An Integrated Approach for Impact Assessment of Water Harvesting Techniques in Dry Areas: The Case of Oued Oum Zessar Watershed (Tunisia)

In the arid regions of Tunisia, considerable investments are being made to maintain the old water harvesting techniques and introduce new ones to capture the scarce amount of rainwater (100 mm to 230 mm annually) for agricultural and domestic purposes. However, no detailed assessment of the multiple effects and the costs and benefits of these techniques have been made so far. This paper summarizes the results of an in depth investigation of the multiple impacts (runoff mobilization, ground water recharge, agro-socio-economic impacts) of the water harvesting works undertaken in the watershed of oued Oum Zessar (southeastern Tunisia). The importance of interdisciplinary and integrated approaches was revealed through this detailed impact assessment and economic evaluation. In fact, the profitability of the water harvesting works depends largely on the criteria chosen. However, further refinements are needed to better include all possible impacts (positive and negative) that occur as a result of the installation of the water harvesting structures.     

Monitoring and Assessment of Persistent Organochlorine Residues in Sediments from the Daliaohe River Watershed, Northeast of China

Surface sediment samples from 12 sites of the three selected rivers in Daliaohe River watershed (Hunhe River, Taizihe River and Daliaohe River) were analyzed with the objective of establishing sources and hazard of the organochlorinae pesticides (OCPs) and polychlorinated biphenyl (PCBs) in surface sediments. The total concentrations of OCPs varied from 3.06 to 23.24 ng g⁻¹. ∑HCH (α-HCH, β-HCH, δ-HCH, γ-HCH), ∑DDT (p, p′-DDE, p, p′-DDD, o, p′-DDT, p, p′-DDT) and ∑Cyclodiene (Heptachlor, Aldrin, Heptachlor epoxide, Dieldrin, Endrin) ranged from 1.86 to 21.48, 0.5 to 2.81 and 0.56 to 1.53 ng g⁻¹, respectively. Results of OCPs also illustrate that the most dominant pollutants among the OCPs was ∑HCH, and γ-HCH was the most dominant isomer in HCH, which was evidence of recent input of lindane. It possibly came from the runoff of polluted soils and long-scale transportation. Total PCB concentrations ranged between 1.88 and 16.88 ng g⁻¹. The peak concentrations of PCBs were found in sediments from station T5 and D3, which are in the vicinity of industrial areas and ferry, respectively. These data show a moderate level of OCPs and PCBs contaminations compared to that in other countries.     

Assessment of Traffic Noise Pollution from 1989 to 2003 in Lanzhou City

On the basis of the continuous traffic noise data observed at 142 sites distributed in 52 roads from 1989 to 2003, the characteristics of traffic noise and effect factors were analyzed through traffic noise indices, such as Lep, L10, L50, L90, TNI, and Pn. Our findings allow us to reach a number of conclusions as follows: Firstly, traffic noise pollution was serious, and its fluctuant characteristic was obvious, resulting in a great intrusion to public in Lanzhou City during last 15 years. Secondly, traffic noise made a distinction between trunk lines and secondary lines, west-east direction roads and north-south direction roads. Thirdly, spatial character and time rule of traffic noise were obvious. In addition, traffic volume, traffic composition, road condition, and traffic management were identified as the key factors influencing traffic noise in this city.     

Dissolved and Total Copper in a Coal Ash Effluent and Receiving Stream: Assessment of In Situ Biological Effects

An in situ chemical and biological study was conducted in the lower Muskingum River (southeast Ohio, U.S.A.) to evaluate potential effects of copper (Cu) discharged from a coal ash effluent. Effluent total Cu, dissolved Cu, TSS and pH measurements were performed monthly during January-December 1995. Benthic macroinvertebrates were sampled at five river locations using artificial substrate samplers, and in situ Cu analyses were conducted. Effluent Cu (total) ranged from 8 to 142 microg L(-1) (mean = 58 microg L(-1)), but dissolved Cu never exceeded 78 microg L(-1) (mean = 20 microg L(-1)). The mean ratio of dissolved Cu to total Cu in these samples was 32%. Total Cu concentrations at the biological sampling sites adjacent to the effluent discharge were higher than levels at ambient sites, but dissolved Cu levels were similar among all sites. The macroinvertebrate community proximal to the coal ash effluent had the highest number of taxa and total number of individuals; a high number of mayfly and caddis fly taxa; and the highest Invertebrate Community Index score. The high water velocity of the discharge (which likely contained particulate organic matter) apparently created a favorable microhabitat that, combined with Cu-complexing constituents in the discharge, superceded potential adverse effects of high Cu levels. This study emphasizes the importance of instream biological data when obtained in conjunction with chemical analyses.     

