engleski

Biomarker responses of earthworms exposed to organophosphate insecticide dimethoate

Pesticides are poisons of synthetic or biological origin that are used to control and suppress the effects of organisms that are considered to be harmful. The usage of pesticides has a very broad implementation and plays a significant role in agricultural production, forestry and public health. However, despite the benefits, there are significant damages associated with the use of pesticides. Namely, many pesticides are toxic to nontarget organisms, including beneficial soil organisms, such as earthworms. Because of their natural habitats and continuous exposure to chemicals present in the soil, earthworms are a suitable indicator species for ecotoxicological assessment of pesticide soil pollution. The aim of this study was to investigate effects of widely used organophosphate insecticide dimethoate on different earthworm species. For assessing the toxicological effects of pollutants on earthworms two most commonly used toxicity tests were applied – preliminary filter paper contact test and artificial soil test which is more representative of the natural earthworm environment. Suborganismic effects of dimethoate were examined by analyzing following biomarkers – acetylcholinesterase (AChE), carboxylesterase (CES), catalase (CAT) and efflux pump activities. The results of this study showed that dimethoate caused significant changes in measured biomarkers and that different earthworm species display different sensitivities to dimethoate exposure. The response of measured molecular biomarkers using different toxicity tests had certain similarities ; however some distinct differences were also evident. The obtained results indicate that the application of environmentally relevant doses of dimethoate, i.e. doses that are applied in agriculture, could have harmful effects on earthworms.

soil pollution; dimethoate; earthworm; toxicity tests; biomarkers

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