The International Atomic Energy Agency (IAEA) has teamed up with local scientists and regulatory authorities on a project aimed at making the air safer by using nuclear “know-how” to analyze air samples collected from across the city. Unlike traditional methods for analyzing air samples, nuclear tools are sensitive enough to extract key information about contaminants in small, fine particles. The smaller a toxic particle the more damaging it is to human health because it can penetrate deeply into the lungs. It is hoped that better information about release rates of elements like sulphur, nickel, copper and zinc in fine particles will help authorities improve health care and preventative strategies. Regular air samples taken throughout Mexico City are analyzed using a technique known as PIXE (proton induce x-ray emission). The IAEA is providing around $300,000 in equipment and training to scientists at the National Nuclear Research Institute of Mexico (ININ) who conduct the analysis. The scientists use an accelerator to shoot a beam of protons at a dust sample collected from the air. The results of the reaction reveal a wealth of information which helps scientists to pinpoint the exact source of toxic emissions, valuable information in a city where industry and the city’s 20 million inhabitants often live side by side. Importantly, it gives decision makers and regulators better information on which to act and develop laws to control harmful emissions.