Effectiveness of Radon Control Techniques in Fifteen Homes

Radon control systems were Installed and evaluated In fourteen homes In the Spokane River Valley/Rathdrum Prairie and In one home In Vancouver, Washington. Because of local soil conditions, subsurface ventilation (SSV) by pressurlzatlon was always more effective In these houses than SSV by depressurlzatlon In reducing Indoor radon levels to below guidelines. Basement overpressurlzatlon was successfully applied In five houses with airtight basements where practical-sized fans could develop an overpressure of 1 to 3 Pascals. Crawlspace ventilation was more effective than crawlspace Isolation in reducing radon entry from the crawlspace, but had to be used In conjunction with other mitigation techniques, since the houses also had basements. Indoor radon concentrations In two houses with alr-toalr heat exchangers (AAHX) were reduced to levels Inversely dependent on the new total ventilation rates and were lowered even further In one house where the air distribution system was modified. Sealing penetrations In the below-grade surfaces of substructures was relatively Ineffective In controlling radon. Operation of the radon control systems (except for the AAHX’s) made no measureable change in ventilation rates or Indoor concentrations of other measured pollutants. Installation costs by treated floor area ranged from approximately $4/m² for sealing to $28/m² for the AAHX’s. Based on the low electric rates for the region, annual operating costs for the active systems were estimated to be approximately $60 to $170.     

Analysis of Toxic Air Contaminant Data Containing Concentrations Below the Limit of Detection

Air quality data often contain several observations reported only as below the analytical limit of detection (LOD), resulting in “censored” data sets. Such censored and/or truncated data sets tend to complicate statistical analysis. This paper discusses various procedures for estimating mean concentration and Its 95 percent confidence bounds from air contaminant data sets which contain values that are reported as below the LOD, A quantitative approach for assessing the uncertainty Inherent In the estimated mean concentration due to (a) presence of values below the LOD In the data set, and (b) natural variability of atmospheric concentration data, is described. The utility of this approach In the analysis and interpretation of ambient pollutant concentration data Is demonstrated for both hypothetical and observed singly-censored data sets, and for a multiply-censored, multi-pollutant observed concentration data set. The methodologies discussed here should be particularly useful In verifying compliance with environmental regulations, and In estimating the risks associated with long-term exposure of populations to toxic air contaminants and assessing the uncertainty associated with these estimates.     

Optimization of energy systems using the concept of balance in the nature

Environmental Science and Pollution Research - In this paper, a concept of balance is used to improve the important parameters of the thermal systems. In fact, using this concept give the designer...     

Evaluation of the Effects of Emission Reductions on Secondary Particulate Matter in the South Coast Air Basin of California

An Aerosol Trajectory Model (ATM) is applied to the South Coast Air Basin of California for a two-day episode in August 1982 to evaluate proposed control strategies that aim to reduce atmospheric aerosols. Model predictions Indicate that secondary organic aerosols decrease linearly with reactive hydrocarbon emissions. In addition, the model shows that If sulf ate is produced only in the gas phase by oxidation of SO₂, then reduction In SO₂ emissions yields a nearly proportional decrease In sulfate levels. Reduction in ammonia emissions, combined with reduction of NO_x emissions, gives the best results In terms of nitrate control. The order in which the emission controls are implemented Is predicted to have a major impact on the reduction of secondary atmospheric aerosols.     

Recycling of biogenic hydroxyapatite (HAP) for cleaning of lead from wastewater: performance and mechanism

Environmental Science and Pollution Research - In China, the utilization and recycling of chicken waste have become a significant environmental issue. In this study, we investigate the efficacy of...     

Sonochemical versus reverse-precipitation synthesis of CuxO/Fe2O3/MoC nano-hybrid: removal of reactive dyes and evaluation of smartphone for colorimetric detection of organic dyes in water media

Environmental Science and Pollution Research - In the present work, an ultrasound-assisted reverse-precipitation method was applied as a new approach for the synthesis of CuxO/Fe2O3/MoC. In the...     

