Is There Something in the Air? Sources, Concentrations and Ionic Composition of Particulate Matter (PM_(2.5)) in an Industrial Coastal City in Southern Brazil

摘要

Rio Grande (RS, Brazil) is a coastal municipality in which the climatic conditions are driven mainly by the wind regime. The city harbours important port and industrial activities that may affect residential areas. In this sense, the main goal of the present study was to investigate, for the first time, concentrations and ion composition of the atmospheric particulate matter (PM 2.5) in this peculiar city. Air samplers were installed in both urban and urban-industrial zones from October 2009 to May 2011, filtering particles 2.5 mu m one to three times a month. PM 2.5 concentrations and their ionic composition (Na+, Mg2+, Ca2+, K+, NH4+, F-, Cl-, NO3-, NO2-, SO42- and PO43-) were determined, as well as the contribution of natural (originated from the sea salt) and anthropogenic ions in the samples. PM 2.5 concentrations ranged from 6.74 to 88.14 mu g m(-3) in the urban-industrial area and from 11.24 to 53.44 g m(-3) in the urban zone, exceeding quality criteria established by WHO and CONAMA in more than 50% of the samples collected, in both areas. Ion analysis in PM 2.5 evidenced a strong contribution of ions coming from industrial sources in the composition of PM 2.5, both in the industrial and the urban zone.