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The object of this study is to compare the results obtained in 2001 with those of the previous years and to continue the study started two years ago, making it possible to compare the daily pollinic accounts observed on two pollen traps located at the same place (Faculty of Science in Amiens), but at different heights. The primary trap is located on the roof of faculty (approximately 15 m of the ground) and the other on the ground of the same building.

At various occasions, we presented the temporal and geographical evolution of pollination during ten to fifteen last years on various sites of the French network. The year 2000 had shown often different characteristics for some tax for part of the towns of France. An hypothesis had been suggested blaming the great storm at the end of December 1999. Work presented has pure goal to prolong of one year (2001) the curves of evolution of all taxa and those of main allergenic pollens so, the share to consolidate or not the assumption 2000 and the another share, to present the assessment of pollination during the season 2001.

The article gives the assessment of the weekly results published in the National Bulletin of RNSA: 35 bulletins were published, 46 sites sent results. Of the tables indicate: the dates of pollen traps departure to record counting for each site 2001, the number of bulletins published over four years, a comparison over six years and one 28 weeks principal period of number of weeks lost for the publication. A histogram shows the evolution of the number of results published per week in 2000 and 2001.

For the third consecutive year, the two sensors of the type HIRST of the National Network of aerobiology monitoring (RNSA) worked on the agglomeration of Lyon. The primary trap (Lyon 1) is located at 26 m height on a roof in southern zone of Lyon (district of Gerland), the second (Lyon 2) is located in northern zone of the city (district of Vaise) on a roof at 15 m height compared to the ground. The study of the daily variations of the pollinic counts over the first two years had shown a perfect parallelism for pollens of trees, Poaceae and Urticaceae. Only the curves of pollens of ambrosia presented different layouts between the two pollen traps. The study of this third year makes it possible to consolidate the proceeding results and to appreciate the value of the cover of a Hirst pollen trap in urban implantation within the framework of the allergo-pollinic monitoring.

The ambrosia (Ambrosia artemisiifolia L.) has been announced in Switzerland for more than 100 years. During the last decade, signs of an increased presence of the ambrosia and its pollen appear in the south-west of Switzerland, in particular in Geneva. Aerobiologic measurements make it possible to highlight the importance of the transport of pollen by the winds since the area of Lyon, where the ambrosia is abundant. It also bring elements making it possible to detect a local production of pollen in the Geneva area, where several invaded fields were discovered with the autumn 2001. A multidisciplinary group was created in Geneva and it attempts to prevent as far as possible probable invasion of the ambrosia.

Within the framework of the decrees taken on the departments of Isère and Rhone concerning the protection of the population with respect to ambrosia, the object of this study is to relate the analysis of the daily pollen counts in the of air along the Lyon-Grenoble axis. With this intention, three sensors of the type HIRST were positioned according to standards of the European networks in Lyon-Gerland, Bourgoin-Jallieu and Grenoble. The results presented show the curves of the daily pollen counts on the three sites and by indicating the allergic thresholds of risks associated defined by the RNSA. The number of days with high risk, for each of the three sites, can thus be compared. Experiment must be prolonged to follow, these comparative results and moreover, possible effectiveness of the obligations of pulling up of the plant on atmospheric pollination.

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.

Marseille has two sites (Centre and North) where airborne pollens are collected and counted. The most numerous pollens are from Cupressaceae Taxaceae. We compared the quantities collected with both pollen traps during February, March and April 1988 and 1989. Most of pollinization takes place in March. In Marseille's Centre, there were three times more trapped pollen during 1989 than in 1988. In 1989, there was 40% more pollen on northern site as compared with the other one. As indicated in 1989 with both sites, it suggests a circadian periodicity of Cupressaceae Taxaceae pollen: their highest count is usually between 9 and 11 hours a.m.

The permanent recording of air pollen contain from more than 25 sites distributed all over France using the same method gives homogeneous results with every two hours daily measures. Among usual pollen taxa harvested in the city of Lyon, Ambrosia pollen data is to be emphasized due to its high allergenic potency. Between years 1987 and 1990, Ambrosia pollen data observed in Lyon have been recorded and completed with data obtained from other places in France where Ambrosia is also to be found during the summer and autumn seasons. Significant annual variations have been observed while the daily repartition of records appear quite steady. Data obtained do emphasize the high allergenic potency of Ambrosia of air pollen origin in a great number of french regions.

We compared, among 153 children 2 to 14 years old, responses to some positive control solutions for prick tests made with a Stallerpoint. We obtained the following values: -6% - 48/80:4.46 +/- 1.88 mm -1 mg/ml Histamine:3.49 +/- 1.67 mm -5 mg/ml Histamine:5.13 +/- 1.78 mm. 1 mg/ml histamine gives too many null responses (12/153) to represent a valuable positive control. 5 mg/ml histamine, on the other hand, gives some very strong reactions which may induce an underestimation of responses to allergen tests. Compound 48/80 seems to remain the best positive control for prick test exploration of immediate allergy in children. An alternative might be an intermediate solution of histamine 2.5 mg/ml.

107 allergic patients (71 children and 36 adults) were desensitized with allergen extracts adsorbed on calcium phosphate. Patients were selected following their symptoms (asthma, rhinitis, juvenile bronchitis, pollinosis), skin tests (ID or Prick) and total or specific IgE levels (PRIST and RAST). A mean of 17 month treatment, usually with house dust and mite extracts, rarely with house dust extract alone and in 6 cases with a mixture of grass and cereal pollens. The major aim of this study was to test the immunotherapy efficiency and to compare the IgE level variations and the clinical results. The treatment was found very good in 62% of the cases, good in 28%, and negative in 10% of the cases. The mean total IgE level has decreased of 58%, and the specific IgE level has decreased in 77% of the patients. The number of patients with a RAST class O to house dust and mites has increased respectively of 23% and 24.4% after the treatment. Besides some very good cases where the IgE levels have dropped there are lew relations between the total or specific IgE antibodies and the clinical results. The tolerance of the hyposensitization treatment was judged excellent. In conclusion, the calcium phosphate absorbed allergen extracts are confirmed as efficient and safe in immunotherapy.

We tested 100 children with clinical signs that occurred in spring or summer. Prick tests were made with extracts of wild grass pollens (Dactylis, Phleum, Lolium) and with separate cereal pollens (Wheat, oats, Sweet-corn Barley and Rye). In 20 children whose test was negative for wild grass pollen, we saw no sensitization to cereals. In 80 children with grass pollenosis, Barley and Rye are the cereals that gave the most positive prick tests, whilst sweet corn is the cereal with most negative tests.

The clinical study for four years running of desensitization treatment to adsorbed pollen calcium phosphate, prepared "at request" by Institut Pasteur, shows that these preparations produced particularly good results. The population of allergic subjects is divided into two categories as from first year of treatment: good responders and non responders. A study on the serums of these patients, in view of a different "immuno-imprint" in these two groups, has not yet been conclusive, whereas we were expecting much from this prognosis test, which would have given us better treatment information.