Jw. Glassheim et al., ANALYSIS OF METEOROLOGICAL VARIABLES AND SEASONAL AEROALLERGEN POLLENCOUNTS IN DENVER, COLORADO, Annals of allergy, asthma, & immunology, 75(2), 1995, pp. 149-156
Background: The observation of low levels of weed pollens following a
freeze and an early autumn snowfall in Denver, Colorado led to this an
alysis of meteorologic variables and pollen counts. Objective: The pur
pose of this study was to examine, in depth, the relationship between
observed pollen counts and a selection of independent meteorologic var
iables. Methods: We prospectively studied in 1991 daily high and low t
emperature, relative humidity, precipitation, barometric pressure, per
cent sunshine, wind velocity and direction, tree, grass, and weed poll
en, as well as dates of the first frost/freeze. Similar data were retr
ospectively analyzed for 1987-1990. Results: Correlation coefficients
for the prospective data were as high as .611 for high temperature and
cottonwood and .718 for high temperature and maple (P < .001). High a
nd low temperature showed strong correlations with the combined weed c
ounts (.598 and .628, respectively, P < .001). Conclusions: Denver wee
d pollens appear impacted more by temperature and less by precipitatio
n and humidity, while the converse is true for tree and grass pollen.
However, weed pollen, especially sage, may appreciably rebound after f
reezing temperatures. While separate meteorologic variables may have h
igh correlations with specific pollen counts in a given year, such eff
ect is not consistent and varies from year to year.