Resumo

UC-PERAZA, Russell Giovanni  e  DELGADO-BLAS, Víctor Hugo. Mean lethal concentration (LC₅₀) of four biodegradable household detergents in Laeonereis culveri (Webster 1879) (Polychaeta: Annelida). Rev. Int. Contam. Ambient [online]. 2012, vol.28, n.2, pp.137-144. ISSN 0188-4999.

The toxicity of four formulations of biodegradable household detergents was experimentally tested (Roma^®, Foca^®, Puro-Sol^® and Blanca Nieves^®), using Laeonereis culveri (Webster 1879) as test organism. The Probit method was used to determine the LC₅₀ of the formula and the active ingredient from Linear Alkylbenzene Sulfonate (LAS), with a confidence level of 95 %. The results obtained showed that Laeonereis culveri when exposed to the detergents, had the following order of sensitivity according to the test LC₅₀-48 h: FOCA^®(formula: 59.56; LAS: 12.88 ppm) > Blanca Nieves^® (formula: 70.79; LAS: 13.03 ppm) > Roma^® (formula: 89.12; LAS: 13.48 ppm) > Puro-Sol^® (formula: 91.83; LAS: 14.12 ppm). Significant differences were found (p <0.05) in relation to the toxicity of the four detergent formulations and also according to the different concentrations. The risk quotient (RQ) in all cases was higher than 1, suggesting that biodegradable detergents can cause damage to living organisms in the sediment and consequently to the entire ecosystem. This species is proposed as a tool for environmental risk assessment for household detergents.

Palavras-chave : Laeonereis culveri; polychaeta; ecotoxicity; linear alkylbenzene sulfonate; bioassays; anionic surfactants.