Heavy metal distribution in sediment profiles along the Adyar River, Tamil Nadu, India

Hema Achyuthan, V. Dhinakaran, K. Selvaraj Kumar, and S. Srinivasalu.
1. Centre for Geoscience and Engineering, Anna University, Chennai 600 025.
2. Dept. of Geology, University of Madras, Chennai 600 25.

In recent years, massive economic growth and development has led to excessive release of waste into the environment. The study of sediment profiles can provide much information on the spatial extent and vertical distribution of metal contamination. In this study seven cores of varying lengths were collected from various sites in the Adyar drainage basin. Adyar river is 42 kms long, originating from the Malaipattu tank and draining into the Bay of Bengal.  Sediment samples were analyzed for organic matter, CaCO₃% and Trace Metal content. The data reveals that there is an increase in the heavy metal concentration in the mouth of the river. The concentration of Ni increases towards the estuary. The amounts of Zn, Pb and Mn fluctuates revealing no particular pattern. Cadmium and cobolt are present in less amounts in the top sediments of the cores  samples analyzed but decrease significantly below 60 CMS with depth at the Adyar estuary. To understand the effect of the drainage on the any landscape, geomorphic and morphometric analysis were carried out using the SOI toposheets.  The analysis revealed that the river is controlled by the lithology and does not have any major structural control. Wherever the river is flowing over the softer rocks of Gondwana shales and sandstone, it has a narrow channel with a thick column of sediments. The channel width is larger with a thin veneer of sediments when the river flows over the Charnockite rock. The tolerance capacity of the vegetation along the river was studied by testing the stems and leaves of plant species, Mimocea Juliflora. The plant pattern of distribution reveals significant correlation to the trace metal influx of the river. These plants show higher tolerance to the accumulation of Ni at the Adyar estuary and hence their prolific growth at this site. The plants are fewer in number towards the origin of the river probably because of less concentration of Ni and Zn, which get mobilized due to the drainage processes.

Dr Esmaeil S. ALSaleh, Department of Biological Sciences, Faculty of Science, Kuwait University, State of Kuwait, AL-Safat P. O. Box 5969, 13060, Tel: 00965 978 7711, Fax:00965 484 7054,  Email: keva5000@hotmail.com
Ms Hana F. Drobiova, Dr Husain A. AL-Awadhi and Dr Christian Obekwi, Department of Biological Sciences, Faculty of Science, Kuwait University, State of Kuwait, AL-Safat P. O. Box 5969, 13060

It has been estimated that a total of 50 Km² in Kuwait contain high concentrations of crude oil. High levels of lead and nickel were also detected in AL-Douha site. Respirometry assay was used to determine the tolerance of soil bacterial communities to Ni, and Pb. Hydrocarbon contaminated and uncontaminated soils were amended with individual metals at three different concentrations, and the results were compared with the results obtained by using the plate count technique. Respirometry was found to be a simple and rapid method for measuring community metal tolerance. Data obtained by this technique were very reproducible. A direct relationship was found between community metal tolerance levels obtained by respirometry and plate count techniques. An increase in tolerance to the lead nitrate added to soils was observed for the bacterial community obtained from hydrocarbon uncontaminated soil compared with the community obtained from contaminated soil. When nickel sulphate was added to soils; no indication of increased Ni tolerance in hydrocarbon contaminated soil was found. The results indicated higher tolerance to lead nitrate at the community level of both soils compared to nickel sulphate. In addition, lower rates of hydrocarbons (hexadecane, nonadecane, naphthalene, pheneathrene and crude oil) and glucose mineralization were measured in nickel amended soils compared to that in lead amended soils. These results were confirmed by GCMS and HPLC assays. Further respiration and measurements of population growth rates (m) of soil suspensions showed similar results confirming that metal adsorption to soil components was not a limiting factor and indicated that the lower rates of hydrocarbons degradation in nickel amended hydrocarbon contaminated and uncontaminated soils compared to lead nitrate amended soils were probably due to available nickel salts, other inorganic constraints and not to presence of hydrocarbons. In addition, Physical and chemical characterization of both soils revealed similar soil characteristics except for the elevated levels of hydrocarbons and Pb in the contaminated soil. These results are discussed in relation to the potential bioremedial options of the contaminated site.

