Fine Particulate Matter in São Paulo During the Winter Months: Concentrations and Black Carbon Comparison Between Techniques and Equipments

Abstract:

During the winter months in São Paulo, Brazil, particulate matter and black carbon were monitored using a Dust Trak (TSI model 8533), a Black Carbon monitor (MAAP-Thermo) and a PM_2.5 sampler (Partisol-Thermo). The concentrations were obtained every 5 minutes, from June to August 2014, for the first and second and every 12 hours for the third. The experiment took place in a site at the University of São Paulo which is located in the Southeast part of the Metropolitan Area of São Paulo (MASP). MASP is one of the biggest urban centers of the world, with more than 20 million inhabitants, 10 million vehicles and high values of some regulated pollutants, as particulate matter, especially in winter. Ambient fine particles associated with vehicle emissions have been linked to adverse health effects. Black carbon has a significant share of particulate mass concentrations. Previous studies showed a contribution of more than 30% for São Paulo. This year the climate was atypical in São Paulo. The summer was the driest of the last 30 years. The winter was hot and also dry. Dust trak monitor showed peaks of more than 120 μg/m³ for PM_2.5. For a specific period, black carbon concentrations from the MAAP monitor were compared to black carbon measured by optical reflectance on teflon filters collected by the Partisol sampler. Monitor values were around 30% higher, but specific characteristics can influence this value. In the past, optical reflectance and thermal techniques for black carbon were compared. The reflectance technique showed higher results for the fine fraction than the thermal method. Now, reflectance is being compared to instrument measurements and results are also satisfactory.