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Resume Introduction Il existe un nombre croissant de recherches traitant des effets du changement climatique sur le pollen et les spores fongiques. Le present article procede a une revue rapide de cette litterature, en insistant sur les points qui font consensus et en attirant l’attention sur les erreurs a eviter. Etat des connaissances La these dominante est que la hausse des temperatures avance le debut des saisons polliniques ou mycologiques, allonge ces saisons, renforce le potentiel allergisant des particules biologiques et augmente leurs concentrations. Mais ce qui vaut pour un taxon, en un lieu donne et a une certaine periode, n’est presque jamais generalisable. Perspectives Quatre priorites peuvent etre enoncees pour les recherches a venir: (1) ne rechercher des tendances que sur des series suffisamment longues, sans negliger de possibles inversions de tendance; (2) privilegier l’echelle locale et la prise en compte separee des differents taxons; (3) faire intervenir tous les parametres du climat comme elements d’explication, et pas uniquement la temperature; (4) ne pas vouloir tout expliquer par le changement climatique. Conclusions Avant de pretendre a une synthese, il convient encore de multiplier les etudes analytiques en accordant la primeur a l’observation sur le raisonnement.

Resume En France, depuis plus de 35 ans, l’information sur le risque d’allergie lie a l’exposition au pollen fait appel a l’utilisation de capteurs specifiques. Le reseau de surveillance aerobiologique, aujourd’hui connu sous le sigle RNSA, s’est progressivement constitue a partir de 1984 et il compte a present environ 80 capteurs « de fond » de type Hirst, episodiquement completes pour des recherches ponctuelles par des capteurs « de proximite ». Initialement, le choix des emplacements devait beaucoup a des contingences locales. Mais la representativite spatiale des sites a ensuite fait l’objet de nombreuses etudes, qui ont permis une certaine optimisation du maillage. Le denombrement et l’identification des grains de pollen sont realises en microscopie optique, selon une methode robuste mais chronophage, necessitant un personnel hautement qualifie et ne fournissant que des donnees depassees au moment ou elles sont diffusees. C’est pourquoi le RNSA participe activement a divers programmes de recherche orientes, soit vers la detection automatique des particules biologiques en suspension dans l’air, soit vers des technologies telles que la surveillance de la teneur en allergenes, l’analyse de l’ADN ou la reconnaissance d’image. Une autre orientation est la modelisation atmospherique, qui permet de realiser des previsions du risque d’allergie, mais qui n’a pas toujours fait l’objet de validations suffisantes. En fin de compte, et grâce a un partenariat avec la Societe francaise d’allergologie, le RNSA se distingue des reseaux etrangers similaires par la priorite donnee a la diffusion d’informations en termes de risque d’allergie du a l’exposition au pollen, et non en termes de concentration du pollen aeroporte, qui n’a pas de reelle signification clinique.

Resume C’est devenu une evidence que le climat change et que cela peut affecter la sante humaine. En particulier, on s’attend a ce que le rechauffement climatique se repercute sur la pollinisation et augmente l’occurrence des allergies respiratoires. Cette etude a ete realisee sur 6 ou 7 sites francais de surveillance aerobiologique, avec l’objectif de detecter d’eventuelles modifications survenues durant les 24 a 32 dernieres annees dans la chronologie, la duree et l’intensite des saisons polliniques de deux taxons tres allergisants, le bouleau et les graminees. Les resultats les plus probants ont ete obtenus pour Betula. D’une part, le debut de la saison pollinique de cet arbre a connu jusqu’aux alentours de 2002 une avance de 0,02 a 0,69 jour/an, apres quoi la tendance s’est inversee, au point que la pollinisation demarre maintenant aussi tard, voire plus tard qu’il y a trente ans ; l’explication la plus plausible est que des hivers plus doux retardent la levee de dormance et annulent l’avance de la phenologie printaniere provoquee par des printemps plus chauds. D’autre part, tous les sites etudies ont presente une forte hausse de la quantite de pollen emise, positivement correlee a la temperature de la periode allant de juillet (annee N−1) a juin de l’annee N. Pour les Poaceae, les resultats sont souvent contradictoires d’un endroit a l’autre. Ils ont neanmoins revele une tendance presque partout decroissante pour les concentrations polliniques. En conclusion, l’accent est mis sur les divergences qui existent entre les effets deja observes en France sur les saisons polliniques et le discours dominant sur la reponse de la pollinisation au changement climatique.

