The document is a 2012 natural gas emissions inventory by county in Pennsylvania that lists emissions of various pollutants such as carbon monoxide, nitrogen oxides, particulate matter, and volatile organic compounds from natural gas operations in each county in tons per year. It finds a total of over 7,300 tons of carbon monoxide, 16,300 tons of nitrogen oxides, and 600 tons of particulate matter emitted across Pennsylvania in 2012 from natural gas activities.