Oxidative stress in earthworms short- and long-term exposed to highly Hg-contaminated soils

► We examined Hg-induced oxidative stress in the muscle of soil-dwelling earthworms. ► Reduced/oxidized glutathione ratio was a good biomarker of short-term Hg exposure. ► Endogenous scavengers had a pivotal role in reducing Hg-induced oxidative stress. ► We suggest the integrated biomarker responses index for assessing Hg-polluted soils.