Resume But de l’etude L’objet de cette etude etait de montrer comment l’implantation de differentes especes vegetales en ville peut contribuer a renforcer l’exposition des citadins au pollen et, de ce fait, accroitre la prevalence des pollinoses. Materiel et methodes Le travail a ete realise sur quatre parcs intra-urbains de Lyon entre mars et juin 2018. Dans chacun d’eux a ete mis en place un capteur pollinique de proximite, de type Sigma2-Like Trap (SLT), et ont ete exploitees les donnees concernant quatre taxons arboreens a potentiel allergisant fort ou modere. Un index de source (fonde sur le nombre d’arbres) et un index d’exposition (reposant sur les quantites de pollen) ont ete calcules pour chaque parc, en se limitant au parc ou en prenant en compte la voirie adjacente. Resultats Les arbres a pollen allergisant sont nombreux dans les parcs et a leurs abords, meme si les especes dominantes varient beaucoup d’un cas a l’autre. Les index de source et d’exposition les plus eleves ont ete obtenus pour le bouleau au jardin d’Erevan, exclusivement plante de cette espece, et pour le platane dans les parcs de Gerland et de la Tete d’Or ou cet arbre est tres abondant dans le voisinage. Conclusion Les resultats obtenus peuvent etre d’un grand interet pour la mise en œuvre de mesures destinees a reamenager les espaces verts existants ou a en creer de nouveaux, avec la perspective de reduire les risques allergiques pour les residents et les visiteurs. La priorite doit etre d’eviter les peuplements monospecifiques.

Pollen and fungal spore concentrations in outdoor air are partly dependent on atmospheric conditions. Since the climate is changing, there is a growing body of research on the effects of climate change on aeroallergens. The present article provides a rapid review of this literature, highlighting the points of agreement, but also drawing attention to the main mistakes to be avoided.For pollen, the prevailing view is that rising temperatures lead to an earlier start to the pollen season, a longer season, increased allergenic potential and higher concentrations. However, there are exceptions: what is true for one taxon, in one place and at one time, can almost never be generalised. For fungal spores, it is even more difficult to state universal rules.Four priorities can be set for future research: (1) to look for trends only on sufficiently long series and not to neglect possible trend reversals; (2) to give priority to the local scale and the separate consideration of the various pollen and mycological taxa; (3) not to limit oneself to temperature as an element of explanation, but also to consider the other elements of the climate; (4) not to try to explain any evolution in the abundance or seasonality of aeroallergens by climate change alone.Many more analytical studies giving precedence to observation over reasoning are still required, without any preconceptions, before it is possible to synthesise the impacts of climate change on pollen and, even more so, on fungal spores.

Resume Le RNSA a participe a une etude europeenne en 2015 et 2016 avec pour objectifs d’evaluer la quantite de pollen et la teneur en allergenes dans plusieurs jardins publics de Paris et de Lyon et sur la base des resultats obtenus, de formuler des recommandations en vue de proteger les personnes allergiques. La conclusion est qu’il y a dans ces parcs beaucoup d’especes allergisantes (bouleaux, platanes, cypres, frenes…).

Introduction Ambrosia artemisiifolia est une plante de la famille des Asteraceae. C’est une espece annuelle, dont le maintien dans un environnement donne est lie a sa capacite de reproduction. Il s’agit d’une espece exotique envahissante originaire d’Amerique du Nord, capable de se reproduire sous nos latitudes (45°N) et de produire une grande quantite de graines matures. Methodes La photoperiode est la succession reguliere de l’alternance d’une periode de lumiere, le jour, et d’une periode d’obscurite, la nuit. La photoperiode est definie comme la duree du jour ou « la periode d’eclairement journalier recu par un organisme » et « a un moment du cycle annuel » ; elle demeure constante d’une annee a l’autre a un endroit geographique donne. La latitude est le facteur qui determine la photoperiode. Resultats De nombreuses etudes tentent de montrer l’expansion possible de l’ambroisie dans les pays du Nord. Si avec le changement climatique (temperature) la plante peut pousser a des latitudes plus au nord, la photoperiode ne lui permet pas de produire des graines. Discussion Cette etude preliminaire a ete realisee en France sur 5 villes (Lille, Nevers, Chalon-sur-Saone, Lyon et Bagnols-sur-Ceze) avec des latitudes variant de 50°38′ Nord a 44°09′ Nord, entre 1987 et 2019 selon les stations polliniques. Pour chaque station, il a ete possible de determiner la date de debut, de pic et de fin de la pollinisation de l’ambroisie. Conclusion La photoperiode est le facteur le plus important limitant la repartition europeenne des plantes envahissantes comme Ambrosia artemisiifolia. Les tentatives de predire le deplacement de l’aire de repartition de l’ambroisie vers le nord ont mene a la conclusion que l’extension de l’aire de repartition est en grande partie limitee par la photoperiode requise pour l’induction de la floraison puis de la production de graines. Le positionnement des dates du debut de la pollinisation, du pic principal et de la fin de la pollinisation sur chacune des courbes permet de comprendre que l’accumulation de jour est retardee d’autant plus que le site est plus au nord. A la latitude de Lille, il n’y a pas assez de pollen dans l’air, donc pas assez de graines pour la reproduction des plantes.

