CODA-CERVA, Veterinary and Agrochemical Research Center, Operational Directorate Chemical safety of the Food Chain, Leuvensesteenweg 17, B-3080 Tervuren, Belgium.
Sci Total Environ. 2012 Apr 15;423:47-54. doi: 10.1016/j.scitotenv.2012.02.008. Epub 2012 Mar 7.
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.
二恶英可以在食物链的任何阶段进入，包括作物施肥。因此，我们根据各种施肥实践开发了一种简单的方法来估计食物链中二恶英的引入。使用从文献中获取的二恶英污染数据，我们估计施肥约占农业土壤中二恶英输入量的 20%，在国家范围内。对于田间尺度的估计，考虑了 6 种施肥情景：污泥、堆肥、消化物、粪肥、矿物肥料和一个常见的施肥情景，该情景对应于比利时的平均情况，并结合了矿物和有机肥料。根据我们的初步估计，矿物肥料、常见施肥实践或粪肥带来的二恶英含量低于 1ng TEQ/m²，而大气沉降或消化物带来的二恶英含量在 1 到 3ng TEQ/m²之间，污泥或堆肥带来的二恶英含量超过 3ng TEQ/m²。使用固体肥料可能会使 30cm 农业土层中二恶英水平每年增加 0 到 1.5%（对于 5cm 厚的表层，最高可达 9%）。对于动物，大多数情况下，与施肥实践相关的二恶英摄入量增加低于 1%，除了堆肥情况。对于常规饲养方法（即放牧动物在户外饲养，而猪和家禽在室内饲养），估计人类膳食中二恶英摄入量的增加低于 1%。尽管在实践中非常有限，但对草地和饲料作物喷洒液体肥料应引起更多关注，因为这种应用方法理论上可能会导致牲畜摄入更高水平的二恶英（从 6 到 300%）。考虑到土壤中二恶英的平均半衰期为 13 年，对于各种施肥情况，土壤和食物链中二恶英积累的风险似乎可以忽略不计。
