Decomposition of DNA staining agent ethidium bromide by gamma irradiation: Conditions, kinetics, by-products, biological activity, and removal from wastewater.

•Decomposition of ethidium bromide by gamma irradiation was investigated.•Reaction conditions, kinetics, and dose constants were determined.•HPLC and TOC studies of the decomposition solutions were conducted.•Biological activity and toxicity experiments of the decomposition solution were performed.•Removal of ethidium bromide from wastewater samples was achieved.