A Physical Explanation of the Lognormality of Pollutant Concentrations

Investigators In different environmental fields have reported that the concentrations of various measured substances have frequency distributions that are lognormal, or nearly so. That is, when the logarithms of the observed concentrations are plotted as a frequency distribution, the resulting distribution is approximately normal, or Gaussian, over much of the observed range. Examples include radionuclides in soil, pollutants in ambient air, Indoor air quality, trace metals In streams, metals in biological tissue, calcium In human remains. The ubiquity of the lognormal distribution in environmental processes is surprising and has not been adequately explained, since common processes in nature (for example, computation of the mean and the analysis of error) usually give rise to distributions that are normal rather than lognormal. This paper takes the first step toward explaining why lognormal distributions can arise naturally from certain physical processes that are analogous to those found in the environment. In this paper, these processes are treated mathematically, and the results are illustrated in a laboratory beaker experiment that Is simulated on the computer.     

An Analysis of Regional Haze Using Tracers of Opportunity

A two-year record of hourly concentrations of halocarbon tracers (methylchloroform and perchloroethylene) and hourly averages of particle light scattering (B_sp) has been analyzed In an effort to understand the sources of haze In the U.S. southwestern deserts and mountains. Measurements were taken on top of Spirit Mountain in southern Nevada. In conjunction with photographs used to interpret visual quality, haze episodes at Spirit Mountain were usually coincident with elevated concentrations of tracers originating from urban sources. Haze obscured an 88-km-distant mountain 17 percent of the total observation time. Of those Incidents, 69 percent were associated with long-range transport of haze from the Los Angeles Basin.     

泡沫陶瓷过滤煤气技术研究

介绍用泡沫陶瓷片作为过滤元件进行模拟高温焦炉煤气除尘 ,采用一种新的除尘工艺 ,增加了有效工作时间 ,避免了传统工艺很容易堵塞的弊端 ;并对相关实验数据进行了记录分析 ,充分验证了实验方案的有效性 ;最后 ,对泡沫陶瓷的相关应用作出探讨性的预测。     

Effects of experimental terbuthylazine exposure on the cells of Dicentrarchus labrax (L.)

The effects of acute exposure to the herbicide terbuthylazine (3.55, 5.01 and 7.08 mg l(-1)) on the cells of farmed European sea bass, Dicentrarchus labrax L., were investigated by means of light and electron microscopy. In gills of treated fish, the number of chloride cells (CCs) and rodlet cells (RCs) increased significantly within 24 h and 48 h, respectively; the intestine showed the largest increase in RCs linked to treatment and exposure time. In kidney, 24 h exposure induced a significant increase in RCs and the number and global area of macrophage aggregates (MAs). Treated fish displayed cellular and/or ultrastructural alterations in all the organs examined. In the gills necrosis, lamellar and cellular oedema, epithelial lifting, telangectasia, and fusion of secondary lamellae were encountered. The liver presented myelin-like figures, cytoplasmic rarefaction and acute cell swelling of hepatocytes. In both organs, the severity of damage was dose-dependent. In RCs of gills, the intestine and kidney of exposed sea bass, high cytoplasmic vacuolization, myelin-like figures, cristolysis and varying degrees of rodlet degeneration were observed. Extensive rodlet expulsion occurred in the gut lumen. Exposure to terbuthylazine also affected the renal tubular epithelial cells, which exhibited 'blebs'. Damage to the intestinal epithelial cells was also observed.     

Assessment of teratogenic potential of trichlorfon in mice and rats

Trichlorfon was evaluated for its teratogenic potential in the CD-1 mouse at doses of 200, 300 or 400 mg/kg/day administered by gavage on days 7-16 of gestation. In the CD-1 mouse, TCF was teratogenic, fetotoxic and lethal at the two highest dose levels which were also maternally lethal. At the lowest dose level which was not maternally lethal, there was a significant decrease in the number of calcified centers in the forepaws and hindpaws indicating fetotoxicity and a delay in maturation. TCF was administered at doses of 50, 100 or 200 mg/kg/day to CD rats by gavage on gestational days 7-19 (study I) or 8-20 (study II). In the CD rat in body study I and II, the highest dose level was maternally lethal. In study I, TCF was teratogenic with a shift in rib profile. In study II, TCF was teratogenic with an increased incidence in malformations of the urinary system. Additionally, TCF was fetotoxic with reduced ossification of the skulls at the lowest and highest dose levels.     

Physicochemical properties of chars at different treatment temperatures

In this study, the physicochemical properties of the char of Indonesian SM coal following heat treatment at various temperatures were evaluated using X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and morphological and specific surface area analysis. Based on these analyses, heat treatment of coal was determined to be the most effective in increasing the coal rank. In the XPS analysis, the C-O and C-O-C groups and quaternary-N species were found to be of a lower grade coal when the pretreatment temperature decreased, meanwhile the C-C group and pyridinic species increased. In the FT-IR analysis, the collapse of the C-O and C-O-C group was observed due to the collapse of the ether group. In SEM and Brunauer-Emmett-Teller (BET) analysis, a decrease in the ether group was shown to be accompanied with the formation of micropores.     

Microalgae biosynthesis of silver nanoparticles for application in the control of agricultural pathogens

The occurrence of diseases in cultivars has caused significant losses in global food production. The advancement of nanobiotechnology makes it possible to obtain new products to be used in the control of pathogens in cultivars. Silver nanoparticles can be synthesized by microalgae and are widely known for their antimicrobial activity. In addition, the biomass produced in microalgal culture for the biosynthesis of the nanoparticles also demonstrates antimicrobial properties, as it can increase the antibacterial and antifungal potential of the silver nanoparticles. In this context, this article addresses the use of microalgae to biosynthesize silver nanoparticles simultaneously with biomass production. In addition, we demonstrate the antimicrobial potential of these nanomaterials, as well as of the microalgal biomass produced in biosynthesis, to use in the control of pathogens in agriculture.     

Air pollution and hospital admissions for diseases of the circulatory system in three U.S. metropolitan areas

Generalized additive models were used to analyze the time series of daily hospital admissions for cardiovascular and cerebrovascular diseases over the period of 1987-1995 in three major metropolitan areas--Cook County, IL; Los Angeles County, CA; and Maricopa County, AZ--in the United States. In Cook and Maricopa Counties, admissions information was only available for the elderly (ages 65 and over), while in Los Angeles County, admissions information was available for all ages. In Cook County, daily monitoring information was available on PM10, CO, SO2, NO2, and O3. In Los Angeles and Maricopa Counties, monitoring information was available daily on the gases, and information on PM10 was available every sixth day. In Los Angeles County, information on PM2.5 was also available every sixth day. In Cook and Los Angeles Counties, associations were found between each pollutant, with the exception of O3, and admissions for cardiovascular disease, with the gases showing the strongest associations. In two-pollutant models with PM and one of the gases, the effect of the gases remained stable, while the effect of PM became unstable and insignificant. In Maricopa County, the gases, with the exception of O3, were weakly associated with hospital admissions for cardiovascular disease, while PM was not. In two-pollutant models with two of CO, SO2, and NO2, the pattern of results is heterogeneous in the three counties. In all three counties, only weak evidence of any association between air pollution and cerebrovascular admissions was found.     

The effects of atmospheric nitrogen deposition on the soil chemistry of coniferous forests in The Netherlands

Nitrogen fluxes, particularly those of ammonium, are extremely high in Dutch forests. In soils exposed to high ammonium deposition, acidification, eutrophication or a combination of both processes may occur. In addition to the amounts of ammonium deposited, the rate of soil nitrification determines which process takes place. A nation-wide investigation, in which three coniferous tree species were involved, was carried out to study the relation between deposition fluxes, measured by means of throughfall and bulk samplers, and the chemical composition of the soil. The ammonium deposition accounted directly for the high ammonium content and the high ammonium/cation ratios in the soil. In the top layer of most of the forest soils which were investigated nitrification rates were low. In these stands ammonium/cation ratios in the soil often reflected ammonium/cation ratios in throughfall water. Even in soils with relatively high nitrification rates, ammonium concentrations exceeded those of nitrate in the top layer of the mineral soil, indicating that ammonium deposition was more important than nitrification rate in determining the predominant form of nitrogen.     

