The effects of cadmium and zinc interactions on the accumulation and tissue distribution of zinc and cadmium in lettuce and spinach

The interactions between Zn and Cd on the concentration and tissue distribution of these metals in lettuce and spinach were studied at levels corresponding to background and Zn-Cd contaminated sites. Plants were grown in nutrient solutions containing 0.398-8.91 microM Zn and 0.010-0.316 microM Cd. Cadmium accumulated more in old than in young leaves of both crops at any solution Cd level, whereas Zn followed that pattern only at Zn levels > or = 3.16 microM. Increasing solution Cd increased Zn concentrations in young leaves of lettuce but not of spinach, regardless of Zn levels. Cadmium concentrations in young leaves of both crops decreased exponentially with increasing solution Zn at low (0.0316 microM) but not at high (0.316 microM) solution Cd. The Zn: Cd concentration ratios in young leaves of lettuce and spinach grown at 0.316 microM Cd became greater as the solution Zn increased. Cadmium and Zn concentrations in young leaves were related more closely to the relative concentrations of Zn and Cd in solution than were the concentrations in old leaves, especially in lettuce. Studies of Zn-Cd interactions and Cd bioavailability should differentiate between basal and upper leaves of lettuce and spinach. Compared to Cd-only pollution, Zn-Cd combined pollution may not decrease Cd concentrations in lettuce and spinach edible tissues, but because it increases their Zn concentrations it lowers plant Cd bioavailability.     

Assessing Changes in Phosphorus Concentrations in Relation to In-Stream Plant Ecology in Lowland Permeable Catchments: Bringing Ecosystem Functioning Into Water Quality Monitoring

Changes in concentrations of soluble reactive phosphorus (SRP), excess partial pressure of carbon dioxide (EpCO₂), and chlorophyll-a were examined for two rivers in the in the upper Thames catchment: the main river Thames at Wallingford and a chalk stream tributary, the River Kennet. Sampling began in the spring of 1997 and has covered extremes in river flow conditions. During the sampling period there was a dramatic reduction in phosphorus (P) inputs from the introduction of effluent P-treatment at sewage treatment works, as a result of the EU Urban Wastewater Treatment Directive. Despite major reductions in baseflow SRP concentrations in the River Kennet, from around 700 μg-P L^-1 to around 100 μg-P L^-1, observations of aquatic plant communities indicate overall degradation in ecological quality since effluent P-treatment was introduced. The degradation was associated with a spring and summer decline in growth of Ranunculus, a macrophyte of high conservation value in chalk streams, particularly from 2000 onwards, linked to shading by epiphytic algae. Although the EpCO₂ records indicate a reduction in primary productivity since effluent P-treatment, the River Kennet may have become more sensitive to epiphyte blooms. Episodes of epiphyte proliferation appear to be linked temporally to small increases in SRP concentrations (typicallyabove a 100 μg-P L^-1 threshold) under summer baseflow conditions. The in-stream system is highly complex and individual processes and causality are difficult to resolve, particularly given changes in river flows linked to background climatic variability and limited availability of biological data. This study demonstrates the need for integrated long-term biological and chemical monitoring of river systems subject to major perturbations to assess timescales required to produce new dynamic equilibria in ecosystem response.     

Science of odor as a potential health issue

Historically, unpleasant odors have been considered warning signs or indicators of potential risks to human health but not necessarily direct triggers of health effects. However, citizen complaints to public health agencies suggest that odors may not simply serve as a warning of potential risks but that odor sensations themselves may cause health symptoms. Mal-odors emitted from large animal production facilities and wastewater treatment plants, for example, elicit complaints of eye, nose, and throat irritation, headache, nausea, diarrhea, hoarseness, sore throat, cough, chest tightness, nasal congestion, palpitations, shortness of breath, stress, drowsiness, and alterations in mood. There are at least three mechanisms by which ambient odors may produce health symptoms. First, symptoms can be induced by exposure to odorants (compounds with odor properties) at levels that also cause irritation or other toxicological effects. That is, irritation--rather than the odor--is the cause of the health symptoms, and odor (the sensation) simply serves as an exposure marker. Second, health symptoms from odorants at non-irritant concentrations can be due to innate (genetically coded) or learned aversions. Third, symptoms may be due to a co-pollutant (such as endotoxin) that is part of an odorant mixture. Objective biomarkers of health symptoms must be obtained, however, to determine if health complaints constitute health effects. One industry that is receiving much attention, worldwide, related to this subject is concentrated animal production agriculture. Sustainability of this industry will likely necessitate the development of new technologies to mitigate odorous aerial emissions. Examples of such "environmentally superior technologies" (EST) developed under the initiative sponsored through agreements between the Attorney General of North Carolina and Smithfield Foods and Premium Standard Farms are described.     

