Disposal of dredged sediments in tropical soils: ecotoxicological effects on earthworms

Abstract

The upper limit concentrations of metals established by international legislations for dredged sediment disposal and soil quality do not take into consideration the properties of tropical soils (generally submitted to more intense weathering processes) on metal availability and ecotoxicity. Aiming to perform an evaluation on the suitability of these threshold values in tropical regions, the ecotoxicity of metal-contaminated dredged sediment from the Guanabara Bay (Rio de Janeiro, Brazil) was investigated. Acute and avoidance tests with Eisenia andrei were performed with mixtures

Ecotoxicological evaluation of swine manure disposal on tropical soils in Brazil

“…3). Other studies indicate that wastes with high OM content may not always influence or even benefit the development of earthworms (Rosa et al, 2007;César et al, 2014;Alves et al, 2015). Furthermore, in this case, the pH values at the end of the test (5.6; 5.6; 5.7 and 5.9 for the concentrations 0; 15; 30; 45 and 60 m 3 ha À 1 , respectively) may also have had a negative influence on E. andrei reproduction.…”

Bioensaios Com Oligoquetas Edáficos Para Avaliação Da Eficácia Do Tratamento De Resíduos De Mineração De Carvão Em Cenário De Disposição Terrestre

“…Esta constatação realça a importância do uso de solos locais na avaliação da ecotoxicidade, tendo em vista que parâmetros como pH, Eh, condutividade elétrica, mineralogia das argilas, oxi-hidróxidos de ferro e alumínio, matéria orgânica, dentre outros, desempenham papel de suma importância na toxicidade e na mobilidade geoquímica da contaminação (Rodrigues-Filho & Maddock, 1997;Matzke et al, 2008;Cesar et al, 2014;Cesar et al, 2015).…”

“…No caso dos solos, os oligoquetas edáficos (Eisenia andrei, Eisenia fetida) têm sido amplamente utilizados como organismos-teste na avaliação ecotoxicológica de solos contaminados, visto que possuem curto ciclo de vida, são simples de serem criados em laboratório e são de alta relevância ecológica servindo de alimento para diversas outras espécies terrestres (Neuhauser et al, 1985;Cesar et al, 2014). Além disso, a determinação dos teores de metais pesados nos tecidos dos oligoquetas sobreviventes dos ensaios possibilita a estimativa das frações potencialmente biodisponíveis daqueles elementos ao ecossistema do solo (Straalen et al, 2005).…”

Soil ecotoxicology in Latin America: Current research and perspectives

“…No feeding inhibition was observed in comparison with the experimental control for any test mixture in tests where collembolans were confined to each mixture. This study was followed by an ecotoxicity evaluation of this dredged sediment diluted with 2 local soils (ferralsol and chernosol) by Cesar et al . Although the chernosol mixtures had the highest total metal concentrations, the influence of the expansive clay minerals (with high ability to adsorb metals) and the high nutrient contents typical of this type of soil seem to have reduced ecotoxicity compared with ferralsol.…”

“…This includes cooperation with Brazilian Agricultural Research Corporation (EMBRAPA) Agrobiologia and EMBRAPA Florestas, the São Paulo Environmental Agency, the Minas Gerais Environmental Agency, and several Brazilian universities. Among the major outcomes are important studies on a metal‐contaminated site in Bahia (Brazil) , effects of waste disposal in soils in Rio de Janeiro (Brazil) , the use of organic residues as soil amendments , and effects of pesticides ; all of these have contributed to improvements in Brazilian protective regulations.…”