Toxicity Study of Endocrine Disrupting Chemicals (EDCs) on Freshwater Fish Cyprinus Carpio

Abstract

Water. It is one of the basic needs of all living creatures; be it man, plant or animal. The pharmaceutical waste dumping in the freshwater bodies in one of the main problems. These wastes contain many chemicals, antibiotics and other substances that degrade the water quality; and make it unworthy of human use and/or aquatic life. This work focuses on one of the main pollutants: Endocrine Disrupting Chemicals (EDCs). Some main examples are: Amoxicillin, Paracetamol and Diclofenac. These are Antibiotics and thus more commonly used. The chosen freshwater fish species for this study was Cyprinus carpio at fingerlings, juveniles and adult life-stages. This species is moderately tolerant to adverse conditions, hence an ideal choice. Also, it is very commonly found in the freshwaters of South Asian regions. The study comprised of two sets of experiments: Enzyme Assays and Predictive Toxicological Analysis. The Enzyme Assays comprise of (a) studying the Behavioral, Physical and Biochemical Responses induced by the pollutant exposure and (b) understanding the effects of presence and/or absence of water plants. The Predictive Toxicological Analysis gives an estimation of the impact of the same pollutants on some other freshwater species. From our experiments (Enzyme Assays), we have come to believe that, the newborn fishes are more susceptible to the pollutants than the adults. Also, one more interesting phenomenon was observed. The juvenile fishes showed more resistance to toxicity than both new-born and adult fishes. Literature says that, the enzymes and their activity at this growth stage is so active that it manages to get acclimatized with the toxic conditions. So, the situation imitates a vaccination procedure where the subject is given lower doses of pathogens (toxins, in this case) to help develop immunity to the higher loads of same pathogens (toxins, in this case). The Amoxicillin affected the liver most, whereas Paracetamol and Diclofenac paralyzed the muscle and brain tissues. The Predictive Toxicological Analysis provided that the genetically closer species (to C. carpio) were more endangered by these pollutants than the taxonomically related ones. The farther the relation from C. carpio, lesser the chances of almost same reactions and toxic effects.