Pollens and other aeroallergens

1
Pollensand other aero-allergens

• Paul Beggs
• Macquarie University
• Wednesday 1st October 2003

2
Outline

• Allergen-related diseases
• Aero-allergens
• Methods
• Examples
• Summary of impacts
• Research needs and challenges
• References

3
Allergen-related diseases

• Asthma
• A disorder affecting the airways.
• Airways narrow in response to certain triggers.
• Australias most widespread chronic health
  problem. It affects
• 1 in 4 children
• 1 in 10 adults
• Prevalence is increasing, especially in
  children (Department of Health and Ageing,
  2003)

4
Allergen-related diseases

• Hay fever (allergic rhinitis)
• Inflammation of the nose caused by allergy.
• Can also cause problems with the eyes, sinuses,
  throat and ears.
• A common disorder affecting up to 40 of the
  population.
• Its prevalence has doubled over the past 25
  years. (ASCIA, 2003)

5
Aero-allergens

• Pollens
• Ryegrass (Lolium)
• Plantain (Plantago)
• Pellitory (Parietaria)

6
Aero-allergens

• Pollens (continued)
• Ragweed (Ambrosia)
• Timothy grass
• Birch (Betula)
• Japanese cedar (Cryptomeria)

7
Aero-allergens

• Mould spores
• Alternaria
• Aspergillus
• Cockroach
• House dust mite

8
Aero-allergens

• Climate has an impact on both aero-allergens and
  the organisms that produce them.
• Important climate variables include
• Carbon dioxide (CO2) concentration
• Temperature
• Rainfall
• Humidity
• Wind speed and direction

9
Methods

• Expert judgment
• Experimentation
• Empirical analog studies
• Impact projections
• Biophysical models

10
ExamplesImpacts on pollen production

• Ziska and Caulfield (2000)
• Experiments using a controlled environment
  chamber.
• Measured growth and pollen production of ragweed
  at three CO2 concentrations
• 280 µmol mol-1 (pre-industrial)
• 370 µmol mol-1 (current)
• 600 µmol mol-1 (a projected future)

11
ExamplesImpacts on pollen production
12
ExamplesImpacts on pollen season

• Emberlin et al. (2002)
• Used records of daily average birch pollen counts
  and weather data from about 1982 to 1999.
• Six European sites
• Kevo
• Turku
• London
• Brussels
• Zurich
• Vienna

13
ExamplesImpacts on pollen season

• Studied relationships between changes in the
  start dates of the pollen seasons and changes in
  spring temperatures.
• Four of the sites showed trends towards earlier
  start dates.
• An advance of about 6 days over the next ten
  years if the trend continues.

14
ExamplesImpacts on plant distribution

• Drummond and Beggs (2003)
• Used a computer model (BIOCLIM) to study
  distribution changes of three species
• Plantago lanceolata
• Lolium perenne
• Parietaria judaica

15
ExamplesImpacts on plant distribution

• Australian focus
• 2050 and 2100
• 2 climate change scenarios
• SRES A1F
• SRES B1
• OzClim (CSIRO) was used to obtain climate for
  these two scenarios in the two years.

16
ExamplesImpacts on plant distribution
Plantago lanceolata
17
ExamplesImpacts on plant distribution
18
Summary of impacts

• A number of studies indicate
• significant increases in pollen production of
  allergenic plants
• an earlier start to, and lengthening of, the
  pollen season of allergenic plants.
• It is also likely that the distribution of
  allergenic plants will change, although the
  nature of this change will vary from species to
  species.

19
Research needs and challenges

• Aero-allergens other than pollens
• Indoor aero-allergens (relationship between
  indoor and outdoor climate)?
• Consideration of other environmental factors
• disturbance (some plants)
• air pollutants (interaction with aero-allergens)
• Relate projected changes in aero-allergens to
  changes in human health.

20
References

• Department of Health and Ageing, Commonwealth
  Government of Australia. Asthma and Asthma
  Statistics. HealthInsite. http//www.healthinsite.
  gov.au/ Accessed 11 September 2003. Updated June
  2003.
• Australasian Society of Clinical Immunology and
  Allergy. What is hay fever? and Rhinitis and
  sinusitis. http//www.allergy.org.au/ Accessed 11
  September 2003. Updated April 2002.
• Drummond E, Beggs PJ. Impacts of climate change
  on three allergenic plant species in Australia.
  2003, in preparation.
• Emberlin J, Detandt M, Gehrig R, Jaeger S, Nolard
  N, Rantio-Lehtimäki A. Responses in the start of
  Betula (birch) pollen seasons to recent changes
  in spring temperatures across Europe.
  International Journal of Biometeorology 2002
  46(4)159-170. Erratum published 2003
  47(2)113-115
• Ziska LH, Caulfield FA. Rising CO2 and pollen
  production of common ragweed (Ambrosia
  artemisiifolia), a known allergy-inducing
  species implications for public health.
  Australian Journal of Plant Physiology 2000
  27(10)893-898.