Oil sands process-affected water (OSPW), a byproduct of the extraction of bitumen in the surface mining of oil sands, is currently stored in massive on-site tailings ponds. Determining the potential effects of OSPW on aquatic ecosystems is of main concern to oil sands companies and legislators concerned about the reclamation of mining sites. In the present study, the interaction of OSPW with the chemosensory system of rainbow trout was studied. Using an electro-olfactography (EOG) technique, a 24 h inhibition curve was established and concentrations that inhibit the olfactory system by 20% and 80% (IC20 and IC80) were estimated at 3% and 22% OSPW, respectively. To study the interaction of exposure time and concentration along with the mechanism of the toxic effects, rainbow trout were exposed to 3% and 22% OSPW for 2, 24, and 96 h. An EOG investigation of olfactory sensitivity demonstrated a positive interaction between exposure time and concentration of OSPW concentration, because an increase in either or both elevated the inhibitory effect. To investigate whether or not structural damage of the olfactory epithelium could account for the observed inhibitory effects of OSPW on fish olfaction, the ultrastructure of the olfactory epithelium of exposed fish was investigated using scanning electron microscopy (SEM) and light microscopy (LM). The SEM micrographs showed no changes in the structure of the olfactory epithelium. The light micrographs revealed an increase in the number of mucous cells in 22% OSPW. The results of the present study demonstrated that exposure to OSPW impairs the olfactory system of rainbow trout and its effects increase gradually with increasing exposure time. The present study demonstrated that structural epithelial damage did not contribute to the inhibitory effects of OSPW on the olfactory system.

油砂受过程影响的水（OSPW）是油砂表面开采中沥青提取的副产品，目前存储在大型现场尾矿池中。确定OSPW对水生生态系统的潜在影响是油砂公司和关注采矿场复垦的立法者主要关注的问题。在本研究中，研究了OSPW与虹鳟鱼化学感应系统的相互作用。使用电子嗅觉（EOG）技术，建立了24小时抑制曲线，估计将嗅觉系统抑制20％和80％的浓度（IC20和IC80）分别为3％和22％OSPW。为了研究暴露时间和浓度之间的相互作用以及毒性作用的机理，虹鳟鱼分别在3％和22％的OSPW中暴露2小时，24小时和96小时。嗅觉敏感性的EOG研究表明，暴露时间与OSPW浓度之间存在正相互作用，因为二者之一或两者的增加会提高抑制作用。为了研究嗅觉上皮的结构损伤是否可以解释观察到的OSPW对鱼嗅觉的抑制作用，使用扫描电子显微镜（SEM）和光学显微镜（LM）研究了裸露鱼的嗅觉上皮的超微结构。SEM显微照片显示嗅觉上皮的结构没有变化。光学显微照片显示，OSPW中22％的粘液细胞数量增加。本研究的结果表明，暴露于OSPW会损害虹鳟鱼的嗅觉系统，并且其影响会随着暴露时间的增加而逐渐增加。本研究表明，结构上皮损伤对OSPW对嗅觉系统的抑制作用没有贡献。