Potential impact of fertilization practices on human dietary intake of dioxins in Belgium

Abstract

Dioxins can enter the food chain at any stage, including crop fertilization. Therefore, we developed a simple method for estimating the introduction of dioxins in the food chain according to various fertilization practices. Using dioxin's contamination data taken from the literature, we estimated that fertilization accounts for approximately 20% of the dioxin inputs on agricultural soils at country scale. For the estimations at the field scale, 6 fertilization scenarios were considered: sludge, compost, digestate, manure, mineral fertilizers, and a common fertilization scenario that corresponds to an average situation in Belgium and combines mineral and organic fertilizers. According to our first estimations, mineral fertilizers, common fertilization practices or manure bring less than 1 ng TEQ/m² while atmospheric deposition or digestate bring between 1 and 3 ng TEQ/m² and sludge or compost bring more than 3 ng TEQ/m². The use of solid fertilizers could potentially increase the dioxin levels in the 30 cm agricultural soil layer by 0 to~1.5% per year (up to~9% for the 5 cm thick surface layer). For animals, the increase in dioxin ingestion linked to the fertilization practices is lower than 1% for most scenarios with the exception of the compost scenario. Increases in human dietary intake of dioxin are estimated to be lower than 1% for conventional rearing methods (i.e. grazing animals are reared outdoor while pigs and poultry are reared indoor). Spraying liquid fertilizers on meadows and fodder crops, even if very limited in practice, deserves much more attention because this application method could theoretically lead to higher dioxin's intake by livestock (from 6 to~300%). Considering an average half-life of dioxins in soils of 13 years, it appears that the risks of accumulation in soils and in the food chain are negligible for the various fertilization scenarios.

Assessing the biological reactivity of organic compounds on volcanic ash: implications for human health hazard

“…Our study confirmed that ash can scavenge organic pollutants from the atmosphere which, upon ash deposition, may promote contact with soil, vegetation and water where they then can be taken up in the food chain (Dumortier et al 2012). Ingestion of contaminated food represents the major route of human exposure to dioxins and dioxin-like compounds (Van den Berg et al 2006).…”

Electricity from poultry manure: a cleaner alternative to direct land application

“…In addition, also animal manure contains approximately 0.6 ng TEQ/kg DM, which is potentially transferred to the food chain when spread on land (Dumortier et al 2012). The recycled ash mixture contains less than 5 ng TEQ per kg.…”

Organic Contaminant Content and Physico-Chemical Characteristics of Waste Materials Recycled in Agriculture

“…This compared to a total atmospheric deposition on agricultural soils equivalent to approximately 33.6 g TEQ year −1 , which was approximately 6 times greater than the total input from fertilizer materials. Fertilization with compost containing PCDD/Fs at the maximum regulatory limit resulted in an input of 10.38 ng TEQ m , estimated in a study conducted by Dumortier et al [41], to prevent harmful dietary intakes of dioxins. Overall, therefore, the concentrations of PCDD/Fs and dioxin-like PCBs present in waste materials spread to land may represent a smaller contamination risk compared to other sources, such as atmospheric deposition [40].…”

“…Venkatesan and Halden [41] analysed 12 PBDD/Fs in composited archived biosolids that were collected in 32 US States and the District of Columbia from 94 wastewater treatment plants as part of the US EPA national sewage sludge survey in 2001. Two PBDDs and five PBDFs were detected in the biosolids (all of which were detected in the present study), with a total mean concentration of 10,000 ng kg (Table 9), and were similar to the mean WHO2005-TEQ contribution observed by Venkatesan and Haldan [41] of 72 ng kg (Table 9). PBDD/Fs and PBBs may be present as impurities in commercial brominated flame retardants [42] which explains their presence in municipal biosolids and CLO derived from MSW.…”