Air quality in South American cities has been a major issue for the past several decades due to growing industrialization and urban expansion. Sources of pollution in large urban centers are emitted by vehicles, industries, residential cooking, and other fuel combustion processes. Air-quality standards are often exceeded in these urban centers and as a result interest in monitoring networks of air-quality have grown substantially in the past several years. New developments in the South American aerosol research community have expanded monitoring into rural areas were sources of concern include mining and the impact of dust on public health, agriculture, and climate. We invite presentations discussing various aerosol observational, modeling, and impact studies over South America. Topics relevant to this session range from public health and air quality to trace gases characterization including aerosol-radiation and chemistry-climate interactions.