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.     

A Comparison of Mass,Lead, Sulfate,and Nitrate Concentrations in a Field Study Using Dichotomous,Size-Selective,and Standard Hi-Vol Samplers

Air monitoring In the San Francisco Bay Area was carried out to measure outdoor community air concentrations of poly cyclic aromatic hydrocarbons (PAH) and mutagenlc activity (mutagenlclty) In participate organic matter (POM). Monitoring began In 1979 and Is currently conducted at six stations. PAH and mutagenlclty tests were performed on organic extracts prepared from high volume (hl-vol) filters composited every four months, by meteorological season. PAH were determined by high pressure liquid chromatography (HPLC) with fluorescence and ultraviolet detection. Mutagenlclty was measured In the Ames Salmonella bloas-say using strain TA98 with and without metabolic activation. The nine-year mean concentration of benzo(a)pyrene (BaP) was 0.4 ng/m³. The mutagenlcfty of this amount of BaP accounted for only about 0.2% of the observed mutagenicity In POM and other measured PAH accounted for even less. Concentrations of PAH and mutagenlclty were three to nine times higher during the winter than during other seasons. Year-to-year wintertime trends In several PAH were also seen. Early In the 1980s, winter concentrations of BaP and benzo (g,h,i)perylene Increased. However since the mld-1980’s, their concentrations have fallen. The decrease In PAH concentrations may be the result of an Increasing proportion of vehicles with relatively low organic emissions. In contrast to PAH, mutagenlcfty did not show significant year-to-year time trends.     

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.     

Air Pollution and Hospital Admissions for Diseases of the Circulatory System in Three U.S. Metropolitan Areas

ABSTRACT

Generalized additive models were used to analyze the time series of daily hospital admissions for cardiovascular and cerebrovascular diseases over the period of 19871995 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 PM₂₅ 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 cere-brovascular admissions was found.     

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。     

Impact of roof rain water harvesting of runoff capture and household consumption

Environmental Science and Pollution Research - In recent years, the occurrence of floods is one of the most important challenges facing in Hamadan city. In the absence/inefficiency of urban...     

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...     

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.     

Smog,media attention,and corporate social responsibility—empirical evidence from Chinese polluting listed companies

Environmental Science and Pollution Research - In recent years, the frequent occurrence of smog in Chinese cities has prompted great changes in the policy environment faced by enterprises. In this...     

Aerobic dehalogenation potentials of four bacterial species isolated from soil and sewage sludge

In Polar regions subject to acid precipitation, the spring flood period is swift and can be divided into three phases. In phase one, dilution and anion substitution by SO4 controls episodic acidification. Phase two is characterized by interaction of snowmelt water with the catchment. A combination of several factors contributes to declines in pH and ANC. In forest and wetland ecosystems, organic acids greatly contribute to the pH depression in the streams. In the coastal tundra and forest-tundra zones, "salt-effect" acidification predominantes. The increase in toxic forms of trace (Ni, Cu) and rare (Fe, Al, Mn) elements during pH depressions may create stress conditions for the fauna of polar fresh waters during a flood period.     

The forecasting model research of rural energy transformation in Henan Province based on STIRPAT model

Environmental Science and Pollution Research - In order to find the model of rural energy transformation in Henan Province. In this paper, Tapio decoupling model is employed to investigate the...     

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.     

Investigating the metal contamination status from recycling e-waste sites from Dakar,Senegal

Environmental Science and Pollution Research - In Senegal, processes employed for recycling e-wastes result in release of so-called heavy metals in the environment. In this study, the metal...     

多相光催化在水污染治理中的应用

多相光催化过程是近年来日益引起重视的污染治理新技术，具有适用范围广、可使污染物彻底破坏、适用于低浓污染物治理等优点，本文对国外近年有关多相光催化在水污染治理中应用的研究结果进行了总结，包括各种有机污染物的氧化及各种无机离子的治理，并讨论了多相光催化过程的优点及实用性。     

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...     

Metal concentrations in Helix pomatia, Helix aspersa and Arion rufus: a comparative study.

In this study we evaluated the differences between concentrations of copper, iron, zinc, manganese, lead and cadmium in three terrestrial gastropods: Helix pomatia, Helix aspersa and Arion rufus, collected in a semi-rural location in Northern Italy. Metal concentrations in the foot and in the digestive gland were measured. In the hepatopancreas, copper and zinc did not differ significantly in the three species; the levels of copper were also similar in the foot. In comparison to Helix sps., A. rufus demonstrated lower concentrations of manganese and cadmium in the hepatopancreas and higher concentrations in the foot. In the slug the mucus produced in the foot could represent an efficient elimination mechanism of some elements. We also investigated correlations between the trace element content in the soft tissues and the mollusk size (weight of the body and height of the shell).     

Plume Dispersion in a Mountainous River Valley during Spring

The dispersion of hot plumes emitted from a smelter complex located In the Columbia River Valley, British Columbia, was evaluated under stable and neutral conditions during two mornings In spring. Spatial measurements of SO₂ and temperature within the plume were obtained by immersion probing using fast response helicopter and automobile mounted Instrumentation. In addition, meteorological measurements of vertical wind and temperature profiles at, and downwind from, the smelter were obtained from minisonde balloon releases. With weak down-valley winds, it was found that the plume axis elevations were generally lower during both stable and neutral conditions than would be predicted by Briggs plume-rise formulae. In contrast, plume dispersion, although confined in the horizontal by the steep valley walls during both stability regimes, was significantly enhanced by exceptionally good lateral mixing, particularly close to the source.     

Forensic Applications of Nitrogen and Oxygen Isotopes in Tracing Nitrate Sources in Urban Environments

Ground and surface waters in urban areas are susceptible to nitrate contamination from septic systems, leaking sewer lines, and fertilizer applications. Source identification is a primary step toward a successful remediation plan in affected areas. In this respect, nitrogen and oxygen isotope ratios of nitrate, in conjunction with hydrologic data and water chemistry, have proven valuable in urban studies from Austin, Texas, and Tacoma, Washington. In Austin, stream water was sampled during stremflow and baseflow conditions to assess surface and subsurface sources of nitrate, respectively. In Tacoma, well waters were sampled in adjacent sewered and un-sewered areas to determine if locally high nitrate concentrations were caused by septic systems in the un-sewered areas. In both studies, sewage was identified as a nitrate source and mixing between sewage and other sources of nitrate was apparent. In addition to source identification, combined nitrogen and oxygen isotopes were important in determining the significance of denitrification, which can complicate source assessment by reducing nitrate concentrations and increasing i 15 N values. The two studies illustrate the value of nitrogen and oxygen isotopes of nitrate for forensic applications in urba areas.     

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.