The high use of ethanol fuel in Brazil leads to an atmosphere particularly rich in alcohols and aldehydes, especially in large urban areas. With the perspective of second generation ethanol production, automotive emissions associated with the use of this fuel are expected to increase, affecting the oxidative capacity of the atmosphere and public health. Acetaldehyde and formaldehyde have great relevance to human health, and the participation of hydrogen peroxide in the oxidation of alcohols, with consequent production of these compounds and organic acids, is still unknown. The emission and transformation processes that occur in the lower troposphere can be investigated via wet deposition since this is an important removal mechanism of gases and particulate matter in that compartment. This fact is evidenced by the particularly high concentrations of dissolved organic carbon and organic oxygenates in rainwater in Brazil, resulting from intense biomass burning and elevated use of ethanol fuel in the country. Little is known about the role of hydrogen peroxide in photochemical processes of formation or loss of ethanol and acetaldehyde, both in the atmosphere and in surface waters. Nor much is known about the role of aquatic environments in the loss or production of oxygen species in the atmosphere. This project aims to investigate the role of hydrogen peroxide as an oxidant both in the atmosphere and in surface waters in order to evaluate sources and sinks of organic species such as ethanol and acetaldehyde. In this study samples of gas phase, rainwater and surface waters will be collected in the city of Ribeirão Preto - a typically sugarcane producing city - and in the city of São Paulo, whose urban environment is highly impacted by automotive emissions. It is expected to better understand the possible direct or indirect impacts on human health caused by the production and use of fuel ethanol in Brazil.
News published in Agência FAPESP Newsletter about the scholarship: