The increasing demands on our water resources require the rapid evaluation of water quality of surface waters near urban areas. The purpose of this study was to examine urban surface waters by rapid and cheap two biochemical-based assays: the peroxidase toxicity (Perotox) test and the prebiotic pyruvate-glyoxalate (pyr-glyox) pathway for malate synthesis. Surface waters samples were extracted on C18 solid phase cartridge and eluted with ethanol. The evaluation of plastic polymers was also determined as a proxy of water pollution. The data revealed that plastic materials were found in both small and large urban areas and were lower downstream a municipal treated effluent. The prebiotic assay for malate production was significantly blocked by water extracts for the most populated city (1.8 million population) and in the corresponding municipal effluent dispersion plume. For the Perotox assay, the same results were obtained for the surface water extracts. An add-on of the Perotox assay included a DNA protection index for the detection of potential genotoxic compounds. The DNA protection index was significantly increased at the most populated city and was lost in the treated municipal effluent dispersion plume. In conclusion, two highly sensitive biochemical assays are presented to quickly monitor changes in water quality from urban pollution where stronger impacts were found from highly populated cities and in some case in the corresponding wastewater dispersion plume.
Keywords: Surface water quality assessment, peroxidase, malate production, probiotic chemistry, plastic pollution.
Citation: Gagné, F., André, C. (2025). Evaluation of Surface Water Quality with Biochemical Assays. Adv Earth & Env Sci; 6(4):1-8. DOI : https://doi.org/10.47485/2766-2624.1083