Análise histórica da poluição ambiental no Estuário de Santos: estudo histológico das brânquias do molusco Mytella falcata (Orbigny, 1846) como bioindicador.

Abstract

It’s well known that estuarine ecosystem is true nursery of biodiversity. Although, the estuary of Santos stands out for being an extreme sensitive region. Which shelter the biggest port of Latin America, the Port of Santos, and the biggest industrial pole of Brazil, the Cubatão Industrial Pole. This ecosystem suffers with anthropic pressure and industrial pollution. In order that, emerge the need to monitor the region, with ecotoxicology and M. falcata molluscs being tools to indicate the quality of the environment. The present study intent to make an analysis of the situation of pollution in the estuary of Santos, ten years after the last study of ecotoxicology in the region. For that, sample collection of bivalves were realizes in three different points, wich expressed difference in anthropic impact. The point A was located in Rio Branco, where was no influence of industries. The B point was located in Ilha Barnabé, left side of Port of Santos, and it was in constant influence of industries and ships traffic. The point C, was located next to Companhia Siderúrgica Paulista (COSIPA), and was in constant contact with industrial pollution. The animals had their gill dissected and processed by histological routine, for final inclusion in paraffin. The gill sections were stained with hematoxylin and eosin for forward identification of any disturb. The slides were analyzed according a system of disturb classification, and attribution of frequency index, for final quantification of the observed alterations. For statistic background was realized normality test and difference significance test. The results indicated severe disturbs in Point B, such as tumors and necroses; in Point C were indentified from severe to mild disorders, such as tumors and infiltration. The A Point showed a lack of sever disorders, however it presented some of mild disturbs. These alterations are related to heavy metals and polycyclic aromatic hydrocarbons presence in high concentration. Through analysis of results and comparation with environmental reports, is possible to claim that ten years after the last study with bivalve ecotoxicology in the region, the estuary of Santos remain negatively impacted with the pollution. The presence of high levels of contaminants harm the health of estuary and their organisms.