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.     

Airborne pollen of Betula,Corylus and Alnus in Zagreb,Croatia. A three‐year record

The aim of this study was to construct a picture of the influence of meteorological conditions on the start and duration of the airborne Betulaceae pollen season and the pollen concentrations in the atmosphere of Zagreb, Croatia. The study during three seasons (2002–2004) used a 7‐day Hirst‐type volumetric pollen and spore trap. Total annual airborne pollen of Alnus, Corylus and Betula greatly varied from year to year. The differences in the dates of onset of airborne pollen presence of Alnus, Corylus and Betula noted in Zagreb in 2002–2004 were controlled by weather conditions, particularly temperature and precipitation. In all years studied, airborne pollen peaks were recorded on days with temperature above 0°C and without or minimal precipitation. The mean number of days with airborne pollen concentrations exceeding levels which provoke symptoms of an allergic reaction was 15, 16 and 29 days for alder, hazel and birch, respectively. The results of the present study may provide useful data for allergologists to reach accurate diagnoses, and timely information on concentrations of airborne pollen types and concentrations for individuals with pollen hypersensitivity.     

Poaceae pollen in the atmosphere of Zagreb (Croatia), 2002 – 2005

Pollen of grasses (Poaceae) is one of the most important airborne allergen sources worldwide. The aim of the study was to determine diurnal, day‐to‐day, weekly, monthly and annual pollen variation, and the effect of selected meteorological parameters on atmospheric pollen concentrations in Zagreb. A preliminary study was carried out during four seasons (2002 – 2005), using a 7‐day VPPS 2000 Hirst volumetric pollen trap. Total annual grass pollen concentrations in Zagreb were constant (2 673 – 3 074 p.g.m^?3), with a relative drop in 2004 (1 196 p.g.m^?3). The beginning of the grass pollen season is usually observed when the average daily temperature exceeds 13.5°C (max. daily temp. 19.5°C), without precipitation. In all four study years the absolute peak of concentrations occurs in the second half of May. The length of pollen season during the study period was 157 – 173 days. A high variability was observed in the maximal concentration and in the number of days when grass pollen concentration exceeded the threshold value of 30 p.g.m^?3 (9 – 40 days). Statistically significant correlations were found between airborne grass pollen concentrations and air temperature, level of precipitation and relative humidity.     

A systematic review of the effects of temperature and precipitation on pollen concentrations and season timing,and implications for human health

Climate and weather directly impact plant phenology, affecting airborne pollen. The objective of this systematic review is to examine the impacts of meteorological variables on airborne pollen concentrations and pollen season timing. Using PRISMA methodology, we reviewed literature that assessed whether there was a relationship between local temperature and precipitation and measured airborne pollen. The search strategy included terms related to pollen, trends or measurements, and season timing. For inclusion, studies must have conducted a correlation analysis of at least 5 years of airborne pollen data to local meteorological data and report quantitative results. Data from peer-reviewed articles were extracted on the correlations between seven pollen indicators (main pollen season start date, end date, peak date, and length, annual pollen integral, average daily pollen concentration, and peak pollen concentration), and two meteorological variables (temperature and precipitation). Ninety-three articles were included in the analysis out of 9,679 articles screened. Overall, warmer temperatures correlated with earlier and longer pollen seasons and higher pollen concentrations. Precipitation had varying effects on pollen concentration and pollen season timing indicators. Increased precipitation may have a short-term effect causing low pollen concentrations potentially due to “wash out” effect. Long-term effects of precipitation varied for trees and weeds and had a positive correlation with grass pollen levels. With increases in temperature due to climate change, pollen seasons for some taxa in some regions may start earlier, last longer, and be more intense, which may be associated with adverse health impacts, as pollen exposure has well-known health effects in sensitized individuals.