Paleoecological Assessment of Watershed History in PRIMENet Watersheds at Acadia National Park, USA

Paleoecological reconstructions of forest stand histories for two upland watersheds at Acadia National Park in Maine were completed to support related watershed chemistry studies. The project hypothesis was that forest type and fire history influence long-term cycling and storage of atmospheric mercury and nitrogen within watersheds. The reconstructions document differences in major vegetation composition and disturbance between the burned and unburned watersheds during the past several centuries. Pollen and charcoal stratigraphies from organic sediment accumulations in forested wet depressions indicate that the present experimental design of contrasting disturbance and forest histories has persisted during recent centuries. The unburned watershed has been dominated by spruce (Picea rubens) and fir (Abies balsamea) for 500 years or more and has not recently burned or been substantially cleared. The burned watershed is dominated by a heterogeneous forest of patchy hardwood, mixed wood, and softwood stands. A large portion of this watershed burned severely in 1947 and probably more than once in the 1800s, and has supported heterogeneous successional forests for 200 years or longer. Overall, these results support the underlying premise that the experimental design of this watershed research can be used to infer landscape controls on biogeochemical processes.     

土壤重金属污染的灰色模糊评价

以灰色聚类为基础,提出了灰色模糊聚类分析法,并将其应用于土壤环境质量评价中,经实例分析表明,这是一种较为简便,合理、有效的评价方法。     

Determination and Assessment of HCHs and DDTs Residues in Sediments from Lake Dongting, China

The contamination of organochlorine pesticides hexachlorocyclohexane (HCH) and Dichlorodiphenyltrichloroethane (DDT) and their eco-environmental assessment in surface sediments from Lake Dongting, the second-largest freshwater lake in China, were studied. Concentrations of ∑HCH (=α-HCH + β-HCH + γ-HCH +δ-HCH) were 0.21--9.59 ng/g dry weight and those of ∑ DDT = p,p'-DDD+p,p'-DDE+o,p'-DDT+p,p'-DDT) ranged from under detectable limit to 10.15 ng/g dry weight. The ratios of α-HCH to γ-HCH were above 7 at most sampling sites while no or a small amount of β-HCH were found at all sites, suggesting the degradation of HCH used in the history and possibly current use of HCH in the region. The low ratios (below 2.0 in most cases) of (p,p'-DDE+p,p'-DDD) to p,p'-DDT and high levels of individual isomers of DDT at some sites also suggested that there have still been fresh inputs of DDT into Lake Dongting. Through the comparison between concentrations of HCH and DDT residues in sediments of Lake Dongting and those from other places in China and also from the results of our eco-environmental assessment, it can be concluded that Lake Dongting is the water body with high contamination of both HCH and DDT in its sediments in comparison with other water bodies in China.     

Model Assessment of Air-Pollution in Prague

Results of relatively simple gaussian dispersion model are presented. This model, developed in the beginning of this decade, is suitable mainly for determination of spatial distributions of annual mean concentrations of such kinds of air-pollution as sulphur dioxide (SO₂), mixture of nitrogen oxides (NO_x) or suspended particulate matter (SPM) from all types of emission sources located within the city - point sources, line sources and area sources. Model has been used in years 1994, 1996 and 1998 to assess the air-pollution distributions of the above mentioned kinds in the Prague area and the development of the air quality state. It contributed to the decision making process when possible impact of some changes in traffic system or in system of domestic heating, for example, has been investigated. In this contribution, behaviour of sulphur dioxide (SO₂) and mixture of nitrogen oxides (NO_x) ground concentration distributions are analyzed with respect to changing emission situation in Prague in recent years. Results show that SO₂ ground concentration level decreases mainly due to changes in local heating methods and type of fuel used. Different trend can be seen in NO_x ground concentrations thanks to rapid increase in the traffic density.     

