The significance of lead entering the human food chain via livestock ingestion from the agricultural use of biosolids, with special reference to the UK
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Published version
Author(s)
Smith, Stephen R
Rigby, Hannah
Type
Journal Article
Abstract
Long-term application of biosolids to agricultural soil results in the slow accumulation of potentially toxic elements (PTEs), which are regulated by maximum permitted limit values to protect human health and the environment. Two programmes of UK government-funded (MAFF/DoE) research were commissioned in the 1990s to investigate the safety of the controls on PTEs in relation to the potential transfer to the food chain via the animal ingestion route by sheep grazing biosolids-amended soil. Here, we re-examine this evidence in the light of other recent research and revised food quality standards, to determine the significance of lead (Pb) accumulation in soil from the agricultural use of biosolids. Direct ingestion of biosolids-amended soil is the main transfer pathway of Pb to grazing livestock. The concentrations of Pb in muscle tissue of animals grazing biosolids-amended soil observed in the MAFF/DoE trials, and reported in the scientific literature, were generally small and similar to background, control values. Lambs and ewes ingesting biosolids-amended soil with a total Pb concentration > 200 mg kg-1 dry soil at a rate of 10 % in the diet exceeded the current maximum permitted concentration of Pb in offal (0.5 mg kg-1 fresh weight). However, the decline in PTE concentrations found in biosolids, due to improved industrial practices and stricter controls on the emissions of contaminants to the environment in general and wastewater in particular, has mitigated the risk of Pb accumulation above the food quality standard for this element in offal. Given the significant improvements in biosolids quality, and particularly in the Pb content, regulatory soil and sludge limits for Pb are no longer likely to have a practical or significant impact on the amount of Pb entering the food chain through the animal ingestion route from biosolids-amended agricultural soil.
Date Issued
2024-06-10
Date Acceptance
2024-03-30
Citation
Science of the Total Environment, 2024, 928
ISSN
0048-9697
Publisher
Elsevier
Journal / Book Title
Science of the Total Environment
Volume
928
Copyright Statement
© 2024 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
License URL
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/38569961
Subjects
Agriculture
Animals
Food Chain
Humans
Lead
Livestock
Sheep
Soil
Soil Pollutants
United Kingdom
Agriculture
Biosolids
Food quality
Human diet
Lead
Livestock ingestion
Publication Status
Published
Coverage Spatial
Netherlands
Article Number
172135
Date Publish Online
2024-04-01