Análise de toxicidade do Rio Parnaíba no perímetro do Distrito Industrial em Teresina – PI

Abstract

This study aimed to analyze the toxicity level of the Parnaíba River water within the perimeter of the Teresina Industrial District, Piauí, using a bioassay with Artemia salina, comparing two collection points located upstream (P1) and downstream (P2) of the industrial area. This was an experimental study with a quantitative approach, using samples collected from the Parnaíba River and analyzed in the laboratory of the Federal Institute of Piauí (IFPI). For the ecotoxicological bioassay, Artemia salina eggs hatched in a 2% saline solution were used. The organisms were exposed to water samples at different dilutions (100, 50, 25, 12.5, 6.25, and 3.12%), in triplicate, with mortality assessed after 24 hours. The interpretation of the results was based on observed mortality, LC50 estimation, and statistical comparison between the samples. The results showed high water toxicity at both evaluated points, with higher lethality at the point located after the Industrial District (P2), indicating a worsening of toxicity along the analyzed stretch. The average lethality rates were 95.26 ± 4.61% at P1 and 99.23 ± 1.33% at P2, with a statistically significant difference. The LC50 values also indicated high toxicity in both samples. It is concluded that the water of the Parnaíba River, in the studied stretch, presents a high ecotoxicological risk for Artemia salina, with evidence of increased contamination after the industrial perimeter. The findings reinforce the need for continuous and integrated monitoring, including complementary physicochemical and microbiological analyses, to support environmental management actions and effluent control in the context of Teresina–PI.