163 Aerobiological monitoring of Taxaceae/Cupressaceae pollen in Timisoara Ianovici Nicoleta* 1 1 West University of Timisoara, Faculty of Chemistry, Biology and Geography, Department of Biology *Corresponding author. Email: nicole_ianovici@yahoo.com Abstract This study analyzes the pollen representation of Taxaceae/Cupressaceae in the atmosphere of Timişoara during the years 2000-2004. Annual variations in the concentration of pollen in the atmosphere were analysed by the volumetric method. During the studied period, inter- annual variations, concerning the total annual pollen counts and the beginning, peak and ending dates of the APS, were reported. Taxaceae/Cupressaceae is one of the best represented taxa in the atmosphere of the city of Timişoara where it constitutes between 2.6% and 4.9% of the total. The highest annual level was attained in 2004 with 854 PG/m 3 . In the 5 years studied, the lowest concentration of Taxaceae/Cupressaceae pollen was observed in 2000. The highest monthly total concentrations were recorded in March and April. The mean annual concentration for 5 years of study was 623,8 PG. Pollen seasons were defined as the periods in which 90% of the total catch occurred. In the course of five years, significantly greater differences in annual totals of pollen grains of the studied taxa were observed in Timişoara. Taxaceae/Cupressaceae airpollen are not nearly as potentially relevant in pollinosis for the western România. Key words Atmospheric Pollen Season (APS), Taxaceae/Cupressaceae Taxaceae/Cupressaceae pollen has been cited by different authors as an important allergen in the Mediterranean region [14; 22; 61; 11]. However, different aerobiological studies show that its presence is also very considerable outside that area [31; 32; 46; 55; 60] since different species of this family are frequently used for ornamental purposes in parks and gardens in many cities. Cupressaceae pollen has commonly been reported as an important aeroallergen and causal factor of autumn and winter pollinosis in Europe and Japan [43; 58]. The importance of allergy to Cupressaceae pollen in Australia has only recently been established (Bass et al., 1991). Juniperus ashei is a major cause of seasonal allergy in the South-West and Texas [42]. The level of allergenicity of the different species largely depends on the quantity of allergen or allergens that the pollen releases 5–10 minutes after coming into contact with the respiratory tract. There are Cupressaceae species with a poor allergenic capacity, but cases have been reported of cross reactivity with some Pinaceae [63] and Taxodiaceae species [21]. In the case of Spain, Cupressaceae pollen is the predominant pollen in the areas such as Toledo, Barcelona and Madrid from January to April (11%) and it is the main cause of the so called “winter allergic cold”, being 20% the prevalence of positive skin prick test to C. arizonica extract [43;12;75]. There is a tendency towards an increase in the reactivity to Cupressaceae pollens because the allergenic load is becoming more intense given that they are frequently used for ornamental purposes and as natural barriers. In addition, the potential adjuvant effect of air pollution may have contributed to this increase. Nevertheless, it has been described several prevalence rates among cypress sensitization with divergent results, all of them collected in geographical areas where cypresses have a high incidence. Whereas some authors think that cypress allergy is underestimated [11; 18; 58], others doing also good epidemiological surveys, stated that the prevalence of sensitization is low, besides the high allergenic pollen load in the studied areas [3]. A possible underestimation of the real prevalence of cypress allergy may be due to the difficulties for allergens extraction from the grains which leads to the lack of good standardization of the extracts. Other possible factors that should be taken in account are genetic protective factors, specially in those populations in close contact with cypresses during centuries [37]. Cupressaceae pollen has two important characteristics: a low protein concentration and its high carbohydrate content. Characterization of the allergenic extract of C. arizonica pollen shows that it contains a