[en] Gamma radiation and electron beams ionize matter similarly. More than 470 low-energy (150-300 KeV) electron accelerators were used in 1984 to cure paints and inks, to treat films, and to crosslink electrical wire insulation. A few higher-energy (5-15 MeV) accelerators are used to crosslink plastics and to sterilize medical disposables. The chief use of more than 135 cobalt-60 gamma irradiation plants in 1988 was to sterilize half the world's production of medical disposables, but also about 467,000 tonnes of food were irradiated annually in 21 countries. Possible future radiation applications include: sterilization of wastewater, of sewage sludge, and of waste from airlines, hospitals and laboratories; sterilization of animal feed and feedstocks for biotechnological processes; dechlorination of PCBs; radiolysis of lignin for paper making or other purposes