Meteorological variables connected with airborne ragweed pollen in Southern Hungary

About 30% of the Hungarian population has some type of allergy, 65% of them have pollen sensitivity, and at least 60% of this pollen sensitivity is caused by ragweed. The short (or common) ragweed (Ambrosia artemisiifolia = Ambrosia elatior) has the most aggressive pollen of all. Clinical investigations prove that its allergenic pollen is the main reason for the most massive, most serious and most long-lasting pollinosis. The air in the Carpathian Basin is the most polluted with ragweed pollen in Europe. The aim of the study is to analyse how ragweed pollen concentration is influenced by meteorological elements in a medium-sized city, Szeged, Southern Hungary. The data basis consists of daily ragweed pollen counts and averages of 11 meteorological parameters for the 5-year daily data set, between 1997 and 2001. The study considers some of the ragweed pollen characteristics for Szeged. Application of the Makra test indicates the same period for the highest pollen concentration as that established by the main pollination period. After performing factor analysis for the daily ragweed pollen counts and the 11 meteorological variables examined, four factors were retained that explain 84.4% of the total variance of the original 12 variables. Assessment of the daily pollen number was performed by multiple regression analysis and results based on deseasonalised and original data were compared.     

The occurrence of Ambrosia pollen in Rzeszów,Kraków and Poznań, Poland: investigation of trends and possible transport of Ambrosia pollen from Ukraine

Previous studies have shown that ragweed pollen arrives in Poland from sources in the south, in Slovakia, the Czech Republic, Hungary and Austria. It is likely that ragweed pollen also arrives from sources in the southeast (e.g. Ukraine). This hypothesis was investigated using 13 years of pollen data and back-trajectory analysis. Ambrosia pollen data were collected at three sites in Poland, Rzeszów, Kraków and Poznań. The amount of ragweed pollen recorded at Rzeszów was significantly higher than in Poznań and Kraków. This can be related to either a higher abundance of local populations of Ambrosia in south-east Poland or the proximity of Rzeszów to foreign sources of ragweed pollen. The combined results of pollen measurements and air mass trajectory calculations identified plumes of Ambrosia pollen that were recorded at Rzeszów, Kraków and Poznań on 4 and 5 September 1999 and 3 September 2002. These plumes arrived at the pollen-monitoring sites from an easterly direction, indicating sources of Ambrosia pollen in eastern Poland or Ukraine. This identifies Ukraine as a possible new source of ragweed pollen for Poland and therefore an important source area of Ambrosia pollen on the European Continent.     

Ragweed in the Czech Republic

During the last years, a well documented expansion ofragweed (Ambrosia artemisiifolia L., Ambrosia trifida L.) over the Mediterranean andtemperate Europe has been in progress. The currentdistribution of ragweed plants in the Czech Republicis summarized and the ragweed pollen concentration asmonitored by 12 pollen stations in the country isdiscussed. The present situation in the ragweed pollensensitization among children and adults with pollenallergy in Brno is described. So far no dangerousexpansion of ragweed plants in our country has beenobserved. Ragweed pollen concentration is occasionallysignificant in the Brno station only, other pollenstations are reporting insignificant amounts ofragweed pollen during August-September periods,although there has been a steady increase in ragweedpollen concentration in the Prague area over the lastfive years. Skin prick tests and/or specific IgEmeasurements with ragweed allergen were performed on94 children with pollen allergy in the Brno region in1995 and on 206, 210 and 229 adult allergic patientsin 1995, 1996 and 1997, respectively. Positive skinreaction or positive specific IgE to ragweed was foundin 22% children and in 25% (1995), 19% (1996) and 25% (1997) adults with pollen allergy. It isconcluded that ragweed does not seem to represent anyimminent major threat to the allergic population inthe Czech Republic until now, however, it remains apotentially very dangerous allergen.     

