The Nairobi Validation Station, the first of its kind in tropical and sub-tropical Africa, has been installed within the grounds of the UN Environmental Programme (UNEP) at Gigiri. The agency, which is involved in the work, said the station would detect ozone, emitted from the East African part of the tropics and formed from sources such as industry, transport, agriculture forest fires and charcoal burning. When the station was inaugurated today, UNEP Executive Director Klaus Toepfer called ozone a “curious chemical,” noting that in the upper atmosphere, it acts as a shield, protecting life on Earth from damaging levels of solar radiation. “In the lower atmosphere, known as the troposphere, small amounts are helpful, acting as a detergent to clean the air,” he added. “But high amounts, formed by sunlight mixing with human-made pollution from cars, factories and other sources, can be harmful, Mr. Toepfer said. “These smogs – increasingly a phenomenon in developing as well as developed countries – can prove fatal for vulnerable people such as those with heart conditions and asthma, and can also damage car tires, electricity cables and crops.” One of the key roles of the new station is to help unravel the fate of ozone damaging chemicals produced in the region from both human-made and natural sources such as vegetation. Scientists are unsure as to how much of this pollution makes its way into the upper atmosphere and how much remains closer to the ground. Understanding this is crucial to knowing how quickly the ozone layer may recover after decades of destruction by substances such as chlorofluorocarbons (CFCs). Once in the upper atmosphere, ozone-damaging chemicals can travel north and south towards the poles where, in the colder conditions, the layer is at highest risk.