Rainwater and aerosol samples were collected for a period of two years in the city of Campo Grande (CG), in the Mato Grosso do Sul State located in the cerrado ecosystem. The concentrations of Na+, Ca2+, K+, Mg2+, Cl-, SO4(2-), NO3- and NH4+, were determined along with the pH of rainwater. Making use of these results, we inferred the dry and wet ionic deposition for the region. We suggest a new method to evaluate the dry deposition using results from bulk rainwater samples (dry + wet deposition) and wet only samples. These results were compared to the deposition estimated by aerosol sampling. Also the deposition in CG was compared to the deposition in other Brazilian cities that were previously studied. Even if there is no industries in CG where the principal sources of pollution are vehicle traffic (a permanent source) and biomass burning (seasonal activity), it can be observed that the wet deposition of various ionic species, in particular nitrogenous species, are equivalent to those obtained for industrialized and more populated cities. The CG results show that biomass burning is responsible for high K+, NO3-, NH4+ e SO4(2-) emissions. The regional charcoal factories are the responsible for the high Cl- emissions.
Pollution; Rainwater; Aerosol; Atmospheric chemistry
