E-Mail IMAGE: Fluorescent innocuous organic substances used as testing techniques to simulate the trajectory followed by a pollutant. view more Credit: University of Malaga Led by Professor Andreas Hartmann, from the University of Freiburg (Germany), the researchers analyzed the presence of several pollutants in water from many karst aquifers of Europe, North Africa, and the Middle East, relating fast infiltration processes to an increased concentration of these substances. The findings of this research are published in the scientific journal Proceedings of the National Academy of Sciences (PNAS). This way, they warn that during rainfall events -when aquifers recharge, especially during autumn rainfall- the concentration of pollutants and pathogenic microorganisms can significantly exceed the safe levels, causing serious consequences for human consumption.