Introduction La hausse des niveaux de CO2 et le changement climatique peuvent entrainer un certain changement de l’aire geographique de certaines especes vegetales, ainsi qu’une augmentation de la photosynthese. Beaucoup de plantes reagissent en consequence avec une croissance et une reproduction accrues et peut-etre des rendements de pollen plus eleves, qui pourraient affecter les maladies allergiques entre autres. L’objectif de cette etude est de suivre et etudier l’evolution des mesures aerobiologiques en France depuis 25–30 ans. Cela permet de suivre les principaux parametres phenologiques en relation avec la pollinisation et le risque d’allergie qui en resulte. Methodes Le RNSA (Reseau francais d’aerobiologie) dispose de capteurs de pollens situes dans plus de 70 villes a travers la France. Les principaux taxons etudies ici sont le bouleau, les graminees et l’ambroisie pour une longue periode de plus de 25 ans dans certaines villes de France. Resultats En ce qui concerne le bouleau, mais aussi d’autres especes d’arbres qui pollinisent a la fin de l’hiver ou au printemps, on peut observer une avancee globale de la date de debut de la saison du pollen jusqu’en 2004, puis un retard progressif, la date actuelle etant presque la meme qu’il y a 20 ans, et une tendance a la hausse des quantites de pollen emises. Pour les graminees et l’ambroisie, nous n’avons trouve que quelques changements mineurs dans la date de debut, mais une duree plus longue de la saison du pollen. Discussion Un changement de la temperature annuelle peut avoir un effet direct sur la physiologie vegetale et donc sur la liberation du pollen. Cela peut aussi expliquer pourquoi les quantites de pollen produites augmentent. Conclusion Depuis 2004 un retard est observe dans les dates de debut de pollinisation des arbres qui fleurissent a la fin de l’hiver ou au debut du printemps tandis que les quantites de pollen emis sont en constante augmentation. Les graminees et l’ambroisie ont des periodes de pollinisation plus longues, avec une production de pollen le plus souvent plus faible.

Introduction Les herbacees regroupent toutes les plantes qui ont une partie ligneuse tres peu ou pas developpee. On trouve ces plantes partout : en ville, en bordure de routes ou de chemins, dans les pres, en foret, etc. Elles sont aussi parfois appelees « mauvaises herbes » ou adventices. La saison des pollens d’herbacees commence en mai avec les Poacees et s’etend jusqu’au mois d’octobre avec les Urticacees, l’ambroisie et l’armoise notamment. Methodes Les caracteristiques qui ont ete retenus pour la creation du poster herbacees sont : – le potentiel allergisant (capacite d’un pollen de provoquer une allergie pour une partie non negligeable de la population. Il est evalue par le RNSA. Il peut etre fort, modere, faible ou negligeable), – la famille (Asteracees, Chenopodiacees, Cannabacees, Euphorbiacees, Urticacees, Plantaginacees, Graminees fourrageres, Graminees cerealieres, Graminees ornementales…), – les caracteristiques morphologiques de la plante, de la feuille et de la fleur, – la periode de pollinisation. Resultats La pollinisation de certaines herbes, tout comme la pollinisation de certains arbres, se fait par le vent (anemophilie). Les herbes produisent, de ce fait, d’importantes quantites de pollens, dont certains sont plus allergisants que d’autres. Parmi les herbes, ont ete selectionnees sur ce poster des plantes classiques et des graminees (Poacees) qui forment un groupe morphologique a part. Les 24 herbes choisies representent les especes importantes sur le plan allergologique et/ou sur les calendriers polliniques. Discussion Ce poster permet de mieux reconnaitre les herbacees notamment celles qui sont tres allergisantes, en vous proposant une information complete. Conclusion Devant le niveau de risque allergique, des recommandations concernent les espaces urbains et tout jardin en proximite d’habitation. Elles doivent permettre soit d’eviter leur plantation soit de proceder a un entretien limitant la dispersion des grains de pollen (tontes, tailles, etc.). En tout etat de cause, il est conseille de consulter le site « vegetation en ville » et les posters « arbres » et « herbacees » disponibles sur le site www.pollens.fr