Ragweed and mugwort pollen in Szczecin, Poland

Ragweed (genus Ambrosia) and mugwort (Artemisia vulgaris) pollen grains are known to be very potent aeroallergens, often noted to enter into cross reactions. The aim of the study was to analyse ragweed and mugwort pollen release in Szczecin (western Poland) during the period 2000–2003. Measurements were performed by the volumetric and gravimetric method. Pollen seasons were defined as the periods of 90% of the total catch. Of the 4 years studied, the lowest concentration of ragweed pollen was observed in 2000. In 2000, the annual ragweed pollen count was very high, threefold higher than in 2001. There was a high Ambrosia pollen count in 2003, with the highest daily value of 84 grains/m³. The mugwort pollen season started in the third 10-day period of July and lasted to the end of August in all of the years studied. Analysis of pollen deposition from different Szczecin city’s districts showed that the highest exposure to ragweed pollen allergens occurred in the Majowe district, which is related to the presence of numerous plants of Ambrosia in that district. The mugwort pollen deposition was more abundant in the Żelechowa district, which is an area with villas and gardens. Statistically significant correlations were found between the ragweed pollen count in the air and the maximum wind speed, air temperature and relative humidity and between the mugwort pollen count in the air and air temperature and relative humidity.     

Ragweed pollen: The aeroallergen is spreading in Italy

Presently in Europe, ragweed pollen as an aeroallergen is not as important as Poaceae,Parietaria or Betulaceae, even if in some countries the plant is beginning to influence the local composition of the airborne pollen spectra. In northern Italy, the presence of ragweed airborne pollen has only been reported since the beginning of the 1980’s and it is increasingly spreading from year to year. Given this situation, the allergologists have begun to regard the potential risk of sensitisation to ragweed pollen with much attention. Up to now, such pollen has not been included in the routine allergological tests. In 1995 in some sites of northern Italy (Turin, Milan, Trieste), the concentration values of ragweed pollen were remarkable (∼ 20–30 p/m³) and on the increase with respect to the previous years. This investigation aims at focusing the atmospheric concentration trend on this new aeroallergen (Ambrosia sp.) in Italy from 1991 throughout 1995.     

Defoliation of common ragweed by Ophraella communa beetle does not affect pollen allergenicity in controlled conditions

Ragweed allergy is one of the primary causes of seasonal allergies in Europe and its prevalence is expected to rise. The leaf beetle Ophraella communa, recently and accidentally established in N-Italy and S-Switzerland, represents a promising approach to control ragweed, but negative side effects should be excluded before its use. Since biotic and abiotic stresses are known to influence the allergenicity of pollen, we set out to assess the effect of sub-lethal defoliation by O. communa on the quantity and quality of ragweed pollen. Seventeen sister pairs (including six clones) of ragweed plants were grown in controlled conditions. One of each pair was exposed to O. communa as soon as the plant started to produce reproductive structures. After 10 weeks of exposure, plant traits were measured as a proxy for pollen quantity. Pollen quality was assessed by measuring its viability and allergenicity. Generally, plants produced very few male flowers and little amount of pollen. Damage by the beetle was severe with most of the leaf tissue removed, but no treatment effect was found on any of the quantitative and qualitative traits assessed. In conclusion, O. communa did not increase the amount or allergenicity of ragweed pollen grains in our experimental conditions.     

Ragweed in Australia

Ragweed (Ambrosia spp.) is awell-recognised cause of fall allergic rhinitisand seasonal asthma in the Northern Hemispherecountries of United States and Canada. InAustralia the appearance of ragweed (Ambrosia artemisiifolia) was first recordedduring the 1930s in Queensland, ragweed hayfeverwas noted in 1959 and ragweed dermatitisdocumented in 1963. Aerobiology studies performedin the capital cities of Eastern and WesternAustralia have not demonstrated ragweed pollen.This study, performed in two towns in theNorthern Rivers area of New South Wales, closeto the Queensland border, documents the ragweedseason between November 1996 and December 1997in one of the towns, by monitoring the air usinga Burkard 7-day spore trap. Two hundred and sixvolunteers were skin tested to a range ofaeroallergens including pollen of ragweed (Ambrosia artemisiifolia) and Tibouchina, a treeflowering at the same time as ragweed. 34% ofvolunteers were skin prick test positive toragweed and 5.4% to Tibouchina. The ragweedseason commenced in the first week of March andextended to early May, with the peak day pollencount, 483/m³, present in the first week ofApril. Although many residents blamed thespectacular purple Tibouchina flowers for latesummer respiratory symptoms, most were sensitiveto ragweed and not Tibouchina.     

