Survival, growth, detoxifying and antioxidative responses of earthworms (Eisenia fetida) exposed to soils with industrial DDT contamination

Abstract

The survival, growth, activity of the biotransformation system phase II enzyme glutathione-S-transferase (GST) and the oxidative defense enzyme catalase (CAT) of earthworms exposed to the contaminated soils from a former DDT plant and reference soils were investigated, and compared with the corresponding indicators in simulated soil-earthworm system, unpolluted natural soils with spiked-in DDT series, to identify the toxic effects of DDT on earthworms and their cellular defense system in complex soil system. The results indicated that DDT level in the contaminated soils was significantly higher than that in the reference soils with similar level of other pollutants and soil characters. The mortality, growth inhibition rates, GST and CST activities of earthworms exposed to the contaminated soils were significantly higher than that in reference soils. The contribution of historical DDT in contaminated soils to earthworms was confirmed by the DDT spiked tests. DDT spiked in soils at rates of higher than 200 mg·kg −1 was significantly toxic to both the survival and the growth of earthworms. DDT significantly stimulated GST and CAT activity in earthworms after 14 days. The CAT and GST activities were also stimulated by DDT exposure at rates of 100 mg·kg −1 after chronic exposure (42 days). The results provide implications for validating the extrapolation from laboratory simulated soils criteria to contaminated soils and for making site risk assessments.

Toxicological assessment of pesticide contaminated soils with use of biotests

“…For example, LC 50 for p,p'-DDT is given as >1000 mg/kg, for γ-HCH as 68 mg/kg; and LC 50 for mancozeb, the most toxic of dithiocarbamates, is 299 mg/kg. Limited acute toxicity of p,p'-DDT against E. foetida is also confirmed by Shi et al (2016), who estimated its 14 d median lethal concentration (LC 50 ) to 273.8 mg/kg soil. Thus, it seems that only in sample MLY3 p,p'-DDT might have contributed to the observed mortality.…”

Toxicity Assessment of a Biolubricant Exposed to Eisenia fetida

“…The results were evaluated by probit analysis [20,[22][23][24][25] using the Statgraphics Centurion statistical program XVI. The experimental design used was completely randomized, with the worm mortality for LC50 used as the response variable.…”

“…All the flasks were subjected to 12/12 h light/dark periods at a temperature of 25-28 • C. Each concentration had four repetitions. The mortality (%) (for LC50) was evaluated at 14 days, without the addition of food [20,21].…”

Impact of Triazophos, Chemical Used in Soybean Crop, on the Growth and Reproduction of Eisenia Fetida

“…According to Wang et al [17], guadipyr showed low toxicity to earthworms and did not elicit an effect on earthworm reproduction or growth in artificial soils at concentrations of 100 mg/kg. Shi et al [18] found that contamination of DDT higher than 200 mg/kg was significantly toxic to both the survival and the growth of earthworms. Miglani and Bisht S.S. [19] concluded that the use of pesticides in agriculture systems results in many ecological problems.…”