Water Quality of Urban Streams: TheAllium cepaSeeds/Seedlings Test as a Tool for Surface Water Monitoring

Abstract

The present study investigates the genotoxic, mutagenic, and cytotoxic potential of surface waters in urban streams using Allium cepa and analyzes the applicability of this assay for environmental monitoring. Water samples were collected from three streams located in the urban area of a municipality in the south of Brazil. For each stream, two samples were collected, one upstream and one downstream of the pollution discharge site. Physicochemical evaluation indicated that all samples had various degrees of environmental impact, but substantial impact was seen for the downstream samples of the Preto and Pedras streams. All samples increased the frequency of chromosome aberrations (P < 0.05). The sample from Pedras downstream site also caused a decrease in mitotic index (P < 0.08) and increase in micronuclei (P < 0.08) frequency, indicating potential cytotoxicity and mutagenicity. The Pedras stream receives mixed industrial and urban wastewater, while the Lajeado and Preto streams receive wastewater predominantly domestic in nature, which may partially explain the difference in toxicity among the samples. Moreover, the Allium cepa seeds/seedlings were shown to be extremely sensitive in detecting the genotoxicity of environmental water samples and can be applied as the first tool for environmental health hazard identification and prediction.

Sediment drying-rewetting cycles enhance greenhouse gas emissions, nutrient and trace element release, and promote water cytogenotoxicity

“…Allium test is a highly sensitive bioassay whose results correlates with those observed in other organisms; thus, it is widely used to investigate chemical contamination and toxicity effects in aquatic ecosystems [77,78]. The mitotic index indicates the number of cells in division during the cell cycle [34].…”

Environmental diagnosis of water quality in situ and ex situ in streams in Upper Paraná River Basin, Brazil

“…Previous studies also reported a decrease in MI and an increase in CAI were also observed in A. cepa cells after exposure to water samples when compared to the NC in different periods and streams (Athanásio et al 2014;Da Silva et al 2018). These studies associated the alterations of these parameters with the agricultural products used around the collection sites.…”

“…The MI serves as an indicator for the analysis of the cytotoxic potential of various substances that may inhibit or increase cell proliferation (Leme and Marin-Morales 2009;Francisco et al 2018;). On the other hand, the chromosomal alterations measured by CAI indicated the presence of clastogenic and aneugenic agents in the environment, which allowed de ning the genotoxic effect (Athanásio et al 2014).…”

Bioassays based on higher plants as excellent dosimeters for ecotoxicity monitoring: A review

“…All treatments of wastewater in April 2012, at S5 in July 2012, at S1 and S5 in November 2012, at S5 in February 2013, and at S1 in April 2013 induced CA's. Athanásio et al (2014) investigated the genotoxic, mutagenic, and cytotoxic potentials of surface waters in urban streams using A. cepa test. Water samples were collected from three streams located in the urban area of a municipality in the south of Brazil.…”