In urban areas, the emission of pollutants produced in combustion processes causes the air contamination. Regarding traditional combustion products released from heating plants of residential sector, a study on their environmental impact and the proposal of appropriate strategies for urban pollution reduction, has been carried out. In the first part, some initiatives to reduce urban air pollution linked to heating systems operation, in order to increase the livableness of cities, are proposed. In the second part, a quantitative comparison among different fossil fuels which supply heating plants, both under the environmental and safety points of view, has been carried out. The investigation has included solar-hydrogen as new and cleaner energy carrier for the future. At this purpose, suitable quality indexes which measure the flammability and the expansiveness characteristics of the fuels have been introduced.