A summary report is presented of the emission inventory for the San Juan, Puerto Rico Metropolitan Area. The report provides estimates of the present levels of air pollutant emissions and status of their control. The pollutants, which include sulfur oxides, particulates, carbon monoxide, hydrocarbons, and nitrogen oxides, are delineated with respect to source type, season of the year, and geographical distribution within the area. The Study Area is comprised of nine municipalities surrounding San Juan. A grid coordinate system was used to show the geographical distribution of emissions within the municipalities. All sources of emissions were classified into one of five categories: transportation, stationary fuel combustion, solid waste disposal, industrial process losses, and evaporative losses. (Author)