Athens air worsens
Athens’s familiar atmospheric pollution, known as nefos (or cloud), has become more complicated lately due to a number of factors, including Olympic construction projects. Recent research shows that aside from nitrogen dioxide, the Greek capital’s pollution has been enriched with ozone and suspended particles. The latter are responsible for a number of cardiovascular and pulmonary diseases and allergies. Suspended particles are divided into two categories according to their diameter – PM10 and PM2.5. Their main source is motor vehicles, uncontrolled heavy industries and the dozens of major construction projects related to the Athens 2004 Olympics. «Motor vehicles are the most to blame, especially those that use diesel, as it is believed that they produce 100 times more particles per kilometer compared to gasoline-consuming vehicles,» Alexandros Papayiannis, an assistant professor of physics at the National Technical University of Athens, told Kathimerini. «Just as problematic is the functioning of heavy industries in the (Attica) basin, while there is also a special category of traveling particles, either from nearby provinces or from the Sahara,» he added. Sand from the Sahara is estimated to fall on Greece more than 20 times a year, mainly in summer. «It is impossible to differentiate between the suspended particles and determine their exact source. However, it is certain that the construction projects have a great share of responsibility for the problem. Their precise effect is not known, but we estimate that they play a significant role in 80 percent of cases where large concentrations of particles are recorded,» said Michael Petrakis of the Institute of Environmental Research at the National Observatory of Athens. The particles from Olympic construction projects, however, are larger and therefore constitute a localized problem around their source, Papayiannis said. The World Health Organization has set a limit of 50 micrograms per cubic meter for concentrations of suspended particles. But the Observatory found concentrations above 50 micrograms, spiking to over 180 micrograms at Pendeli, north of Athens. «These are momentary levels but they make us think,» Petrakis said. «Because if we have such high concentrations in Pendeli, think of what is happening in the center of the city where there are more sources generating particles.»
