Related by context. Frequent words. (Click for all words.) 70 volcanic ash 58 soot 57 ash cloud 54 particulate matter 53 sulfur dioxide 53 plume 52 particulates 51 lava 50 volcano 50 volcanic 50 volcanic ash cloud 50 sludge 49 debris 49 particulate 47 sawdust 47 coal ash 46 mercury 46 dust 46 silt 46 vapor 46 smoke 45 plumes 45 radioactive 45 creosote 45 hazardous waste 45 toxic gases 45 embers 45 volcanic activity 44 radioactivity 44 Icelandic volcano 44 slurry 44 volcanic eruption 44 pollutants 44 sediment 43 eruption 43 toxic fumes 43 sulfur 43 radioactive material 43 sulfur dioxide emissions 42 volcanic eruptions 42 wood chips 42 tailings 42 smokestack 42 volcanic rock 42 pollen 42 dust particles 42 radioactive waste 41 carbon dioxide 41 gases 41 pollutant 41 vapors 41 snow 41 landfill 41 methane 41 slag 40 pine needles 40 ozone 40 basalt 40 eruptions 40 gypsum 40 Merapi 40 dioxins 40 particle pollution 40 nitrate 40 arsenic 40 smog 40 sediments 40 NOx 40 water vapor 39 fumes 39 hazardous chemicals 39 carbon dioxide CO2 39 asbestos 39 contaminated soil 39 mercury emissions 39 Ash 39 radioactive iodine 39 flue gas 39 methane gas 39 chimney 39 acid rain 39 manure 39 mud 39 toxic chemicals 39 carbon monoxide 39 toxic waste 39 wood stoves 39 clouds 39 flammable 39 Mount Merapi 39 cesium 39 powdery 39 Radiation 39 leachate 38 radiation 38 fire retardant 38 mulch 38 biosolids 38 groundwater 38 brine 38 magma