Histopathological Effects of Pyrethroid-Based Mosquito Coil Smoke on the Reproductive Organs of Rabbits

Abstract

Pyrethroids are used as pesticides to control agricultural pests and ectoparasites in animals and humans. Compared with other insecticides, they are readily biodegradable and exhibit relatively low mammalian toxicity while remaining highly effective against insects. This study aimed to assess the toxic effects of mosquito‑repellent coils (Mortein) on mammalian gonads using rabbits as the model organism. A total of 16 mature rabbits were divided into four groups (n=4/group). Four rabbits served as the control group, exposed only to normal room air, while 12 rabbits were assigned to experimental groups (R1, R2, R3) and exposed to mosquito‑coil smoke for 3, 5, and 8 hours per day, respectively, for 30 days. On day 31, all rabbits were sacrificed and the gonads were extracted for histopathology. In males, microscopic evaluation revealed degeneration of the spermatogenic layer, reduced spermatocytes, and proliferation of intertubular connective tissue. In females, irregular follicles, decreased follicular number, and cellular necrosis were observed. Given that Mortein coils are commonly used indoors in Pakistan, these findings indicate potential risks to human reproductive health. Therefore, alternative control methods should be considered, and exposure time minimized when coils are used.