Air en Pittsburgh Under Code Orange Air Quality Alert <p>The Pennsylvania Department of Environmental Protection (DEP) is warning children, the elderly and those with respiratory issues to limit outdoor activities in the Pittsburgh area Thursday.</p><p>The DEP issued a code orange air pollution alert for five Pennsylvania regions.</p><p>The pollution comes from an overabundance of ground-level ozone, a fundamental element of smog. The ozone forms during hot, sunny days when pollution from cars, factories, homes and power plants mix with nitrogen oxides in the air, causing people to breathe in the volatile organic compounds.</p> Thu, 30 May 2013 15:40:25 +0000 Michael Lynch 10478 at