Constructing a 7-day Ahead Forecast Model for Grass Pollen at North London, United Kingdom

A number of media outlets now issue medium-range (~7 day) weather forecasts on a regular basis. It is therefore logical that aerobiologists should attempt to produce medium-range forecasts for allergenic pollen that cover the same time period as the weather forecasts. The objective of this study is to construct a medium-range (< 7 day) forecast model for grass pollen at north London. The forecast models were produced using regression analysis based on grass pollen and meteorological data from 1990-1999 and tested on data from 2000 and 2002. The modelling process was improved by dividing the grass pollen season into three periods; the pre-peak, peak and post peak periods of grass pollen release. The forecast consisted of five regression models. Two simple linear regression models predicting the start and end date of the peak period, and three multiple regression models forecasting daily average grass pollen counts in the pre-peak, peak and post-peak periods. Overall the forecast models achieved 62% accuracy in 2000 and 47% in 2002, reflecting the fact that the 2002 grass pollen season was of a higher magnitude than any of the other seasons included in the analysis. This study has the potential to make a notable contribution to the field of aerobiology. Winter averages of the North Atlantic Oscillation were used to predict certain characteristics of the grass pollen season, which presents an important advance in aerobiological work. The ability to predict allergenic pollen counts for a period between five and seven days will benefit allergy sufferers. Furthermore, medium-range forecasts for allergenic pollen will be of assistance to the medical profession, including allergists planning treatment and physicians scheduling clinical trials

Palinologia do componente herbáceo na atmosfera de Caxias do Sul, RS, Brasil Palinology of the herbaceous component in the atmosphere of Caxias do Sul, Rio Grande do Sul State, Brazil

Este estudo foi realizado na cidade de Caxias do Sul de 1/janeiro/2001 a 31/dezembro/2002 e objetivou identificar os tipos polínicos de táxons herbáceos presentes na atmosfera e suas oscilações sazonais. A cidade está localizada na Encosta Superior Nordeste, Estado do Rio Grande do Sul. Seu clima é tropical pluvisazonal e apresenta três diferentes tipos de vegetação: Floresta Ombrófila Mista, Floresta Decidual e Campo. O monitoramento polínico foi realizado utilizando o captador volumétrico de sucção Burkard®, instalado no topo do Hospital Geral a uma altura aproximada de 20 m. Durante o período de estudo foram identificados 40 tipos polínicos, sendo 11 de táxons herbáceos, representando 23,22% do total de grãos coletados. A concentração máxima das táxons herbáceos registrou-se nos meses de outubro e novembro. O tipo polínico Poaceae R.Brown apresentou a maior incidência, seguido por Cyperaceae Juss., Plantago L., Amaranthus L., Rumex L., Iridaceae Juss., Brassicaceae Burnett, Apiaceae Lindl., Alternanthera Forssk., Convolvulaceae Juss. e Caryophyllaceae Juss.<br>This study was carried out in the city of Caxias do Sul, from January 1, 2001 to December 31, 2002 and aimed to identify pollen types and seasonal fluctuation of herbaceous taxa in the atmosphere. The city is located on the Upper Northeast Slopes in Rio Grande do Sul State. The climate is tropical with seasonal rainfall and there are three different types of vegetation: mixed ombrophilous forest, deciduous forest and grassland. Pollen monitoring was done with a Burkard® volumetric spore-trap sampler placed on top of the Hospital Geral, about 20m above ground level. During the study period 40 pollen types were identified, 11 from herbaceous taxa, which represents 23.22% of the total number of grains collected. Maximum concentration of herbaceous taxa was registered in October and November. The Poaceae R.Brown pollen type had the highest incidence, followed by Cyperaceae Juss., Plantago L., Amaranthus L., Rumex L., Iridaceae Juss., Brassicaceae Burnett, Apiaceae Lindl., Alternanthera Forssk., Convolvulaceae Juss. and Caryophyllaceae Juss