As spring pollen fills the air, it may be doing more than triggering sneezes. New research suggests it could also be quietly lowering students’ performance in high-stakes exams that shape their academic futures.
Study: Pollen exposure and matriculation exam performance among students in Finland. Image credit: Alexander_Safonov/Shutterstock.com
Pollen allergy is one cause of seasonal allergy, with hundreds of millions of cases occurring worldwide every year. While its impact on health and well-being is well known, little is known about how it affects academic performance. A recent study published in the Journal of Epidemiology and Community Health assessed this aspect using data from more than 92,000 students who took the Finnish national high school matriculation examination during the pollen season between 2006 and 2020.
Seasonal pollen may affect student performance outcomes
Research has suggested that seasonal allergies can affect certain aspects of cognitive performance, with people experiencing allergies during pollen season performing worse on some mental tasks than those without allergies. However, only three studies have examined the association between pollen concentration and school performance.
This prompted the present study, which sought to evaluate how ambient pollen levels affected examination scores in the Finnish national high school matriculation exam. This is an important milestone for students, as it carries significant weight in determining university eligibility.
Analyzing exam scores alongside pollen and weather data
The study included students who wrote the examinations in Helsinki and Turku metropolitan areas and neighbouring municipalities in southern Finland between 2006 and 2020. Daily counts of alder and hazel pollen were measured during the study period, as these are the main tree species releasing pollen during the spring examination period in Finland. Air pollution was also assessed, and weather data were obtained from the Finnish Meteorological Institute.
A student-semester fixed-effects regression model was used to assess the association of pollen exposure with student performance in the matriculation examination.
Higher alder and hazel pollen linked to lower exam scores
On average, every increase of 10 pollen grains per cubic meter of air was linked to a small reduction in examination scores. For alder and hazel pollen, scores declined by 0.0034 and 0.0144 standard deviations (SD), respectively, equivalent to drops of 0.042 and 0.17 exam points. The association became slightly stronger after accounting for temperature, air pollution, and rainfall during examination hours.
When the results were analysed by sex, a statistically significant decrease in scores was observed among female students exposed to higher levels of alder pollen. For every 10 additional alder pollen grains, scores declined by 0.0053 SD (0.0652 exam points). A similar trend was observed among male students, although the association was not statistically significant.
The effect was most pronounced in mathematics-related subjects. Alder pollen exposure was associated with lower mathematics scores in both sexes, while hazel pollen exposure was linked to reduced scores mainly among males. In these subjects, a 10-grain increase in alder and hazel pollen corresponded to score reductions of 0.0118 and 0.0328 SD, respectively. Researchers suggest this may reflect the higher levels of accuracy and sustained concentration required in mathematical tasks.
Further analysis grouped pollen exposure into low, moderate, and abundant levels. This revealed an inverted U-shaped relationship between alder pollen levels and exam performance. At low pollen concentrations, mathematics and overall exam scores declined by 2.066 and 0.738 points, respectively. For hazel pollen, the reductions were 0.962 and 0.615 points.
At moderate pollen levels, the association with exam scores was not statistically significant. However, when alder pollen concentrations exceeded 100 grains per cubic meter, the effect became strongest, with declines of 5.065 points in mathematics scores and 1.390 points across all subjects.
Strengths and limitations
The pollen data came from nationally established monitoring systems, but are not directly traceable to individuals or schools. Instead, it reflects regional average pollen concentrations measured at monitoring sites and represents broader surrounding areas. Standardized data were obtained from multiple monitoring sites, providing a comprehensive picture of air quality and of the weather.
The statistical approach used captured variation in each student’s performance over time, without requiring between-student comparisons. This helped avoid multiple confounding factors, such as natural learning style or learning ability.
Both pollen sources were studied separately, even though the flowers together partially share pollen seasons. This could lead to multicollinearity. Moreover, the study population was not selected based on allergy status, and the dataset did not include information on whether individual students had pollen allergies.
The researchers also conducted a falsification test using pollen counts from one week after the examination dates, which showed no association with exam scores and strengthened confidence that the observed effects were linked to pollen exposure during the exam period.
The findings compared well with previous studies showing that primary school students performed better on reading and math tests on days when pollen levels were low.
The putative explanations include the taxing symptoms of allergic rhinitis, which affect well-being. Another hypothesis is that airborne allergens may influence brain function through mechanisms such as systemic inflammation and immune activation, thereby reducing mental clarity and impairing memory.
Future research should examine whether students with pollen allergy experience a greater decrease in examination scores than those without it. If so, pollen exposure can affect the future of students with pollen allergy who are undertaking important examinations.
Pollen exposure may subtly influence performance in crucial exams
The study suggests that pollen exposure is associated with lower examination scores at matriculation, potentially affecting future opportunities. If validated, these findings indicate that better awareness of pollen exposure and timely management of allergy symptoms, including appropriate medication, could help reduce symptoms that might otherwise affect performance during important examinations.
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