Agricultural application of digestates derived from agricultural and municipal organic wastes: a health risk-assessment for heavy metals

• Published in: Journal of environmental science and health. Part A, Toxic/hazardous substances & environmental engineering Toxic/hazardous substances & environmental engineering, 2021, Vol.56 (13), p.1409-1419
• Main Authors: Beggio, Giovanni, Bonato, Tiziano, Schievano, Andrea, Garbo, Francesco, Ciavatta, Claudio, Pivato, Alberto
• Format: Article
• Language: English
• Subjects: Adult; Agricultural land; Agricultural wastes; Agriculture - methods; background concentrations; Bioavailability; Carcinogens; Child; China; Environmental Monitoring; Health risk assessment; Health risks; Heavy metals; Humans; Metal concentrations; Metals, Heavy - analysis; Modelling; Moisture content; Organic wastes; plant uptake; Risk Assessment; Sediment pollution; Soil; Soil contamination; Soil investigations; Soil Pollutants - analysis; Soil pollution; Soil water; Soil-plant transfer; Soils
• ISSN: 1093-4529; 1532-4117
• DOI: 10.1080/10934529.2021.2002628

A Human-health Risk Assessment was performed for an agricultural site in North-East Italy undergone digestate application to (i) check the compliance of digestate land spreading with the Italian and European regulations on contaminated agricultural soils and (ii) evaluate how resulting risk estimations can be influenced by the applied modeling assumptions. The assessment estimated the risk related to adults and children intake of Heavy Metals (HM) contained in crops at concentrations estimated by a soil-plant transfer model based on the substance-specific soil-water partition coefficients. Eight different scenarios were investigated, according to different digestate type (from biowaste and agro-industrial byproducts), digestate application techniques and soil background concentrations. Non-risky situations resulted in all scenarios involving digestate application. The totality of calculated non-carcinogenic Hazard Indexes ( ) and carcinogenic total risk ( ) resulted below 0.02 and 3E10 −9 , respectively. In contrast with the definition, non-carcinogenic risks were associated with the considered soil background concentrations, with s up to 1.7 for child receptors, while carcinogenic risk was calculated below the concern threshold (i.e., < 10 −5 ). Accordingly, this study highlighted (i) non-concerning situations related with lawful application of digestates and (ii) the need to improve the modeling of bioavailability to plant of HMs background content of soil.