The relationship between birch pollen, air pollution and weather types and their effect on antihistamine purchase in two Swedish cities

Abstract

Exposure to elevated air pollution levels can aggravate pollen allergy symptoms. The aim of this study was to investigate the relationships between airborne birch (Betula) pollen, urban air pollutants NO2, O3 and PM10 and their effects on antihistamine demand in Gothenburg and Malmö, Sweden, 2006–2012. Further, the influence of large-scale weather pattern on pollen-/pollution-related risk, using Lamb weather types (LWTs), was analysed. Daily LWTs were obtained by comparing the atmospheric pressure over a 16-point grid system over southern Sweden (scale ~3000 km). They include two non-directional types, cyclonic (C) and anticyclonic (A) and eight directional types depending on the wind direction (N, NE, E…). Birch pollen levels were exceptionally high under LWTs E and SE in both cities. Furthermore, LWTs with dry and moderately calm meteorological character (A, NE, E, SE) were associated with strongly elevated air pollution (NO2 and PM10) in Gothenburg. For most weather situations in both cities, simultaneously high birch pollen together with high air pollution had larger over-the-counter (OTC) sales of antihistamines than situations with high birch pollen alone. LWTs NE, E, SE and S had the highest OTC sales in both cities. In Gothenburg, the city with a higher load of both birch pollen and air pollution, the higher OTC sales were especially obvious and indicate an increased effect on allergic symptoms from air pollution. Furthermore, Gothenburg LWTs A, NE, E and SE were associated with high pollen and air pollution levels and thus classified as high-risk weather types. In Malmö, corresponding high-risk LWTs were NE, E, SE and S. Furthermore, occurrence of high pollen and air pollutants as well as OTC sales correlated strongly with vapour pressure deficit and temperature in Gothenburg (much less so in Malmö). This provides evidence that the combination of meteorological properties associated with LWTs can explain high levels of birch pollen and air pollution. Our study shows that LWTs represent a useful tool for integrated daily air quality forecasting/warning.

The influence of atmospheric circulation conditions on Betula and Alnus pollen concentrations in Wrocław, Poland

“…The lowest pollen concentration concerns cold, wet, and cloudy cyclonic types: SWCC, NWCC, and NWAC. Contrary to Grundström et al (2017) in terms of birch in Sweden, the pollen concentrations of Betula and Alnus in Wrocław are to a small extent influenced by wind speed. However, this is difficult to surmise, as the frequency of circulation types with calm wind conditions (especially from XX group of circulation types) favourable to pollen accumulation is very low (below the threshold frequency of 4% in pollen seasons).…”

“…This complex description of weather conditions made it possible to analyse the influence of meteorology on pollen concentration and determine the circulation types with the highest and lowest pollen concentration. This approach was used earlier by Grundström et al (2017) for birch in Gothenburg and Malmö. Our results show that, similar to the Swedish study, the highest pollen concentrations for Betula and Alnus are noted for warm, sunny, and dry anticyclonic circulation types, especially when the anticyclone vorticity concerns the lower and upper troposphere.…”

“…Grundström et al (2017) have found the approach based on weather types to be a relatively simple method for characterizing the weather condition in a synoptic scale, thereby grouping together many meteorological variables that are important for processes that determine the high or low levels of pollen concentration. Conducted in Gothenburg and Malmö, their study indicated that high birch pollen concentrations are correlated with dry and moderately calm conditions during an anticyclone and weather types with NE, SE, and S geostrophic wind direction, whereas the lowest concentration levels were found in wet and windy types with direction from SW, W, and NW and for the cyclonic type (Grundström et al 2017). The number of studies that applied weather types for pollen analysis is rather limited, and according to the authors, it has yet to be done for Central Europe.…”

Impacts of Synoptic Weather Patterns and their Persistency on Free Tropospheric Carbon Monoxide Concentrations and Outflow in Eastern China

“…When the three SWPs persist for nearly a week, the CO concentrations increase by a maximum of 10–15% (Figures b, g, and h). Previous studies through observations and simulations suggested that the SWPs characterized by anticyclonic conditions are likely associated with high pollution episodes in the source regions (Grundström et al, ; Miao et al, ; Pope et al, , ; Shu et al, ). Studying CO transport in the free troposphere, Thomas and Devasthale () showed that this kind of SWPs lead to a 1% increase in free tropospheric CO over Nordic countries.…”

Associations among air pollutants, grass pollens, and daily number of grass pollen allergen‐positive patients: a longitudinal study from 2012 to 2016

“…This increased bioavailability of airborne pollen allergens has been shown to cause an increased incidence of allergic disease. Several studies have shown that air pollution can affect pollen viability, production, and allergenicity . Hence, there is a need to identify conditions that coincide with high exposure to pollen and air pollution, and to determine the extent to which pollutants contribute to airway symptoms.…”