Effects of formalin on some biomarker activities of earthworms pre-exposed to temephos

► Effects of temephos and formalin on AChE, CAT, oximes and efflux pump in earthworms. ► Inhibition of AChE and CAT activity after exposure to temephos. ► Inhibition of AChE activity and induction of CAT activity after exposure to formalin. ► Short-term post-exposure to formalin changes effects caused by exposure to temephos. ► Exposure to formalin during the sampling could change effects caused by temephos.