Abstract
Recycling of materials (for example composts, industrial wastes, manures) to soil for agricultural benefit or ecological improvement represents a significant opportunity to maintain organic matter levels in soils as well as providing other benefits to soil. However, some organic returns can present soil with a range of potential pollutants such as metals, organic contaminants (e.g. veterinary medicines, pharmaceuticals, POPs, pesticides, personal care products and biocides) and microbial contaminants. Some of the contaminants can accumulate in the soils to levels where they can impair the long-term functioning. One of the objectives set out in the draft Soil Strategy for England is to establish the degree of risk from putting organic materials on soils and the consequences for human, animal and plant health and the environment, and seek to keep these risks at an acceptable level. As part of this work, it is necessary to establish whether the concentrations of these pollutants can be reduced prior to land application and further upstream. The aim of the project is to examine the sources of contaminants, with particular focus on metals, present in organic materials spread to land and what may influence these sources in order to to develop a strategy on how to reduce the loadings of these contaminant at source. The specific objectives are to: 1) Identify the contaminants and sources of contaminants present in materials spread onto land; 2) Quantify the relative contribution of the total load that the sources represent in each type of materials; 3) Identify ways in which these loadings could be reduced at source and during production of the organic materials; 4) Review the current legislation and voluntary/advisory initiatives that would enable these reductions and identify gaps; 5) Estimate by how much and in what timescales it may be possible to reduce the loading for each source and also as a proportion of the total load in the organic materials; and 6) Recommend the best option(s) for reducing these loadings at source.
United Kingdom