Stakeholder Involvement in Coastal Decision-making Processes

This article discusses the current framework of coastal decision making which tends to exclude participation by individuals and those without a strong institutional representation. A distinction is drawn between institutional and local stakeholders to illustrate weaknesses in the existing decision framework. It is argued that particularly in the coastal environment, the relationship between changes in physical form and changes in social welfare is critical to understanding how decision making may engage more fully with local stakeholders and ultimately improve decision outcomes. A reordering of stakeholder engagement in decision systems at the coast is proposed and a framework is outlined which enhances the capacity of local stakeholders to influence decision making.     

Book reviews

“Water Planning and the Regions”

Edited by P. J. Purdy, R. S. A.

Discussion Paper No. 9, 1977, £1.50.

Tenant participation in council housing management; Housing Development.

Directorate Occasional Paper 2/77, DoE London, 1977.

Getting tenants involved: a handbook on systems of tenant participation in housing management; DoE London, 1977.

La politica dei servizi tra razionalizzazione e rinnovamento

Alberto L'Abate (1978)

Marsilio Editori, Padova, pp. 316

Handbook for Environmental Planning: the social consequences of environmental change.

J. McEnvoy & T. Dietz (1977)

New York, J. Wiley, pp. 323. Price £15.50

Planning and Urbanism in China

Progress in Planning Vol. 8, Part 2, Fo. 1 N. Jeffrey and M. Caldwell, pp. 97–182, 1977

Pergamen, £4.00

The European Community's Regional Fund

Ross B. Talbot

Progress in Planning, Vol. 8, Part 3, pp. 183–281

Pergamon Press, 1977

Providing the Posh Words

W. Hampton, DoE

1978. £1.50. 60pp.

Four Titles on Conservation

A Critical Bibliography of Building Conservation. John F. Smith. Mansell, London 1978. 207 pages including index. Hard back, £12.90.

Conservation and Planning. Alan Doby. Hutchinson — The Built Environment. 1978. 173 pages. Some illustrations. Paper back, £3.25.

A Study in Conservation. Winston Barnett and Cyril Winskell. Oriel Press, 1977. 45 pages, in English, French and German. Illustrated. Paper back, £3.75.

Interpreting the Conserved Environment. Working Paper No. 29. Brian Goodey. Oxford Polytechnic Department of Town and Country Planning, 1977. 65 pages. Paper back, not priced.

“Belgium”, R. Riley, £3.25, 205 pp.

“The Netherlands”, D. Pinder, £3.25, 194 pp.

“The USSR”, J. C. Dewdney, £3.25, 262 pp.

Development Strategy of Bangladesh

Nurul Islam

Oxford, Pergamon Press, 1978, 109 pp.     

VARIABILITY OF SOIL WATER PROPERTIES AND CROP YIELD IN A SLOPED WATERSHED1

ABSTRACT: Spatial distribution of soil and water properties and the correlations between them and crop yield were determined for a natural rainfall environment. Hydraulic conductivity, soil texture, water retention, and soil-water flux were variables used to investigate their relationship to crop yield using multiple regression techniques. Variations in crop yields on a watershed with a 3 to 4 percent slope and moderately erosive soils were related to soil-water characteristics and soil properties along slope and with depth. Climatic conditions to sustain crop growth and yield ranged from inadequate soil water in 1983 to adequate soil water in 1984. Crop yield was predicted with models using both available and measured soil-water content. Available water content provided a better model for the prediction of water yield and does not require field measurements of actual soil-water content. Soil water holding capacity was more significant for predicting crop yield in soils with moderate to high silt content than infiltrability of water into the soil.     