Integrated Pathway Models to Refine Arsenic and Selenium Concentration Estimates from a Proposed Fly Ash Mono-Fill Re-use 

Jeffrey A. Berk, URS Corporation, 800 West St. Clair, Cleveland, Ohio 44113, Tel:  216-622-2400, Fax:  216-622-2428
Joanna Moreno, CGWP, PH-GW, URS Corporation, 1225 17th Street, Suite 200, Denver CO 80202, Tel: 303-299-7938, Fax: 303-299-7909

The proposed use of 1.5 million tons of fly ash as structural fill was evaluated on behalf of a confidential client to determine if leachate resulting from the structural fill would adversely impact groundwater at hypothetical downgradient drinking water wells. The approach used in the investigation included the integration of four models (VLEACH, HELP, MT3D, and MODFLOW) to evaluate several inorganic metals (primarily arsenic and selenium) contained within the fly ash.  The HELP model was used to establish an infiltration rate from the base of the disposal area to the aquifer.  This rate, along with laboratory-measured leachate concentrations and the physical characteristics of the natural soil, were used in VLEACH to evaluate the attenuation of the metals entering the aquifer.  MODFLOW was used to construct a two-dimensional groundwater flow model extending to downgradient hypothetical receptors at assumed exposure points.  Reduction in contaminant mass by the attenuation capacity of the aquifer was evaluated by using MT3D.  The integrated models were used to simulate the mass loading and its cessation after 130 years.  At this time, the fly ash would be depleted of leachable metals.  The integrated models predicted that a maximum of approximately 2 percent of the arsenic's and 10 percent of the selenium's initial leachate concentrations would reach the exposure points.  These results were used to select an appropriate ratio of fly ash to amendments (either cement or lime kiln dust) to ensure that drinking water Maximum Contaminant Levels (MCLs) would not be exceeded at the assumed exposure points.  

Developing a Risk Assessment Tool to Evaluate the Impact of Heavy Metals from Mine Waste

Scott L. Bruce, National Research Centre for Environmental Toxicology, The University of Queensland, 39 Kessels Road, Coopers Plains, Brisbane, Australia 4108, Tel:  (+61 7) 3274 9009, Fax: (+61 7) 3274 9003
Barry N. Noller, National Research Centre for Environmental Toxicology, The University of Queensland, 39 Kessels Road, Coopers Plains, Brisbane, Australia 4108, Tel:  (+61 7) 3274 9020, Fax: (+61 7) 3274 9003
Jack C. Ng, National Research Centre for Environmental Toxicology, The University of Queensland, 39 Kessels Road, Coopers Plains, Queensland, Australia 4108, Tel:  (+61 7) 3274 9221, Fax: (+61 7) 3274 9003
Andrew H. Grigg, Centre for Mined Land Rehabilitation, The University of Queensland, St Lucia, Queensland, Australia 4072, Tel:  (+61 7) 3365 8541, Fax: (+61 7) 3365 3452
Ben F. Mullen, Centre for Mined Land Rehabilitation, The University of Queensland, St Lucia, Queensland, Australia 4072, Tel:  (+61 7) 3365 3474, Fax: (+61 7) 365 3452
David R. Mulligan, Centre for Mined Land Rehabilitation, The University of Queensland, St Lucia, Queensland, Australia 4072, Tel:  (+61 7) 3365 2954, Fax: (+61 7) 3365 3452
Nick Currey, Kidston Gold Mine Limited, RAMS House, Level 2, 189 Coronation Drive, Milton, Queensland, Australia 4064, Tel:  (+61 7) 3510 6700, Fax: (+61 7) 3365 3452
Paul J. Ritchie, Kidston Gold Mine Limited, P.O.Box 7020, Cairns, Queensland, Australia 4870, Tel:  (+61 7) 4062 4211, Fax: (+61 7) 4062 4120

