Aerobiology

Aerobiology (from Greek ἀήρ, aēr, "air"; βίος, bios, "life"; and -λογία, -logia) is a branch of biology that studies the passive transport of organic particles, such as bacteria, fungal spores, very small insects, pollen grains and viruses.[1] Aerobiologists have traditionally been involved in the measurement and reporting of airborne pollen and fungal spores as a service to those with allergies.[1] However, aerobiology is a varied field, relating to environmental science, plant science, meteorology, phenology, and climate change.[2]

Some common air-borne spores

Overview

The first mention of "aerobiology" was made by Fred Campbell Meier in the 1930s.[2] The particles, which can be referred to as Aeroplankton, generally range in size from nanometer to micrometers which makes them challenging to detect.[3]

Aerosolization is the process of a small and light particle becoming suspended in moving air. Pollen and fungal spores can be transported across the ocean, or even travel around the globe.[4] Due to the high quantities of microbes and ease of dispersion, Martinus Beijerinck once said "Everything is everywhere, the environment selects".[5] Aeroplankton is found in significant quantities even in the Atmospheric boundary layer (ABL).[6]

Dispersal of Particles

The process of dispersal of aerobiological particles has 3 steps: removal from source, dispersion through air, and deposition to rest.[7] The particle geometry and environment affect all three phases, however once it is aerosolized, its fate depends on the laws of physics and the air flow.

Removal from Source

Pollen and spores can be blown from their surface or shaken loose. Generally the wind speed required for release is higher than average wind speed. Rain splatter can also dislodge spores. Some fungi can even be triggered by environmental factors and actively eject spores.[7]

Dispersion through Air

Once released from rest, the aeroplankton is at the mercy of the wind and physics. Particles have been found between heights of 500 and 1,000m in the atmosphere. The settling speed of spores and pollen vary and is a major factor in dispersion; the longer the particle is floating, the longer it can be caught by a turbulent wind gust. Wind speed and direction vary with time and height, so the specific path of once neighboring particles can vary significantly.[7]

Deposition to Rest

Deposition is a combination of gravity and inertia. The spore fall speed for small particles can be modeled, but it is noted that the complex shapes of pollen and spores often fall slower than their estimated speed calculated with simple shapes.[8] The rate of deposition by impaction is also modeled, as the inertia of particles will cause them to hit surfaces along their fall, instead of flow around them like air.[7]

Experimental Studies

There have been many studies performed to understand real-life dispersal patterns of pollen and spores. Studies often use an automatic volumetric spore trap such as a Hirst-type sampler. Particles stick to a sampling strip and then can be inspected under a microscope.[2] Scientists will then analyze sample DNA by Amplicon sequence variant (ASV) or another common method.

A challenge repeatedly cited in literature is that due to different testing or analysis methodology, results are not consistent across study. Therefore, unfortunately there is no common database to compare results to.[5]

Effects on Human Health

Up to date data on pollen levels is critical for humans that suffer from allergies. A current limitation is that many spore traps like the Hirst-type sampler require a scientist to remove a slide from the machine, and count individual pollen under magnification. This causes data to be delayed, sometimes by over a week. There are currently a number of fully automatic spore traps in development, and once they are fully functional they will improve the lives of allergy sufferers.[9]

Effects of Climate Change

Scientists have predicted that the meteorological results of climate change will weaken pollen and spore dispersal barriers, and lead to less uniqueness in different regions.[4] Precipitation increases richness of biodiversity. Also, clouds formulate in the upper atmosphere where there is different biodiversity. Specifically in the Arctic, climate change has dramatically increased precipitation, and scientists have seen new microbes in the area because of it.[4]

Rising summer temperatures and CO2 levels have shown to increase total amounts of pollen released by certain Quercus trees, as well as delay the start of pollen season.[10] However, more studies are needed to see long term effects of climate change.

See also

References
  1. "Spotlight on: Aerobiology". The Biologist. Royal Society of Biology. Retrieved 26 October 2017.
  2. Lancia, Andrea; Capone, Pasquale; Vonesch, Nicoletta; Pelliccioni, Armando; Grandi, Carlo; Magri, Donatella; D’Ovidio, Maria Concetta (January 2021). "Research Progress on Aerobiology in the Last 30 Years: A Focus on Methodology and Occupational Health". Sustainability. 13 (8): 4337. doi:10.3390/su13084337. ISSN 2071-1050.
  3. Hofmann, Frieder; Otto, Mathias; Wosniok, Werner (17 October 2014). "Maize pollen deposition in relation to distance from the nearest pollen source under common cultivation - results of 10 years of monitoring (2001 to 2010)". Environmental Sciences Europe. 26 (1): 24. doi:10.1186/s12302-014-0024-3. ISSN 2190-4715.
  4. Malard, Lucie A.; Avila-Jimenez, Maria-Luisa; Schmale, Julia; Cuthbertson, Lewis; Cockerton, Luke; Pearce, David A. (1 November 2022). "Aerobiology over the Southern Ocean – Implications for bacterial colonization of Antarctica". Environment International. 169: 107492. doi:10.1016/j.envint.2022.107492. ISSN 0160-4120.
  5. Kellogg, Christina A.; Griffin, Dale W. (1 November 2006). "Aerobiology and the global transport of desert dust". Trends in Ecology & Evolution. 21 (11): 638–644. doi:10.1016/j.tree.2006.07.004. ISSN 0169-5347.
  6. Archer, Stephen D. J.; Lee, Kevin C.; Caruso, Tancredi; Alcami, Antonio; Araya, Jonathan G.; Cary, S. Craig; Cowan, Don A.; Etchebehere, Claudia; Gantsetseg, Batdelger; Gomez-Silva, Benito; Hartery, Sean; Hogg, Ian D.; Kansour, Mayada K.; Lawrence, Timothy; Lee, Charles K. (1 May 2023). "Contribution of soil bacteria to the atmosphere across biomes". Science of The Total Environment. 871: 162137. doi:10.1016/j.scitotenv.2023.162137. ISSN 0048-9697.
  7. McCartney, H. Alastair (April 1994). "Dispersal of spores and pollen from crops". Grana. 33 (2): 76–80. doi:10.1080/00173139409427835. ISSN 0017-3134.
  8. Sabban, Lilach; van Hout, René (1 December 2011). "Measurements of pollen grain dispersal in still air and stationary, near homogeneous, isotropic turbulence". Journal of Aerosol Science. 42 (12): 867–882. doi:10.1016/j.jaerosci.2011.08.001. ISSN 0021-8502.
  9. Maya-Manzano, José M.; Tummon, Fiona; Abt, Reto; Allan, Nathan; Bunderson, Landon; Clot, Bernard; Crouzy, Benoît; Daunys, Gintautas; Erb, Sophie; Gonzalez-Alonso, Mónica; Graf, Elias; Grewling, Łukasz; Haus, Jörg; Kadantsev, Evgeny; Kawashima, Shigeto (25 March 2023). "Towards European automatic bioaerosol monitoring: Comparison of 9 automatic pollen observational instruments with classic Hirst-type traps". Science of The Total Environment. 866: 161220. doi:10.1016/j.scitotenv.2022.161220. ISSN 0048-9697.
  10. López-Orozco, R.; García-Mozo, H.; Oteros, J.; Galán, C. (1 October 2021). "Long-term trends in atmospheric Quercus pollen related to climate change in southern Spain: A 25-year perspective". Atmospheric Environment. 262: 118637. doi:10.1016/j.atmosenv.2021.118637. ISSN 1352-2310.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.