Environmental behaviour of airborne Amaranthaceae pollen in the southern part of the Iberian Peninsula, and its role in future climate scenarios.

The Amaranthaceae family includes a number of species which, through a series of specific adaptations, thrive in salty soils, arid environments and altered human settlements. Their ability to tolerate high temperatures favours summer flowering, giving rise to the widespread involvement of Amaranthaceae pollen grains in summer allergies, both in Mediterranean Europe and in areas with arid climates. This study analysed a 21-year set of historical airborne Amaranthaceae pollen records for an area located in the southern part of the Iberian Peninsula, in order to chart species' environmental reaction to changing climate conditions which occurred in the last decades. Airborne pollen data were collected from January 1991 to December 2011 using a Hirst-type volumetric impact sampler. Results showed that Amaranthaceae pollen remained in the atmosphere for over 6 months along the year, from early spring until early autumn. The annual Pollen Index ranged from barely 200 grains to almost 2000 grains, and was strongly influenced by rainfall during the flowering period, which prompted the development of new individuals and thus an increase in pollen production. A trend was noted towards increasingly early pollen peak dates; peaks were recorded in August-September in years with summer rainfall, but as early as May-June in years when over 50% of annual rainfall was recorded in the months prior to flowering. The gradual decline in the annual Pollen Index over later years is attributable not only to growing urbanisation of the area but also to a change in rainfall distribution pattern. High maximum temperatures in spring were also directly related to the peak date and the Pollen Index. This ability to adapt to changeable and occasionally stressful and restrictive, environmental conditions places Amaranthaceae at a competitive advantage with respect to other species sharing the same ecological niche. An increased presence of Amaranthaceae is likely to have a greater impact on future scenarios for pollen allergy diseases associated with climate change.

Analysis of solid particulate matter suspended in the air of Córdoba, southwestern Spain.

An analysis was made of solid particulate matter suspended in the air in the city of Cordoba. Particles greater than 10 micra were collected using volumetric particle samplers (Lanzoni VPPS 2000, Bologna, Italy), and analysed by means of aerobiological methods enabling identification of the source of biological particulate material (BPM). Particles smaller than 10 micra were collected using automatic high-volume air samplers. Subsequent analysis showed that traffic, and particularly diesel engine exhaust emissions, were the main source of non-biological particulate matter (nBPM). The dynamics of airborne BPM and nBPM were also studied over one year: although distribution patterns differed--BPM displaying marked seasonality and non-BPM exhibiting dependence on human activity--the curves ran parallel at certain times of the year. Statistical results point to the possible presence of plant residues on smaller particles. The occurrence of simultaneous peaks in airborne pollen-grain and PM10 counts suggests potential coadjuvant activity, which may lead to high-risk situations for people with respiratory disease.

Bioclimatic requirements for olive flowering in two Mediterranean regions located at the same latitude (Andalucia, Spain and Sicily, Italy).

The Mediterranean Region is the major area devoted to olive tree crop, and therefore a study of olive flowering is of great interest for the European Community. On the other hand, olive pollen is one of the main causes of pollen allergy in the Mediterranean area. Olive flowering is affected by climatic factors such as temperature and photoperiod, which vary geographically in latitude and altitude. Temperature has been used to study those processes that lead to flowering in the olive tree. The aim of the present paper is firstly the comparison of the flowering full bloom dates in two Mediterranean areas, Sicily (Italy) and Cordoba (Spain), located in the same latitudinal band (37-38 degrees N) and to calculate the heat requirement until flowering by determination of different threshold temperatures and methods of heat accumulation. A delay of the full flowering dates in the Spanish compared with the Italian olive groves was observed. The most suitable threshold temperatures were carried out in a 7 degrees -15 degrees C range by considering the heat accumulation start on 1 January in each olive grove. In particular, some causes were indicated as responsible for the different threshold temperatures recorded in the 2 study areas: First, the different climatic conditions (continental and insular climate) secondly the different cultivars present in the olive groves.

Analysis of the particles transported with dust-clouds reaching Cordoba, southwestern Spain.

Dust-cloud episodes were detected in summer 1999 in the city of Cordoba, southwestern Spain, with a higher frequency than usual. Solid airborne particles were collected using a suction volumetric sampler and analyzed to determine both their nature and their origin. Nonbiological material was mostly identified as mineral sand and partially burned remains of hydrocarbons and stubble. Amounts were estimated in terms of the percentage of microscopic field of view covered. Biological materials, in this case pollen grains, were identified and classified as belonging to either autochthonous or remote flora; in the latter case, the possibility was examined that they might originate in North Africa. Some pollen types were also used as tracers to chart the path followed by the sand clouds within the Iberian Peninsula. Meteorological conditions on the days in which episodes occurred were analyzed. In all cases, very dry southwesterly winds were recorded, at moderate to high speeds, together with temperatures of over 35 degrees C. The increase in airborne pollen detected, together with the large amount of particles collected, could have an adverse effect on health, particularly in pollen allergy sufferers, for whom dust-clouds represent an added risk.

Pollen allergy related to the area of residence in the city of Córdoba, south-west Spain.

The aim of this study was to analyse the relationship between the distribution of hay-fever patients in the city of Córdoba, south-western Iberian Peninsula, and the specific atmospheric biological content originating from local sources. Four different districts were established in the metropolitan area of the city, according to vegetational and urbanistic characteristics. Air samples were taken in each area using portable Hirst-type samplers (Lanzoni VPPS 1000) and the spectrum of biological content was defined. Patients attending the Allergy Unit at Córdoba Teaching Hospital in 2000 with allergic rhinitis and/or asthma, and displaying a positive reaction to aeroallergen extracts, were distributed within the areas as a function of their district of residence. Aerobiological results revealed differences in pollen content between areas, in terms of both quantity and number of pollen types recorded. These differences were largely due to proximity to rural areas, prevalence of pollen from typically urban species and the possible effect of urban architecture as a barrier to the dispersal/ concentration of particles and other pollutants. Patients were not uniformly distributed within the city. The majority lived in districts in which pollen from rural species was mixed with pollen from ornamentals. Patients living in typically urban districts displayed a higher prevalence of allergy to pollen from ornamentals. It is concluded that a high degree of exposure to the same environment may influence the development of sensitisation to the particular pollen load associated with that area.