[Flora, distribution of vegetation and pollen content of the air: significance for allergics]. / Flore, repartition de la végétation et contenu pollinique de l'air: intérêt pour les allergiques.

The wealth of the flora of a given region cannot be seen in its airborne pollen list. Actually, for some plants there is a low probability that their pollens are recorded in the pollen counts (entomogamous plants, in particular). Moreover, the light microscopy reduces the possibilities of determination. In France, The Aerobiological Network of Surveillance (RNSA) retains 92 taxa at different levels (gender, family, group of families), and among them allergenic as well as non allergenic taxa. From the 130 families of the France flora, 63 are taken into account in the pollen studies, 57 taxa being determined at the gender level. The comparison between the surface occupied by the tree species in the French departments of Côte-d'Or and Saône-et-Loire, and the average airborne pollen concentrations showed that usually there is no correspondence between the abundance of a plant and the number of its pollen in the records. So the flora of a region does not give enough information allowing to know the taxonomic composition and the pollen quantities in the air, which is of particular importance for allergic people.

[2003, a year of extremes in Burgundy: pollen counts and meteorological influences]. / 2003, année des extrêmes en Bourgogne: comptes polliniques et influences météorologiques.

The year 2003 was marked by some particular meterological situations (mild conditions at the end of winter and during spring) which had consequences on the quantity of pollen in the air during the year. These meteorological influences differ from one taxa to another and mostly from one season to another. These quantities very quite different in comparison with the previous years, in particular a notable increase of many winter and spring tree taxa and a decrease of herbaceous taxa, particularly those pollinating in summer.

[How to predict the date of the start of the pollination of a plant from the meteorological data: the example of ragweed at Lyon]. / Comment prévoir la date de début de pollinisation d'une plante a partir des données météorologiques: l'exemple de l'ambroisie a Lyon.

The pollen of Ambrosia, highly allergenic, can be found in high quantities in the French regions of Burgundy, Auvergne and mostly a great part of the Rhône-Alpes region. The aim of this study was to establish some forecast models of the Starting Date of the Pollen season (SDP) of Ambrosia, in order to provide early information to allergists and allergic people. The pollen data came from the Hirst trap set up in Lyon since 1987 by the RNSA, and the meteorological data for the same period were provided by Météo-France. Two models were used, a sum of daily average temperatures and a multiple regression on all the 10-day period meteorological data. The results were quite accurate, except for 2003 with the temperature sums, probably because of very special meteorological conditions. So the models will have to be updated in this way.

[The French Airborne Pollen Network: current situation and prospects for improvement]. / Le réseau français de surveillance aéropollinique: situation présente et perspectives d'optimisation.

The french network of aeropalynology includes traps very close together and vast areas without any trap as well. A study was launched in order to optimise this network, without the number of traps increasing too much. Five criteria are successively reviewed to rationalise the spatial cover. Equi-distance of sites has to be balanced by the number of concerned people. But the need for having long time series is incentive to delete only as a last resort the traps which are reliable for a long time. Moreover, apart from the general network, some local or regional features make indispensable a trap in such-and-such a place (health resort), or justify a higher density of traps in such-and-such an area (the Rhône-Alpes concerning ragweed, the Mediterranean South concerning cypress).

[Evolution of pollinization in France (2002)]. / Evolution de la pollinisation en France (2002).

It was traditional until these last years to supervise the evolution of pollination by taking account only of the evolution of the number of grains of pollens present per m3 of air per year on each site. If this factor is significant, it is not sufficient. Indeed, it is essential to be able to supervise the evolution of the number of days in the year when the allergic risk related to a pollen is significant. The work which is presented shows over the years 1992 to 2002, for some sites of the RNSA (Amiens, Paris, Rouen, Strasbourg, Montlucon, Bordeaux, Lyon, Marseille, Toulouse) that there can be parallelism of the curves "pollinic counts" and "allergic risk", but also of light discordances. Should a thorough study of the dates of appearance supplement this work because these modifications can be the consequence of the climatic motions of these last decades.

[Pollen counts and allergies in Burgundy: profile and perspectives]. / Comptes polliniques et allergies en Bourgogne: bilan et perspectives.

The aim of this study was to assess the situation of pollen counts and epidemiological studies on allergies in Burgundy (France), and to talk about the future prospects of this kind of work. Pollen data came from two Hirst traps set up in Dijon and Chalon-sur-Saône, and the medical data (prick-test results) came from an epidemiological study. Pollen counts showed that Betula, Poaceae and Urticaceae were the first pollens in the air. The frequency of the other taxa varied according to the site, such differences also concerning the year-to-year pollen counts evolution. The epidemiological study showed that Poaceae and Betula were the first involved allergens, with some differences between the two departments as regards the other taxa. The study, taken up again in 2002, will allow to involve more patients, in the whole Burgundy, and to include Ambrosia in the prick-tests. However, results will not be able to be compared to those of pollen counts in the departments of the Yonne and the Nièvre where there is no pollen trap. So three new traps will be set up in 2003 (collaboration DRASS/RNSA) in order to optimise the Burgund network and to be used as an experimental model for the optimisation of the French network, which is now under consideration.

[The Poaceae pollen season in France in 2001]. / Etude de la saison pollinique 2001 des Poacées en France.

The aim of this study was to determine the main characteristics of the Poaceae pollen season in France (seasonal and daily quantities) in 2001, and to compare them to those of the previous years. The data came from seven volumetric Hirst traps, located in the cities of Amiens, Paris, Lyon, Nîmes, Bordeaux, Montluçon and Strasbourg. The study period range from the beginning of March to the end of August. The pollen quantities of 2001 were particularly high in three sites (Montluçon, Bordeaux et Lyon); they were higher than those of 2000 in Amiens and Strasbourg, but in those sites the peak of the whole series was situated in 1994; lastly the pollen quantities of 2001 were little different or lower than those of 2000 in Nîmes and Paris. This was probably not without effect on allergic people.

Forecasting the start of the pollen season of Poaceae: evaluation of some methods based on meteorological factors.

The pollen of anemogamous plants is responsible for half the allergic diseases, that is to say a prevalence of 10% in the French population. Poaceae produce the first allergenic pollen almost everywhere. The work described in this article aimed to validate forecast methods for the use of physicians and allergic people who need accurate and early information on the first appearance of pollen in the air. The methods were based on meteorological parameters, mainly temperature. Four volumetric Hirst traps were used from 1995 to 1998, situated in two departments of Burgundy. Two of the methods tested proved to be of particular interest: the sum of the temperatures and the sum of Q10 values, an agrometeorological coefficient integrating temperature. A multiple regression, using maximum temperature and rainfall, was also performed but it gave slightly less accurate results. A chi 2-test was then used to compare the accuracy of the three methods. It was found that the date of onset of the pollen season could be predicted early enough to be useful in medical practice. Results were verified in 1999, and the research must be continued to obtain better statistical validity.