DDT residues in the River Jamuna in Delhi,India

Water, Air, &; Soil Pollution - DDT residues in water, bottom sediments and certain non-target organisms from four different sites of the river Jamuna in Delhi were monitored periodically from...     

Organochlorine insecticide residues in the rain water in Delhi,India

Rain water samples were regularly collected from three sites, namely, Netaji Nagar, Moti Nagar and Town Hall within the Delhi city area from July, 1980 to June, 1982. The pesticide residues were adsorbed on polyurethane foam coated with 0.5 % DC-200 and subsequently extracted and analyzed for DDT, HCH and their metabolites/isomers. The concentration of total DDT ranged from 0.22 to 108 μg L^?1 with a mean value of 12.5 μg L^?1. The samples of rain water contained varying levels of 4,4-DDT, 2,4-DDT, 4,4-DDE, and 4,4-DDD. The 4,4-DDT, 4,4-DDE and 2,4-DDT were the main components of total DDT. The range of HCH residues in rain water was from 0.08 to 43 μg L^?1 with a mean of 5.3 μg L^?1. The residues of HCH consisted mainly of α- and γ-isomers with traces of β and δ-isomers. The α- and γ-isomers accounted for 76 and 24% of total HCH, respectively. The concentrations of DDT and HCH in rain water were generally less than 10 μg L^?1 and exceeded 10 in only 4 and 3 cases, respectively. The residues of these insecticides were generally higher during October to December. Residues of DDT were higher at Moti Nagar which is near a DDT factory. Residues of HCH were maximum at Town Hall, a commercial area of the city.     

Influence of alkaline particulates on the chemistry of fog water at Delhi,North India

Chemical analysis of fog water collected by impaction in a pre-cooled chamber in Delhi has shown high concentrations of major ions. The dominant ions measured were Na⁺, K⁺, Ca⁺², and Mg⁺². The concentrations of acidic ions, SO₄ ^?2 and NO₃ ^?, were low. The pH values in the fog water were highly alkaline and varied from 6.4 to 7.6. The high concentrations of soil-oriented components, especially Ca⁺², were more than sufficient to neutralize the small acidity in the fog water and were responsible for maintaining high alkaline pH. The pH values of fog water did not attain the low values in India (Delhi), as found in other polluted environments of Europe and the northeast United States.     

Study on Winter Air Pollution Control in Lanzhou,China

Air pollution control is one of the most important issues in thecities of the developing countries. Based on an analysis of the local economic and technological development the paper puts forward 9 air pollution control schemes. They are 4 briquette schemes, 2 coal gas schemes, 1 centralized heating system and 2 comprehensive schemes. A comprehensive diffusion model combined with a 3-D advection-diffusion equation and the Gaussian puffmodel is developed and verified. According to the calculation ofpotential reduction of pollutant discharge and the correspondingair quality improvement made by each air pollution controlscheme, the paper then works out a feasible and comprehensiveair pollution control scheme, which is characterized by lowinvestment and better environmental benefits. When the scheme isefficiently carried out, 19.3% SO₂ and 24.4% sootdischarge is to be reduced annually in the city. There is aclear descent of air pollution concentration. The daily mean concentration of SO₂ and TSP declines 24.6–75.4%and 10.4–45.4%, respectively. SO₂ concentation of the whole city does not exceed the second grade of the Ambient Air Quality Standard of China except at a few grid points.     

Changes in the Abundance of Vascular Plants under the Impact of Industrial Air Pollution: A Meta-analysis

We applied a meta-analytic approach to improve an understanding of the effects of pollution on the primary productivity of terrestrial ecosystems. We identified 73 data sources reporting changes in the abundance of vascular plants (measured as the percentage of ground cover, biomass per unit area, canopy closure and stem basal area) around 75 polluters located in 18 countries (137 effect sizes). The overall effect was negative but varied among the vegetation layers and types of polluters. The strongest detrimental impact on productivity was due to non-ferrous smelters. The abundance of trees was decreased around both acidifying and alkalifying polluters, whereas the abundance of shrubs and field-layer vegetation decreased only near acidifying polluters. Overall, a decline of vegetation was observed in boreal and temperate forests but not in treeless biomes (deserts, tundra or grasslands). The magnitude of the detrimental effects on trees increased with the duration of the polluters?? impact around acidifying polluters but decreased around alkalifying polluters. Adverse effects on the field layer became more severe with increasing community productivity; in combination with the conclusions of previous meta-analyses, this result indicates that diverse and highly productive communities are likely to be the most susceptible to pollution impacts. In general, the pollution effects on the abundance of vascular plants were less detrimental than the effects on their growth and diversity, indicating that primary productivity in polluted ecosystems is maintained by the preferential growth of several pollution-tolerant species.     