Air and surface soil samples – two different pairs of shoes? Comparing the pollen spectrum on different days of the pollen season

The pollen spectra of air and surface soil samples from a rooftop (at 14 m) and from ground level (at 1.6 m) in the suburbs of Vienna (Austria) were compared. Two soil samples and two air samples were taken on four different days to account for possible differences: in winter when no pollination occurred (reference day), in spring during the main flowering of Betula (birch day), in spring/summer during the main flowering of Poaceae (grass day), and in autumn during the main flowering of Ambrosia (ragweed day). Thirty-five different pollen types were used to describe the pollen spectra. Frequencies of certain pollen types reflect a seasonal impact on both the surface soil and air samples and show a similarity between air and soil samples on most of the days. However, the seasonal impact is higher in the air samples and shows a high consistency for ground and rooftop level. Kendall’s tau correlation coefficients further substantiate the similarities of the samples especially for the pollen season days. Exceptions include the winter day when pollination was low and the air samples recorded nearly no pollen at all, and the ragweed day when Ambrosia pollen was abundant in three of four samples but not in the ground surface soil sample. Thus, (1) air and surface pollen samples record similar signals during the pollen season but not during the ragweed and winter season and (2) air and surface pollen samples show the impact of local vegetation also in pollen traps located at different heights.     

Airborne ragweed (Ambrosia artemisiifolia L.) pollen concentrations in Croatia, 2002–2004

The aim of this study was to determine the onset, length and end of the ragweed pollen season, taking into account diurnal, day-to-day, monthly and annual pollen variations, the effect of some meteorological parameters on atmospheric pollen concentrations and possible differences in the airborne pollen season and concentration due to sampling site. Airborne pollen was collected at three sites in central Croatia (Zagreb, Samobor and Ivanić Grad) during three pollen seasons (2002–2004). Seven-day Hirst-type volumetric pollen traps were used for pollen sampling. Ragweed pollen was the third most abundant pollen type to occur in the atmosphere of central Croatia. Total Ambrosia pollen concentration was the highest in the 2003 pollen season and the lowest in 2004 at all sampling sites. Maximum emissions were restricted to August and September. Intradiurnal periodicity showed a peak from 1000 to 1200 hours. The concentration of ragweed pollen during the pollen season was greatly influenced by temperature and precipitation: on rainy days accompanied by temperature decline, the air pollen concentration decreased abruptly. The results of this study are aimed at helping to alleviate the symptoms of allergic reactions in individuals with ragweed pollen hypersensitivity, thus improving their quality of life.     

The contribution of long-distance transport to the presence of <Emphasis Type="Italic">Ambrosia</Emphasis> pollen in central northern Italy

Ragweed is an allergenic weed of public health concern in several European countries. In Italy ragweed occurs prevalently in north-north-eastern regions, where sensitization is increasing. Because of the small diameter of pollen grains, ragweed pollen is often involved in episodes of long-range transport, as already shown in central Italy. The objective of this study was to evaluate the extent of such transport by comparing pollen and meteorological data for two northern Italian cities (Parma and Mantova) with data from Pistoia and Florence in central Italy. In 2002 and 2004 peaks in ragweed pollen levels were detected in these four cities on the same day, and concentrations of the grains were above clinical thresholds. Weather-map analysis and computation of back-trajectories showed that air masses from eastern Europe might carry ragweed pollen to a wide area of central and northern Italy. These findings suggest that episodes of long-range transport of ragweed pollen could be clinically relevant, resulting in sensitization of a large number of people. The results might provide a basis for monitoring and forecasting periods of long-distance transport with the objective of reducing their effects on allergic patients.     

Allergy to ragweed: clinical relevance in Turin

This study evaluates the contribution of ragweed tothe development of allergic manifestations in a groupof outpatients and the atmospheric pollenconcentration trend in the city of Turin (Italy) fromJanuary 1996 to December 1997.We examined 5680 subjects affected byrhinoconjunctivitis and/or bronchial asthma duringspring and summer or by perennial respiratory symptomswith seasonal increase. All subjects were submittedto: (a) a clinical questionnaire; (b) skin prick testswith standard inhalant allergens battery includingpollens of Gramineae, Compositae (Artemisia andAmbrosia), Parietaria, Plantago,Olea, Betula, house dust mite, cat and dogdanders, mould spore (Alternaria and Cladosporium); (c) measurement of specific IgEantibodies in serum (RAST). A weekly programmed Hirstspore-trap was used to sample airborne pollengrains. Pollen was identified and quantified at thePlant Biology Institute of Turin University.The highest concentration of ragweed pollen was 28.6 P/m³ in 1996 and 9.66 P/m³ in 1997.The number of subjects allergic to Ambrosiapollen alone was 8 (0.14% of the total), while thenumber of those allergic to Artemisia absinthiumwas 22 (0.38% of the total). The subjects allergicto both pollens of the Compositae family was 57(1%).Our results show a low prevalence of sensitization toragweed pollen, which is contrary to what we see inother Italian regions like Lombardy and Veneto. Onecause of low sensitization may be the low percentageof Ambrosia pollen in the atmosphere.     

