Phytotoxicity and genotoxicity assessment of organic and inorganic contaminants detected in pharmaceutical industrial wastewaters using Vigna radiata and Allium cepa

Abstract

The discharged effluent of pharmaceutical industrial wastewater treatment plants (PIWWTPs) exhibits substantial environmental toxicity due to the intricate combination of organic and inorganic pollutants. This study assessed the phytotoxicity, genotoxicity, and cytotoxicity of untreated and treated pharmaceutical industrial wastewater (PIWW). Most of the physicochemical parameters viz. COD, BOD, EC, sulfide, sulfate, nitrate, phosphate, grease, phenols, and metal concentrations viz. B, Cr, Ca, Cd, Cu, Zn, Pb, Hg, and As in untreated wastewater (UTW) were noted beyond the permissible limit and remained higher in treated wastewater (TW). The findings revealed that the performance of PIWWTP was woefully inadequate. The GC-MS spectra of UTW and TW revealed the presence of various organic contaminants. The toxicological studies showed that the UTW had a high degree of phytotoxicity, which persisted even after the treatment as it inhibited the seed germination in Vigna radiata. The seed germination was inhibited up to 70% and 50% tested at 50% concentration of UTW and TW respectively. Genotoxicity was measured by determining mitotic index and chromosomal aberrations in Allium cepa root apex grown in untreated and treated PIWW. Compared to the negative control, the mitotic index dropped to 85% and 75% at the 50% concentrations of UTW and TW, respectively. Chromosomal aberrations were also found in the cellular mass of root apex growing in both UTW and TW. According to the findings, it is unsafe for the environment to release PIWW that has not been properly treated, as this could pose serious risks to environmental health.