Lactational exposure to chlorinated dioxins ond related chemicals and evaluation of their toxicologicak risks to suckling

对产后2至3个月的12 4名母亲的母乳样本进行了二恶英、k二苯并呋喃和其他有机氯化合物的分析，括号中显示的它们的平均浓度和范围如下：二恶英、二苯并呋喃和共面多氯联苯为2，3，7，8-二恶英；0.957 ppt(0.146-2.92 ppt)，β-六氯环己烷；17.1 ppb(0.70-94.1 ppb)，总滴滴涕；13.9 ppb(1.03-61.4 ppb)，环氧七氯乙烷；0.18 ppb(0.02-1.39 ppb)，狄氏剂；0.17 ppb(0.02-1.04 ppb)，氯丹；3.22 ppb(0.33-14.5 ppb)和多氯联苯；4.78 ppb(1.00-20.9 ppb)。估计了母乳喂养中这些化学物质的总摄入量。出生后大约一年，106名母乳喂养的婴儿也采集了血液样本，以下是本次调查的主要结果。(1)母乳中二恶英、二苯并呋喃和共面多氯联苯As 2，3，7，8-二恶英含量与血液中CD8阳性淋巴细胞百分率呈负相关。因此，CD_4阳性…的比率CD8阳性淋巴细胞的活性随其水平的升高而增加。(2)母乳中高水平的二恶英、二苯并呋喃和共面多氯联苯如2，3，7，8-二恶英被认为显著增加了血液中TSH的浓度。在估计母乳中这些化学物质的总摄入量的情况下，也观察到TSH水平的这种增加。(3)高水平的DDT、狄氏剂或HCE可显著降低乳汁中CD4+淋巴细胞的百分率，使CD4+/CD8+淋巴细胞的比例随农药水平的升高而呈下降趋势。估计每种农药的总摄入量也会对淋巴细胞亚群产生同样的影响。(4)母乳中高水平的DDT和估计的母乳总摄入量可显著降低哺乳期血液中T_4的浓度，显著提高TSH的浓度。(5)多氯联苯对免疫系统和甲状腺激素状态的影响似乎没有二恶英和相关化学品或杀虫剂那么强和弱。较少

Breast milk samples obtained from 124 mothers at 2 to 3 months after childbirth were analyzed for dioxins, k dibenzofurans and other organochlorine chemicals and their mean concentrations and ranges, which were indicated in parentheses, were as follows : Dioxins, dibenzofurans and coplanar PCBs as 2,3,7,8-dioxin ; 0.957ppt (0.146-2.92ppt), beta-HCH ; 17.1ppb (0.70-94.1ppb), total DDT ; 13.9ppb (1.03-61.4ppb), heptachlor epoxide (HCE) ; 0.18ppb (0.02-1.39ppb), dieldrin ; 0.17ppb (0.02-1.04ppb), chlordane ; 3.22ppb (0.33-14.5ppb) and PCBs ; 4.78ppb (1.00-20.9ppb). Total intakes of these chemicals from breast-feeding were estimated.About 1 year after birth, blood samples were also obtained from 106 breast-fed babies and the following were the main results in this investigation. (1) Levels of dioxins, dibenzofurans and coplanar PCBs as 2,3,7,8-dioxin in the breast milk negatively correlated with the percentages of CD8-positive lymphocytes in the blood. Consequently, the ratios of CD4-posit … More ive to CD8-positive lymphocytes showed increasing tendency with their levels. (2) High levels of dioxins, dibenzofurans and coplanar PCBs as 2,3,7,8-dioxin in the breast milk were considered significantly enhance the concentration of TSH in the blood. This kind of increase in TSH level was also observed in case of the estimated total intake of these chemicals from the breast milk. (3) High level of DDT,dieldrin or HCE in the breast milk seemed significantly decrease the percentages of CD4-positive lymphocytes, and as a consequence, the ratio of CD4-positive to CD8-positive lymphocytes showed decreasing tendency with each level of these pesticides. Estimated total intake of each pesticide also elicited the same effects on the lymphocyte subpopulations. (4) High level in the breast milk and estimated total intake from the breast milk of DDT were considered significantly decrease the concentration of T_4 and significantly increase that of TSH in the blood of the suckling. (5) Effects of PCBs in the immune system and thyroid hormone status seemed not so strong and weaker than those of dioxins and related chemicals or the pesticides. Less