Background 

Little is known about the association between direct pollen exposure and cognitive performance. The aim of our study is to investigate the effect of pollen exposure on performance in the Finnish matriculation examination.

Methods 

The study was conducted among students who participated in the national high school matriculation examinations in the metropolitan area of Helsinki and Turku in southern Finland between 2006 and 2020. Daily regional pollen counts of alder and hazel were monitored throughout the study period as part of the Finnish pollen monitoring network. Extensive data on matriculation examination results were retrieved from Statistics Finland, and air pollution and weather data from the Finnish Meteorological Institute. A fixed effect regression analysis was used to identify the effect of pollen exposure (as independent variables) on matriculation examination results (as dependent variable) controlling for student-semester fixed effects, pollutants and precipitation.

Results 

The regression coefficients indicated that on average an increase of 10 pollen grains in alder and hazel reduced the matriculation examination score by 0.0034 (p<0.01) and 0.0144 (p<0.05) standard deviations (SDs), respectively. Increasing pollen exposure per additional unit (an increase of 10 pollen grains) especially dropped examination scores in mathematical subjects among males (alder –0.0118 (p<0.001) and hazel –0.0328 (p<0.05) SDs). The association between alder pollen exposure (low, moderate and abundant) and examination scores was inversely U-shaped.

Conclusion 

Exposure to pollen can hinder a student’s performance in the matriculation exam, which strongly determines the future opportunities and emphasises early initiation of medication.