There is need globally for appropriate mine closure criteria, in order to meet a variety of local environmental conditions.  In Australia, a strategic framework has been developed for mine closure identifying “the need for targeted research to assist both government and industry in making better and more informed decisions.”  A key issue in Australia is the utilisation of mined land for future pastoral activity.  As there is an absence of specific data the bioavailability of such contaminants in Australia, is assumed to be 100%.  To overcome this deficiency, this study aims to generate a risk assessment tool by comparing metal and metalloid bioavailability from controlled doses of mine waste in both cattle and laboratory rats, to rumen in vitro methods. The correlation between these models provides an inexpensive tool for risk assessment of rehabilitated mine facilities under Australian conditions.  Future planned work involving bioavailability in juvenile pigs will also provide information regarding human risk assessment. During the controlled cattle feeding trial, regular tissue biopsies provided relative bioavailability data of the metals and metalloids from various mine waste.  Bioavailability of arsenic ranged up to 40%, and lead approximately 20%.  Field cattle grazing trials, conducted directly on rehabilitated mine waste, identified three exposure pathways: ingestion of plant material; ingestion of contaminated dust adhered to plant material; and direct ingestion of mine waste (soil) during grazing.  It was found that the major pathway of exposure to arsenic and lead was derived from direct ingestion of soil during grazing, as cattle ingest up to 1kg of soil per day.   This study therefore provides quantitative information about the success of the mine closure process.  Thus, the comprehensive risk assessment procedure being developed allows for more accurate design of mine covers, minimising the mobilisation and transfer of toxic elements into the environment.

Remediation of Lead Shot Contaminated Soils on Residential Properties in Southeastern Massachusetts

Dan Crafton, Massachusetts Department of Environmental Protection, 20 Riverside Drive, Lakeville, MA 02347, Tel: 508-946-2721, Fax: 508-946-2835, Email: daniel.crafton@state.ma.us
Mark Begley, Massachusetts Department of Environmental Protection, 1 Winter Street, Boston, MA , Email: mark.begley@state.ma.us
Mike Whiteside, Massachusetts Department of Environmental Protection, 20 Riverside Drive, Lakeville, MA 02347, Tel: 508-946-2704, Fax: 508-947-6557, Email: michael.whiteside@state.ma.us

Field screening and laboratory analysis of surficial soils revealed lead contamination as high as 42,000 parts per million (ppm) on residential properties developed in the drop zone of a former trap range.   Initial assessment focused on the area of the estimated drop zone where exposure risk was high, specifically, the transition from woodlands to landscaping, and native soils buried beneath the landscaping.  Field screening downgradient and outside of the estimated drop zone revealed migration of lead via storm water runoff.  The assessment delineated approximately 3 acres of surficial contamination on 5 residential properties. 

In July of 2001, the Massachusetts Department of Environmental Protection began removal of lead contaminated soils from the residential properties.  The removal plan included removal of all underbrush and small trees, excavation of the upper 6 to 8 inches of soil, the use of a vactor to remove contaminated soils in around the roots of remaining trees, and very limited excavation of lawn areas.  Within the first week of removal activities, the removal plan was modified, due to site specific characteristics, to include removal of the majority of the trees, excavation to depths of 3 feet in some areas due to numerous rocks and boulders, and extensive excavation of lawn areas.  A vactor was used to remove lead contaminated soils from the root zones of the few remaining trees.    As the removal progressed, field screening with an X-ray Florescence Spectrum Analyzer (XRF) was done to confirm removal.  Contaminated soils were reused on the Club's property to construct a shooting berm in the drop zone of the active trap range.

Analysis of Heavy Metals and Inorganic Anions from Stormwater Runoff in Two Taunton River Tributaries

Cielito M. DeRamos-King, Department of Chemistry, Bridgewater State College, Bridgewater, MA 02325, Tel: 508-531-2115, Fax: 508-531-1785
Janelle Breton and Joseph Worrall, Department of Chemistry, Bridgewater State College, Bridgewater, MA 02325, Tel: 508-531-1233, Fax: 508-531-1785

