Airborne Poaceae pollen concentrations in the atmosphere of Bahía Blanca, Argentina and correlation with meteorological data. First prediction models

MURRAY, M G; GALÁN SOLDEVILLA, C

Granada, España

Congreso; XI International Palynological Congress; 2004

Universidad de Granada, España

  Records of grass pollen concentrations and meteorological data from three years of sampling in Bahía Blanca, Argentina (38°44´S; 62°16´W) are used to analyse the behavior of Poaceae pollen in the atmosphere and the correlations with meteorological data. Daily data were obtained using a volumetric impact sampler Rotorod model 40 situated at height of 10 m above ground level on a building located in a residential zone near the downtown. Bahía Blanca city is located within the Pampas phytogeographic province, characterized by the lack of  trees and the dominance of herbs of the grass family. Grass (Poaceae) pollen was selected for the analysis due to its being the taxonomic group of highest allergogenic relevance in Bahía Blanca area (Ramón et al., 1995 and Carignano et al., 1998).     Analysis of the results identifies the characteristic of grass pollen series in this period. We consider three pollen seasons for the study: August 2000 - June 2001; June 2001 - May 2002 and May 2002 - June 2003. The three curves are very similar and the total pollen emissions were: 3060 grains in 2000/2001; 2586 grains in 2001/2002; 2416 grains in 2002/2003.  The pollen concentration are examined in relation to the main meteorological variables: temperature, relative humidity, accumulated temperature and rainfall, wind velocity and different wind directions. In addition, are used some others variables like accumulated pollen concentration and 3-day running mean of the prior day with a very important results. The concentration of pollen grains from Poaceae were found to be positively correlated with the average temperature (maximum, medium, and minimum) and predominant winds direction of the north and northeast, negatively correlated with relative humidity and predominant winds direction of the east to the south and southwest.    Although grass pollen was always present in the air during the studied period, a significant raise was detected between October and February. The highest relative concentration was reached in November. The beginning of the Spring raise in airborne pollen was detected in October for all the periods. The striking magnitude of the Spring peak can be attributed to the predominance of species of the pooid group (of winter-to-spring growing cycle mainly).    Some models are proposed to predict daily Poaceae pollen counts. These studies represents a very important advance in the development of the Aerobiology in South America because these are the first prediction models that have been carried out.