Impact of Ambient Air Pollution on Locally Grown Rice Cultivars (Oryza Sativa L.) in Malaysia

This study presents the first experimental evidence of the sensitivity of rice plants to ambient air pollution from the Southeast Asian tropical region. Two widely adopted local cultivars of rice (Oryza sativa L.), MR84 and MR185, were grown in open top chambers ventilated with charcoal-filtered air and non filtered air, and in adjacent open plots on the campus of University Putra Malaysia. This is located on the south side of the Klang Valley, a rapidly developing area embracing Kuala Lumpur and other satellite cities, but where agriculture remains important The experimental period was from October 2000 to January 2001, corresponding to the main rice growing season in peninsular Malaysia. Adverse impacts on rice growth and yield were observed and were attributed to phytotoxic levels of ambient ozone. There was a clear difference in the sensitivity of the two selected cultivars. A yield reduction of 6.3% was observed for cultivar MR185 (p < 0.01) which was largely due to an increase in grain sterility, whilst the yield reduction for cultivar MR84 was not statistically significant. The reasons for these differing responses are discussed, and a comparison of the present findings with crop responses to ozone found under European conditions suggests a higher sensitivity in our study crops. With increasing industrialisation and urbanisation, this study highlights the need for further examination of the sensitivity of a wider range of crops and cultivars to ambient air pollution in this region, and also points to the potential for appropriate cultivar selection to ameliorate impacts.     

Phytosequestration of Metals in Selected Plants Growing on a Contaminated Okhla Industrial Areas, Okhla, New Delhi, India

Contamination of metal ions in soil and water represents more pressing threats to resources as well as human health. The present research was carried out to screen the phytosequester plants growing in industrial waste- and wastewater-affected industrial areas of Okhla, New Delhi, India. Accumulation trend of metal Fe, Zn, Cu, Cr, Pb, Cd, Hg, and As from soil and wastewater by plants were collected for study. Among aquatic plants Hydrilla verticillata, Marsilea quadrifolia, and Ipomea aquatica were found to be highest metals accumulator, Eclipta alba and Sesbania cannabina among terrestrial plant were highest accumulator of metals. Among the algal spp. Spirulina platensis and Phormidium papyraceum were the most efficient in accumulating Cd and Hg. The maximum bioconcentration factor (BCF) was recorded in Hygroryza aristata for the metals (Hg, Cd) in M. quadrifolia (Cd, Cr), in E. alba (Cr, Cu), and in S. platensis (Hg, Pb). However, the translocation factor (TF) of metals was found more in M. quadrifolia followed by I. aquatica than other plants. Among all the plants, H. verticillata showed high TF and low BCF values for toxic metals (Pb, Cr) and was suitable for phytostabilization of these metals. Our study showed that native plant species growing on contaminated sites may have a potential of phytosequestration of these metals.     

基于污染足迹的太湖流域稻作农业污染评估——以常州市和宜兴市为例

稻作农业在保障粮食安全方面贡献巨大,但因经济利益驱动,化肥农药被过量施用,造成了氮、磷等营养物质流失,对水环境产生严重影响。本文基于全国第一次污染普查数据,结合各类污染物的产排污系数计算了稻作农业COD、TN和TP入河量,通过污染足迹模型计算了稻作农业COD、TN和TP的污染足迹,通过污染压力模型计算了稻作农业COD、TN和TP的污染压力指数,并对其进行评估。结果表明:(1)常州市、宜兴市稻作农业生产过程中向水环境排放的污染物中以COD和TN为主,其入河量分别为792.96 t·a-1和605.28 t·a-1,TP入河量为27.16 t·a-1;(2)常州市、宜兴市稻作农业TN污染足迹最大(3 944.50 hm2),其次为TP污染足迹(2 578.95 hm2),最小的是COD污染足迹(523.52 hm2);(3)常州市、宜兴市稻作农业对水环境的污染压力指数为2.10,处于中度污染压力状况,表明常州市、宜兴市稻作农业生产活动超出了当地水域的承载能力,对当地水环境产生了压力。     

