Related by context. Frequent words. (Click for all words.) 67 sulfur dioxide nitrogen oxides 62 sulfur dioxide SO2 61 SO2 emissions 61 nitrous oxides 60 particulate matter emissions 60 sulfur dioxide 59 nitrogen oxide 58 smokestack emissions 58 sulfur oxide 58 nitrogen oxides NOx 57 harmful pollutants 57 nitrogen oxides 57 nitrogen oxide emissions 55 sulfur dioxide emissions 55 particulate emissions 55 pollutants emitted 55 mercury emissions 55 SO2 55 nitrogen oxide NOx 54 NOx emissions 53 pollutants 53 air toxics 52 pollutant emissions 52 NOx 52 coal fired 52 toxic pollutants 51 Sulfur dioxide 51 diesel particulate matter 51 mercury arsenic 51 pollution 50 hydrogen chloride 50 Ambient Air 50 air pollution 50 furans 50 fine particulate 49 scrubbers 49 fine particle pollution 49 arsenic mercury 49 selective catalytic reduction 49 greenhouse gases GHGs 48 fine particulates 48 flue gases 48 particulate matter PM 48 sulfur fuels 48 harmful gases 48 particulate matter 48 sulfur oxides 48 emissions 48 pollutant 48 Emissions 48 Clear Skies 48 Hydrogen sulfide 48 mercury pollution 48 flue gas 47 harmful contaminants 47 dissolved solids 47 incomplete combustion 47 GenOn 47 greenhouse gases GHG 47 EPA 47 highly combustible methane 47 SOx 47 particulates 47 emission 47 aggravate asthma 47 ozone smog 46 Generating Station 46 sulfur hexafluoride 46 Environmental Protection Agency 46 scrubber 46 acid rain 46 VOC emissions 46 soot particles 46 Particulate matter 46 volatile organic compounds 45 Brayton Point 45 perchlorethylene 45 NAAQS 45 Clean Air 45 exhaust emissions 45 airborne pollutants 45 dischargers 45 polluters 45 emit CO2 45 CO -2 45 disinfection byproducts 45 chemical solvents 45 baghouse 45 sewage discharges 44 Emission Control 44 USEPA 44 carbon dioxide 44 Whiting refinery 44 greenhouse gases 44 particulate filters 44 TECO Coal 44 IGCC plant 44 greenhouse gas 44 emission reductions 44 fly ash 44 dioxide