The aim of this review is to describe the health impact of exposure to pollen based on recently published epidemiological studies. The methodology chapter, describes a review of the literature and outlines important elements of these studies: measurement of exposure to pollens, study types used, study populations and the health indicators related to pollen exposure. In this review, two types of studies have been used to assess the epidemiological evidence of short-term links between pollen exposure and hay fever or asthma. Ecological time-series studies use daily indicators of asthma exacerbations (emergency room admissions or hospitalizations), consultations for rhinitis or conjunctivitis, or anti-allergic drug consumption within general population. Panel studies relate measurements of pollen grain concentrations to nasal, ocular and bronchial symptom severity in a group of subjects sensitized to a specific pollen, monitored during the pollen season. In both cases, the studies show a relationship on a day-to-day basis between health indicators and daily rates of atmospheric pollen collected by a pollen trap. These studies take into account confounding factors, such as air pollution, weather factors and sometimes exposure to outdoor molds. Unlike earlier studies, more and more studies focus on the shape of the dose-response relationship and the lag between pollen exposure and symptoms. Only rarely, individual susceptibility factors, the clinical phenomenon of priming and polysensitization are reported. Thus, ecological time-series studies and panel studies assess respectively the impact of pollen exposure in the general population and in groups of sensitized patients. Using appropriate statistical tools, these studies provide insight into the shape of the dose-response relationship, with a potential threshold below which symptoms are absent, then a linear relationship for nasal, ocular and bronchial symptoms and a plateau where the symptoms do not increase despite the continued increase in pollen.

Resume Introduction Le pollen est une des principales causes d’allergie. Sa surveillance apporte une aide precieuse au diagnostic, au traitement et a la prevention. De nombreuses etudes aerobiologiques ont ete realisees, un peu partout dans le monde, pour caracteriser la concentration et la saisonnalite des grains de pollen. Etat des connaissances La surveillance aeropollinique recourt a differentes techniques, gravimetriques ou volumetriques. Le capteur de type Hirst, dans sa version moderne (Burkard® ou Lanzoni®), est le plus largement utilise. Le denombrement et l’identification des pollens se fait ensuite en microscopie optique. Les donnees obtenues peuvent servir a la realisation de calendriers polliniques, qui seraient avantageusement remplaces par des calendriers de risque allergique. Les comptes polliniques fournissent aussi des informations utiles sur l’origine geographique des pollens. Perspectives La demarche classique etant longue et fastidieuse, un interet croissant est porte aux procedures automatiques de surveillance aerobiologique. Par ailleurs, les divergences parfois constatees entre observations cliniques et comptes polliniques incitent a etudier directement les aeroallergenes. Enfin, la surveillance des pollens pourrait etre amelioree par l’utilisation de capteurs individuels. Conclusions L’aerobiologie a considerablement progresse depuis un siecle, mais il reste beaucoup a faire, notamment dans le domaine de la standardisation des methodes.

Resume Introduction Le rechauffement de la planete au cours des dernieres decennies ne fait plus guere de doute, et il a des repercussions inevitables sur la pollinisation. L’opinion prevaut que la tendance va se poursuivre et meme s’amplifier dans l’avenir. Etat des connaissances Un climat plus chaud a une forte probabilite d’anticiper les dates de floraison, d’allonger la saison pollinique et d’augmenter les concentrations de pollen dans l’air. Il peut egalement accroitre le contenu allergenique des grains de pollen et entrainer un deplacement vers le nord, ou en altitude, de l’aire d’extension de certaines especes. Des taux croissants de CO2 atmospherique sont en outre susceptibles de renforcer ces diverses tendances. Perspectives Les previsions sont inevitablement entachees d’incertitudes. Une meilleure comprehension de l’ampleur et du sens des changements affectant la pollinisation est indispensable si l’on veut quantifier le fardeau des allergies et modeliser les impacts a venir dans le cadre de differents scenarios d’evolution du climat. Conclusions Le changement climatique influence l’exposition de la population au pollen anemophile, ce qui peut affecter la prevalence et la severite des symptomes allergiques. Il y a la une preoccupation majeure de sante publique, qui requiert la mise en œuvre sans delai de strategies appropriees d’adaptation.

