"Microcystins (MC) are potent cyclic heptapeptide toxins that are produced by many cyanobacterial genera e.g. Planktothrix, Microcystis. Human exposure occurs primarily during bloom events, via drinking or contact with contaminated water, food or aerosols. While food exposure and corresponding health effects are rare, exposure to high MC concentrations via drinking water has resulted in morbidity and mortality. However, little is known about the level of MC exposure in humans when sub-chronically or chronically exposed via aerosols or drinking water as is the case in populations living within close proximity to water bodies experiencing toxic blooms, e.g. the population of San Roque dam, Argentina. To accurately determine human exposure, an in-depth understanding of the physical and physiological events governing toxic bloom formation and regulating MC production is critical. In this study we will (1) undertake a series of in-lake mesocosm studies to explore thresholds and triggers of up-regulation of MC. Samples will be analyzed using a suite of sensitive molecular (QPCR, RT-QPCR, metagenome analysis), immunological and chemical techniques in concert with physical and geochemical measurements , (2) undertake a series of field-experiments, incl. the San Roque location, in which we will monitor a range of physiochemical parameters, and in-lake and aerosolized MC levels, and (3) use a hydrodynamic model to define water movement coupled to an ecological model enabling predictions of toxins in aerosols and water. Laboratory techniques and questionnaires specifically developed to allow monitoring of human toxin exposure, will be used to assess health impacts of toxins and aerosols. The consortium represents aquatic ecologists, microbiologist, molecular biologist, modelers, toxicologists and medical staff. Exchanging staff will ensure increased understanding and implementation of technologies and lead to improved human risk assessment."