**4. Risk of emerging pollutants**

PPCPs are present in our environment at very low concentrations ranging from ng/L to μg/L but there is paucity of information about the various secondary metabolites generated during the biotransformation of parent compounds [16] The impact of the metabolites could be more toxic than the main compounds and their adverse effect on non-target organism is less understood [30]. The longtime exposure to PPCPs pose severe threat to aquatic biota and human life. Also, many studies on environmental toxicology on the exposure of non-target organs to PPCP are results from acute toxicity data [31–33]. Many PPCPs contained bioactive ingredient that could have a chronic effect non-target biota. Goldfish shows bio-centration factor of 113 when it is exposed to high concentration of PPCPs for 14 days [34]. Chronic effect could lead to gene mutation and decline in fish population. For instance, diclofenac may cause ill-effect on fish organs. Fish are susceptible to PPPCPs contaminants since they live in the environment where these contaminants are present [35]. The presence of carbamazepine and diclofenac in aquatic environs damaged algal chloroplasts [36]. Long time exposure to Sulfamethoxazole cause severe toxicity and inhibit photosynthesis process [37]. Also, ciprofloxacin is toxic to green algae [38]. Natural bacteria developed antibiotic tolerance in PPCP antibiotic contaminated environments [39]. Endocrine disrupting chemicals are also referred to as hormones in aquatic or aqueous environments. Some endocrine chemicals reduce the proper functioning of endocrine system (ES) that is physiological activities [40]. For example, retardation in reproductive processes such as sex variation, poor metabolic and embryonic developments [41]. These environmental hormones could cause serious effects on both aquatic and terrestrials animals through inhibition and modification of hormonal growth in ES and hormones in the cell correspondingly [42].