International audience; An 18-month survey of indoor fungal contamination was conducted in one haematology unit during a period of construction work. Air was sampled with a portable Air System Impactor and surfaces with contact Sabouraud plates. During this survey the mean concentration of viable fungi in air was 4.2 cfu/m(3) and that for surfaces was 1.7 cfu/plate. At the beginning of construction work, there were increases in airborne fungal spores (from 3.0 to 9.8 cfu/m(3)) in the unit, but concentrations did not exceed 10 cfu/m(3) during the 18-month period. The most frequently recovered airborne fungi were Penicillium spp. (27-38%), Aspergillus spp. (25%) and Bjerkandera adusta, a basidiomycete identified with molecular tools (7-12%). Blastomycetes accounted for more than 50% of the fungal flora on surfaces. Investigating the impact of a new air-treatment system (mobile Plasmair units), there were significant reductions in fungal contamination for the Plasmer -treated rooms, and in these rooms we observed the same level of fungal load whether construction work was in progress or not.

The aim of this paper was to study the seasonal and Monthly distribution of different subtypes of strokes, and also the influence of the most usual meteorological factors on their incidence. The study, based on the population-based data of the Dijon register of stroke (France), involved 3287 patients with a cerebrovascular event during the Years 1985-1998. The seasonal distribution pointed out a summer decrease for all stroke subtypes. The cerebrovascular risk was the highest in autumn for small artery atheroma infarcts and for cerebral infarcts and, among these later, for cardioembolic infarcts and large artery atheroma infarcts, as well as for subarachnoid hemorrhages and for the total number of strokes. It was followed by spring (total number of strokes, small artery atheroma infarcts, cerebral infarcts) and/or winter (subarachnoid hemorrhages, cerebral infarcts, cardioembolic infarcts and large artery atheroma infarcts). For intracerebral hemorrhages, the risk peaked in spring and secondly in autumn. But the difference from one season to another was significant only for total number of strokes, cerebral infarcts and, among the later, for cardioembolic infarcts and large artery atheroma infarcts. As regards the Monthly distribution, the difference between Months was significant only for the total number of strokes and cerebral infarcts, with a minimum from July to September and a maximum in October for the later. Correlations with meteorological data were found for the total number of strokes, cerebral infarcts, cardioembolic infarcts, large artery atheroma infarcts and small artery atheroma infarcts. They showed an influence of temperature and relative humidity of the day of stroke or of the one to five days before. Correlations with wind speed, duration of sunshine or snow, even if less frequent, could also be found. Such results sometimes differ from those of some earlier studies, for which the climate and the risk factors were not the same, showing that regional epidemiological studies are necessary in order to determine the relations between seasons, meteorological factors and strokes.

Ragweed, Ambrosia artemisiifolia, is a highly allergenic annual herbaceous plant that is spreading quickly across the globe. Few studies have investigated the relationship between ragweed pollen counts and hay fever symptoms. We investigate the dose-response relationship between ragweed exposure in patients sensitized to ragweed and daily hay fever symptoms.A panel study was conducted among 31 adult patients sensitized to A artemisiifolia in France and Switzerland. Rhinitis, conjunctivitis, and bronchial symptoms were recorded daily, as well as daily pollen counts of ragweed, air pollutants, and meteorological data over 2 successive years. Data were analyzed with generalized estimating equation models to quantify effects of ragweed pollen whilst controlling for confounders.The relationship between ragweed pollen and the percentage of patients with nasal, ocular, and bronchial symptoms was linear. For every increase of 10 grains/m3, the odds ratio (OR) (95% confidence interval) for nasal symptoms was, in 2009, 1.18 [1.04-1.35] on weekdays and 1.43 [1.16-1.75] at weekends, and in 2010, 1.04 [1.00-1.07] on weekdays and 1.25 [1.06-1.46] at weekends.The OR for ocular symptoms was 1.32 [1.16-1.56] in 2009 and 1.05 [1.02-1.07] in 2010. Finally, the OR for bronchial symptoms was 1.14 [1.03-1.25] in 2009 and 1.03 [0.97-1.08] in 2010.There is a statistically significant linear relationship between ragweed pollen counts and hay fever symptoms. Our study shows that nasal symptoms differ on weekdays and at weekends.