     

Ambrosia pollen in the air of Lublin, Poland

Studies on Ambrosia pollen concentrations were carried out in Lublin in the period 1995–2004. The effects of a number of meteorological factors were analysed. In the first period of the study, the gravimetric method was used (1995–1999), while in the second period, the volumetric method was applied. The results show an increasing trend in the amount of airborne pollen. The Ambrosia pollen season in Lublin lasts from August to October. Over a period of 5 years, the highest number of pollen grains was recorded in September (53%), followed by August (44%) and October (3%). There were wide variations in annual totals. The annual total pollen counts was 167–1180 grains, with the peak value in 2002. Maximum daily pollen concentrations (56–312 pollen grains m⁻³) were recorded in the first half of August and in the first half of September. On the days when high Ambrosia pollen concentrations occurred, the temperature was above 21°C and the winds were mainly from the southeast, south and east. Maximum intradiurnal concentrations of pollen grains occurred in the afternoon hours. These results indicate, to some degree, that Ambrosia pollen is transported for long distances before descent.     

Variations in mugwort (Artemisia spp.) airborne pollen concentrations at three sites in central Croatia, in period from 2002 to 2003

In spite of the low atmospheric pollen levels, Artemisia sensitisation and allergy has been reported widely. The aim of the study was to determine the length of pollen season, intradiurnal, daily and monthly pollen variation, and the effect of some meteorological parameters on atmospheric pollen concentrations in Central Croatia. Seven-day Hirst volumetric pollen and spore traps were used for pollen sampling. The Artemisia pollen season lasted from the end of July until the end of September with the highest concentrations in August. The percentage of the total pollen count ranged from 0.52% to 0.92%. The intradiurnal peak occurred between 10 a.m. and 12 a.m. Statistical analysis showed a significant correlations between higher air temperature and high pollen concentration as well as high precipitation and low pollen concentration. Results of this study are expected to help in preventing the symptoms of allergic reaction in individuals with Artemisia pollen hypersensitivity.     

The dispersion characteristics of airborne pollen in the Shijiazhuang (China) urban area and its relationship with meteorological factors

In this study, a Tauber pollen trap was used in the urban area of Shijiazhuang to monitor continuously the outdoor air pollen from 2007 to 2011. The trap was emptied at regular intervals (typically 15 days). The results show that airborne pollen assemblages are generally similar each year among 2007–2011 and are responsive to the flowering times of plants, being dominated by pollen from woody plants in the spring and by pollen from herbaceous plants in summer and autumn. Two peak pollen influx periods, especially for the main allergenic pollen taxa, are seen, one between early March to early June and a second between late August to early October. During the four seasons, the main pollen taxa are Juglans, Artemisia, Platanus, Populus, Chenopodiaceae, Urtica + Humulus, Rosaceae, Pinus, Poaceae, Cereals, Quercus, and Betula, and all taxa other than Rosaceae were confirmed by relevant studies to be allergenic pollen taxa. RDA analysis of pollen influx and meteorological factors shows that in spring, temperature and humidity have significant effects on the pollen influx of woody plants; in summer, humidity and precipitation have significant negative effects on pollen influx of herbaceous plants; in autumn, temperature, water vapor pressure, and precipitation have a significant positive influence on herbaceous pollen influx; in winter, there were no significant correlations between airborne pollen influx and meteorological factors. The results reveal the dispersion patterns of airborne pollen and provide an important reference to appropriate construction of urban green systems and the reliable reduction in regional pollinosis.     

Effect of meteorological parameters on Poaceae pollen in the atmosphere of Tetouan (NW Morocco)