Estimating economic benefits of biological control of Ambrosia artemisiifolia by Ophraella communa in southeastern France

The North American common ragweed, Ambrosia artemisiifolia, which produces highly allergenic pollen, is invasive in different parts of the world, including Europe. In 2013, common ragweed in northern Italy was found attacked by another accidentally introduced species, the North American leaf beetle Ophraella communa, which is used for biological control of common ragweed in China. Since the establishment of O. communa, ragweed pollen concentrations in northern Italy have significantly dropped. Here we set out to estimate the potential economic benefits of establishment of O. communa in the Rhône-Alpes region in south-eastern France, where detailed data on the economic impact of common ragweed are available. Extrapolating from the change in airborne ragweed pollen concentrations in the Milan area, we estimated that establishment of O. communa in the Rhône-Alpes region will reduce the number of days with ragweed pollen concentrations at which sensitive people express symptoms by 50% and the medical costs due to common ragweed by 5.2–6.8 M € annually. Our findings suggest that investments of public funds are justified to conduct a complete assessment of the potential risks and benefits associated with the accidental establishment of O. communa in Europe.     

Ragweed evidence in Brianza (a hilly area North to Milan)

Summary Since 1982 we have been monitoring allergological pollen, by means of a Lanzoni pollen trap VPPS 2000. In 1988 we detected the ragweed pollen for the first time, and subsequently in 1989 and in 1990.In 1988 it had been monitored from 16/8 to 26/9 (highest concentration 66.5 gr/m³/24 h on 3/9), in 1989 from 7/8 to 23/9 (highest concentration 30.0 gr/m³/24 h on 10/9) and in 1990 from 3/8 to 23/9 (highest concentration 80.9 gr/m³/24 h on 2/9). During the same years the prick test for ragweed pollen turned out to be positive in 27 patients out of 1526 (1.76%) in 1988, in 25 patients out of 1517 (1.64%) in 1989 and in 56 patients out of 1614 (3.41%) in 1990.The presence of specific IgE turned out to be positive in 12 patients out of 189 (6.35%) in 1988, in 17 patients out of 195 (8.71%) in 1989 and in 22 patients out of 230 (9.56%) in 1990.During out 3-years investigation, on the basis of the severity of symptoms and of the possible multi-sensitization, only 2 patients have undergone a specific immunotherapy to ragweed pollen.Our data confirm the presence of ragweed pollen in Lombardy, even if the sensitization is low in our population and the clinical significance of ragweed pollinosis is even lower.Nevertheless the high sensitizing power of this pollen makes a higher incidence of ragweed pollinosis possible in coming years.     

恶性入侵植物豚草的繁育系统特性

豚草(Ambrosia artemisiifolia L.)是原产于北美的一年生恶性入侵植物,目前已广泛分布在我国东北、华北、华中和华东等地,威胁农业、生态和民众健康。该种雌、雄头状花序同株,以种子繁殖,因而其有性繁殖特性对其扩散和爆发具有重要影响。运用套袋授粉和联苯胺-过氧化氢法等实验方法,对入侵江苏常熟的豚草种群的繁育系统特性进行了研究。结果表明,豚草花粉活力在开花后第4天开始出现,第8天到第10天花粉活力比较高;柱头可授性在开花第2天开始出现,第5天到第8天柱头可授性较高;同植株上同一时期开花的雌花的柱头可授性和雄花的花粉活力有5d左右的重叠期。不套袋处理(自然条件)和异株授粉处理下,豚草的结实率都比较高,分别达48.4%和44.4%,两者间无显著差异(P0.05);而同株授粉处理的结实率较低,仅3.4%,极显著低于不套袋处理和异株授粉的结实率(P0.01)但显著大于0(P0.05)。分析表明,豚草属于自交不亲和种,但又可部分自交亲和,不具有无融合生殖特性。因此,对在新分布区的零星豚草植株进行及时防除,将取得事半功倍的效果。     

Ragweed – An allergy risk in Sweden?