基于GIS和RS的德令哈市城市扩展研究

借助RS和GIS技术,对德令哈市1989年TM影像数据、1999年ETM影像数据和2009年土地利用现状图进行分析处理,采用人机交互目视解译法提取德令哈市建成区边界图,并将3个时期的建成区范围图叠加;然后从城市扩展强度、重心坐标转移、紧凑度指数、分形维数指数以及城市扩展弹性系数等角度对德令哈市建成区的空间扩展状况进行分析;结果显示:1989—1999年、1999—2009年这两个阶段,德令哈市建成区的面积都在增加,但是1999—2009年,建成区面积的扩展速度和强度都大于1989—1999年;建成区重心坐标第一阶段向西北方向偏移,第二阶段向南偏移,紧凑度指数偏小,并逐渐减小,分形维数指数比合理值1.12大很多,城市空间演变形态趋于复杂;城市扩展弹性系数偏大,并有上升趋势,城市人口增加与城区面积扩展不协调。德令哈市在未来的发展中,需要注重城市内部建设用地填充,合理控制外延扩展规模,尽力确保城市形态紧凑发展。     

Measurement and Modelling of Particulate Pollution over Kashmir Himalaya,India

In major cities, air quality is of significant concern because of its negative effect on the health of the region’s living conditions, climate, and economy. Recent studies show the significance of the data on microlevel pollution which includes severe air pollutants and their impacts on human. Conventional methods of measuring air quality need skilled personnel for accurate data measurement that are based on stationary and limited measuring station networks. However, it is costly to seize the spatio-temporal variability and to recognize pollution hotspots that are necessary to develop real-time exposure control strategies. Due to the restricted accessibility of information and the non-scalability of standard techniques for air pollution monitoring, a real-time system with both higher spatial and temporal resolution is crucial. In recent times, unmanned aerial vehicles (UAVs) mounted with various sensors have been implemented for on-site air quality surveillance as they can offer new methods and research possibilities in air pollution and emission tracking, as well as in the study of environmental developments. An extensive literature review has been conducted, and it was observed that there are types of UAVs and types of sensors that are used for air quality monitoring for the parameters like CO, SO₂, NO₂, O₃, PM_2.5, PM_1.0, and black carbon. Low-cost wireless sensors have been using for monitoring purpose in the past studies, and when results obtained are validated with the stationary monitoring instruments, the coefficient of correlation (R²) is found to be varied from 0.3 to 0.9. The difficulties, however, are not just technical, but at present time, policies and laws, which vary from country to country, symbolize the major challenge to the extensive use of UAVs in air quality/monitoring studies.

     

Sediment Pollution, Transport, and Abatement Measures in the City Canals of Delft, the Netherlands

This paper presents an overview of a long-term study on sediment pollution in the city canals of Delft, the Netherlands. This pollution was most evident for the inner city canal system, with copper, lead, zinc, and polycyclic aromatic hydrocarbons (PAHs) as main pollutants. Sediments of the outer city canals generally had a much better quality. Pollution levels, mutual correlations, and spatial variations were investigated for the various sediment parameters. Also, heavy metal binding forms onto Delft sediments were assessed with the help of sequential extraction techniques; results were found to be in line with expected preferential physicochemical binding processes. Input of sediments into the Delft inner city canals was shown to be largely driven by busy shipping traffic on the main canal surrounding the inner city. Mass balances for the inner city were used to quantify internal and external pollution sources; 65?C85?% of the heavy metal pollution can be attributed to sources outside the Delft area. As shown by factor and cluster analyses, it is highly probable that these external sources derive from the river Rhine. A gradual improvement of the sediment quality has set in; it is expected that, due to further pollution abatement measures, this improvement will continue over the years to come. With respect to the ship-induced sediment input into the inner city canals, it was estimated that a reduction of ship velocities to <1.5?m/s will bring down the sediment input mentioned above to about 85?%.     