The aim of this review is to describe the health impact of exposure to pollen based on recently published epidemiological studies. The methodology chapter, describes a review of the literature and outlines important elements of these studies: measurement of exposure to pollens, study types used, study populations and the health indicators related to pollen exposure. In this review, two types of studies have been used to assess the epidemiological evidence of short-term links between pollen exposure and hay fever or asthma. Ecological time-series studies use daily indicators of asthma exacerbations (emergency room admissions or hospitalizations), consultations for rhinitis or conjunctivitis, or anti-allergic drug consumption within general population. Panel studies relate measurements of pollen grain concentrations to nasal, ocular and bronchial symptom severity in a group of subjects sensitized to a specific pollen, monitored during the pollen season. In both cases, the studies show a relationship on a day-to-day basis between health indicators and daily rates of atmospheric pollen collected by a pollen trap. These studies take into account confounding factors, such as air pollution, weather factors and sometimes exposure to outdoor molds. Unlike earlier studies, more and more studies focus on the shape of the dose-response relationship and the lag between pollen exposure and symptoms. Only rarely, individual susceptibility factors, the clinical phenomenon of priming and polysensitization are reported. Thus, ecological time-series studies and panel studies assess respectively the impact of pollen exposure in the general population and in groups of sensitized patients. Using appropriate statistical tools, these studies provide insight into the shape of the dose-response relationship, with a potential threshold below which symptoms are absent, then a linear relationship for nasal, ocular and bronchial symptoms and a plateau where the symptoms do not increase despite the continued increase in pollen.

There is growing evidence to support an increase in air temperature over recent decades, with significant effects on aeroallergens such as pollen. It is generally accepted that the trend will continue, and become even more pronounced in the future.Global climate change is already affecting, and will continue to affect, with earlier floral initiation, the timing of the production of allergenic pollen. In addition, a warmer climate might lead to a longer pollen season and more days with high pollen counts. It could also increase the allergen content of pollens, and result in extension of plant species towards the poles and higher altitudes. Finally, rising levels of atmospheric CO₂ are likely to reinforce these trends.These predictions are subject to uncertainties that may lead to outcomes that differ materially from what is expected. Understanding the magnitude and direction of the changes affecting pollinisation is critical in order to quantify the future allergic disease burden and model the impacts of different climate change scenarios.Climate change influences the production, distribution, dispersion and allergenicity of anemophilous pollen and the growth and distribution of weeds, grasses and trees that produce it. These changes in aeroallergens and subsequent human exposure could affect the prevalence and severity of allergic disorders. There is, therefore, an important public health issue that requires development and implementation of appropriate response strategies without delay.

Pollen is a major cause of allergy and monitoring pollen in the air is relevant for diagnosis, treatment and prevention, as well as for biomedical and biological research. Many aero-biological studies have been conducted all over the world to ascertain aerial concentrations and seasonality of pollen grains.Monitoring of airborne biological particles is carried out by various gravimetric, impaction, and suction sampling devices. The Hirst trap, later modified to Burkard(®) or Lanzoni(®) traps, is the most widely used sampler. Counting and identifying pollen grains is then performed under optical microscopy. Based on differences in airborne pollen recorded over several years of observation, pollen calendars have been drawn up as aids to allergy diagnosis and management but they could be replaced advantageously by allergy-risk calendars. Pollen counts also provide valuable information about the geographical origin of pollen grains.Since the identifying and counting of pollen grains in ambient air samples is still a demanding and time-consuming task, there is an increasing interest in the automation of pollen monitoring. Furthermore, the divergence sometimes observed between clinical observations and pollen counts provides an incentive to collect aero-allergens directly. Lastly, pollen monitoring could be improved through the use of personal bioaerosol samplers.Great progress has been made in aerobiology for over a century, but much remains to be accomplished, particularly in relation with the standardization of methods.

