No abstract

Purpose-The São Lourenço River (SLR) is used to supply potable waters for the cities of São Lourenço da Serra and Juquitiba, but receives the residues from the water treatment plants (WTPs) and sewage treatment plants (STPs), respectively. The purpose of this paper is to evaluate the impacts of the discharges of Juquitiba's WTP and STP on the quality of the SLR, by using an integrated approach based on different lines of evidence. Design/methodology/approach-Six sampling sites were established along the river and comprised areas situated upstream and downstream of the discharges. Five sampling surveys were performed between 2004 and 2006 for collecting water and sediment samples for ecotoxicological assays. In two of these campaigns, benthic community structure and geochemistry (metals, nutrients and sediment texture) were also assessed. Findings-Concentrations of P, Fe and Al in waters exceeded the national standards, but sediments were not considered to be contaminated by metals or nutrients. Water and sediments tended to exhibit marginal toxicities, excluding the sediments from JQT007 and JQT008 that were frequently toxic. Combination of geochemistry, toxicity and ecological indices indicated that some sites are not degraded, but in some stations the benthic alteration may be due to non-measured contaminants, especially in JQT007 and JQT008. Practical implications-As the use of waters from SLR for public supply has increased, these results show that action should be taken in order to reverse the environmental degradation of SRL. Originality/value-This research combined sediment and water quality assessments in order to provide a more suitable and reliable diagnostic of the environmental quality of the SLR.

This study evaluates the toxicity of the Microcystis aeruginosa strain RST9501, isolated from Patos Lagoon, to cladocerans using standard tests with Ceriodaphnia dubia. The strain RST9501 was compared with the non-toxic M. aeruginosa strain NPJT-01. Chronic effects were estimated by evaluating reproduction and growth in C. dubia exposed to increasing concentrations of M. aeruginosa. Alternative food source constituted by Pseudokirchneriella subcapitata and Artemia chow was made available for all treatments. The presence of the two strains of M. aeruginosa inhibited both reproduction and growth in C. dubia. Also, regardless the presence of microcystin, there was an increase in toxicity as the cell concentration of both strains increased.

Due to the need of showing the reliability of results from biological essays, such as in health and environmental areas, laboratories have been implementing quality systems, particularly ABNT NBR ISO/IEC 17025 (ABNT, 2001), which include as one of the requirements, the calculation of uncertainty in essays results. It is of common knowledge that estimating uncertainty in essays using organisms, such as animal and vegetal species, is difficult, preventing from meeting that requirement in the standard. The paper shows the calculation of uncertainties in influences quantities in these essays as a tool to allow validating the measuring process, by using the essays performed by Rhodia Environmental Impact Analysis Laboratory and IPEN Ecotoxicology Laboratory as examples.
Devido à necessidade de demonstrar a confiabilidade dos resultados de ensaios biológicos como, por exemplo, nas áreas de saúde e ambiental, laboratórios vêm implementando sistemas da qualidade, em especial a ABNT NBR ISO/IEC 17025 (ABNT, 2001) que inclui como um dos requisitos o cálculo da incerteza dos resultados dos ensaios. É reconhecidamente difícil de estimar a incerteza de ensaios que utilizam organismos, como com espécies animais e vegetais o que impede, consequentemente, o atendimento deste requisito da norma. O trabalho apresenta o cálculo de incerteza das grandezas de influências nestes ensaios como uma ferramenta que permite validar o processo de medição, utilizando como exemplos aqueles realizados pelos Laboratórios de Análise de Impacto Ambiental da Rhodia e de Ecologia e Ecotoxicologia do IPEN

ResumoO rio São Lourenço faz parte da bacia do rio Ribeira de Iguape, fornecendo água para o abastecimento dos municípios de São Lourenço da Serra e Juquitiba. O rio é utilizado também como corpo receptor de grande parte da carga poluidora gerada por esses municípios. Nesse contexto, o objetivo deste trabalho foi avaliar os impactos do lançamento de resíduos de estações de tratamento de água (ETA) e esgotos (ETE) sobre os sedimentos do rio São Lourenço. Foram estabelecidos seis pontos de coleta no rio (incluindo pontos a montante e a jusante, tanto para a ETA quanto para a ETE), tendo ocorrido seis campanhas de amostragem. Em todas foi coletado material para ensaios ecotoxicológicos, e em duas foi coletado material para caracterização da comunidade bentônica (março e setembro de 2006) e uma para avaliação química (setembro de 2006 AbstractSão Lourenço River (SLR) is part one of the Ribeira de Iguape River basin, and provides water to supply the cities of São Lourenço da Serra and Juquitiba. The SLR also receives large amounts of pollution from these municipalities. In this context, this study aimed to evaluate the impacts of the release of residues from water treatment (WTP) and wastewater treatment plants (WWTP) on the sediments of the SLR. Six sampling stations were established along the river (including upstream and downstream of both WTP and WWTP), and 6 sampling campaigns for sediments were conducted. In such 6 surveys sediments were collected for ecotoxicological tests, in 2 surveys, material was also collected for benthic community evaluation (March and September 2006), and in one survey samples for chemistry were taken (September 2006). Seven campaigns were conducted for water sampling aiming to ecotoxicological tests. The metal levels were low for all samples. The results indicate that SLR is influenced by other anthropic activities, beyond to WTP and WWTP discharges, and that sediments are more affected in this ecosystem.