A Seasonal Assessment of the Impact of Coal Fly Ash Disposal on the River Yamuna,Delhi, II. Biology

The impact of fly ash on the biology of the Yamuna River, Delhi, was studied. Effluents come from a 200 MW capacity I.P. thermal power station. Seasonal variations in the biological features in the non-impacted (Y-1) and the impacted (Y-2) segments of the river receiving fly ash effluents were studied. 60 genera of phytoplankton including 29 Chlorophyceae, 19 Bacillariophyceae, 8 Cyanobacteria, and 4 Euglenophyceae were recorded. Phytoplankton diversity was reduced at the impacted site in comparison to the non-impacted site of the river and substantial changes in the composition of various groups inhabiting these areas were observed. Zooplankton were also reduced at Y-2 compared to Y-1, especially rotifers and protozoans, while copepods and nauplii larvae were not affected to the same degree. Species diversity was not significantly different at Y-2 and Y-1 but similarity index varied from low to high between the two stations. Thus, not only was the density, number of genera and diversity reduced, even the generic composition of the plankton was markedly affected in the impacted waters. The observed perturbations could be due to sedimentation of ash particles, pH or elevated metal or salt concentration. A change in the concentration of one or more constituents disturbs the relationship between biota and could be the possible cause of reduced densities in the impacted waters.     

Impact of protection and free grazing on sand dune vegetation in the Rajasthan Desert,India

In the Thar (Rajasthan) Desert of India, sand dunes and sandy plains dominate the landscape. Livestock raising and marginal land cultivation are the main occupations. Owing to the high growth rates of human and livestock populations and a decrease in pasture area and its primary productivity, these lands bear acute grazing pressure. Average rainfall is low and vegetation growth is restricted to the short rainy season of two to four months duration. Often there are years of lower than normal rainfall. In these circumstances, fenced areas, established to stabilize formerly active sand dunes, are increasingly opened to grazing to prevent high stock mortality during droughts. This study was conducted in four fenced and one open site, representative of the region's different vegetation types and grazing pressures. The impact of 2 and 5 per cent free grazing pressure on protected sand dune vegetation density and cover was tested in the two fenced sites. The vegetation data for grazed sites are compared with those for the two ungrazed fenced (protected) and one unfenced (open) site subjected to unlimited grazing pressure throughout the year. The vegetation sampling was carried out by the qaudrat and line-transect method before and after grazing from November 1984 to October 1986. It shows a significant reduction in the density and cover of many palatable species and an increase of unpalatable plants. The effect of vegetation degradation is greater in the unfenced area. The low grazing pressure on the fenced sand dunes sites can still cause drastic changes in the vegetation density and cover. Protection resulted in reduced sand erosion and enhanced growth of palatable plants in the fenced sites under similar climatic and edaphic conditions to the unfenced sites. The grazing pressure in the unfenced areas remains high to extreme during the year, due to low land productivity and high feed demand. The regeneration rate is very slow under the constant (3rd to 5th degree) overgrazing. Low intensity grazing pressure on the fenced sites during droughts can cause heavy utilization and mortality of palatable vegetation.     

Analytical Studies on Lead Pollution in Roadside Soil Samples of Raipur and Bhilai,Chhattisgarh State,India

Abstract

Although lead in gasoline represents only 2.2% of total global lead use, this fuel remains by far the single largest source of this heavy metal in urban areas. In developing countries like India approximately 90% of all lead emissions into the atmosphere are due to the use of leaded gasoline. In many countries in Southeast Asia, unleaded gasoline is scarce, and the maximum allowed lead content might reach or exceed 0.8 ppm per liter. Emissions from the metallurgical operations and the waste incineration are also responsible for the rising levels of lead in the environment. Battery recycling, lead‐glazed pottery, and lead pigments industries are other sources of lead in the environment. In the present work, lead pollution in soil samples from Raipur (capital city) and Bhilai, Chhattisgarh State, India, has been investigated. The lead concentration in the surface soil of Raipur and Bhilai was found in the range of 7.2–84.0 and 9.5–79.7 ppm, respectively. The seasonal and temporal variations in the concentration of metal, its distribution pattern, and trend are discussed as well as the mobility, deposition, and sources of lead in the area. The enrichment factor of lead in the urban soil was found to be very high, depending on the nature of sources.     

Geochemistry of Trace Elements in the Ground Water of Cuttack City,India

The concentration of some trace metals, like Fe, Mn, Cu, Pb, Zn, Co, Cr and Ni, was measured in the potable water of Cuttack City,India during winter, summer and rain events in the course of a two year period. Apart from Fe, all other trace metals fell well within the maximum permissible limit set by WHO for drinking water. On the basis of spatial/temporal variations, weathering of rocks and anthropogenic input were found to be main sources of trace elements in the ground water. The considerable temporal changes indicate that a majority of trace metals is entering the aquifer during rain fall.Factor analysis of the trace element data suggest that Fe, Mn and Cr are interrelated with each other and derived significantly from the aquifer, whereas input of Pb and Co may be due to atmospheric deposition in the study area.     