Stormwater runoff is one of the leading causes of contamination of the nation’s rivers, lakes and estuaries. Impaired rivers and streams threaten aquatic life, fish consumption, recreational activities and drinking water supplies. Metals, siltation, bacteria and nutrients (nitrates and phosphates) are among the major pollutants causing water quality problems. Some heavy metals, such as cadmium, lead, mercury, chromium and zinc, are toxic to plants and animals at very low levels. Inorganic anions, such as nutrients and chloride, also contribute to water quality impairment. Excessive levels of nutrients lead to algal blooms and reduce the supply of dissolved oxygen, which results in fish kills. Both nutrients and chloride are potentially harmful to human health at excessive levels. Preliminary studies of heavy metals and inorganic anions from storm water runoff into two Taunton River tributaries were conducted during summer 2001. Our results reveal river sites that have levels of lead and cadmium above what are considered protective for aquatic life. Nutrient levels also increased during rain events at both sites, while chloride levels remained relatively unchanged, except in one storm drain. This drain had chloride levels ten times than that of the adjoining river. Furthermore, the drain discharges in dry weather, indicating a possible point source of pollution. This study will provide information that will help the town of Bridgewater meet Stormwater Phase II regulations.

Sorption of Heavy Metals on Mineral and Organic Fractions of Contaminated Sludge Lagoon Sediment

Lindy Hartley, Graduate Student, Department of Earth, Ecological and Environmental Science, University of Toledo, MS 604, Toledo, Ohio 43606-3390, Tel: 419-530-2009, Email: lhartle@pop3.utoledo.edu
Alison L. Spongberg, Associate Professor, Department of Earth, Ecological and Environmental Science, University of Toledo, MS 604, Toledo, Ohio 43606-3390, Tel: 419-530-4091, Email: aspongb@utnet.utoledo.edu
Deborah A. Neher, Associate Professor, Department of Earth, Ecological and Environmental Science, University of Toledo, MS 604, Toledo, Ohio 43606-3390, Tel: 419-530-2585, Email: dneher @utnet.utoledo.edu

Phytoremediation has been proposed as an cost-effective technology to alleviate contamination at the many Brownfield sites in metropolitan areas, such as Toledo, Ohio.  The goal of the proposed study was to determine the feasibility of using resident plants to remove heavy metals from contaminated soils at an industrial site in Northwest Ohio.  A 2-ha field site was characterized for depth profiles (25 cm intervals) of heavy metal concentrations by analyzing 11 cores (1.5 to 3.0 m total depth).  The site had previously been used to dump heavy metal contaminated sludge and other industrial waste.  Typically, concentrations of zinc, copper, chromium, and nickel decreased, and manganese increased, with increasing depth.  Cadmium was absent in most cores, and no trend with depth was observed when present.  Representative plant species growing on the site were harvested, divided by organ (fruit, stems, leaves, and roots), and analyzed for heavy metal concentration four times during the 2000 growing season.  Concentrations in certain species were elevated compared to those growing on uncontaminated soils.  We hypothesize that plants translocate these metals from deep soils during the growing season and deposit them on the soil surface when they die.  Sorption characteristics of the lagoon soils demonstrate weak retention capabilities of the mineral fraction.  After reaching equilibrium, sediments retained about half the metals than that of local soils.  Desorption experiments also indicate a rapid loss of these sorbed metals.  Currently being run are similar analyses of the upper sediment fraction, that is relatively rich in root and other plant biomass. 

Some Peculiarities of Mercury Migration in the Dubasari Reservoir of the Dniester River

Vera Munteanu, National Institute of Ecology, MD-2028 Chisinau Republic of Moldova, munteanu@citc.asm.md, tel./fax: 373-2 739781/373-2 739775

Mercury is a global scale contaminant, due to its dominance of the atmospheric transport and its long residence time in the atmosphere. Therefore, in non-polluted natural waters the dissolved mercury is found in a range of 0.02-0.1 mkg/L.

The mercury study was designed to establish the details of migration in the Dubasar’s basin of the Dniester River and to assess the concentration and sources of dissolved mercury in this reservoir, whose water is used by the population of Chisinau  city  (700,000) for drinking.

The concentration of mercury has been determined by anodic differential pulse stripping voltammetry on a cylindrical carbon fibre microelectrode modified in situ with gold metallic.

