Athanasios Damialis

Changes to Airborne Pollen Counts across Europe

A progressive global increase in the burden of allergic diseases has affected the industrialized world over the last half century and has been reported in the literature. The clinical evidence reveals a general increase in both incidence and prevalence of respiratory diseases, such as allergic rhinitis (common hay fever) and asthma. Such phenomena may be related not only to air pollution and changes in lifestyle, but also to an actual increase in airborne quantities of allergenic pollen. Experimental enhancements of carbon dioxide (CO) have demonstrated changes in pollen amount and allergenicity, but this has rarely been shown in the wider environment. The present analysis of a continental-scale pollen data set reveals an increasing trend in the yearly amount of airborne pollen for many taxa in Europe, which is more pronounced in urban than semi-rural/rural areas. Climate change may contribute to these changes, however increased temperatures do not appear to be a major influencing factor. Instead, we suggest the anthropogenic rise of atmospheric CO levels may be influential.

Allergenic pollen records (15 years) and sensitization in patients with respiratory allergy in Thessaloniki, Greece

Background:  Very limited allergenic pollen records exist in Greece so far; moreover, there is a lack of investigation on patient sensitization. The above data are necessary for respiratory allergy diagnosis and treatment worldwide.

Monitoring, Modelling and Forecasting of the Pollen Season

The section about monitoring covers the development of phenological networks, remote sensing of the season cycle of the vegetation, the emergence of the science of aerobiology and, more specifically, aeropalynology, pollen sampling instruments, pollen counting techniques, applications of aeropalynology in agriculture and the European Pollen Information System. Three data sources are directly related with aeropalynology: phenological observations, pollen counts and remote sensing of the vegetation activity. The main future challenge is the assimilation of these data streams into numerical pollen forecast systems. Over the last decades consistent monitoring efforts of various national networks have created a wealth of pollen concentration time series. These constitute a nearly untouched treasure, which is still to be exploited to investigate questions concerning pollen emission, transport and deposition. New monitoring methods allow measuring the allergen content in pollen. Results from research on the allergen content in pollen are expected to increase the quality of the operational pollen forecasts.

Airborne allergenic fungal spores and meteorological factors in Greece: Forecasting possibilities

Specific airborne fungal spore types trigger respiratory allergy symptoms in sensitive individuals. Aiming to reduce the risk for allergic patients, we constructed predictive models for the fungal spore circulation in Thessaloniki, Greece. Monthly and daily autoregressive forecasting models were developed (Dynamic Regression) for the airborne spore concentrations of Alternaria and Cladosporium, the most abundant fungal taxa in the area. The forecast horizons were respectively 12 months and one week. The accuracy of each predictive model was tested by means of six statistical criteria. Special attention was paid to the lag effect of all factors, both meteorological and fungal spore records. Aerobiological sampling was conducted over 1996–2002, using a Burkard trap. Records of 18 meteorological parameters were used for the same period. Residual analyses tested the adequacy of the models. Monthly forecasting models were highly significant, with adjusted R2 = 0.68 for Alternaria, and 0.81 for Cladosporium. The respective values of adjusted R2 for the daily models were 0.62 and 0.70. Cladosporium spore counts were consistently influenced by solar radiation, whereas Alternaria was influenced by air temperature (mean and minimum). For monthly forecasts, records of the preceding month, and the 12 month spore record was significant for Alternaria, whereas for Cladosporium, the lags were 12 and 24 months. With the daily models, the respective required periods were mainly the preceding one to two weeks and the last two years for both fungal taxa, in addition to a one‐year lag in the case of Cladosporium. Daily models could be further improved by co‐estimating interdiurnal variability and fungal spore sources.

15-Year aeroallergen records. Their usefulness in Athens Olympics, 2004

Introduction: About 5–25% of 16 000 athletes involved in preparation for the Athens 2004 Olympics may encounter respiratory allergy (asthma and rhinoconjunctivitis) triggered by exposure to aeroallergens (pollen and fungi spores).

Estimating the abundance of airborne pollen and fungal spores at variable elevations using an aircraft: how high can they fly?

Airborne pollen and fungal spores are monitored mainly in highly populated, urban environments, for allergy prevention purposes. However, their sources can frequently be located outside cities’ fringes with more vegetation. So as to shed light to this paradox, we investigated the diversity and abundance of airborne pollen and fungal spores at various environmental regimes. We monitored pollen and spores using an aircraft and a car, at elevations from sea level to 2,000 m above ground, in the region of Thesssaloniki, Greece. We found a total of 24 pollen types and more than 15 spore types. Pollen and spores were detected throughout the elevational transect. Lower elevations exhibited higher pollen concentrations in only half of plant taxa and higher fungal spore concentrations in only Ustilago. Pinaceae and Quercus pollen were the most abundant recorded by airplane (>54% of the total). Poaceae pollen were the most abundant via car measurements (>77% of the total). Cladosporium and Alternaria spores were the most abundant in all cases (aircraft: >69% and >17%, car: >45% and >27%, respectively). We conclude that pollen and fungal spores can be diverse and abundant even outside the main source area, evidently because of long-distance transport incidents.

Forecasting airborne pollen concentration of Poaceae (Grass) and Oleaceae (Olive), using Artificial Neural Networks and Genetic algorithms, in Thessaloniki, Greece

The impact of airborne pollen on human health was recognized many years ago as high pollen concentrations of specific taxa are responsible for triggering allergic reactions to humans, therefore affecting the quality of life. In this study, we develop data-driven pollen concentration forecasting models for the city of Thessaloniki (Greece), using Artificial Neural Networks - Multi-Layer Perceptron (ANN-MLP). The data correspond to the time period 1987 – 2002 and consist of daily time-series of pollen concentrations and several meteorological parameters. We focus on the taxa of Poaceae (Grass) and Oleaceae (Olive), both known to be of high allergenicity to humans. The input variables (features) for the models were selected with the aid of a multi-objective optimization method that employed genetic algorithms. For this purpose, the number of features and the performance of the models were optimized. The resulting models indicated satisfactory performance with an Index of Agreement (IA) up to 0.93 when predicting pollen concentrations 1 day ahead, whereas the same statistical index decreases to 0.85 when the forecasting horizon is 7 days ahead, meaning that they are suitable for operational implementation.