A building-based data capture and data mining technique for air quality assessment

Recently, a building-based air quality model system which can predict air quality in front of individual buildings along both sides of a road has been developed. Using the Macau Peninsula as a case study, this paper shows the advantages of building-based model system in data capture and data mining. Compared with the traditional grid-based model systems with input/output spatial resolutions of 1–2 km, the building-based approach can extract the street configuration and traffic data building by building and therefore, can capture the complex spatial variation of traffic emission, urban geometry, and air pollution. The non-homogeneous distribution of air pollution in the Macau Peninsula was modeled in a high-spatial resolution of 319 receptors·km^-2. The spatial relationship among air quality, traffic flow, and urban geometry in the historic urban area is investigated. The study shows that the building-based approach may open an innovative methodology in data mining of urban spatial data for environmental assessment. The results are particularly useful to urban planners when they need to consider the influences of urban form on street environment.     

Restoration of hyper-eutrophic water with a modularized and air adjustable constructed submerged plant bed

A modularized and air adjustable constructed submerged plant bed (CSPB) which can be used to restore the eutrophic water is introduced in this paper. This plant bed helps hydrophyte grow under poor conditions such as frequently changed water depth, impaired water transparency, algae bloom and substantial duckweed in summer, which are not naturally suitable for growing hydrophyte. This pilot study in Waihuan River of Tianjin, China, revealed that reduction of Chemical Oxygen Demand (COD), Total Nitrogen (TN) and Total Phosphorus (TP) by the use of CSPB could be reached 30%–35%, 35%–40%, 30%–40% respectively in the growing season (from March to October) and 5%–10%, 5%–15%, 7%–20% respectively in the winter (from November to February) when the detention time was 6 d. The relationships between the concentration of COD, TN, TP and the detention time fit the first-order kinetic equation well and the coefficients of determination (R²) were all above 0.9. The attenuation coefficients k of the kinetic equation were a function of the water temperature. When the water temperature was quite low or quite high, k was not significantly changed with increasing or decreasing water temperature. While when the temperature was in a moderate range, an increase or decrease of water temperature would lead to a rapid increase or decrease in k.     

Employment of passive sampling in monitoring indoor air quality in selected residences in a Tri-city area in Poland

Time-weighted average concentrations of selected volatile compounds were measured in chosen residences in a Tri-City area of Poland by means of passive sampling. The results were compared to those obtained by dynamic technique – sorption tubes filled with Tenax TA sorbent. Results obtained by employing the two techniques were similar. Total volatile organic compound (TVOC) parameters were also determined. An attempt was also made to evaluate the influence of outdoor air pollutants on indoor air quality.     

An assessment of the air pollution data from two monitoring stations in Kuwait

This article assesses the air pollution data from two monitoring stations in Kuwait. The measurements cover major pollutants, i.e., CO, CO₂, methanated and non-methanated hydrocarbons, NO _x , SO₂, O₃, and particulate matter (PM10). The data also includes meteorological parameters, i.e., solar intensity, temperature, wind speed, and wind direction, and has been collected over a period 4 years, from 2001 to 2004. Data analysis includes the assessment of annual hourly averages and 1-h maxima. Typical pollutant concentration trends, similar to those previously reported for Kuwait and for other locations around the world, are observed except for particulate matter measurements, which have higher values because of proximity to the desert. Emissions of nitrogen oxides show a consistent increase over the years. This is caused by the increase in the number of motor vehicles and the expansion in power generation and industrial activities. The data collected is a subset of the air quality criteria, as defined by the US EPA (United States Environmental Protection Agency).     

Acute toxicity of the synthetic pyrethroid pesticide fenvalerate to some air breathing fishes

Lethal concentrations (LC₅₀) of a synthetic pyrethroid pesticide, fenvalerate, for three species of air breathing fish Clarias batrachus, Channa punctatus and Heteropneustes fossilis were determined under water and acetone soluble condition in the laboratory using the static bioassay procedure of the American Public Health Association (APHA,1995). Acetone soluble fenvalerate was found more toxic than the water-soluble fenvalerate irrespective of species and exposure periods. The LC₅₀ value upon 96 days exposure to acetone soluble fenvalerate for C. batrachus, Channa C. punctatus and Heteropneustes H. fossilis were 1.35, 1.0 and 0.65?µg?L^?1, respectively. It is concluded from the present study that fenvalerate is highly toxic even to the hardy air breathing fishes and the pesticide, when dissolved in water, remains photostable and active to render toxicity for long duration.     