Poaceae pollen is one of the most prevalent aeroallergens causing allergenic reactions. The aim of this study was to characterise the grass pollen season in Tetouan during the years 2008–2010, to analyse the effect of some meteorological parameters on the incidence of the airborne Poaceae pollen, and to establish forecasting variables for daily pollen concentrations. Aerobiological sampling was undertaken over three seasons using the volumetric method. The pollen season started in April and showed the highest pollen index in May and June, when the maximum temperature ranged from 23 to 27 °C, respectively. The annual pollen score recorded varied from year to year between 2,588 and 5,404. The main pollen season lasted 114–173 days, with peak days occurring mainly in May; the highest concentration reached 308 pollen grains/m³. Air temperature was the most important meteorological parameter and correlated positively to daily pollen concentration increase. An increase in relative humidity and precipitation was usually related to a decrease in airborne pollen content. External validation of the models performed using data from 2011 showed that Poaceae pollen concentration can be highly predicted (64.2–78.6 %) from the maximum temperature, its mean concentration for the same day in other years, and its concentration recorded on the previous day. Sensitive patients suffering allergy to Poaceae pollen are at moderate to highest risk of manifesting allergic symptoms to grass pollen over 33–42 days. The results obtained provide new information on the quantitative contribution of the Poaceae pollen to the airborne pollen of Tetouan and on its temporal distribution. Airborne pollen can be surveyed and forecast in order to warn the atopic population.     

Allergenic pollen season variations in the past two decades under changing climate in the United States

Many diseases are linked with climate trends and variations. In particular, climate change is expected to alter the spatiotemporal dynamics of allergenic airborne pollen and potentially increase occurrence of allergic airway disease. Understanding the spatiotemporal patterns of changes in pollen season timing and levels is thus important in assessing climate impacts on aerobiology and allergy caused by allergenic airborne pollen. Here, we describe the spatiotemporal patterns of changes in the seasonal timing and levels of allergenic airborne pollen for multiple taxa in different climate regions at a continental scale. The allergenic pollen seasons of representative trees, weeds and grass during the past decade (2001–2010) across the contiguous United States have been observed to start 3.0 [95% Confidence Interval (CI), 1.1–4.9] days earlier on average than in the 1990s (1994–2000). The average peak value and annual total of daily counted airborne pollen have increased by 42.4% (95% CI, 21.9–62.9%) and 46.0% (95% CI, 21.5–70.5%), respectively. Changes of pollen season timing and airborne levels depend on latitude, and are associated with changes of growing degree days, frost free days, and precipitation. These changes are likely due to recent climate change and particularly the enhanced warming and precipitation at higher latitudes in the contiguous United States.     

A 10-year survey of allergenic airborne pollen in the city of Porto (Portugal)

Airborne pollen calendars are useful to estimate the flowering season of the different plants as well as to indicate the allergenic potential present in the atmosphere at a given time. In this study, it is presented a 10-year survey of the atmospheric concentration of allergenic pollen types. Airborne pollen was performed, from 2003 to 2012, using a 7-day Hirst-type volumetric trap. The interannual variation of the daily mean concentration of the number of pollen grains and the main pollen season was determined as well as the hourly variations and correlation with meteorological parameters. During the study period, 18 different allergenic pollen types were considered based on its representativeness on the total annual airborne pollen concentration. The lowest annual concentrations were sampled in 2006 and the highest in 2007. The highest airborne pollen concentration was found during early spring and early summer. On the contrary, December was the month with the lowest pollen concentration. The major pollen sampled belongs to trees followed by weeds and grasses, being the most representative pollen types in the atmosphere: Urticaceae, Platanus, Poaceae, Pinaceae, Cupressaceae, Acer, Quercus, Castanea, Plantago, Alnus, Olea europaea, Betula, Myrtaceae and Populus. Intradiurnal distribution patterns of the pollen types studied presented differences with some taxa being predominantly sampled in the morning (9–11 a.m.) while others in first night hours (between 9 and 12 p.m.). Significantly correlations were found between the airborne pollen concentration and meteorological parameters.     

