城市高压输变电工程电磁辐射污染危害及防治措施探讨

以乌鲁木齐市区高压输变电工程为研究对象,重点论述了城市高压输变电工程电磁辐射产生的机理、特征及危害,并通过实地监测,说明了城市高压输变电工程电磁辐射水平现状及发展趋势,以国家电磁辐射环境保护法律法规及技术标准为准则,从多方面提出了城市高压输变电工程电磁辐射的污染防治措施。     

Arsenic Background Concentrations in Florida,U.S.A. Surface Soils: Determination and Interpretation

Background concentrations of soil arsenic have been used as an alternative soil cleanup criterion in many states in the U.S. This research addresses issues related to the interpretation of background concentrations of arsenic in near pristine soils in Florida. Total arsenic was measured in 448 taxonomic and geographic representative surface soil samples using USEPA Method 3052 (HCl-HNO 3 -HF, microwave digestion) and graphite furnace atomic absorption spectrophotometry analysis procedure. Values were log-normally distributed, with geometric mean and baseline concentration (defined as 95% of the expected range of background concentrations) providing the most satisfactory statistical results. An upper baseline concentration of 6.21 mg As/kg was estimated for undisturbed soils (n=267) compared to 7.63 mg As/kg for disturbed soils (n=181). Temporal trend of total soil arsenic concentrations from 1967 to 1989 paralleled decreased usage of arsenic in U.S. agriculture. Soil arsenic background concentrations were generally higher in south Florida than in north and central Florida, and associated with wet soils. Individual high arsenic sites were scattered throughout the state, but the most highly concentrated of these occurred in the Leon-Lee belt along the Ocala uplift district extending to the southwestern flatwoods district. Extrapolation of the data using a single arsenic value regardless of the taxonomic and geographical differences in soil arsenic distribution would underestimate potential arsenic contamination in upland soils.     

Statistical Issues in Assessing Anthropogenic Background for Arsenic

Conceptual and statistical issues surrounding the estimation of a background concentration distribution for arsenic are reviewed. How background area is defined and samples collected are shown to impact the shape and location of the probability density function that in turn affects the estimation and precision of associated distributional parameters. The overall background concentration distribution is conceptualized as a mixture of a natural background distribution, an anthropogenic background distribution and a distribution designed to accommodate the potential for contamination site samples being included into the background sample set. This concept is extended to a discussion of issues surrounding estimation of natural and anthropogenic background distributions for larger geographic areas. Finally, the mixture model is formally defined and statistical approaches to estimating its parameters discussed.     

Physical and motor development in male and female rat offspring prenatally exposed to gamma radiation

Abstract

The effects of radiation on physical and motor development of male and female rats exposed to ionizing radiation in utero were studied. Rats were exposed to three different doses of radiation (150 rad, 15 rad and 6.8 rad, considered as high, moderate and low doses of radiation respectively) on the 20th day of prenatal life. Exposure to 150 rad contributed to significantly lower body weights of both male and female rat offspring. Upper jaw tooth eruption was delayed in 150 rad treated male offspring, as well as in 15 rad and 150 rad treated female offspring. Cliff‐avoidance response was delayed in 6.8 rad, 15 rad, and 150 rad treated male offspring; and 150 rad treated female offspring. Lower jaw tooth eruption, eye opening, and crawling were not affected by radiation in male or female animals. Results indicate that radiation affected the developmental parameters of both male and female rat offspring, and sex of the offspring played no role in the magnitude of radiation induced damages.     

Cell size dependence of additive versus synergetic effects of UV radiation and PAHs on oceanic phytoplankton

Polycyclic Aromatic Hydrocarbons’ (PAHs) toxicity is enhanced by the presence of ultraviolet radiation (UVR), which levels have arisen due to the thinning of the ozone layer. In this study, PAHs’ phototoxicity for natural marine phytoplankton was tested. Different concentrations of a mixture of 16 PAHs were added to natural phytoplankton communities from the Mediterranean Sea, Atlantic, Arctic and Southern Oceans and exposed to natural sunlight received in situ, including treatments where the UVR bands were removed. PAHs’ toxicity was observed for all the phytoplankton groups studied in all the waters and treatments tested, but only for the pico-sized group a synergetic effect of the mixture and UVR was observed (p = 0.009). When comparing phototoxicity in phytoplankton from oligotrophic and eutrophic waters, synergy was only observed at the oligotrophic communities (p = 0.02) where pico-sized phytoplankton dominated. The degree of sensitivity was related to the trophic degree, decreasing as Chlorophyll a concentration increased.     

电视台卫星地面站电磁辐射对城市其它微波站的干扰分析

通过理论分析计算 ,掌握电视台卫星地面站电磁辐射对城市其它微波站的干扰情况 ,为此类电磁辐射源环境影响管理提供参考性意见     

GSM数字移动通信基站电磁辐射测量与分析

通过对联通齐齐哈尔 GSM数字移动通信基站电磁辐射的测量与分析 ,明确其对周围环境可能造成的影响 ,为环境保护管理提供参考性意见     

广州市GSM移动电话基站发射电磁波对环境污染影响分析

依据国标《环境电磁波卫生标准》(GB91 75 -88) ,从理论上讨论了 GSM移动通信基站电磁辐射对环境的影响 ;并利用若干基站的实际测试数据 ,说明在一般情况下 ,对于基站周围的民居或其它楼宇里居住或工作的人群 ,移动通信基站的电磁辐射强度远低于国家标准 ,也远低于美国的标准     

移动通信网基站电磁辐射调研及居民环境超标原因分析

对北京市区近 2 0 0个移动电话基地站电磁辐射进行了测试 ,结合基地站电磁辐射特征对电磁辐射超标原因进行分析。从规划布局、天线架设规范方面提出了减小移动电话基地站电磁辐射污染的对策     

Nuclear power development and radiationsafety control in China

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