Pollen Allergy in Cordoba City: Frequency of Sensitization and Relation with Antihistamine Sales

The occurrence of symptoms in pollen allergy patients in urban areas may be affected by local environmental factors such as sources of pollution, natural and ornamental vegetation, local architecture impeding dispersion, etc. The aim of this study was to analyse the frequency of sensitization in pollen allergy patients and the relationship with antihistamine sales. For this study, a large number of clinical records, together with pharmaceutical and pollen data, were collected between 1999 and 2001 in the city of Córdoba, in the south of the Iberian Peninsula. Differences were observed in the symptoms suffered by pollen allergy patients in different areas of the city due to varying local emission of both biological and non-biological particles. Temporal distribution of symptoms over the three study years was influenced by meteorological factors, especially rainfall patterns; higher water supply to plants was associated with increased airborne pollen concentrations. Air pollution might be one of the main factors affecting the distribution of pollen allergy patients within the city. Recent years have seen a worsening of symptoms and increased sensitization to urban species such as plane-trees.

Long-range Transport of Ambrosia Pollen to Poland

The long-range transport of Ambrosia pollen to Poland is intermittent and mainly related to the passage of air masses over the Carpathian and Sudetes mountains. These episodes are associated with hot dry weather, a deep Planetary Boundary Layer (PBL) in the source areas and winds from the south. Such episodes can transport significant amounts of Ambrosia pollen into Poland. The study investigates Ambrosia pollen episodes at eight sites in Poland during the period 7th to 10th September 2005, by examining temporal variations in Ambrosia pollen and back-trajectories. PBL depths in the likely source areas were calculated with the Eta meteorological model and evaluated against the mountain heights. Considerable amounts of Ambrosia pollen were recorded at several monitoring sites during the night or early in the morning of the investigated period. Trajectory analyses shows that the air masses arriving at the Polish sites predominantly came from the south, and were in the Czech Republic, Slovakia and Hungary the previous day indicating these countries as potential source areas. We have shown the progress of Ambrosia plumes into Poland from the south of the country, probably from Slovakia and Hungary, and demonstrated how Lagrangian back-trajectory models and meteorological models can be used to identify possible transport mechanisms of Ambrosia pollen from potential source regions.

Are the Birch Trees in Southern England a Source of Betula Pollen for North London?

Birch pollen is highly allergenic. Knowledge of daily variations, atmospheric transport and source areas of birch pollen is important for exposure studies and for warnings to the public, especially for large cities such as London. Our results show that broad-leaved forests with high birch tree densities are located to the south and west of London. Bi-hourly Betula pollen concentrations for all the days included in the study, and for all available days with high birch pollen counts (daily average birch pollen counts >80 grains/m3), show that, on average, there is a peak between 1400 hours and 1600 hours. Back-trajectory analysis showed that, on days with high birch pollen counts (n=60), 80% of air masses arriving at the time of peak diurnal birch pollen count approached North London from the south in a 180 degree arc from due east to due west. Detailed investigations of three Betula pollen episodes, with distinctly different diurnal patterns compared to the mean daily cycle, were used to illustrate how night-time maxima (2200–0400 hours) in Betula pollen counts could be the result of transport from distant sources or long transport times caused by slow moving air masses. We conclude that the Betula pollen recorded in North London could originate from sources found to the west and south of the city and not just trees within London itself. Possible sources outside the city include Continental Europe and the Betula trees within the broad-leaved forests of Southern England.

Airborne Olive Pollen Counts are not Representative of 1 Exposure to the Major Olive Allergen Ole e 1

Pollen is routinely monitored, but it is unknown whether pollen counts represent allergen exposure. We therefore simultaneously determined olive pollen and Ole e 1 in ambient air in C"ordoba, Spain, and "Evora, Portugal, using Hirst-type traps for pollen and high-volume cascade impactors for allergen. Pollen from different days released 12-fold different amounts of Ole e 1 per pollen (both locations P < 0.001). Average allergen release from pollen (pollen potency) was much higher in C"ordoba (3.9 pg Ole e 1/pollen) than in "Evora (0.8 pg Ole e 1/pollen, P = 0.004). Indeed, yearly olive pollen counts in C"ordoba were 2.4 times higher than in "Evora, but Ole e 1 concentrations were 7.6 times higher. When modeling the origin of the pollen, >40% of Ole e 1 exposure in "Evora was explained by high-potency pollen originating from the south of Spain. Thus, olive pollen can vary substantially in allergen release, even though they are morphologically identical.