The results obtained show that the water from the Dubasar’s reservoir is polluted by dissolved mercury (0.72 mkg/L). The content of dissolved mercury in reservoir’s water decreases from Northern to the Southern part. In the same direction decreases the content of particulate mercury and mercury from sediments.

The high level of mercury in sediments (357 mkg/kg) can be accounted for by anthropogenic pollution, e.g. industrial outlets, atmospheric deposition, and leaching.

Acknowledgement
This work was supported by the Research Support Scheme of the Open Society Support Foundation, grant No.: 246/2000

Addressing Multiple Sources of Lead Exposure with a Community-Based Environmental Health Program

Kathy Tegtmeyer, MFG, Inc., 4900 Pearl East Circle, Suite 300W, Boulder, CO  80301, Tel: 303-447-1823, Fax: 303-447-1836
Amy Morrison, MFG, Inc., 130 W. 9^th St., Leadville, CO  80461, Tel: 719-486-3538, Fax: 719-486-3556
Bob Litle, Asarco Incorporated, 495 E. 51^st Ave., Denver, CO  80216, Tel: 303-296-5115, Fax: 303-298-7869 

An integrated environmental remediation and community health program, known as the Lake County Community Health Program, was selected as the remedial action for residential areas within the California Gulch CERCLA Site (Colorado).  The site was the location of extensive mining and smelting operations for more than 100 years.  Various site investigations performed during the 1980s and 1990s revealed more than 5,000 ppm lead in some residential soils, and an environmental health study performed in 1991 indicated elevated blood lead levels in some resident children.

The integrated program has been in place in some form since 1994, and to date more than 200 families with young children have participated voluntarily.  The program provides blood lead testing and case-management services to young children as well as environmental testing for potential sources of lead exposure, including yard soil, indoor dust, paint and drinking water.  Rather than focusing on yard-soil remediation, as is typical for mining communities, this approach allows for case-by-case evaluation of numerous exposure and risk factors to develop appropriate risk-reduction actions for individual residences.  The program then completes response actions to address potential sources of lead exposure. 

Since 1994, the percentage of young children with elevated blood lead levels (above 10 μg/dL) has dropped by 50 percent, and the community-average blood lead level (geometric mean) has decreased by 15 percent. The remedial actions completed to date are relatively few (<5% of residences) and therefore not likely to be the only factor contributing to lower blood lead levels in the community.  The combination of outreach and education programs, availability of blood lead testing and health services, completion of remedial actions in non-residential areas of the site, and the various factors that have produced a steady decline in blood lead levels nationwide are all likely contributors to the observed improvement in blood lead levels. 

Valtcho Zheljazkov, Department of Plant and Animal Sciences, Nova Scotia Agricultural College, PO Box 550, Truro, NS B2N 5E3 Canada, Tel: 902-893-7859, Fax: 902-897-9762, Email:vjeliazkov@nsac.ns.ca
Andrew Wilcox, Crop and Environment Research Centre, Harper Adams College, Newport, Shropshire, TF10 8NB, UK Tel: 01952-815-373, Fax: 1952- 814-783, Email: awilcox@harper-adams.ac.uk

A container experiment was conducted to study the effect of heavy metal polluted soil on productivity and quality of the basil varieties Trakia and Mesten (Ocimum basilicum L.).  Soils were sampled from the vicinities of a smelting plant near Plovdiv, Bulgaria at distances of 0.5, 3, 6, and 9 km from the smelter.  The two cultivars of basil were grown under standard and controlled conditions on the collected soil samples. 

Heavy metal concentration in soils was greatest close to the smelter.  Nitric acid extractable Cd, Pb, and Cu in soil at 0.5km distance were higher than their critical concentrations in soil.  Heavy metal concentration in plants was correlated to HNO₃ extractable metal concentration in sols.  Different plant parts (roots, leaves, inflorescences, stems) contained various amounts of Cd, Pb, Cu, Mn, and Zn.  Herbage and essential oil yields of plants grown in soil taken at 0.5 km from the smelter were reduced compared to yields from soils taken at 3, 6, and 9 km from the smelter.   Soils taken at 3 and 6 km of the smelter did not influence herbage and essential oil productivity.  Despite metal accumulation in aboveground tissue, essential oils from all treatments were not contaminated wtih heavy metals.  Plants grown on soils from various distances from the smelter showed some variation in essential oil composition. The tested cultivars of basil could be successfully grown on heavy metal polluted soils without contamination of the essential oil and any major changes in oil quality. 

