Imperial College Consultants Ltd., 58 Prince's Gate, Exhibition Road, London SW7 2PG, UK.
Chemical Contaminants and Residues Branch, Food Safety Policy, Food Standards Agency, Clive House, 70 Petty France, London SW1H 9EX, UK.
Sci Total Environ. 2023 Aug 15;886:163546. doi: 10.1016/j.scitotenv.2023.163546. Epub 2023 Apr 18.
Recycled bioresources (biosolids, compost-like-output, meat and bonemeal ash, poultry litter ash, paper sludge ash) were added to the feed of dairy cattle to simulate incidental ingestion from agricultural utilisation, to investigate the transfer of organic contaminants from the ingested materials to milk. The bioresources were blended with a loamy sand soil at agronomic rates to simulate a single application to land, which was added to the diet at 5 % of the total intake on a dry matter (DM) basis. Biosolids, and control treatments consisting of unamended soil, were also added directly to the feed at 5 % DM. The cattle were fed the bioresource amended diets for a target period of three to four weeks, depending on material, and monitoring continued for four weeks after treatment withdrawal. Milk samples were taken weekly with chemical analysis of selected samples for a range of organic contaminants including: polychlorinated, polybrominated and mixed-halogenated dioxins, furans and biphenyls, polychlorinated naphthalenes and alkanes (often called chlorinated paraffins), polycyclic aromatic hydrocarbons and chlorobenzenes. No statistically significant additional transfer of organic contaminants to the milk was detected due to the relatively low levels of contaminants present when the bioresources were incorporated with soil at agronomic rates. However, direct biosolids ingestion by cattle significantly increased the transfer of contaminants to milk in comparison to control animals. Although present in larger concentrations in biosolids than their chlorinated counterparts, the carry over rates and bioconcentration factors of brominated dioxins and furans were considerably smaller. Direct ingestion of biosolids resulted in most contaminants approaching, but not always completely reaching, steady state concentrations within the treatment feeding period, however, concentrations generally declined to control values within four-weeks after withdrawing the biosolids-amended diet.
回收生物资源（生物污泥、类似堆肥的产物、肉骨粉、家禽粪灰、纸浆污泥灰）被添加到奶牛饲料中，以模拟农业利用中的偶然摄入，研究从摄入的材料向牛奶中转移有机污染物。将生物资源与壤土混合，以农业比例模拟单次施用于土地，然后将其以干物质 (DM) 基础的总摄入量的 5%添加到饮食中。还将生物污泥和由未添加土壤组成的对照处理直接以 5% DM 添加到饲料中。根据材料的不同，奶牛以生物资源添加的饮食喂养目标期为三到四周，处理停止后继续监测四周。每周采集牛奶样本，并对选定样本进行一系列有机污染物的化学分析，包括：多氯、多溴和混合卤代二恶英、呋喃和联苯、多氯萘和烷烃（通常称为氯化石蜡）、多环芳烃和氯苯。由于在农业比例下将生物资源与土壤混合时存在的污染物水平相对较低，因此没有检测到有机污染物向牛奶中转移的统计学上显著增加。然而，与对照动物相比，牛直接摄入生物污泥会显著增加污染物向牛奶中的转移。尽管溴代二恶英和呋喃在生物污泥中的浓度比氯化物高，但它们的残留率和生物浓缩因子要小得多。直接摄入生物污泥导致大多数污染物接近，但并非总是完全达到处理喂养期内的稳定状态浓度，然而，在停止添加生物污泥添加的饮食后四周内，浓度通常会降至对照值。