Ragweed pollen, which is a major cause of allergic rhinitis in North America and during the last decades, also in parts of the European continent, has not been regarded as a risk in Sweden, since occurrences of Ambrosia have been rare and with two exceptions, ephemeral. During the last four years, however, long-distance transported pollen has been registered in South Sweden. Moreover, seeds are dispersed by man with birdseed and reports on ragweed plants growing at birdtables are becoming more and more common. In warm years, the fruits of these plants mature and are germinative. We argue that there is a risk that ragweed pollen may be a problem in the future in Sweden. Long-distance transport from the continent is likely to be increasingly more common, and in larger amounts, as ragweed is rapidly spreading in Europe. Among the plants now appearing within Sweden, selection is likely to favour phenotypes which are able to fulfil their life-cycle during the indigenous vegetation period, especially in a scenario of global warming.     

Some details about ragweed airborne pollen in Hungary

Ambrosia elatior – the only species living inHungary – appeared at the beginning of this centuryon the southern border of the country, along theDanube. Since then, unfortunately, it has become themost common weed in Hungary, and the quantity of itspollen is many times higher than the European average(Jäger, 1998; Juhász, 1998). Based on theresults of our ten-year (1989–1998) monitoring inHungary, there is no doubt than more than 60% of latesummer-early autumn pollen originates from ragweed,causing the most serious pollinosis in Hungary. Thequantity and ratio of ragweed pollen is much higherand the length of Ambrosia pollen season islonger in the southern than in the northern part ofHungary.     

Daily Ambrosia Pollen Concentration in the Air of Ankara,Turkey (1990-1999)

The airborne ragweed pollen spectrum was investigated in the air of Ankara, Turkey for aperiod of ten years (1990-1999) using a Burkard seven-day volumetric recording trap. In our study period,long distance transported Ambrosia pollen has been registered. Daily pollen levels varied from low to highin Burge's system. In last three years, the pollen concentration of Ambrosia showed a clear increasingtendency. Our results prove that ragweed pollen may be an important threat for ragweed sensitive patientsin Ankara city in near future.     

A New Allergen from Ragweed (Ambrosia artemisiifolia) with Homology to Art v 1 from Mugwort

Art v 1, the major pollen allergen of the composite plant mugwort (Artemisia vulgaris) has been identified recently as a thionin-like protein with a bulky arabinogalactan-protein moiety. A close relative of mugwort, ragweed (Ambrosia artemisiifolia) is an important allergen source in North America, and, since 1990, ragweed has become a growing health concern in Europe as well. Weed pollen-sensitized patients demonstrated IgE reactivity to a ragweed pollen protein of apparently 29–31 kDa. This reaction could be inhibited by the mugwort allergen Art v 1. The purified ragweed pollen protein consisted of a 57-amino acid-long defensin-like domain with high homology to Art v 1 and a C-terminal proline-rich domain. This part contained hydroxyproline-linked arabinogalactan chains with one galactose and 5 to 20 and more α-arabinofuranosyl residues with some β-arabinoses in terminal positions as revealed by high field NMR. The ragweed protein contained only small amounts of the single hydroxyproline-linked β-arabinosyl residues, which form an important IgE binding determinant in Art v 1. cDNA clones for this protein were obtained from ragweed flowers. Immunological characterization revealed that the recombinant ragweed protein reacted with >30% of the weed pollen allergic patients. Therefore, this protein from ragweed pollen constitutes a novel important ragweed allergen and has been designated Amb a 4.     

Parameters of ragweed pollination in the Lyon’s area (France) from 14 years of pollen counts

This study analyzes the pollen counts obtained from the air of the greater Lyon (corresponding to the urban area of Lyon) an area which has been overrun by ragweed in the last 40 years. Two periods are investigated, 1982–1989 and 1990–1995. The year 1995 deserves specific attention because for the first time a campaign of ragweed eradication was launched in greater Lyon. From the data of the 14 pollination seasons it was possible to define some parameters: subpathological risk period, pathological risk period and the position and level of the pollen peak. Our study indicates the progression of the weed in the infested area over the two periods. In 1995 a slight decrease in the pollen count was observed but this was followed by a second peak probably related to later growth of some plants which had been cut. In this connection, 4 weeks weeding campaign is not long enough and in the future a 6-week campaign without the use of weedkillers should be planned. Determining the parameters of ragweed pollination every year will be useful both to patients and physicians concerned by allergy to ragweed pollen. According to the level of the ragweed pollen in the air, the patients may take appropriate medication. This study emphasizes the necessity to record air pollen concentrations over many years. In particular, the actual impact of cutting ragweed before pollination on ragweed pollen counts can only be evaluated after several years of eradication.