Recovery from eutrophication: experiences of reduced phosphorus input to the four largest lakes of Sweden

In-lake concentration changes of phosphorus (P) and nitrogen (N) in lakes V?ttern, V?nern, M?laren, and Hj?lmaren in response to diminished input has been examined from the mid-1960s onwards. In the former two deep and oligotrophic lakes with slow water renewal, drastic reductions in P-input from the middle of 1970s caused just minor reductions in P-concentration over a very long time. At the same time accumulation occurred in the water mass of inorganic N and possible reasons are discussed. In the latter two mesotrophic to hypertrophic lakes, two shallow basins in L. Hj?lmaren showed slow recovery due to release of P from sediments. The same basins and two basins in L. M?laren have suffered from N-deficiency, particularly during the pre-phosphorus reduction years, and nitrogen fixation was indicated. In two L. M?laren basins recovery of in-lake P concentrations was better than expected in comparison to the so-called IMSA-model for lake recovery from nutrient pollution. In the other five lakes/basins chlorophyll concentrations after 20 years were similar compared to those modeled.     

Governance of Water Resources in the Phase of Change: A Case Study of the Implementation of the EU Water Framework Directive in Sweden

In this article, focusing on the ongoing implementation of the EU Water Framework Directive, we analyze some of the opportunities and challenges for a sustainable governance of water resources from an ecosystem management perspective. In the face of uncertainty and change, the ecosystem approach as a holistic and integrated management framework is increasingly recognized. The ongoing implementation of the Water Framework Directive (WFD) could be viewed as a reorganization phase in the process of change in institutional arrangements and ecosystems. In this case study from the Northern Baltic Sea River Basin District, Sweden, we focus in particular on data and information management from a multi-level governance perspective from the local stakeholder to the River Basin level. We apply a document analysis, hydrological mapping, and GIS models to analyze some of the institutional framework created for the implementation of the WFD. The study underlines the importance of institutional arrangements that can handle variability of local situations and trade-offs between solutions and priorities on different hierarchical levels.     

分散剂在溢油污染控制中的应用

使用分散剂来控制海上溢油污染是常用的应急措施之一。本文介绍了油分散剂的发展历史、作用机理及其优越性 ,列出了分散剂用于溢油污染控制的实例。针对分散剂使用中存在的问题 ,指出施加分散剂时应综合考虑多种因素 ,并做环境风险评价。最后根据我国的实际情况 ,提出应加强与分散剂有关的科学研究     

预处理后的活性污泥对锌吸附的研究

剩余活性污泥处理是当今的热点问题,从活性污泥资源化的角度出发,将活性污泥加工成为锌离子的生物吸附剂,比较了8种方法预处理后的活性污泥对锌的吸附效果,分析了这8种方法对污泥吸附能力的影响机理.对经过NaOH和H2O2处理的污泥的吸附特性和影响因素进行了研究,结果表明该吸附过程符合Psemio-seconal Order吸附动力学模型及Freunomch吸附等温模型,低pH不利于吸附,适当提高温度可以增强吸附效果,增加污泥吸附剂浓度可以增加金属离子去除率,但是单位质量吸附剂吸附金属离子的量减小.用红外光谱对比的手段对吸附机理进行了探讨,结果表明污泥颗粒表面一些含氮氧的基团对zn.'的络合作用是主要的吸附机理.该研究在污泥资源化和废水中锌离子的去除方面有重要意义.     

浙江省生物多样性保护对策研究

由于森林的破坏与片段化、湖泊面积缩小、水域污染、滩涂湿地围垦和物种资源过度开发利用等原因，使生物多样性严重受协。在对浙江省生物多样性保护进行系统研究的基础上，提出了浙江省生物多样性保护的目标和主要对策。