The city that pioneered the use of emissions-free electric buses is promoting the vehicles as a way to relieve pollution in developing countries. Environmentalists and transportation officials from around the world have gathered at Chattanooga this week to learn how the buses can help the clear the air in busting Third World cities."We are starting to develop an awareness of pollution in Egypt," said Talaat Ghabbour, Chairman of Afico Filters in Cairo, which next month will begin making electric cars.