Risk assessment of the use of PAS100 green composts in sheep and cattle production in Scotland

• Published in: Waste management (Elmsford) 2012, Vol.32 (1), p.117-130
• Main Authors: Hough, Rupert L., Booth, Philippa, Avery, Lisa M., Rhind, Stewart, Crews, Colin, Bacon, Jeffrey, Campbell, Colin D., Tompkins, David
• Format: Article
• Language: English
• Subjects: Animal Husbandry - standards; Animal wastes; Animals; Applied sciences; Cattle; Dioxins; Dioxins - analysis; Exact sciences and technology; Furans - analysis; Heavy metals; Herbicides - analysis; Metals, Heavy - analysis; Organic pollutants; Other wastes and particular components of wastes; PAHs; PCBs; Plants, Toxic; Pollution; Polychlorinated Biphenyls - analysis; Polycyclic Aromatic Hydrocarbons - analysis; Risk Assessment; Scotland; Sheep; Soil - analysis; Soil Pollutants - analysis; Toxic alkaloids; Toxins, Biological - analysis; Wastes
• ISSN: 0956-053X; 1879-2456
• DOI: 10.1016/j.wasman.2011.08.008

► First quantitative risk assessment of use of greenwaste compost in agriculture. ► 497 potentially hazardous agents screened, 147 quantitatively assessed. ► Risk estimates compared to those associated with six comparator materials. ► PCB28, PCB138, PCB153, 1,2,3,4,6,7,8-HpCDD, Clopyralid posed risks to livestock. ► Greenwaste compost found to pose less risk than other soil amendments. A generalized quantitative risk assessment for the use of source-segregated green waste (SSGW) compost use in livestock production is presented. This assessment focussed on potential risks associated with a specific product, PAS100 compost that meets the UK publicly available specification 100 and represents the majority of compost available for use in extensive Scottish livestock systems. A hazard screening approach was used to identify all potentially hazardous agents present in compost. A total of 497 potentially hazardous agents were screened, with 147 finally put forward for quantitative risk assessment. Scenarios modelled in the assessment included surface application of compost to grazing land and also incorporation into soil and subsequent uptake by fodder crops. Risk estimates were compared to those associated with six comparator materials, including various sludges, slurries and farm yard manures. Overall, five potentially hazardous agents (PCB28, PCB138, PCB153, 1,2,3,4,6,7,8-HpCDD, Clopyralid) returned a hazard quotient >1 but within margins of uncertainty, indicating that further investigation may be required. Within the limitations of available information, SSGW compost was found to pose less risk to grazing livestock, or the environment, than other commonly-used soil amendments. While this assessment relates to a specific product/standard used in the UK, the methodology could easily be applied to other composts/products/situations. Therefore these results have wider applicability.