ABSTRACT
One of today's major concerns endangering our lives in big metropolitan cities around the world is the complicated phenomenon of smog formation in hot weather. Air pollution episodes and alerts bring home the need to understand how all of us contribute to creating these problems so that we can find ways to protect the quality of the air we share. The aim of a major Air Quality Study [AQS] is to provide the basis for developing appropriate and cost effective strategies to control air pollution. A pivotal component of an AQS programme is to provide an up-to-date and computerized air emissions inventory. The inventory in turn can be used to develop and validate other computer models which are being produced as part of AQS to assess air quality, particularly in relation to photochemical smog in summer and brown haze in winter. The purpose of this paper is to give an overview of the complex task of preparing an emission inventory for an AQS. It draws experiences gained in developing an extensive inventory affecting an area in excess of 30,000 km2. Estimates of volatile organic compounds, oxides of nitrogen, carbon monoxide, sulfur dioxide and air-borne particulates were summarized on a 3 km 3 km grid system. The sources were principally: motor vehicles, industry, domestic and natural sources [vegetation and soils]. The paper also discusses key cost effective strategies to control sources of photochemical smog and brown haze