Identifying environmental risk to male reproductive function by occupational sperm studies: Logistics and design options
Identifying environmental risk to male reproductive function by occupational sperm studies: Logistics and design options
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DOI：
10.1136/oem.53.8.511
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发表时间：
1996-08-01
影响因子：
4.9
通讯作者：
Baranski, B
中科院分区：
文献类型：
--
作者：
Bonde, JP;Giwercman, A;Baranski, B
男性生殖系统功能障碍可能是环境危害的敏感标志，其影响可能超出生殖功能范围。睾丸比身体的任何其他器官更容易受到热和电离辐射的影响，并且已知一些外源性物质在低水平暴露后会破坏精子发生。在暴露程度较高且易于记录的工作场所进行环境对人类健康影响的研究通常信息最丰富、最准确。精液分析提供了有关睾丸功能的容易获得的信息。与生育率和受孕时间等功能性指标相比，其主要优点是可以独立于婚姻和怀孕对男性进行检查，发现同一个人不同暴露情况下生育力的变化，并在生育力尚未发生变化时检测不利影响。在实施职业精子研究时，必须高度重视后勤问题。在某些情况下，用于初始精液制备和处理的移动实验室装置可以提高工作人员的依从性和精子细胞运动的质量。迄今为止，几乎所有男性生殖研究中使用的横断面设计存在一些严重的局限性，包括由于参与差异而导致的选择偏差、难以确定合适的参考组以及缺乏因果关系时间维度的信息。纵向设计充分解决了大多数这些限制。精液样本是在暴露于感兴趣的风险因素之前、期间和可能之后收集的，并且因果推论是基于一个人内精液变量随时间的变化而不是基于男性之间的差异。纵向研究的后勤工作可能会受益于雇佣前的健康检查，以招募新雇用的工人，并且需要更少的参与者来获得可比较的统计能力。总之，男科学方法和流行病学设计可用于实施有关环境对人类睾丸功能影响的有效研究。当目标是初步筛查环境对生育力的影响时，职业精子研究可能不应该是首选，但当需要证实或拒绝特定暴露对睾丸功能影响的早期证据时，应进行职业精子研究。
Malfunction of the male reproductive system might be a sensitive marker of environmental hazards, the effects of which may extend beyond reproductive function. The testis is more vulnerable to heat and ionising radiation than any other organ of the body and several xenobiotics are known to disrupt spermatogenesis after low level exposure. Studies of environmental impact on human health are often most informative and accurate when carried out in the workplace where exposures can be high and easy to document. Semen analysis provides readily obtainable information on testicular function. The main advantages in comparison with functional measures such as fertility rates and time taken to conceive are the possibilities to examine men independently of marriage and pregnancy, to find changes of fecundity with different exposures within the same person and to detect adverse effects when no alteration of fertility is yet taking place. In the implementation of an occupational sperm study considerable attention must be paid to logistic issues. A mobile laboratory unit for initial semen preparation and processing may in some situations increase worker compliance and the quality of sperm cell motility. The cross sectional design which has been used in almost all male reproductive studies so far has several severe limitations including selection bias because of differential participation, difficulties in defining a suitable reference group, and lack of information about the time dimension of the cause-effect relation. The longitudinal design deals adequately with most of these constraints. Semen samples are collected before, during, and possibly after exposure to the risk factor of interest and causal inferences are based upon change of semen variables within at man over time rather than upon differences between men. The logistics of the longitudinal study may benefit from pre-employment health examinations to enrol newly hired workers and require fewer participants to obtain comparable statistical power. In conclusion, andrological methods and epidemiological designs are available for the implementation of valid studies concerned with environmental impact on human testicular function. Occupational sperm studies should probably not be the first choice when the objective is initial screening of environmental impact on fertility but should be implemented when their is a need to corroborate or refuse earlier evidence that specific exposures have impact on testicular function.