Abiotic pollutants and solar radiation involved in Cupressaceae pollen rupture

This study investigates the influence of atmospheric pollutants and solar radiation on Cupressaceae pollen dynamics in Murcia, southeastern Spain, during five consecutive pollen seasons (2019–2024). The main aim was to evaluate the effects of these environmental stressors considering the high solar irradiance and arid climate of the area. Daily airborne pollen concentrations were monitored using the standardised method EN 16868, and meteorological and pollutant data were integrated to assess their relationships with pollen variables. Spearman correlation analysis revealed a negative association between carbon monoxide and nitrogen oxides levels and both Cupressaceae pollen concentration and ruptured pollen concentration. The robust association between carbon monoxide and the pollen variables persisted when controlling for wind direction through partial correlations. Solar radiation showed a positive correlation with pollen concentration and ruptured pollen. Cupressaceae pollen shows a remarkable morphological fragility, making it particularly sensitive to adverse environmental conditions. Atmospheric stagnant conditions, associated with high levels of urban pollutants such as CO, reduce the pollen concentration and transport. These findings highlight the importance of integrating pollutant emissions and atmospheric dynamics into the study of pollen grains, given its impact on air quality and public health.