Christine A. Rogers, Ph.D Research Assistant Professor Environmental Health Sciences School of Public Health & Health Sciences University of Massachusetts Amherst
Impact of Climate Change on Aeroallergens Christine A. Rogers, Ph.D Research Assistant Professor Environmental Health Sciences School of Public Health & Health Sciences University of Massachusetts Amherst Adjunct Assistant Professor Exposure, Epidemiology & Risk Harvard School of Public Health
Overview • Climate projections relevant to aeroallergens • Importance of climate change to health & allergic disease • Climate change effects on – – – – – –
Plant physiology Pollen production Pollen timing and duration Allergens Fungal spore production Indoor environment
The Climate Record • Rate of temperature increase greater than in last 10,000 yrs • CO2 concentrations higher than in the last 400,000 years • Carbon emissions at an all time high • Tropospheric Ozone has doubled at mid & high latitudes
Increase ~2.2 ppm/yr
Dr. Pieter Tans, NOAA/ESRL (www.esrl.noaa.gov/gmd/ccgg/trends/) and Dr. Ralph Keeling, Scripps Institution of Oceanography (scrippsco2.ucsd.edu/).
Dr. Pieter Tans, NOAA/ESRL (www.esrl.noaa.gov/gmd/ccgg/trends/) and Dr. Ralph Keeling, Scripps Institution of Oceanography (scrippsco2.ucsd.edu/).
IPCC 2007, 4th Assessment Report –WG1
Health Effects of Climate Change Direct Effects
Indirect Effects
• Increased heat stress and related diseases & deaths • Increase in kidney stones • Reduction in wintertime slips & falls
• Increased mosquito& tick-borne infectious diseases • Increased waterborne diseases • Increased pollen and fungal allergens & allergic diseases
Causes of Allergic Disease • Genetic – parental history of asthma • Environmental – Indoor environment • Chemical – NO2, Pesticides, VOC’s, Formaldehyde, ETS • Allergens – animal, cockroach, mites, fungi, endotoxin
– Outdoor environment • SO2 , NO2 , Ozone • Particulates PM2.5, PM10 – Diesel exhaust particles (DEP)
• Allergens – Pollen grains, fungal spores
Aeroallergens • Pollen – 17% of the general population is sensitized to pollen • Tree - birch, cedar, oak, mulberry • Grass • Ragweed
• Fungi – 10% of the general population – 40% of the asthmatic population • Basidiomycetes (mushrooms) • Alternaria
Climate change influences on airborne pollen • CO2 has a fertilization effect on plants – grow larger, put more effort into reproduction, higher pollen production • CO2 induces increases in water use efficiency – better drought tolerance, increasing pollen production in drought years • Increased temperature – causes plants to flower earlier – timing of pollen seasons is shifted earlier and duration can be longer • Increase in frequency and intensity of rainfall events – rain within the season causes airborne pollen concentrations to decrease
Common Ragweed Ambrosia artemisiifolia L.
•Native C3 plant
•Common in open disturbed ground •Pollen abundant in the air in early fall •Potent allergens •Primary cause of allergic rhinitis
Ragweed Pollen Production & CO2
Wayne et al 2002
Pollen Production • Increase in pollen production of ~ 90% in elevated CO2 • No significant increase in amount of pollen per spike • Increase in # of flowering spikes Ziska & Caufield 2000
Amb a 1 Allergen • Suspension of pollen in buffer and extraction of protein • Amb a 1 allergen measured by ELISA
• 1.6 X more allergen at elevated CO2 Singer et al 2005
Temperature Effects on Phenology Stages of Temperature Influence on Pollen Release 100 90
Anthesis
Onset of Dormancy
80
Onset of Bud Development
70
End of Dormancy Quiescence
50
Pollen season
40 Chilling Temperatures
30
Forcing Temperatures
20 10
5/25/1994
5/11/1994
4/27/1994
4/13/1994
3/30/1994
3/16/1994
3/2/1994
2/16/1994
2/2/1994
1/19/1994
1/5/1994
12/22/1993
12/8/1993
11/24/1993
11/10/1993
10/27/1993
10/13/1993
9/29/1993
9/15/1993
0
9/1/1993
Degrees F
60
Emberlin J, Detandt M, Gehrig R, Jaeger S, Nolard N, Rantio-Lehtimaki A. Int J Biometeorol (2002) 46:159–170 & (2003) 47:113–115
Advance of 0.5 d/yr
Early birch pollen seasons Switzerland
Advance of 0.84 days/year
Clot 2003
Timing influences exposure and duration of symptoms
Average spring
Early Spring
Early spring and CO2 effects on ragweed pollen production
Rogers et al. 2006
Duration • Defined as # of days between start and end of the season • Start and end of the season defined as 1% and 99% respectively of the seasonal total • Compare with # of frost free days • Compare sites along a latitudinal gradient
Sites & Change in Durations
Increasing Duration of Ragweed Pollen Season • Duration increases along a south to north latitudinal gradient associated with an increase in # days to first frost Ziska, Knowlton, Rogers et al 2011 PNAS
Lengthening of fungal fruiting seasons
Gange et al 2007 Science 316: 71
Average date of first fruiting and the average date of last fruiting
Urban CO2 Domes • Phoenix, AZ – Peak CO2 – 650 ppm •
Idso, CD, Idso, SB, Balling Jr, RC. 2001. An intensive two-week study of an urban CO2 dome in Phoenix, Arizona, USA. Atmospheric Environment 35: 995-1000
• Baltimore, MD - Avg CO2 – 511ppm –
Ziska, LH, et al. 2003 Cities as harbingers of climate change: Common ragweed, urbanization, and public health. J Allergy Clin Immunol 111(2):290-295.
Cities as harbingers of climate change
Ziska et al 2003
Study effect of CO2 and O3 on grasses Phleum pratense L. TIMOTHY GRASS
• The grass family – Poaceae - has a world wide distribution with more than 10,000 species • Grasslands comprise more than 20% of the vegetation cover of the Earth and grasses are present in other vegetation types • Allergy to grass pollen is a major public health issue affecting • •
20% of general population 40% atopic individuals
• Allergens are highly crossreactive throughout the grass family • Grass pollen production in response to elevated CO2 has not been studied
1= 30 ppb O3; 400 ppm CO2 2= 80 ppb O3; 400 ppm CO2 3= 30 ppb O3; 800 ppm CO2 4= 80 ppb O3; 800 ppm CO2
Projected Increase in Grass Pollen Production • Increase in pollen production per flower plus the increase in # of flowers per treatment • Potential for up to 200% increase in grass pollen in the future
Grass & Alternaria • Timothy grass plants (Phleum pratense) were grown under different CO2 conditions (300, 400, 500, 600 ppm) in controlled climate chambers. • Plants were harvested and 2 gm fresh weight leaf tissue was surface sterilized (5% bleach), rinsed, and oven dried (48 hr). • Dried leaves were inoculated by dipping into an Alternaria alternata (EGS 34-016) spore suspension, and transferred to media bottles for 1 wk incubation.
Increased Allergen from Alternaria on Phleum grown at 300 – 600ppm CO2
Wolf , O’Neill, Rogers et al 2010 Env Health Persp. 118: 1223-1228
Extreme Precipitation • Heavy rainfall events are becoming more frequent across the Northeast • Under both emissions scenarios – rainfall is expected to become more intense. – periods of heavy rainfall are expected to become more frequent.
AP Photo/Lee Marriner
Indoors: How bad can it get?
Bad!