Mercury in Compost-Soil-Plant System

Valtcho Zheljazkov and Michael Munroe, Department of Plant and Animal Sciences, Nova Scotia Agricultural College, PO Box 550, Truro, NS, B2N 5E3 Canada, Tel: 902-893-7859, Fax: 902-897-9762, Email: vjeliazkov@nsac.ns.ca

The paper discusses Hg movement in soil-plant-system, maximum permissible Hg concentration in compost in different countries, and the relevance of Canadian guidelines for maximum Hg concentration in composts.

Currently, the Canadian guidelines for maximum trace element concentration allow maximum of 0.8 and 5 mg/kg air-dried mass of mercury in type AA and A compost and B compost, respectively (CCME 1996).  These are the lowest concentration of any trace element in composts subject to control by CCME 1996.  Before the acceptance of national standards, Ontario and Alberta provincial guidelines for compost A were even more stringent; the values for Hg were 0.15 and 0.2 mg/kg, respectively.

These relatively low maximum permissible concentrations for Hg in compost may restrict the use of compost thus, may encourage incineration and landfilling.  Research has been shown that the mean values for Hg in 14 samples of composts from Europe to be 0.9 mg/kg, the range being 0.17 to 3.8 mg/kg. Even source-separated composts in North America have mean concentrations of 1 mg/kg.  That means the Canadian guidelines in this respect would be difficult to meet, that is they may be not practically feasible.  Introducing of 1 or 2 more classes of composts (such as in Finland) to allow wider range of Hg concentration in the composts may eliminate this problem.

Interactions Between Cadmium and Other Heavy Metals (Lead, Copper, Zinc and Arsenic) in Soil-rice Systems of Liaoning Province, China

Qixing Zhou, Key Laboratory of Terrestrial Ecological Process, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, P. R. China, Tel: +86-24-23997170, Fax: +86-24-23843313, E-mail: Zhouq@mail.sy.ln.cn or Zhouqixing@hotmail.com
Xin Wang, and Yanyu Wu, Key Laboratory of Terrestrial Ecological Process, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, P. R. China

Influences of interactions between Cd and other heavy metals (Pb, Cu, Zn and As) on the growth and development of rice plant and the absorption of these heavy metals by rice were studied using the pot-culture method combined with chemical measurement and statistical analysis. The results showed that the growth and development of rice plants were strongly influenced by double-element combined pollution. The decrement in the height of ripe rice plant was up to 4-5 cm, and the yield of rice was decreased by 20-30%, compared with those used for the control condition. The absorption of Cd by rice tissues was promoted due to interaction between Cd and Pb, Cu, Zn or As when added to the tested soil; in particular, when the concentration of Cd added into the tested soil was equal to 1.5 mg kg^-1. The increment of Cd in roots, stems/leaves and seeds was up to 31.6-47.7, 16.69-61.5 and 19.6-78.6 %, respectively. The absorption of Pb, Cu and Zn in roots, stems/leaves was inhibited due to the addition of Cd, when concentrations of Pb, Cu and Zn added to the tested soil were equal to 300, 100 and 200 mg kg^-1, respectively. The decrement of Pb, Cu and Zn in roots was 42.11, 28.22 and 6.66% and the decrement of Pb, Cu and Zn in stems/leaves was 17.69, 3.75 and 2.54%, respectively. On the other hand, the accumulation of Pb, Cu and Zn in seeds was increased due to the interaction between Cd and the other heavy metals. When the concentration of As added to the tested soil was 30 mg kg, the absorption of As by roots was increased by 9.8% and the absorption of As by stems/leaves was reduced by 3.25% due to the addition of Cd. The upward transporting ability of the heavy metals absorbed by rice plant was increased due to interaction of the heavy metals.

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