Air pollution and replacement of bus fleet in Salvador, BA, Brazil

Abstract

INTRODUCTION: Air pollution is a major problem that affects public health in urban areas around the world. Salvador is a big city with a fleet of 819 237 000 vehicles. The bus fleet corresponds to 8775 vehicles. The risk analysis approach involving the health surveillance agency and research sector was instituted in Salvador since 2005 to support policies that aimed to reduce pollution sources in the city. In January 2015 a political decision decreed the renewal of the fleet with the circulation of 850 new vehicles. The objective of this study was to evaluate the impact on air quality in urban areas after the replacement of the fleet. METHODOLOGY: Daily records of PM10, CO, SO2, NO2, O3, were obtained from the eight air monitoring stations of Salvador. Data were analyzed using geographic information system. Daily averages were calculated of the all pollutants for the years 2014 and 2015. The averages were compared before and after the new vehicle circulation. RESULTS: Our results showed reduction of air pollution pollutants in 2015, especially particulate matter. Conclusions: The replacement of new fleet was a decision that improved the air quality in Salvador city. The risk management is a relevant phase in the risk analysis. Periodic analysis on the air quality data by surveillance agency is a crucial point. These information can be usefull to measure the impact about public actions for reduction of pollution sources.