Airborne Pinuspollen in the atmosphere of Brisbane, Australia and relationships with meteorological parameters

Relationships between weather parameters andairborne pollen loads of PinusinBrisbane, Australia have been investigated overthe five-year period, June 1994–May 1999.Pinuspollen accounts for 4.5% of the annualairborne pollen load in Brisbane where thePinusseason is confined to the winter months,July–early September. During the samplingperiod loads of 11–>100 grains m3wererecorded on 24 days and 1–10 grains m3on204 days. The onset and peak dates wereconsistent across each season, whereas the enddates varied. The onset of the Pinuspollen season coincided with the coolestaverage monthly temperatures (< 22°C),lowest rainfall (< 7mm), and four weeks afterdaily minimum temperatures fell to 5–9°Cin late autumn. Correlations obtained betweendaily airborne Pinuspollen counts andtemperature/rainfall parameters show thatdensities of airborne Pinuspollen arenegatively correlated with maximum temperature(p < 0.0001), minimum temperature (p < 0.0001)and rainfall (p < 0.05) during the mainpollination period. The mean duration of eachpollen season was 52 days; longer seasons wereshown to be directly related to lower averageseasonal maximum temperatures (r2= 0.85,p = 0.025). These results signify that maximumand minimum temperatures are the majorparameters that influence the onset andduration of the Pinuspollen season inthe environs of Brisbane. Respiratory allergyis an important health issue in Brisbane,Australia, but it remains unknown whether ornot airborne Pinuspollen is acontributing factor.