MMDA scores billboards for light pollution

Metro Manila Development Authority (MMDA) Chairman Francis Tolentino has urged operators of outdoor advertising billboards to switch off their lights at night. This latest call follows the renewed campaign of the MMDA against outdoor billboards that do not comply with the National Building Code and public safety regulations. Tolentino claimed, during the launch of a curated street art project over the weekend, that scientists have discovered how outdoor lighting worsens smog by interfering with a natural process that cleans the air at night. The United States’ National Oceanic and Atmospheric Administration (NOAA) and the University of Colorado’s Cooperative Institute for Research in Environmental Sciences (CIRES) conducted one such study. Dr. Harald Stark, one of the NOAA CIRES scientists said there are nitrate radicals which exist only at night and break down air pollutants into harmless substances. The scientists used a NOAA research airplane to measure light intensity and take air samples over Los Angeles, California. With lab tests and using models of chemical reactions in the atmosphere, the team learned that visible, artificial light destroys air-cleaning nitrate radicals in the night air. At the December 2010 meeting of the American Geophysical Union, Stark said that their preliminary research shows that the artificial lights that shine up to the sky hamper night air cleansing by 7 percent and increase smog pollutants by 5 percent. He said pointing the light downward should help. Stark noted that red light does not destroy nitrate radicals in the air but this type of light is not usually used for outdoor lighting. Light pollution, as some investigators have called it, has been the subject of studies since the 1990s. — TJD, GMA News