价及应用--以天津市为例

在海岸带城市的环境一经济系统分析的基础上,建立了适用于海岸带城市的环境一经济协调发展评价指标体系。并以天津市为例。采用综合指数法对其协调度和综合发展水平进行了计算。结果表明。天津市环境与经济发展关系相对趋于协调。但1995年后天津市的环境经济协调发展模式已从经济增长滞后型发展为环境质量滞后型。利用灰色系统GM(1,1)模型对天津市未来15年的经济协调度和发展水平进行预测,发现天津市环境与经济发展协调度在未来将显现下降趋势,从2000年的0．95下降到2015年的0．59。城市综合发展水平在2005年之后也开始呈下降趋势。     

安全煤岩柱性能研究及综合评价

在对里彦煤矿采矿地质条件分析的基础上,对安全煤岩柱的化学成分及其阻水性能、岩性及力学特征进行了研究.针对里彦煤矿的具体情况,分析了里彦安全煤岩柱的阻水性能,认为其阻水性能良好,可以适当减小防水防砂煤岩柱宽度,以提高开采上限,释放部分煤炭储量.     

论楔块运动与地震带的关系

目前，地震和地震带的成因问题仍然是世界性的科学难题。本研究认为圈闭隐爆作用能形成正楔块、倒楔块；负荷均衡作用能引起楔块运动；楔块运动形成了断陷盆地，也就是说，地堑、地垒是楔块运动的产物；最终，试图通过对楔块运动模式的研究揭示地壳凹陷与地震带的成因问题。     

Conservation and management of the Bangladesh coastal ecosystem: Overview of an integrated approach

Although the coastal ecosystem of Bangladesh contains a highly functional and structurally diverse ecology, this ecology is gradually being degraded. As a consequence, the quality of life of a large section of the coastal community is in economic decline. This poses a daunting challenge to the sectoral coastal management programmes, active since the 1960s, aiming at simultaneously ameliorating people's livelihood and supporting the ecosystem. These programmes have been reasonably successful in managing the ecosystem, but in many cases, the situation has become worse. The limitations of these programmes include the tendency to adopt an exclusionist approach, a narrowly departmentalized administration and weak management. Currently, the integrated coastal zone management (ICZM) approach is espoused as the main strategy. With the adoption of Bangladesh's Coastal Zone Policy of 2005, the foundation for integrated management was laid. The next realistic target will be to bring about changes in culture and mandate among coastal institutions in favour of integrated management.     

HOW RIPARIAN ECOSYSTEMS ARE PROTECTED AT LAKE TAHOE1

Riparian ecosystems are designated for special protection from development and disturbance at Lake Tahoe. The Tahoe Regional Planning Agency (TRPA) required protection of Stream Environment Zones (SEZs) in its Regional Plan for the Lake Tahoe Basin in 1987. These zones are identified by the presence of key indicators such as the evidence of surface water flow, riparian vegetation, near‐surface ground water, designated floodplain, and alluvial soils. They are mapped on each potential building site and assigned a setback that is also off limits to building construction. The SEZs are protected to maintain their functions and values, including flood attenuation, water quality enhancement, and wildlife habitat. Strict regulations control use or disturbance of SEZs on public and private property throughout the watershed. The TRPA has set restoration targets to increase the acreage of naturally functioning SEZs in the Tahoe Basin. Many SEZ restoration projects have been designed and implemented, but SEZ restoration targets have not been met. More SEZ restoration projects are being designed and funded each year. Restoration designers would benefit from increased effectiveness monitoring of completed projects and Web‐based dissemination of monitoring results.     

SEWAGE DISCHARGES FROM SHIPS TRANSITING COASTAL SALT WATERS1

ABSTRACT: A number of aspects of the discharging of non-oily wastewaters by transiting ships are treated in this overview paper. In the introduction, options to discharging (the use of holding tank, on board treatment) and the impact of changing regulations are discussed. Assessment of the effects of sewage discharges on coastal waters required that data, at first not available, be generated. An account is given of the characterization of Navy shipboard wastewaters and of experiments involving sewage discharges at sea, measurements of water quality before, during and after an amphibious operation, and fore and aft of transitting Navy ships. A better understanding of sewage dilution after discharge led to the verification of a method for controlled discharging of sewage (and other wastewaters). This method permits limiting the coliform bacteria count in the ship's wake to values below acceptable limits. The final sections contain information on long range effects of ships’sewage discharges, obtained in studies by the U.S. Navy and others, as well as public health considerations.