Quercus pollen allergy risk in Alentejo, Portugal, in a climate change scenario

Abstract

Background: The Quercus genus, representing an important natural resource, is also described as a high sensitizing pollen type. As the most prevalent pollen type in Alentejo, it potentially impacting respiratory health of susceptible individuals. The aim of this study was to evaluate the impact of Quercus pollen on respiratory allergic disease in Alentejo, in a climate change scenario. Method: Data on antihistamines sales (group-1 histamines antagonists – G1); group-2 SOS drugs – G2) were obtained from the National Pharmacy Association (ANF) (2004–2021). The pollen was monitored (2002–2021) using standard Hirst-type traps and identified by optical microscopy, according to the standard methodology (REA.com). The meteorological variables were obtained from ICT/CGE platform (Portugal) and their impact on the Seasonal Pollen Index (SPIn), Pollen Season Duration (PSD) and Daily Pollen Concentrations (DPC) was investigated by statistical methods. Results: The results evidenced an impact on allergic disease, by positive associations of the April's SPIn with April's antihistamines sales, both G1 and G1+G2 (R: 0.656*; p = 0.028 and R: 0.642*; p = 0.033,respectively). Meteorology strongly influenced the SPIn but not the PSD. The meteorological factors on SPIn, a negative correlation with precipitation (P) (R: - 0.549*; p = 0.022), relative humidity (RH) (R:- 0.506*; p = 0.045) was observed, while the wind speed (WS) was positively correlated (R: 0.689**; p = 0.002). Meteorology also influenced the DPC. Positive correlations between the temperature, global solar radiation and wind speed and direction and DPC were observed. On the contrary, P and RH were negatively correlated with DPC. Conclusion: The results suggest that Quercus pollen contributes to the worsening allergy symptoms in Alentejo evidenced by the in-crease in the antihistamines sales. Moreover, it suggests that by influencing the pollen loads, climate affects the risk of exposure to this sensitizing agent thus changing allergic respiratory outcomes over the years.