Pollens of Poaceae are among the most allergenic pollen in Europe with pollen of birch. It is therefore useful to elaborate models to help pollen allergy sufferers. The objective of this study was to construct forecast models that could predict the first day characterized by a certain level of allergic risk called here the Starting Date of the Allergic Risk (SDAR). Models result from four forecast methods (three summing and one multiple regression analysis) used in the literature. They were applied on Nancy and Strasbourg from 1988 to 2005 and were tested on 2006. Mean Absolute Error and Actual forecast ability test are the parameters used to choose best models, assess and compare their accuracy. It was found, on the whole, that all the models presented a good forecast accuracy which was equivalent. They were all reliable and were used in order to forecast the SDAR in 2006 with contrasting results in forecasting precision.

Introduction La relation entre l’exposition aux pollens et la RCA traitee est bien connue 1 . L’objectif de cette etude est de voir si l’exposition aux moisissures exterieures met en evidence la meme association. Methodes L’assurance-maladie (regime general) a fourni les donnees de consommation de medicaments anti-allergiques (maa) par les 300 000 habitants du grand Clermont pendant 5 ans (2008–12). Un episode de RCAT etait defini par la prescription sur une meme ordonnance d’un maa par voie orale ET par voie locale (nasale ou oculaire). Les relations entre les variations quotidiennes de la concentration de spores de moisissures et les variations quotidiennes de RCAT etaient analysees par un modele de regression de Poisson, en tenant compte de la pollution atmospherique, des donnees meteorologiques, et des pollens. Resultats Toutes classes d’âge confondues, le risque de RCAT associee a une augmentation d’un interquartile de la concentration de spores exterieures n’augmentait pas de facon significative. En revanche, en analyse par sous-classe d’âge, on observe, pour la classe d’âge ≥ 65 ans, une augmentation significative de la RCA traitee avec Cla : RR [intervalle de confiance] : 1,03 [1,001–1,07]. Conclusion L’exposition aux spores exterieures de Cla est associee a une augmentation de la RCAT chez les sujets de plus de 65 ans sur le grand Clermont pendant une periode d’observation de 5 ans.

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 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).

The purpose of this paper was to verify the effect of pollen peaks on blood eosinophilia in an all and sundry population, including allergic as well as non-allergic subjects, so that we can open up new horizons in the understanding and prevention of pollinosis. Daily eosinophilia counts of hospital patients were measured at the time of a blood checkup (1996-1998), and divided into six classes. Those data were compared to daily pollen counts of twelve taxa, coming from the Hirst trap of Dijon (France). An eosinophilia increase occurred when hazel, hornebeam, birch, oak, grasses, ragweed and plantain were present in high concentration. In other cases, only simultaneous presence of several taxa seemed to play a part, because of cross-reactivity or polysensitization. Lastly, Cupressaceae-Taxaceae and ragweed were seen as increasing eosinophilia in seemingly non allergic people. The analysis of eosinophilia in the general population was able to reveal potential allergic patients and potential allergic diseases.

Over a 28-year period cerebrospinal meningitis, in sporadic as well as epidemic situations, mainly affected the Beninese territory from November to March, April or sometimes May. On the average, the acme occurred in February-March. A regression analysis confirmed that 14 to 34.5% of the temporal variability of the disease was due to the northern trade wind (harmattan) and a low absolute humidity in the northern areas, which constitute the main epidemiological pole of the country. On the contrary, cerebrospinal meningitis and climate turned out to be fully independent one from the other in the southernmost areas, where the harmattan is seldom experienced although the meningitis belt is at the present time spreading southwards. But the case-fatality ratio was especially high in the coastal region and during the off season, i.e. when endemic meningitis predominantly affected small children aged under one year. In any way, the climate-meningitis relationship proved to be weaker than is sometimes assumed, perhaps because this relationship is partly overshadowed by both anthropic effects (vaccination campaigns) and latency before disease outbreak.

In addition to being a determinant factor for the development of infectious and parasitic diseases, tropical weather conditions can have harmful effects for the human organism different from those of temperate climates. Adverse effects can result from aggressive environmental factors such as ultraviolet radiation, extreme heat, abrupt changes in temperature, and tropical storms. In weather-sensitive subjects, exposure to tropical conditions increases the risk of acute reactions including ischemic heart disease, asthma attacks, and kidney stones. Adverse effects can be enhanced by suddenness of change in climate as underlined by the stress experienced by air travelers. In practice it is important to recognize that different tropical climates have different effects on health. Intertropical climates range from dry and rainy areas to plains and mountain areas. Knowledge of the concepts of climatopathology is necessary to advise patients on the choice of destination and the most favorable period for travel.