Analysis of airborne allergenic pollen spectrum for 2009 in Timişoara, Romania

The objective of this investigation was to identify the overall pollen types and, more particularly, the allergenic pollen content in the investigated area and then to explore their seasonal variations. The measurement point was located in the Timi?oara city, Romania. A Lanzoni volumetric trap was used for sample collection. Duration of the pollen season of allergenic plants and respective variation in airborne pollen concentration are presented in the pollen calendar for the year 2009. Among the identified pollen of 23 types, 20 were allergenic: Taxaceae/Cupressaceae, Alnus sp., Fraxinus sp., Betula sp., Corylus sp., Carpinus sp., Salix sp., Populus sp., Ulmus sp., Juglans sp., Quercus sp., Pinaceae, Tilia, Poaceae, Urticaceae, Chenopodiaceae/Amaranthaceae, Rumex sp., Plantago sp., Artemisia sp., Ambrosia sp. These species prevail throughout almost the entire pollen season, from February–October, accounting for 87.03 % of the total pollen count. The greatest diversity of pollen types is detected in the months of spring. The summer months were characterized mostly by non-arboreal pollen types. In late summer and early autumn, Ambrosia airpollen was the most abundant in the atmosphere. The relationships between pollen concentrations and nine meteorological parameters are presented too. To analyze the correlation between pollen data and variables, the Spearman rank correlation coefficient was used. The correlation analysis of daily pollen counts and meteorological parameters showed that arboreal pollen and non-arboreal pollen counts were significantly correlated with temperature. The prevalence of pollen sensitization resulted to be very high in our patients with respiratory symptoms.     

Atmospheric invasion of non-native pollen in the Mediterranean region

Most research on the impacts of plant invasion focuses on native plant performance, community structure, and ecosystem functioning. Some non-native species can also pose a risk to human health. One such risk is the allergenic nature of the pollen of some introduced plants. We examined whether patterns of airborne pollen differed between non-native and native taxa by summarizing data from seven Spanish Mediterranean localities monitored over 13 yr. The pollen spectra contained 27 native pollen taxa and 18 non-native taxa. Even though pollen from native taxa were more diverse and were present longer in the atmosphere than the non-native, in some years neither the prevalence of the two nor their weekly maximum pollen values differed significantly. However, maximum values for non-native taxa were found earlier in the season than for native pollen. A small percentage of non-native pollen includes pollen from introduced taxa that have not invaded natural habitats (e.g., ornamental plants). Non-native pollen has a larger proportion of allergenic pollen than native pollen. Therefore, the results reveal that the presence of non-native airborne pollen from naturalized and non-naturalized plant species increases the total amount of airborne allergenic pollen grains and the period of allergenic susceptibility.     

The effect of temperature, relative humidity and rainfall on airborne ragweed pollen concentrations

Major weather parameters have long been known to alter airborne pollen and spore concentrations. The following study was conducted to study the effect of three of these parameters on airborne ragweed pollen concentrations.During the ragweed (RW) season for the years 1997 and 1998, 10 minute pollen collections were taken at least every 4 hours using an Allergenco MK-3 spore trap. Slides were fixed, and counted microscopically at 400X. During this same period, weather parameters were monitored by an Automated Weather Systems recording station located within a few meters of the collector.The ragweed season for this region begins in mid August and ends by mid October. Temperature patterns for the period demonstrated usual daily fluctuations with highs 13 to 35 °C and lows 8 to 24 °C. Relative humidity readings for the period varied between 25 and 100%. Highest RW values were seen after seasonal cooling in September. Daily rainfall for the period varied between 0 and 100 mm. Airborne RW always declined sharply after strong rainfall events (> 10 mm/day). Peak airborne RW concentrations were often associated with the passing of frontal boundaries and the change in wind direction and velocity that accompanies that passing.Factors influencing airborne RW concentrations are multiple and complex, but atmospheric forces have great influence. The passing of major weather fronts and the associated temperature drops, wind disturbances and rainfall are the major factors.     

