Schoenfuss H L, Levitt J T, Rai R, Julius M L, Martinovic D
Aquatic Toxicology Laboratory, St Cloud State University, St Cloud, MN 56301, USA.
Arch Environ Contam Toxicol. 2009 Apr;56(3):397-407. doi: 10.1007/s00244-008-9219-1. Epub 2008 Sep 4.
Many toxic effects of treated wastewater effluent on organismal and reproductive health have been documented. However, the physicochemical environment of treated wastewater effluent frequently differs considerably from that of its receiving waters and may affect organismal function independently of toxic effects. Teleost sperm, for example, may be affected by the higher osmolality of treated wastewater, as this sperm is activated for a brief period of time following ejaculation due to the sudden decrease in osmolality of its surrounding environment. In this study, we examined the effects of treated wastewater effluent on sperm motility to test the hypothesis that the higher osmolality of effluent compared to river water will adversely affect sperm activation in a concentration-dependent relationship. Treated wastewater effluent was collected on 5 days from the outflow of the Metropolitan Wastewater Treatment Plant, St. Paul, Minnesota, and from an upstream site on the Mississippi River. Milt aliquots collected from goldfish were diluted in an isotonic extender solution and subsequently activated in either deionized water, 100%, 50%, or 10% effluent, a synthetic ion mixture, or river water. Sperm motility and velocity were assessed at 15-s intervals for 1 min using a computer assisted sperm analyzer. Significant differences in performance parameters were found only at 15 s, with sperm motility and velocity declining rapidly at later sampling times. Predictably, deionized water resulted in the greatest activation of sperm motility, while motility exhibited a concentration-dependent decline in 10%, 50%, and 100% treated wastewater effluent. Interestingly, Mississippi River water and a synthetic ion mixture with an osmolality comparable to 50% effluent both resulted in the least amount of sperm activation. However, sperm activation in river water varied between collection days during the study. River water and 100% effluent both had low sperm activation characteristics despite a 10-fold difference in osmolality between these two treatments (1 and 10 mOsmol kg(-1), respectively). Results of this study indicate a concentration-dependent decrease in sperm motility in treated wastewater effluent as well as significant fluctuations of sperm activation in Mississippi River water. This study illustrates the complexity of assessing the effects of treated wastewater effluents and the difficulty of determining appropriate reference sites for such studies.
已记录了处理后废水流出物对生物和生殖健康的许多毒性作用。然而，处理后废水流出物的物理化学环境通常与其受纳水体有很大差异，并且可能独立于毒性作用而影响生物功能。例如，硬骨鱼精子可能会受到处理后废水较高渗透压的影响，因为射精后精子会因周围环境渗透压的突然降低而在短时间内被激活。在本研究中，我们研究了处理后废水流出物对精子活力的影响，以检验以下假设：与河水相比，流出物较高的渗透压将以浓度依赖关系对精子激活产生不利影响。从明尼苏达州圣保罗市城市污水处理厂的流出物以及密西西比河的上游站点在5天内收集处理后废水流出物。从金鱼收集的精液等分试样在等渗稀释液中稀释，随后在去离子水、100%、50%或10%的流出物、合成离子混合物或河水中激活。使用计算机辅助精子分析仪每隔15秒评估一次精子活力和速度，持续1分钟。仅在15秒时发现性能参数存在显著差异，在后续采样时间精子活力和速度迅速下降。不出所料，去离子水导致精子活力的最大激活，而在10%、50%和100%的处理后废水流出物中，活力呈现出浓度依赖性下降。有趣的是，密西西比河水和渗透压与50%流出物相当的合成离子混合物都导致精子激活量最少。然而，在研究期间，河水中的精子激活在不同收集日有所变化。尽管这两种处理的渗透压相差10倍（分别为1和10 mOsmol kg(-1)），但河水和100%流出物都具有低精子激活特性。本研究结果表明处理后废水流出物中精子活力呈浓度依赖性下降，以及密西西比河水中精子激活存在显著波动。本研究说明了评估处理后废水流出物影响的复杂性以及为此类研究确定合适参考站点的困难。
