Human Exposure To Halogenated Aromatic Compounds

目的：多氯联苯及类似化合物是一个世界性的污染问题，在人体组织中普遍存在。多年来，我们一直在研究接触这些化合物对儿童发育的影响，在台湾的一次食物中毒事件中，在明显有毒的水平下，在墨西哥农村相对较高的农业暴露水平下，在美国的背景水平下。今年，只有玉城对台湾中毒人员的研究产生了新的分析，尽管我们使用了墨西哥研究的数据，为使用DDT抗击疟疾死灰复燃的新的全球辩论提供了信息。程序和技术：在另一项单独的研究中，我们检查并跟踪了1979年“雨城”事件中被多氯联苯和剧毒的多氯二苯并呋喃毒死的母亲所生的孩子。我们也跟踪了成虫。我们假设，在1995年，这些儿童将继续受到他们出生前接触多氯联苯/多氯二苯并呋喃的影响，就像他们在1991-1992年一样。我们假设成年人会报告更高的已知与多氯联苯相关的问题，如粉刺，但我们也假设女性会报告月经流量增加，可能还会出现月经困难，因为长期低水平暴露的二恶英毒性灵长类动物模型显示子宫内膜异位症。成就：在台湾，我们跟踪了大约117名通过胎盘暴露于高剂量多氯联苯和相关化合物的儿童。从1985年开始，我们记录了在1979年中毒发生到1985年期间出生的儿童有外胚层缺陷、发育迟缓和行为障碍。今年，我们第一次能够证明，到1995年，报告的儿童行为异常正在减少，尽管他们的发育迟缓仍然是固定的。这对多氯联苯如何影响大脑的研究具有影响，因为在之前的数据中，认知和行为异常一起发生，很难区分它们是通过相同还是不同的机制发生的。提交了一篇描述这项工作的论文。我们对台湾中毒成年人的一般健康状况进行了调查，其中一些人是我们一直在研究的孩子的母亲。由于这些化合物在猴子身上研究时对女性生殖系统有很大的毒性，我们非常感兴趣地发现，在老年女性中可以看到轻微的月经功能紊乱，只有微小的月经流量差异，而报告的月经异常、生育能力、家庭规模或性欲没有变化。那些主张使用滴滴涕控制疟疾的人声称，使用滴滴涕导致的发病率很低或根本没有。我们声称，缩短哺乳时间--我们在北卡罗来纳州和墨西哥观察到的与DDE暴露相关的情况--可能会导致相同地区的婴儿死亡率增加，因为那里的贫困和感染率很高，在这些地区喷洒疟疾是最合理的。如何最好地控制疟疾以及如何研究所使用策略的后果将是未来几年的一个活跃领域，因为已经有25个国家免除了S使用滴滴涕杀死蚊子的全球禁令。

Aims: PCBs and similar compounds are a worldwide pollution problem, and appear with high prevalence in human tissue. For many years we have been studying the consequences for child development of exposure to these compounds, at obviously toxic levels in a food poisoning incident in Taiwan, at relatively high agricultural exposures in rural Mexico, and at background levels in the US. This year, only the Yucheng, or oil disease, study of poisoned persons from Taiwan produced new analyses, although we have used the data from the Mexico study to inform the new, worldwide debate on the use of DDT to combat the resurgence of malaria. Procedures and techniques: In a separate study, we examined and then followed children who were born to mothers poisoned by PCBs and the highly toxic polychlorinated dibenzofurans in the 1979 "Yucheng" incident. We have also followed the adults. We hypothesized that, in 1995, the children would continue to be affected by their prenatal exposure to PCBs/PCDFs as they were in 1991-1992. We hypothesized that the adults would report higher rates of problems known to be associated with PCBs, like acne, but we also hypothesized that the women would report increased menstrual flow and perhaps dyspareunia, because of the primate model of dioxin toxicity showing endometriosis from long term, low level exposure. Accomplishments: In Taiwan, we have been following about 117 children who had transplacental exposure to high doses of PCBs and related compounds. Beginning in 1985, we have documented that the children who were born between 1979 when the poisoning occurred and 1985 have ectodermal defects, developmental delay, and a behavior disorder. This year, for the first time, we were able to show that, by 1995, the reported behavioral abnormalities in the children were diminishing, although their developmental delay remained fixed. This has implications for the study of how PCBs affect the brain, since in previous data the cognitive and behavioral abnormalities occurred together, making it difficult to tell whether they occurred through the same or different mechanisms. A paper describing this work is submitted. We did a survey of the general health of the adults who were poisoned in Taiwan, some of whom were the mothers of the children we have been studying. Since these compounds are very toxic to the female reproductive system when studied in monkeys, we were very interested to find the mild disturbance of menstrual function seen among the older women, with only minor differences in menstrual flow reported, and no change in reported dysmennorhea, fertility, family size, or libido. Those who advocate the use of DDT for malaria control claim that little or no morbidity results from its use. We claim that shortened duration of lactation, which we have observed in association with DDE exposure in North Carolina and Mexico, might result in increased infant mortality in the same regions where it would be most logical to spray for malaria, since poverty and infection rates are high there. The question of how best to control malaria and how to study the consequences of the tactics used will be an active area for the next several years, since 25 countries have gotten exemption s from the world wide ban on DDT to use it to kill mosquitoes.