空气致敏花粉污染研究进展

对空气致敏花粉污染概念的提出 ,空气致敏花粉污染的特点和影响因素 ,花粉采集方法的改进以及空气致敏花粉污染的研究进展等方面进行了总结 ,指出了研究中存在的问题 ,并对研究前景进行了展望     

Monitoring of <Emphasis Type="Italic">Ambrosia</Emphasis> pollen concentration in the atmosphere of Bratislava (Slovakia) during years 2002–2007

Ambrosia pollen represents a significant allergenic risk for pollen-sensitive people also in Slovakia. The aim of this study was to compare the results of the monitoring of Ambrosia pollen concentrations and pollen seasons in Bratislava during years 2002–2007. Measurements were performed by the volumetric method using Burkard volumetric spore trap at the height of 10 m above ground level. During six monitored years, a total of 11,334 Ambrosia pollen grains per cubic meter of air were recorded. The highest total ragweed pollen amount was detected in 2002 (2,577 pollen grains of the total annual pollen concentration) and the lowest ragweed pollen concentration (1,213 pollen grains) was determined in 2007. However, mentioned year was represented as the year with the longest pollen season among the all monitored years in Bratislava (41 days). The pollen season peak day of 2002, 2004, 2005 and 2006 was recorded at the beginning of September; in 2003 and 2007 the peak was at the second half of August. The highest daily amount of Ambrosia pollen grains (more than 100 grains per cubic meter of air) was in 2002 (12 days). The results can be utilized to help to prevent symptoms of allergic reactions to Ambrosia pollen and improve quality of life during seasonal allergic diseases in ragweed pollen-sensitive people.     

Poaceae pollen concentrations in the atmosphere of three inland Croatian sites (2003-2004)

The aim of the study was to determine the length of Poaceae pollen season, intradiurnal, daily and monthly pollen variation, and the effect of some meteorological parameters on atmospheric pollen concentration, at three monitoring sites in inland Croatia during the 2003-2004 period. Seven-day Hirst volumetric pollen and spore traps were used for pollen sampling. At all three monitoring sites considerably higher precipitation and lower average temperature in 2004 led to a marked decrease in the grass pollen concentration in the air at all three monitoring sites. The highest grass pollen concentrations were recorded in Ivani? Grad (typical rural area), considerably lower in Samobor (effect of forest vegetation), and lowest in Zagreb (urban area). The highest atmospheric Poaceae pollen concentrations in inland Croatia were generally recorded in May and June. The highest intradiurnal concentrations were recorded between 8.00 and 12.00 a.m. Results of this aeropalynologic study are expected to help in preventing the symptoms of allergic reaction in individuals with Poaceae pollen hypersensitivity.     

A mathematical model for mugwort (Artemisia vulgaris L.) pollen forecasts

Pollen forecasts are a fundamental prerequisite to obtain prophylactic measures for allergic individuals. Mugwort belongs to the most relevant allergenic pollen types after grasses and birch. An approach to modeling of mugwort pollen concentrations has not been attempted previously in Germany. A process-oriented mathematical model for the relative local daily average mugwort airborne pollen concentration was developed on the basis of pollen and weather data measured during a 6-year period. The model depends on the daily minimum and maximum temperature, amount of precipitation and atmospheric pressure, which have to and can be supplied by measurement and prediction. The comparison of modeling results and pollen counting for an additional year confirms the fitness of the model. A computer program was written, which rests upon the model and supplies daily predictions of mugwort pollen flight during the period of the weather forecast. The latter should allow a pollen forecasting period of about 5 days, with an accuracy of about 32–63% explained variance, which in view of the low mugwort pollen counts (nine grains/m³ maximum in the validation year) represents a high relative measurement error. The mathematical model may serve to improve and rationalize of present pollen forecasts.     

Diurnal variation in airborne pollen concentrations of the selected taxa in Zagreb, Croatia

