• Particulatesare tiny pieces of solids and tiny droplets of liquids floating in the air.
  • Moreparticulates are found in urban areas than in rural areas. The concentration of particulates in urban areas is around 10-40 pg/m^3, compared to less than 10 pg/m^3 in rural area.


Sources of Particulates

  • Vehicle exhaustswhich produce very fine particulates. About 80% of fine particulates in urban areas are from vehicle exhausts.
  • Burningof refuse, cigarettes and fuel such as coal which produces both fine and coarse particulates.
  • Construction, miningand quarrying with these activities produce coarse particulates.
  • Plants and moulds, also generate coarse particulates.
  • Particulates can cause health problems. Coarser particulatesare usually filtered out by the nose and throat, but finer particulates less than 10 pm in diameter can enter the
  • PM10 could causeor make worse problems like asthma, bronchitis, lung cancer and heart disease.
  • Pollutants, such as nitrogen oxides, sulphur oxidesand hydrocarbons, come from burning fossil fuels.
  • When these pollutantscome into contact with sunlight, the UV light causes them to break down into harmful chemicals which form photochemical smog.
  • Photochemical smog is a problemin many cities including Los Angeles, Beijing, Mexico City and Barcelona.
  • It’s more common in places with hotand sunny climates because there’s more sunlight.
  • These locations often have a temperature inversion, which keeps the pollutants at ground level.
  • Photochemical smog is linked to health problems, such as breathing difficulties, respiratory disordersand