Osweiler G D, Olesen B, Rottinghaus G E
Am J Vet Res. 1984 Feb;45(2):244-6.
Six calves were fed grain and hay from a pentachlorophenol (PCP)-treated feeder twice daily. Samples of blood were collected twice a week. Plasma PCP concentrations increased rapidly to a maximum of 1,086 microgram/L within 10 days. After the 3rd week, calves were denied access to the treated feeder; PCP values returned rapidly to near base line (before calves were fed from the treated feeder). After base-line plasma PCP values were reached, 4 of the 6 calves were housed in a total confinement building and exposed (by inhalation) to lumber that was commercially treated with PCP. The building itself was free of structural PCP-treated lumber. The ratio of building volume to treated wood surface was approximately 49 to 1. During the 3 weeks the calves were confined, PCP values did not increase and were markedly lower than those associated with oral exposure to treated wood. Oral dosing of calves with PCP in capsules--0.05 and 0.5 mg/kg--resulted in maximal plasma PCP values of 1,449 and 9,555 micrograms/L, respectively. Oral exposures (feeding from contaminated feeder; capsule) appeared to be more important than inhalation in causing increased plasma PCP concentrations in cattle. Exposure from these sources may be estimated by comparison with experimental values from dose-response studies. Feeding from treated feeders resulted in lower plasma PCP values than did dosing with 0.05 mg/kg daily.
六头小牛每天两次从用五氯苯酚（PCP）处理过的饲料槽中进食谷物和干草。每周采集两次血样。血浆中五氯苯酚浓度在10天内迅速上升至最高1086微克/升。第三周后，不再让小牛使用经处理的饲料槽；五氯苯酚值迅速恢复到接近基线水平（小牛开始从经处理的饲料槽进食之前）。在达到基线血浆五氯苯酚值后，6头小牛中的4头被安置在完全封闭的建筑中，并（通过吸入）接触用五氯苯酚进行商业处理的木材。建筑本身没有经过结构处理的含五氯苯酚木材。建筑体积与处理过的木材表面积之比约为49比1。在小牛被关在建筑中的3周内，五氯苯酚值没有增加，且明显低于与口服接触处理过的木材相关的值。给小牛口服含五氯苯酚的胶囊——剂量分别为0.05和0.5毫克/千克——导致血浆五氯苯酚的最高值分别为1449和9555微克/升。在导致牛血浆中五氯苯酚浓度升高方面，经口暴露（从受污染的饲料槽进食；口服胶囊）似乎比吸入更重要。可通过与剂量反应研究的实验值进行比较来估算来自这些来源的暴露量。从经处理的饲料槽进食导致的血浆五氯苯酚值低于每天口服0.05毫克/千克的剂量。
