Affiliations: Key Laboratory of Terrestrial Ecological Process,
Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016,
China | College of Environmental Sciences and Engineering,
Nankai University, Tianjin 300071, China | College of Energy and Power Engineering, Xi'an
Jiaotong University, Xi'an 710049, China
Abstract: Acetochlor and methamidophos are two important agrochemicals which
are widely applied to agricultural production in northeast China. The
investigation on the earthworm Eisenia fetida as an important type of soil
animals exposed to single and binary-combined contamination of acetochlor and
methamidophos was thus carried out. The single toxic effect test showed that
the two agrochemicals had their toxicity to the earthworms living in phaiozem.
Acetochlor had a stronger acute toxic effect on the earthworms than
methamidophos. The mortality of the earthworms exposed to individual acetochlor
and methamidophos changed with an increase in the exposure time and the exposed
concentrations. The LD_{50} value of acetochlor and
methamidophos toxic to the earthworms was 115.6–275.3 and
29.5–228.6 mg/kg, respectively. The weight of the earthworms was a more
sensitive index compared to the mortality in indicating toxic effects of
acetochlor and methamidophos in phaiozem. When considering both the mortality
and the body-weight change, the combined pollution of acetochlor and
methamidophos in phaiozem resulted in their synergic toxic effects on the
earthworms.