Reviews

Shadrach Woods, The Man in the Street, Harmondsworth, Penguin, 1975

W. Houghton Evans, Planning Cities, London, Lawrence & Wishart, 1975, £7

R. Taylor, M. Cox & I. Dickens eds., Britain's Planning Heritage, London, Croom Helm for The Royal Town Planning Institute, 1975. £5.75 (hardcover) £3.50 (paperback)

Development Plan Evaluation and Robustness: Application of an Analytical Programme and a Review of Measures of Performance, Department of the Environment Research Report 5 Local Government Operations Research Unit Report C217, 1976. Gratis.

J. Appleton, The Experience of Landscape, London, John Wiley, 1975

J. D. Hunt & P. Willis eds., The Genius of the Place: The English Landscape Garden 1620–1820, London, Paul Elek, 1976. £12.50

N. Pevsner, Staffordshire, Harmondsworth, Middx., Penguin Buildings of England Series, 1974, £3.50 (hardcover)

R. Bailey & M. Brake eds., Radical Social Work, London: Edward Arnold, 1975. £4.25 (hardcover) £1.95 (paperback)

and

The Use of Action Research in Developing Urban Planning Policy: Report of Colloquium, Bristol, June 1975 London, Department of the Environment, 1975.

M. Harloe, Swindon: A Town in Transition, London, Heinemann for the centre for Environmental Studies, 1975.

D. W. Pearce ed., The Economics of Natural Resource Depletion, London, Macmillan, 1975.

J. B. Goddard, Office Location in Urban and Regional Development

B. Fullerton, The Development of British Transport Networks

B. T. Robson, Urban Social Areas

P. L. Knox, Social Well‐Being: A Spatial Perspective

Four volumes in the Theory and Practice in Geography series, edited by J. W. House, A. S. Gouldie & J. H. C. Patten and published by Oxford University Press, 1975. All paperback at £0.90.

James A. Swan & William B. Stapp eds., Environmental Education: Strategies Toward a More Liveable Future, Halstead Press — John Wiley, 1974.

A. G. Wilson & M. J. Kirkby, Mathematics for Geographers and Planners, Oxford: Clarendon Press, 1975     

受西班牙阿斯纳科利亚尔黄铁矿有毒污染液影响的土壤和植物中镉和锌浓度

引言 阿斯纳科利亚尔矿处于自西班牙中南部延伸至葡萄牙的黄铜矿丰富地带,劳斯福若斯是该矿的一个新开采地点,位于西班牙南部塞维尔以西45km,于1996年开工.提炼具有极高商业价值的锌(Zn)、铅(Pb)和汞(Hg)等高等级矿石产生了大量的重金属矿泥污水和高酸度废水(pH 2),而这些废水贮存在残渣围坝内,1998年4月25日,一处50m宽的决口使600万m3富含重金属的酸性废水和有毒矿渣泥浆(2:1的比例)泄漏到流经唐娜纳的高迪亚玛河(Gaudiamar).     

DNA adducts as early bioindicators of chemical exposure

Sensitive analytical methods indicate the presence of hundreds of chemical contaminants in our environment. However, concentration of these pollutants is usually at the low parts per million or parts per billion level. At such low levels, toxicants induce long-term (chronic) rather than short-term (acute) toxicities. Experiments are designed to evaluate chronic toxicity using early bioindicators. Recently, fish have been used as experimental animals because some species show early (weeks as opposed to years in other research animals), sensitive responses. Thus, medaka (Oryzias latipes), following exposure to diethylnitrosamine (DEN), exhibited liver tumors in several weeks; more interestingly its DNA was modified (to a DNA-adduct) after only 24–48 hours exposure. Such adducts show promise as early bioindicators because they are formed within hours of exposure. The formation of DNA-adducts were monitored in medaka and rainbow trout (Salmo gairdneri) exposed to DEN by aqueous or intra-peritoneal routes. Using HPLC-Fluorimetry, O ⁶-ethylguanine (O ⁶-EtGua) was detected and monitored in acid thermal hydrolysates of DNA isolates. (Detection limit for O ⁶-EtGua was as low as 3 ng, 1.7×10^-11 moles). Fourier transform cyclotron resonance mass spectrometry with IR laser desorption/ionization was used advantageously to establish the structure of nucleotides, bases and nucleosides directly, without further cumbersome derivatizations. Other aspects of DNA-adducts are discussed.