Screening of natural surface waters of the Almaty region of the Republic of Kazakhstan for toxic and mutagenic activity

Abstract

Natural aquatic ecosystems are a habitat for many organisms, a source of drinking water, and a resource for human economic activity. However, natural surface waters have been subjected to intense anthropogenic pressure in recent decades. The current study was dedicated to investigating genotoxic potential in 15 rivers and 2 lakes of Almaty agglomeration (Kazakhstan) using a battery of bioassays. Non-diluted surface water samples were tested for mutagenic potential using Lux-based bacterial biosensors and a chromosome aberration test on Hordeum vulgare and Mus musculus. The studies involved lux-biosensors pRecA-lux, pColD-lux, pSoxS-lux, pKatG-lux did not find any genotoxic and oxidative effects. However, the mutagenicity of the studied water samples was detected by using plant and animal tests (Hordeum vulgare and Mus musculus). Mutagenic (increase in the frequency of chromosomal aberrations) activity of the water samples was observed. Among 17 sample collection points, surface waters of 12 were considered to possess mutagenic activity when tested on Hordeum vulgare. The results of the cytogenetic assay on mice bone marrow are alarming, as the survey proposed the strong genotoxic potential of water for mammals. Among 17 sample collection points, surface waters of 7 were considered to possess mutagenic activity when tested on Mus musculus. This comprehensive study indicates that the contamination of the surface natural waters poses a threat to river dwellers and the human population in the rivers and lakes areas.