Aerosol particles in the developing world; a comparison between New Delhi in India and Beijing in China

In developing countries, aerosol particles damage the health of hundreds of millions of people. Migration from the country side to megacities increases emissions and exposure to particles. Some countries have started to limit emissions based on particulate mass, but this may increase particle number concentrations. In this study we discuss some earlier measurements carried out in the developing world and compare results from one-week measurement campaigns concerning the particle number size distribution and PM₁₀ mass concentrations in New Delhi, India and Beijing, China. Our results show that submicron particle concentrations are high in both places. The average PM₁₀ concentration was 360 μg/m³ in New Delhi and 120 μg/m³ in Beijing. The corresponding total particle number concentrations in the size range 3–800 nm were 63 000 cm^?3 and 35 000 cm^?3. Number and mass concentrations and their characteristics showed significantly different behaviour between these two locations, which stresses the importance of long-term simultaneous measurements of both quantities in different types of megacities.     

A Seasonal Assessment of the Impact of Coal Fly Ash Disposal on the River Yamuna,Delhi. I. Chemistry

The impact of fly ash on the chemistry of the River Yamuna was studied. By-products from a 200 MW capacity I.P. thermal power station on the west bank of the River Yamuna, Delhi are largely from coal combustion (fly ash) and are disposed of as a slurry to off-site ash ponds. Many elements associated with fly ash are soluble and become available to the biota. A two-year survey was made of the seasonal variations in limnochemical features in the non-impacted and the impacted segments of the river receiving fly ash effluent and the ash treatment ponds. Conductivity, TDS, DO, hardness, sulphate and nitrate increased significantly in the receiving waters over background values. The reverse was noticed for free CO₂, alkalinity and phosphate. Changes in some other parameters were insignificant. Fly ash effluents from the ash ponds significantly increased the concentration of some elements, viz., Al, Sb, Bi, Cd, Cr, Co, Li, Mn, Mo, K, Si, and Zn in river water. Generally, the highest concentration of most parameters were recorded in the ash ponds. This investigation was helpful in assessing the effect of wet ash disposal on the river limnology and understanding the solubility of various elements in the ash ponds.     

大冶市农田土壤中镉的空间分布特征及污染评价

矿山开采和冶炼是造成土壤重金属Cd污染的主要原因,了解典型区域土壤中Cd的空间分布特征及其污染现状,可为区域土壤污染防治与安全利用提供重要信息。本研究针对湖北省大冶市所有农田采集92个表层土壤样品和3个土壤剖面,利用GIS方法对土壤重金属Cd空间分布特征及污染状况进行了研究。结果表明大冶市土壤中Cd的含量范围为0.6 ~ 4.6 mg/kg,平均值为1.41 mg/kg,Cd迁移深度可达 40 cm。区域内土壤Cd污染范围较广,空间变异较大,还地桥镇、罗桥街办、陈贵镇等地农田土壤Cd含量较高。地积累指数评价结果显示大冶市大部分农田土壤为轻度、中度污染程度,在合理调整种植结构等方式下仍可保障农田安全利用。     

新乡市环宇大道工业区周边土壤重金属的污染特征和评价

通过实地采样及室内化学分析的方法,研究了新乡市环宇大道工业区周边土壤Pb、Cd、Ni、Zn、Cu和Cr 6种重金属污染特征和风险评价,并应用Tessier五步连续萃取的方法对土壤中超标的Cd,Ni和Zn进行形态分析。结果表明:(1)土壤中Pb、Cd、Ni、Zn、Cu和Cr的平均含量分别是63.08 mg kg-1、176.85 mg kg-1、307.2 mg kg-1、485.6 mg kg-1,38.7 mg kg-1和47.9 mg kg-1,Pb、Cu、Cr平均含量达标,Cd、Ni、Zn平均含量均超标,分别是国家土壤环境质量二级标准的176.85、5.12、1.62倍。(2)Ni和Zn主要以铁锰氧化物结合态和残渣态存在,Cd主要以铁锰氧化物结合态存在,其次为碳酸盐结合态,3种重金属的迁移能力依次为:Cd>Zn>Ni。(3)每种重金属都存在不同程度的潜在生态风险,Cd的潜在生态风险最大并构成了很强的危害。