The number of individuals allergic to plant pollen has recently been on a constant increase. The knowledge of diurnal distribution and abundance of allergenic pollen types, their patterns and response to source position and weather is useful to correlate hay fever symptoms with the presence of allergenic pollen in the atmosphere. The aim of this study was to determine diurnal distribution of total airborne pollen, pollen of particular allergenic taxa, possible variation in diurnal pollen distribution at measuring sites placed at different heights, and effect of some meteorological parameters on airborne pollen concentrations. A 7-day Hirst-type volumetric pollen trap was used for pollen sampling. Qualitative and quantitative pollen analysis was performed under a light microscope (magnification x400). Total pollen of all plant taxa (Ambrosia sp., Betula sp., Cupressaceae, Urticaceae, Poaceae, Quercus sp., Fraxinus sp., Alnus sp., Corylus sp., Populus sp., Pinus sp., Picea sp.) observed showed a regular diurnal distribution at both sampling sites in both study years, with a rise in the pollen concentration recorded after 4.00 a.m. and 6.00 a.m., respectively. The peak pollen concentration occurred between 12.00 a.m. and 4.00 p.m., and the lowest diurnal pollen concentrations were recorded overnight. About 50% of the 24-h pollen concentration were released to the atmosphere between 10.00 a.m. and 4.00 p.m. The timing and size of diurnal peaks were closely related to high temperature, low humidity and south-west maximum wind direction.     

The influence of the hot and dry summer 2003 on the pollen season in Switzerland

A record-breaking heat wave affected the European continent in summer 2003. In Switzerland, the temperature in June, July and August exceeded the 1961–1990 mean by about 5 °C. These extreme temperatures had significant effects on the pollen production and on the airborne pollen loads. Especially affected was the grass pollen season, which started 1–2 weeks earlier than in the mean. During May and the first part of June the grass pollen production and dispersion was favoured by the warm and dry weather and many days with high pollen concentrations were registered. First water deficiencies occurred in June so that the grasses ceased to grow. The grass pollen season ended 7–33 days earlier than normal. For many of our stations of the Swiss pollen network this had never occurred as early as in 2003. The other herbaceous plants were not affected as much as the grasses. We measured very high Chenopodium and Plantago pollen concentrations, about normal concentrations of Urtica and Rumex and slightly lower Artemisia pollen concentrations than normal. The summer 2003 was exceptional and its reoccurrence is at the moment statistically extremely unlikely. But models of climatologists show that in the future, climate variations will increase and that in the period 2071–2100 about every second summer could be as warm or warmer and as dry or dryer than 2003.     

Size distribution of allergenic Cry j 2 released from airborne <Emphasis Type="Italic">Cryptomeria japonica</Emphasis> pollen grains during the pollen scattering seasons

Japanese cedar (Cryptomeria japonica) pollinosis is one of seasonal allergic rhinitis that mainly occurs in Japan. The pollinosis is caused by two main kinds of allergenic proteins called Cry j 1 and Cry j 2 which exist in Cryptomeria japonica pollen. In our previous study, we reported that the size-segregated of airborne fine allergenic Cry j 1 and morphological change of Cry j 1 due to the contact with rainfall. However, the study on airborne allergenic Cry j 2 in different particle sizes has not been identified until now. Therefore, the main aim of this study is to investigate the size distribution and scattering behavior of allergenic Cry j 2. The Cry j 2 particles were collected and determined in different particle sizes at the urban sampling points during the most severe pollination season of 2012 in Saitama, Japan. After the size-segregated Cry j 2 allergenic particles were collected using an Andersen high-volume (AHV) atmospheric sample, the airborne Cry j 2 concentrations were determined with a surface plasmon resonance (SPR) method. At the same time, the airborne Cryptomeria japonica pollens were also counted by the Durham pollen sampler. The higher concentrations of the allergenic Cry j 2 were detected even in particle sizes equal to or less than 1.1 μm (PM_1.1) than other particle sizes. The airborne particles ranges from 0.06 to 11 μm were also collected by a low-pressure impactor (LPI) atmospheric sampler. After that, the concentrations of Cry j 2 allergenic particles in fine particle sizes were measured by the SPR method either. With the help of this study, we have confirmed the existence of fine daughter allergenic particles, which clearly differ from the parent pollen grains in size, especially after the rainy days. It is possible that the daughter allergenic species will be released from the fractions of cell wall and burst pollen grains. We concluded that rainwater was one of the important factors that affects the release of pollen allergenic proteins of both Cry j 1 and Cry j 2 from the parent pollen grains.