Quality of Natural Waters Surrounding Campo Mourão, State of Paraná, Southern Brazil: Water Resources Under the Influences from Urban and Agricultural Activities

Abstract

The Campo and Km 119 rivers are sources of irrigation and water supply for the city of Campo Mourao, State of Parana, Southern Brazil. However, these rivers are under the influence of agricultural and urban activities, which compromise the quality of their waters. The present study evaluated the waters of these rivers in the vicinity of this municipality in two different hydrological periods of 2018 for physical and chemical parameters and potential cytotoxic, genotoxic, and toxic effects. Among the eight sites, in the dry and rainy periods, P1, P2, P3, P4, and P6—sites surrounded by agricultural activities, with nearby residences and with low and/or reduced riparian forest—presented a low concentration of dissolved oxygen and high concentration of nitrite, phosphate, and chlorine. The waters of P1, P2, P3, P4, and P6, in the two samplings, were cytotoxic to the root meristem cells of Allium cepa at 24 and 48 h of exposure, and toxic to Artemia salina nauplii at 24 h of exposure, with LC50 < 100 ppm. The results characterize water contamination by pesticides and urban waste from stormwater drains and runoff from the urban area. Therefore, waters of the Campo and Km 119 rivers in the vicinity of the city of Campo Mourao demonstrate the potential to cause adverse effects to man and the aquatic ecosystem. These results represent an alert to the public authorities of Campo Mourao and the State of Parana regarding the need to inspect the anthropic activities in that city in the vicinity of these rivers, and in the implementation of a management plan for the replacement of riparian forests in places close to urban area, in order to preserve the health of the population and the ecosystems that depend on these water resources.