The quality of riverine water is largely influenced by anthropogenic activity; however, worldwide monitoring practices remain largely limited to assessing water physicochemical parameters. To evaluate the potential of river contaminants to cause biological effects, two standard tests with the Tradescantia plant were used: Trad-SHM (stamen hair mutations) and Trad-MN (appearance of micronuclei in sporogenic cells). Water samples were collected from nine localities along the two rivers of the Kura basin: before and after the towns of Spitak, Vanadzor, Tumanyan, Alaverdi, and before Akhtala. The sampling locations were impacted by different anthropogenic sources—domestic and agricultural (Spitak and Vanadzor) and domestic and mining (Tumanyan, Alaverdi, and Akhtala). The biological responses were compared to water quality monitoring data based on physicochemical parameters (ions and metals). Monitoring results indicated “good” or “average” water quality, except for the exceedance of Fe, Mn, Cu, and Pb concentrations in the mining-affected areas. However, Tradescantia showed significantly increased frequency of hair cell mutations and micronucleus formation from urban/agricultural to mining-affected samples. The multivariate PCA analysis distinguished between the samples by associating ammonium and nitrate levels with the samples from urban/agricultural areas and the concentrations of Fe, Mn, Co, and Al with the biological responses in mining-affected samples. However, most likely, toxic substances in the riverine waters acted synergistically. The results indicated that compliance with chemical standards does not necessarily equate to biological safety. They emphasize the need to incorporate biological effects into monitoring programs to improve their contribution to informed decision-making regarding environmental impacts.
Avalyan et al. (Sat,) studied this question.