Environmental Monitoring and Impact Assessment of a Solid Waste Disposal Site

The objective of this study is an attempt to conduct an environmentalmonitoring and impact assessment of the On-Nooch solid waste disposal sitein Bangkok, Thailand. Four water and five air sampling stations (2 upwindand 3 downwind directions) were established at the site. Grab water samplesfrom leachate treatment plant and Khlong Song Hong, a nearby stream, werecollected during the rainy and dry seasons. Analytical results of the wastewater discharged by the leachate treatment plant, during dry season showedchemical oxygen demand: 618 mg/l; biochemical oxygen demand: 80 mg/l;suspended solid: 101 mg/l; Total Kjeldahl Nitrogen: 283 mg/l, which werestill higher than standard limit for effluents in Thailand. During the dryseason, results also showed widespread heavy metal pollution from leachate(chromium: 1.03 mg/l; manganese: 1.07 mg/l; mercury: 0.025 mg/l) and werehigher than the allowable level of heavy metals for the Industrial EffluentStandard in Thailand. The direct discharge of untreated leachate into inlandwater will cause considerable water pollution in the study area. Compositeair samples in this study area were collected during the rainy and dryseasons and were analyzed for methane (CH₄), carbon dioxide(CO₂), carbon monoxide (CO), sulphur dioxide(SO₂), nitrogen dioxide (NO₂) andsuspended particulate matter (SPM). The average concentration of SPM rangedbetween 0.1–0.36 mg/m³ for 24-hour average, dependingupon the season. The level of CH₄ and CO₂ inthe ambient air of the study area were found to be 3.48–65.71mg/m³ and 886-1758 mg/m³ respectively which weremuch higher than the normal concentration of CH₄ andCO₂ in the air (CH₄: 2.41 mg/m³;CO₂: 585 mg/m³). Hence, adverse health andenvironmental effects could be expected from water and air pollution.     

Development of a New Approach to Cumulative Effects Assessment: A Northern River Ecosystem Example

If sustainable development of Canadian waters is to be achieved, a realistic and manageable framework is required for assessing cumulative effects. The objective of this paper is to describe an approach for aquatic cumulative effects assessment that was developed under the Northern Rivers Ecosystem Initiative. The approach is based on a review of existing monitoring practices in Canada and the presence of existing thresholds for aquatic ecosystem health assessments. It suggests that a sustainable framework is possible for cumulative effects assessment of Canadian waters that would result in integration of national indicators of aquatic health, integration of national initiatives (e.g., water quality index, environmental effects monitoring), and provide an avenue where long-term monitoring programs could be integrated with baseline and follow-up monitoring conducted under the environmental assessment process.     

Dissolved and particulate metals in water from Sonora Coast: a pristine zone of Gulf of California

The purpose of this study was to investigate the distribution of metals (Cd, Pb, Hg, Cu, Fe, Mn, and Zn) in dissolved and particulate fractions in seawater from Bacochibampo Bay, Northern part of Mexico. Water samples were collected from November 2004 to October 2005. Metal analysis was done by graphite furnace atomic absorption spectroscopy. Results indicated highest concentrations of dissolved Cd and Zn in the sites localized at the mouth and center of the bay. During summer and spring, the highest levels of Cd, Mn, and Fe were detected, Zn in fall, and Pb and Cu in winter and spring. Mercury was the only metal that was not found in this fraction. In particulate fraction, Fe, Hg, and Mn were the most abundant elements in all the sampling sites, followed by Zn, Cu, Pb, and Cd. The highest levels of the majority of the metals were observed in the coastline, suggesting a continental and/or urban source for these chemicals. The highest level of Cd was detected during the summer and the rest of the metals in the fall. Statistically significant correlations were observed between dissolved and particulate forms of Pb:Mn, Cu:Fe, and Cu:Mn. The mean partition coefficient values were as follows: Fe>Mn>Cu>Pb>Cd>Zn. All dissolved metal concentrations found, except Pb, were lower than EPA-recommended water quality values. The levels of dissolved metals in this study reveal low bioavailability and toxic potential. However, further toxicological and sediment chemistry studies in this area are needed for a full risk assessment.     

