Since German reunification in 1990, most heavy industries in Eastern Germany have been shut down. Although air quality has improved in terms of sulfur dioxide and particulate matter (PM), the content of certain metals in PM in industrial areas is persistently high. Lifetime pneumonia prevalence in schoolchildren born after unification in the heavy-metal industrial area Hettstedt remain elevated. One difference between low and high pneumonia-prevalence areas seems to be the residual concentrations of heavy metals in respirable air. Toxicological and human exposure studies of Hettstedt particles have shown metal-rich PM from Hettstedt to have greater toxicity and inflammatory properties than the PM of the control region. Past industrial emissions might still play a decisive role decades after the closing of sources, and pneumonia should be considered a possible acute health burden caused by metal-rich air pollution.