Assessing potential indicator of endocrine-disrupting property of chemicals using soil invertebrates

Vitellogenin has been regarded as an acceptable indicator for evaluating the endocrine-disrupting property of chemicals using fish. However, the endocrine-disrupting property of chemicals has been rarely evaluated using soil species. This study aimed to find evidence that endocrine-disrupting chemicals (including the natural hormones estradiol and dihydrotestosterone) can affect the reproductive organs of earthworms. Earthworms were exposed to 17β-estradiol, dihydrotestosterone, bisphenol A, and methylparaben for seven days. The four EDCs inhibited normal oogenesis and maturation of oocytes in earthworm ovary, and dihydrotestosterone and bisphenol A were observed to damage earthworm seminal vesicle tissues and inhibit normal spermatogenesis. The evidence showed that the tested EDCs have an adverse effect on female and male reproductive systems of soil invertebrates. The results suggest that the evaluations of oogenesis and spermatogenesis in the ovary and seminal vesicles of earthworms are useful indicators for investigating the endocrine-disrupting property of chemicals. Additionally, our results encourage further studies on developing novel indicators using soil invertebrates to evaluate the effects of the toxicity of endocrine-disrupting chemicals on the soil ecosystem.