Kaur Rajbir, Dua Anish
Aquatic Biology Laboratory, Department of Zoology, Guru Nanak Dev University, Amritsar, 143005, Punjab, India.
Environ Sci Pollut Res Int. 2015 Apr;22(7):5100-10. doi: 10.1007/s11356-014-3710-1. Epub 2014 Oct 24.
The aim of the study was to evaluate the toxic impact of wastewater from sites 1 and 2 of Tung Dhab drain in the state of Punjab, India, on fish behaviour, morphology and gill histopathological biomarkers in comparison to control group. Static non-renewal tests were conducted for 96 h to determine LC50 of the wastewater for both sites using five concentrations (6.25-100%). Fish were regularly noticed for any deviation in behaviour and external morphology. Physico-chemical analysis of wastewater was done using standard methods recommended by APHA/AWWA/WEF (2005). Chronic toxicity tests were conducted for 15 and 30 days with sublethal concentrations of wastewater (50-90% of LC50) and gill histopathology was assessed. Wastewater near a paper mill was more toxic as observed from LC50 values of 72.45%. There was evident deterioration of water quality as the recorded values of some parameters were higher than the standard discharge limits. The test fish exhibited increased air gulping and surfacing, erratic movements initially and decreased opercular movements as the exposure period increased. Morphological observations include increased body colouration, mucus secretion, scale loss and haemorrhages on the skin and lower lip. Alterations in the gill histology such as complete lamellar fusion, epithelial lifting and intraepithelial oedema, haemorrhages, lamellar necrosis and aneurysm were noted in the test fish. Results demonstrate that the fish exposed to wastewater from both sites showed significantly greater change in gill organ index (IG) as compared to control fish for 15 and 30 days.
本研究的目的是评估印度旁遮普邦通德哈布排水渠1号和2号站点的废水，与对照组相比，对鱼类行为、形态和鳃组织病理学生物标志物的毒性影响。进行了96小时的静态非更新试验，使用五种浓度（6.25 - 100%）确定两个站点废水的半数致死浓度（LC50）。定期观察鱼类的行为和外部形态有无任何偏差。废水的理化分析采用美国公共卫生协会/美国水行业协会/水环境联合会（2005年）推荐的标准方法进行。使用废水的亚致死浓度（LC50的50 - 90%）进行了15天和30天的慢性毒性试验，并评估鳃组织病理学。从72.45%的LC50值可以看出，造纸厂附近的废水毒性更大。由于一些参数的记录值高于标准排放限值，水质明显恶化。随着暴露时间的增加，试验鱼出现了更多的吞气和浮出水面现象，最初运动不稳定，鳃盖运动减少。形态学观察包括体色加深、黏液分泌增加、鳞片脱落以及皮肤和下唇出血。在试验鱼中观察到鳃组织学的改变，如完全的鳃小片融合、上皮隆起和上皮内水肿、出血、鳃小片坏死和动脉瘤。结果表明，与对照鱼相比，暴露于两个站点废水的鱼在15天和30天时鳃器官指数（IG）的变化显著更大。