Assessment of the Usefulness of Semipermeable Membrane Devices for Long-Term Watershed Monitoring in an Urban Slough System

Semipermeable membrane devices (SPMDs) were deployed at eight sites within the Buffalo Slough, near Portland, Oregon, to (1) measure the spatial and seasonal distribution of dissolved polycyclic aromatic hydrocarbon (PAH) and organochlorine (OC) compounds in the slough, (2) assess the usefulness of SPMDs as a tool for investigating and monitoring hydrophobic compounds throughout the Columbia Slough system, and (3) evaluate the utility of SPMDs as a tool for measuring the long-term effects of watershed improvement activities. Data from the SPMDs revealed clear spatial and seasonal differences in water quality within the slough and indicate that for hydrophobic compounds, this time-integrated passive-sampling technique is a useful tool for long-term watershed monitoring. In addition, the data suggest that a spiking rate of 2–5 μg/SPMD of permeability/performance reference compounds, including at least one compound that is not susceptible to photodegradation, may be optimum for the conditions encountered here.     

Ecological Risk Assessment of Abandoned Shrimp Ponds in Southern Thailand

The potential ecological risks associated with contaminants from 15 abandoned shrimp ponds in southern Thailand were assessed at the screening level. Shrimp ponds reported as out of production for more than 2 years were selected as sampling sites. The assessment endpoint was identified as the protection of aquatic life from hazard of multiple agents or stressors in water or sediment from the ponds. The measurement endpoints were amount of toxic phytoplankton species, Yellow Head Viruses, SEMB viruses, oxytetracycline, cadmium, copper, and manganese. Data from field measurements and laboratory analyses obtained primarily from April to June 2003 were used in the risk analysis. The results showed that insignificant amounts of stressors were present, except for the metals. So, only concentration values of the metals were used in the calculation of hazard quotients (HQ) for risk characterization. The highest potential ecological risk characterized by the highest HQ value observed for each metal was 19 for manganese, 4.3 for cadmium, and 1.8 for copper. These findings indicated a need for further ecological risk assessment at a more detailed level to focus on the bioavailability and effects of metals from abandoned shrimp farms, with manganese the highest priority.     

Distribution of Iron, Manganese, Zinc and Atrazine in Groundwater in Parts of Palar and Cheyyar River Basins, South India

A study was carried out in a part of Palar and Cheyyar river basin to evaluate the current status of iron, manganese, zinc and atrazine concentrations, their origin and distribution in groundwater. Groundwater samples were collected during post-monsoon (March 1998 and February 1999) and pre-monsoon (June 1999) periods from 41 sampling wells distributed throughout the study area. The groundwater samples were analyzed for trace metals using AAS and atrazine using HPLC. The concentration of the trace elements in groundwater is predominant during pre-monsoon period. Distribution pattern indicates that the concentration of these elements increases from west to northeast and towards Palar river. Lower concentrations in the central part may be due to recharge of fresh water from the lakes located here. During most of the months, as there is no flow in Palar river, the concentrations of trace elements in groundwater are high. Drinking water standards indicate that Mn and Zn cross the permissible limit recommended by EPA during the pre-monsoon period. A comparison of groundwater data with trace element chemistry of rock samples shows the abundance of trace elements both in the rock and water in the order of Fe > Mn > Zn and Fe > Zn > Mn. This indicates that iron in groundwater is derived from lithogenic origin. Further, Fe, Mn and Zn have good correlation in rock samples, while it is reverse in the case of water samples, indicating the non-lithogenic origin of Mn and Zn. Atrazine (a herbicide) was not detected in any of the groundwater samples in the study area, perhaps due to low-application rate and adsorption in the soil materials.     

