Fries G F, Marrow G S, Cook R M
Environ Health Perspect. 1978 Apr;23:43-50. doi: 10.1289/ehp.782343.
Cows fed a constant amount of polybrominated biphenyl (PBB) reached a steady-state concentration in milk fat within 30 days. This concentration was approximately four times the concentration in the total diet. When feeding of PBB was stopped, the concentration in milk was adequately described as a sum of two first-order elimination rates. Biological half-life in environmentally contaminated cows, studied for 6 months about a year after contamination, was 60 days. The stage of lactation affected the rate of elimination, and in some concentrations increased shortly after calving. Residues were distributed in body tissues proportionally to concentration of fat in the tissues. Liver and brain were exceptions. Concentration in liver fat was generally higher than other tissues and possibly related to the treatment of some cows with phenobarbital. Residues in brain fat were significantly lower than all other tissues. The ratio of the concentrations in milk fat to concentration of residues in the blood of calves and fat of fetal tissues to the concentration in the corresponding tissue in the dams was 0.36:1. It was estimated that people consuming milk from the highly contaminated Michigan cows could have received PBB doses as great as 10 g from this source alone.
给奶牛投喂恒定剂量的多溴联苯（PBB）后，30天内乳脂中的浓度达到稳态。该浓度约为总日粮中浓度的四倍。停止投喂PBB后，牛奶中的浓度可用两个一级消除速率之和充分描述。在污染约一年后对受环境污染的奶牛进行了6个月的研究，其生物半衰期为60天。泌乳阶段影响消除速率，在某些情况下，产犊后不久浓度会升高。残留物在身体组织中的分布与组织中的脂肪浓度成正比。肝脏和大脑是例外。肝脏脂肪中的浓度通常高于其他组织，这可能与一些奶牛用苯巴比妥治疗有关。脑脂肪中的残留物明显低于所有其他组织。乳脂中浓度与犊牛血液中残留物浓度以及胎儿组织脂肪中浓度与母体相应组织中浓度的比值为0.36:1。据估计，食用来自密歇根州受高度污染奶牛的牛奶的人仅从这一来源就可能摄入高达10克的PBB剂量。
