KnowraParticulate matterLinked fromLinked fromThe 63 pages that link to Particulate matter, each with the reason it gives.All 63Broader topic 9Related 40Narrower topic 11Compared with 3Acid rainCompared with: Particles can share emission sources with acid precursors but are a separate class of pollutant.Nitrogen dioxideCompared with: NO₂ is a gas, whereas nitrate-containing pollution formed from it can become particulate matter.Tropospheric ozoneCompared with: It is another major air pollutant, but consists of particles rather than a reactive gas.