Department of Occupational and Environmental Medicine, Bispebjerg and Frederiksberg Hospital, University of Copenhagen, Copenhagen, Denmark.
Department of Public Health, University of Copenhagen, Copenhagen K, Denmark.
Hum Reprod. 2022 Jun 30;37(7):1594-1608. doi: 10.1093/humrep/deac079.
Is fetal exposure to lower-chlorinated polychlorinated biphenyls (LC-PCBs) in indoor air of private homes built with PCB-containing materials associated with semen characteristics and testicular volume in adult men?
We observed only marginal and inconsistent associations between maternal exposure to PCBs in indoor air and semen quality, testicular size and reproductive hormones in the adult offspring.
Recent studies have shown LC-PCBs to exhibit endocrine-disrupting properties and increase the risk of cryptorchidism. Although exposure to LC-PCBs in indoor air is relatively common, the long-term impact of prenatal exposure on male reproductive health has not yet been investigated.
STUDY DESIGN, SIZE, DURATION: In this cohort study, participants were men (18+ years) whose mothers carried them while living in one of two residential areas where indoor air had been contaminated by LC-PCB evaporating from building materials in subsets of the apartments. Men were considered prenatally exposed if their mother had lived in a PCB-contaminated apartment and unexposed if their mother had lived in an uncontaminated apartment for a minimum of 1 year during the 3.6 years before conception or during the first trimester. Mothers of prenatally unexposed men could not have lived in a contaminated apartment at any point. Recruitment lasted from 2017 to 2019. In total, 73 exposed and 111 unexposed men gave a blood and semen sample.
PARTICIPANTS/MATERIALS, SETTING, METHODS: Percentage differences in semen volume, sperm concentration, total sperm count, morphologically normal spermatozoa, progressively motile spermatozoa and DNA fragmentation index (DFI) between prenatally exposed and unexposed men were estimated using negative binomial regression. Associations with total and calculated free testosterone (CFT), LH and FSH were modeled using the linear regression. Odds of small testicular volume was estimated with logistic regression.
Overall, the results of this study were conflicting. No differences in semen volume, sperm concentration, testosterone and CFT were observed between the groups, but there were slight indications of lower total sperm count, increased FSH and risk of small testicles, alongside lower sperm DFI and a higher proportion of normal spermatozoa in men exposed to LCB-PCBs from indoor air during fetal life. There is no apparent biologically plausible explanation for the apparently improved measures of DNA fragmentation and morphology, and these findings may have occurred purely by chance.
LIMITATIONS, REASONS FOR CAUTION: Owing to the indirect measure of exposure, lack of adjustment for paternal factors, the potential for self-selection due to known exposure status and fertility issues, inability to take time spent away from the residence, limited statistical power and lack of comparable literature, independent replication of the study in larger cohorts is warranted.
While our findings may appear reassuring for the large number of people residing and/or working in buildings with indoor air contaminated with LC-PCBs, further efforts to understand the full range of health consequences of fetal LC-PCB exposure are needed.
STUDY FUNDING/COMPETING INTEREST(S): The study was supported by the Independent Research Fund Denmark (ref no. 6110-00085B), Bispebjerg Hospital, Landsbyggefonden, Realdania (ref. no. PRJ-2017-00176), Grundejernes Investeringsfond (ref. no. 18-58) and Helsefonden (ref. no. 16-B-01-22 and 21-B-0412). K.S.H. was supported by FFIKA, Focused Research Effort on Chemicals in the Working Environment, from the Danish Government. The authors declare that they have no financial, personal or professional competing interests.
Not applicable.
在使用含多氯联苯材料建造的私人住宅室内空气中，胎儿接触低氯化多氯联苯（LC-PCBs）是否与成年男性的精液特征和睾丸体积有关？
我们仅观察到母体在室内空气中接触 PCB 与精液质量、睾丸大小和生殖激素之间存在轻微且不一致的关联。
最近的研究表明，LC-PCBs 具有内分泌干扰特性，并增加隐睾症的风险。尽管室内空气中 LC-PCBs 的暴露相对常见，但产前暴露对男性生殖健康的长期影响尚未得到研究。
研究设计、规模、持续时间：在这项队列研究中，参与者是男性（18 岁以上），他们的母亲在居住在两个住宅区之一时携带他们，这两个住宅区的室内空气中都含有从公寓中建筑材料蒸发的 LC-PCB。如果母亲在受孕前至少 1 年居住在受污染的公寓中，或者在受孕前的头三个月居住在受污染的公寓中，那么男性就被认为是宫内暴露的。如果母亲在任何时候都没有居住在污染的公寓中，那么宫内未暴露的男性就可以不考虑。招募工作从 2017 年持续到 2019 年。共有 73 名宫内暴露的男性和 111 名宫内未暴露的男性提供了血液和精液样本。
参与者/材料、设置、方法：使用负二项式回归估计宫内暴露和未暴露男性的精液体积、精子浓度、总精子数、形态正常精子、前向运动精子和 DNA 碎片化指数（DFI）的百分比差异。使用线性回归模型来评估与总睾酮和计算游离睾酮（CFT）、LH 和 FSH 的关系。使用逻辑回归估计睾丸体积小的几率。
总的来说，本研究的结果存在冲突。两组之间的精液体积、精子浓度、睾酮和 CFT 没有差异，但有一些轻微的迹象表明总精子数减少，FSH 增加，睾丸体积小的风险增加，同时精子 DFI 降低，形态正常的精子比例增加，宫内接触 LC-PCBs 的男性。对于 DNA 碎片化和形态的明显改善措施，没有明显的生物学上合理的解释，这些发现可能纯粹是偶然发生的。
局限性、谨慎的原因：由于暴露的间接测量、缺乏对父亲因素的调整、由于已知的暴露状况和生育问题导致的自我选择的可能性、无法考虑离开居住地的时间、有限的统计能力以及缺乏可比的文献，需要在更大的队列中对该研究进行独立复制。
虽然我们的研究结果可能会让居住在室内空气受到 LC-PCBs 污染的建筑物中或在这些建筑物中工作的大量人群感到安心，但仍需要进一步努力了解胎儿 LC-PCB 暴露的全部健康后果。
研究资金/利益冲突：该研究得到了丹麦独立研究基金会（6110-00085B）、比斯加普伯格医院、兰德斯比耶根基金会、Grundejernes 投资基金（18-58）和健康基金会（16-B-01-22 和 21-B-0412）的支持。K.S.H. 得到了丹麦政府 FFIKA（化学品在工作环境中的重点研究）的支持。作者声明他们没有财务、个人或专业利益冲突。
不适用。
