The use of burning or drying treatments to process waste is acceptable but only in big cities and combined with improved recycling, according to a study by the Andreas Papandreou Institute of Strategic Development Studies (ISTAME). Large cities like Athens and Thessaloniki, which dump virtually all their garbage, should aim to reuse, recycle or compost 60 percent of waste, submit up to 35 percent to «heat treatment» and send just 15 percent to landfills, the study said. Medium-sized cities (with up to 50,000 residents) can send 40 percent of garbage to landfills but are too small to warrant the creation of a heat treatment unit, the report said. It was unclear whether «heat treatment» meant burning or drying (which reduces the volume of garbage by removing moisture). «We do not back the unconsidered burning of refuse… but new technologies, if properly implemented, do not harm the environment,» said ISTAME President Costas Kartalis. ISTAME said it backed plans for three extra landfills in Attica but said dumping cannot continue indefinitely.