Pollitt F
Department of Health, London, United Kingdom.
Regul Toxicol Pharmacol. 1999 Oct;30(2 Pt 2):S63-8. doi: 10.1006/rtph.1999.1328.
Polychlorinated dibenzodioxins and polychlorinated dibenzofurans (dioxins) are contaminants with long biological half-lives. The most toxic dioxin, 2,3,7,8-tetrachlorodibenzodioxin (TCDD), has a half-life in humans of 9 years. A tolerable daily intake (TDI) of 10 pg/kg body wt/day has been recommended, which was derived from steady-state concentrations of TCDD at the no-observed-adverse-effect level in animal studies. Intakes of dioxins by breast-fed babies can exceed the TDI by almost 20-fold. However, assuming a half-life of 9 years for all dioxins, it can be shown that the steady-state body burden is not increased by the short period of high intake during breast feeding, compared to that resulting from ingestion of the TDI daily from birth. Therefore, the TDI appears to accommodate the high intakes of dioxins by breast-fed babies. For dioxins with a significantly shorter half-life than TCDD, it can be shown that breast feeding will lead to higher body burdens in early life than would have been reached by ingestion of the TDI daily from birth. However, these peak body burdens will still be below the steady-state body burden achieved by ingestion of 10 pg TCDD/kg body wt/day from birth.
多氯二苯并二恶英和多氯二苯并呋喃（二恶英）是具有长生物半衰期的污染物。毒性最强的二恶英，2,3,7,8 - 四氯二苯并二恶英（TCDD），在人体中的半衰期为9年。已建议每日耐受摄入量（TDI）为10皮克/千克体重/天，这是根据动物研究中未观察到不良影响水平下TCDD的稳态浓度得出的。母乳喂养婴儿的二恶英摄入量可能超过TDI近20倍。然而，假设所有二恶英的半衰期均为9年，与从出生起每日摄入TDI所导致的稳态身体负担相比，可以证明母乳喂养期间短时间的高摄入量不会增加稳态身体负担。因此，TDI似乎能够适应母乳喂养婴儿对二恶英的高摄入量。对于半衰期明显短于TCDD的二恶英，可以证明母乳喂养在生命早期会导致比从出生起每日摄入TDI所达到的身体负担更高。然而，这些身体负担峰值仍将低于从出生起每日摄入10皮克TCDD/千克体重所达到的稳态身体负担。
