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The vulnerability of soils to pollution by heavy metals (extension to OC9325) - SP0127

Previous studies have shown that atmospheric deposition accounts for the greatest overall heavy metal inputs to soils; however, this route is the least understood of the major pathways for metals entering the soil due to difficulties in measurement. This study will extend for a further year the monitoring of rural heavy metal deposition from the atmosphere as a way of evaluating soil vulnerability to pollution (originally under project CSA 2736). The study will be composed of 3 objectives which are outlined as follows, together with ways in which they might be achieved: 1. Continuation of monitoring atmospheric deposition at 35 existing sites in England and Wales. Elements analysed will include toxicologically important elements (e.g. As, Cd, Cr, Cu, Ni, Pb and Zn), base cations which counteract acidification (Ca, K, Mg and Na) and other metals of interest both in terms of their contribution to metal inputs in soil and their role as pollution indicators (e.g. Ag, Al, Ba, Be, Co, Fe, Mn, Mo, Pt. Sr and Ti). Filtrates of rainfall and dry deposits will be analysed using electrical conductivity, inductively coupled plasma optical emission spectroscopy (ICP-OES) and hydride generation atomic absorption spectroscopy (HG-AAS, for arsenic). Insoluble residues will also be determined by membrane digestion in concentrated nitric acid followed by analysis using ICP-OES and HG-AAS; 2. Comparison of deposition from different monitoring sites. Using established monitoring sites, additional deposit collectors and rainfall gauges will be set up alongside existing frisbees. Standard frisbees will also be placed near to ground level for comparison with deposition levels collected at standard heights. Moreover, particle sizes of the deposits collected will be analysed using light and scanning microscopy. Any consistent and significant differences in deposition will be incorporated into estimates; and 3. Collation of data and preparation of reports. Results will be used to ensure that national soil resources are not subject to long-term, irreversible degradation or loss through environmental pressures.
Project Documents
• Final Report : Atmospheric deposition of metals in rural areas of England and Wales   (9219k)
• Final Report : The vulnerability of soils to pollution by heavy metals (extension to OC9325)   (1282k)
Time-Scale and Cost
From: 1998

To: 1998

Cost: £109,258
Contractor / Funded Organisations
Water Research Centre, ADAS UK Ltd., University - Reading
Environmental Protection              
Fields of Study
Soil Protection