Lead Pollution, Demographics, and Environmental Health Risks: The Case of Philadelphia, USA.

Lead (Pb) soil contamination in urban environments represents a considerable health risk for exposed populations, which often include environmental justice communities. In Philadelphia, Pennsylvania (PA), Pb pollution is a major concern primarily due to extensive historical Pb-smelting/processing activity and legacy use of Pb-based paints and leaded gasoline. The U.

Popular epidemiology and "fracking": citizens' concerns regarding the economic, environmental, health and social impacts of unconventional natural gas drilling operations.

Pennsylvania sits atop the Marcellus Shale, a reservoir of natural gas that was untapped until the 2004 introduction of unconventional natural gas drilling operations (UNGDO) in the state. Colloquially known as fracking, UNGDO is a controversial process that employs large volumes of water to fracture the shale and capture gas; it has become a multi-billion dollar industry in Pennsylvania. We analyzed letters to the editor of the most widely circulated local newspaper in the most heavily drilled county in Pennsylvania (Bradford County) in order to characterize residents' concerns and their involvement in popular epidemiology--the process by which citizens investigate risks associated with a perceived environmental threat.