Radiocaesium Activity Concentrations in Milk in the Republic of Croatia and Dose Assessment

Results of systematic measurements of radiocaesium activities in milk after the Chernobyl nuclear accident are summarized. ¹³⁷Cs fallout activity affects milk activity, the coefficient of correlation being 0.89. The ¹³⁷Cs activities in milk in Croatia are log-normally distributed, reflecting the exponential decrease of activity. After the Chernobyl nuclear accident the ¹³⁴Cs:¹³⁷ Cs activity ratio in milk was 0.5, and did not differ from that for other environmental samples. The dose due to radiocaesium ingestion by milk consumption was estimated for the Croatian population, the annual collective equivalent dose being approximately 205 manSv in 1986 and 1.5 manSv in 1994.     

Assessment of Air Quality, Emissions and Management in a Local Urban Environment

This paper describes one example of how the UK National Air Quality Strategy (NAQS) is implemented in a local urban environment. The paper reviews the beginning of this process, by examining the review and assessment procedures of the NAQS in the London Borough of Barnet. By the application of available UK tools of local air quality management (LAQM), the process began through analysis of the levels of local emissions and progressed onto modelling of current and future air quality. A map showing combined emission hotspot areas for the Borough indicated and higher emission rates occur in the south of the Borough and along the major transport corridors, as road sources dominate emissions. Dispersion modelling studies were also conducted for this purpose, using the screening models GRAM, PGRAM and ADMS Urban for an in-depth assessment. These analyses found that some local point sources and the majority of Borough roads with over 20,000 vehicles per day produced exceedances of the future objectives for air quality for some pollutants.Recommendations for the progression of LAQM in the Borough are made and include the update and expansion of the emissions information held for use in future modelling studies. The paper demonstrates the experience of implementing the Strategy, using the tools and procedures available for this purpose, in a local urban environment that is similar to many in the UK.     

Risk Assessment of Organic Pesticides Pollution in Surface Water of Hangzhou

Advances in research on pollution of organic pesticides (OPs) in surface water, pollution survey and risk assessments of organochlorine pesticides (OCPs) and organophosphorus pesticides (OPPs) of surface water in Hangzhou are conducted. Total concentrations of dichloro-diphenyl-trichloroethane (DDT) and hexachloride-benzene (HCH) in surface water were observed to be 0–0.270 μg/L and 0–0.00625 μg/L respectively. DDE, as a metabolite of DDT and many species of OPP_S were determined in some samples of surface water. Parathion, the main pollutant among OPPs in surface water of Hangzhou, was observed to be 0–0.445 μg/L. Based on these experimental results, health risk assessments on the organic pollution are developed. It is observed that the total risk “R ^T” at present time of surface water in Hangzhou is mainly contributed by organophosphorus pesticides, especially Parathion; HCH and DDT are not the main contaminants; on the contrary, organophosphorous pesticides, especially Parathion, must be of concern at the present time.     

奎屯市大气降水现状分析及评价

为了解奎屯市大气降水状况及主要污染物,奎屯市监测站于2002年对大气降水进行了为期一年的酸雨监测。本文根据监测结果,介绍了奎屯市酸雨现状,对其成因进行了分析,并提出防治酸雨污染的可行性建议。     

氟化物应作为建陶行业环境影响评价的因子

对建陶行业氟化物的来源及其在环境中的化学行为进行了分析,结果表明,在釉面砖生产过程中排放的氟化物浓度超过国家规定的标准。并以此提出总量控制和评价因子的问题,探讨了氟污染排放标准和质量标准的相关性。     

Assessment of Urban Air Quality in South Estonia by Simple Measures

In countries having limited resources, it is difficult to assess urban air quality on contemporaneously, due to the absence of on-line information about air pollution levels and emission rates. An alternative approach is recommended for smaller cities with lower demands of resources. The applied scheme consists of a database of air pollution sources (NO _x and CO from industry, traffic, and domestic heating), the simple Gaussian-plume model AEROPOL and a series of measurements by passive monitors. This method was used in Tartu, a small city situated in the valley of the river Emajõgi, within a landscape with noteworthy topographical variations. Simulations of annual average and maximal concentrations were performed, and a fair agreement obtained with NO₂ monitoring results from passive Palmes monitors. Inventories of pollution sources in 1998 revealed that official statistics of stationary sources covered 64% of SO₂,36% of CO, 37% of NO _x and 32% of total particulate matter emissions. Recommendations for measures for reducing air pollution levels and for further investigations towards improving air quality assessment and management, are given.