Societal relevance

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Atmospheric aerosols, atmospheric particles small enough to be invisible to the human eye, impact our lives in many ways:

  • Atmospheric particles form one of the largest uncertainties in the current estimates of climate change. Read more
  • Atmospheric particles that are 10 micrometers in diameter or smaller because those are the particles that generally pass through the throat and nose and enter the lungs. Once inhaled, these particles can affect the heart and lungs and cause serious health effects. Read more
  • Volcanic ash particles are a major hazard to airplanes. The plumes of ash (and smoke) emitted during volcanic eruptions are difficult to locate with present monitoring techniques. Therefore, they can completely disrupt air traffic. Read more

To assess the above impacts, atmospheric particles need to be measured in fine detail.

Eruption of the Eyjafjallajökull volcano on Iceland in 2010

Eruption of the Eyjafjallajökull volcano on Iceland in 2010

Aerosols and climate

Atmospheric aerosols play a complex role in the Earth’s energy balance. Most of them are considered to attribute to a net cooling of our atmosphere since they mostly reflect sunlight back into space. Some aerosols, however, contribute to atmospheric heating, as they mostly absorb sunlight such as soot particles that consist of mostly black carbon. Both these effects are typified as direct aerosol effects. In addition, aerosols influence clouds and precipitation in a poorly understood manner, indirectly affecting the Earth’s energy balance. They are mostly thought to suppress precipitation because the particles decrease the size of water droplets in clouds. An example of such an indirect aerosol effect are long lasting shipping contrails. These direct and indirect effects highly depend on the type, size and occurrence of aerosols, all of which can vary widely depending on location and time. Therefore, their precise impact on climate change is, as up to date, is poorly known.

Aerosols and health

According to a 2014 report from the World Health Organization, about one in eight deaths is associated with exposure to air pollution, making it “the world’s largest single environmental health risk.” This mortality is due to exposure to atmospheric particles of 10 microns or less in diameter that can penetrate human tissue, causing adverse health problems that vary from ischaemic heart disease and strokes to chronic obstructive pulmonary disease and acute lower respiratory infections, to lung cancer. The monitoring of air pollution, or air quality, as carried out by Environmental Policy Agencies (EPA’s), and by local councils, industry, research bodies and environmental pressure groups, includes measurements of these atmospheric particles. These measurements are expressed in terms of atmospheric particulate matter, also known as particle pollution or PM.

Volcanic ash and air traffic

The plumes of smoke and ash that are produced during volcanic eruptions can reach great heights, thereby forming a danger to air traffic. This volcanic smoke and ash can not only reduce visibility needed for visual navigation, the tiny ash particles are incredibly abrasive and melt in the heat of aircraft turbine engines, damaging engines and making them fall out. The location and height of these volcanic plumes is difficult to monitor, therefore, crude safety measures are usually needed. Remember the eruption of the Icelandic Eyjafjallajökull volcano in 2010? It caused an entire closing of the airspace of many European countries, with major economic impact.

External links

  • Atmospheric particulates at Wikipedia
  • Aerosols, their Direct and Indirect Effects, IPCC report
  • Ambient (outdoor) air quality and health fact sheet, World Health Organisation
  • Air pollution and health portal of the World Health Organisation
  • Air pollution website of the European Commission
  • Air pollution portal of the European Environmental Agency