Evaluation of the genotoxicity of waters impacted by domestic and industrial effluents of a highly industrialized region of São Paulo State, Brazil, by the comet assay in HTC cells

Abstract

The problems that most affect the quality of the waters of rivers and lakes are associated with the discharges performed in these environments, mainly industrial and domestic effluents inappropriately treated or untreated. The comet assay is a sensitive tool and is recommended for studies of environmental biomonitoring, which aim to determine the genotoxicity potential of water pollutants. This study aimed to assess the genotoxic potential of the Ribeirão Tatu waters, region of Limeira, São Paulo (SP), by the comet assay with mammalian cells (hepatoma tissue culture (HTC)). Water samples were collected along the Ribeirão Tatu at three distinct periods: November 2008, February 2009 and August 2009, and five collection sites were established: P1, source of the stream; P2, site located downstream the urban perimeter of the municipality of Cordeirópolis and after receiving the pollution load of this city; P3, collection site located upstream the urban perimeter of the city of Limeira; P4, urban area of Limeira; and P5, rural area of Limeira, downstream the discharges of the city sewage. The results showed that for the November 2008 collection, there was no water sample-induced genotoxicity; for the February 2009 collection, the sites P1 and P2 were statistically significant in relation to the negative control (NC), and for the August 2009 collection, the site P5 was statistically significant. These results could be explained by the content of different metals during the different seasons that are under the influence of domestic, industrial and agricultural effluents and also due to the seasonality, since the water samples collected in the period of heavy rain (February 2009) presented a higher genotoxicity possibly due to the entrainment of contaminants into the bed of the stream promoted by the outflow of rainwaters. The comet assay showed to be a useful and sensitive tool in the evaluation of hydric resources impacted by pollutants of diverse origins, and a constant monitoring should be done in order to verify the influence of different factors (season, amount of contaminants) in the water quality.

Genotoxic and mutagenic effects of polluted surface water in the midwestern region of Brazil using animal and plant bioassays

“…According to Kabata-Pendias and Pendias (1992) and Manzano et al (2014), when the levels of metals are above the national regulation standards, they might become toxic to plants and other organisms. The high metal concentrations in the stream water found in our study might have resulted from the disposal of untreated effluent from the industrial district and agricultural areas.…”

“…The development of economic activities in the last five decades has caused an increase in the concentrations of metals in water resources, impacting the natural environment ( Matsumoto and Marin-Morales, 2005 ). According to Kabata-Pendias and Pendias (1992) and Manzano et al (2014) , when the levels of metals are above the national regulation standards, they might become toxic to plants and other organisms. The high metal concentrations in the stream water found in our study might have resulted from the disposal of untreated effluent from the industrial district and agricultural areas.…”

Ecotoxicological risk assessment of the “Acid Black 210” dye

“…In our study Acid Black 210 showed no genotoxic effects on the HepG2 cells at concentrations between 0.5 and 5000 mg/mL by comet assay. Matsumoto et al (2003) showed the genotoxic potential of the water of a river receiving tannery effluents by the comet assay and Manzano et al (2015) showed the genotoxicity of waters impacted by domestic and industrial effluents. Both authors suggest that the genotoxicity could be associated with the metals discharged by the tanneries industries, especially chromium.…”

Toxicogenetic effects of low concentrations of the pesticides imidacloprid and sulfentrazone individually and in combination in in vitro tests with HepG2 cells and Salmonella typhimurium

“…A limit of 80% of viable cells was considered to perform the comet assay (Manzano et al, 2015). The genotoxicity tests with insecticide imidacloprid, herbicide sulfentrazone and the mixture of them were performed separately in this study.…”