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

对124名母亲在分娩后2至3个月的母乳样本进行了二恶英、k-二苯并呋喃和其他有机氯化学品的分析，其平均浓度和范围（括号内显示）如下：二恶英、二苯并呋喃和共面多氯联苯，即2，3，7，8-二恶英; 0.957ppt（0.146-2.92ppt），乙型六氯环己烷; 17.1ppb（0.70-94.1ppb），总滴滴涕; 13.9ppb（1.03-61.4ppb），环氧七氯（HCE）; 0.18ppb（0.02-1.39ppb），狄氏剂; 0.17ppb（0.02-1.04ppb），氯代甲烷; 3.22ppb（0.33-14.5ppb）和多氯联苯; 4.78ppb（1.00-20.9ppb）。估计了母乳喂养中这些化学物质的总摄入量。出生后约1年，还从106名母乳喂养的婴儿身上采集了血液样本，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（如2，3，7，8-二恶英）的水平与血液中CD 8阳性淋巴细胞的百分比呈负相关。因此，CD 4-T细胞的比例 关于我们 对CD 8阳性淋巴细胞的杀伤作用随其水平的升高而呈上升趋势。(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）被认为会显著提高血液中TSH的浓度。在估计从母乳中总摄入这些化学物质的情况下，也观察到TSH水平的这种增加。(3)高浓度DDT、狄氏剂和HCE可显著降低母乳中CD 4 ~+淋巴细胞的百分率，其结果是CD 4 ~+/CD 8 ~+淋巴细胞的比值随农药浓度的升高而呈下降趋势。每种农药的估计总摄入量也引起了对淋巴细胞亚群的相同影响。(4)母乳中高浓度DDT和估计母乳中DDT摄入量可显著降低哺乳动物血液中T_4浓度，显著升高TSH浓度。(5)多氯联苯对免疫系统和甲状腺激素状况的影响似乎不如二恶英和相关化学品或杀虫剂那么强。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