Indoor and outdoor air pollution and lung cancer in New Hampshire and Vermont

Indoor and outdoor air pollution is known to contribute to increased lung cancer incidence. This study is the first to address the contribution of home heating fuel and geographical course particulate matter (PM₁₀) concentrations to lung cancer rates in New Hampshire, USA. First, Pearson correlation analysis and geographically weighted regression were used to investigate spatial relationships between outdoor PM₁₀ and lung cancer rates. While the aforementioned analyses did not indicate a significant contribution of PM₁₀ to lung cancer in the state, there was a trend towards a significant association in the northern and southwestern regions of the state. Second, case-control data were used to estimate the contributions of indoor pollution and secondhand smoke to the risk of lung cancer with adjustment for confounders. Increased risk was found among those who used wood or coal to heat their homes for more than 10 winters before the age of 18, with a significant increase in risk per winter. Resulting data suggest that further investigation of the relationship between heating-related air pollution levels and lung cancer risk is needed.     

1981~2010年深圳市不同等级霾天气特征分析

利用1981~2010年深圳市地面观测及空气质量监测资料,分析深圳不同等级霾天气的长期变化特征以及大气水平能见度、空气质量与霾的关系.结果表明:深圳霾日数总体呈增多趋势,强度增强,中度以上霾增多;各等级霾日数均呈增多态势,但不同等级霾日占年总霾日的比例变化趋势不同,轻微霾所占比例下降,轻度以上霾上升; 霾天气呈现冬季>秋季>春季>夏季的季节特征,但重度霾却是夏季最多; 霾导致大气水平能见度明显下降,霾日平均能见度较非霾日低6~7km,霾等级越高,能见度下降越明显,霾日能见度日变化幅度较非霾日小;霾日SO2、NO2浓度为非霾日的1.4~1.7倍,PM10是非霾日的2.2倍,大气颗粒物污染加剧可能是深圳能见度恶化、霾天气增多的一个重要原因;针对荔香站霾日SO2浓度日变化不明显,PM10 、NO2浓度呈双峰型分布,与上下班时段吻合,说明机动车的增加也是深圳霾天气增多的主因之一;霾等级越高,空气中PM10、SO2、NO2的浓度越高,从轻微到重度霾各级之间SO2、NO2和PM10浓度增幅大都在15%~20%.     

Mechanistic aspects of the thermal formation of halogenated organic compounds including polychlorinated dibenzo‐p‐dioxins. Part V†: Hypotheses and summary

The hypotheses on the de novo syntheses of polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo‐p‐dioxins (PCDDs), based on known literature, are presented. Polychlorinated benzenes and polychlorinated phenols are probably key intermediates.

In the present article, hypotheses that may account for the presence of polychlorinated dibenzofurans (PCDFs) and dibenzo‐p‐dioxins (PCDDs) in the effluents from municipal and industrial incinerators are put forward. These hypotheses are based on the previously surveyed literature (Ref. 203–206) and experimental results on laboratory scale and thermodynamic calculations are considered. The interconnections of various reaction steps are speculative and no technological information was added to account for conditions in real incinerators. Conclusion of the discussions on the related subject matter, presented in the Parts I‐IV (Ref. 203–206), are also described in this paper.     

Determination of metallic cobalt in the atmosphere

Due to the fact that, among the different chemical species, metallic cobalt is characterized by the highest toxicity, in this paper is proposed a procedure for its determination in the atmospheric paniculate. The air is filtered on a cellulose or glass fiber membrane, to collect the paniculate containing among the other species, metallic cobalt: the determination is based on a selective dissolution of the metallic cobalt possibly present followed by its determination by atomic absorption spectroscopy. The typical interferences that can be present in the matrix are discussed and suggestions for their minimisation are proposed. By the following procedure is also possible to determine separately the sum of the insoluble and water soluble cobalt compounds.     

中国东部春季一次强冷锋活动空气污染输送过程分析

利用CMAQ(4.7.1)和HYSPLIT后向轨迹模式,结合长岛和洪泽湖站点污染物观测数据,对2011年3月31日—4月3日影响我国东北部地区的一次典型强冷锋天气空气污染过程进行模拟分析,验证表明模式能较好地模拟此次强冷锋过程. 由结果可知,此次强冷锋前后污染物浓度呈先升后降又上升的现象. 在冷锋移动过程中,锋前出现一条高浓度污染带,锋面将污染物抬升至800～500 hPa的高度,使污染物在对流层中层快速向西太平洋传输;冷锋对当地污染物的去除不仅有水平方向的推动作用,还会使污染物向高空输送. 锋面过后污染物浓度急剧降低,冷锋对长岛站点SO₂、O₃、NO_x、PM_2.5的清除率分别为90.87%、34.10%、50.56%、72.69%,对洪泽湖站点则分别为82.53%、50.45%、65.11%、36.80%. 锋面过去1~2 d后,高压控制天气形势下污染物再次开始积累、浓度回升. 冷锋前后污染物形成一个“积累—锋前抬升—高空平流输送—锋后大风清除—积累”的循环.