PoCHAS - Effects of airborne pollen on cardiorespiratory health and allergic symptoms

Airborne pollen allergies are increasing across Europe, and are a major health issue for 20% of the Swiss population. At the same time, the duration and intensity of the pollen season are changing due to climate change. Pollen allergy is often dismissed as “not so serious”, though missed workdays, and millions spent on medication suggest otherwise. Affected people have gotten used to seasonal episodes of sneezing and teary eyes. Yet, it is not well recognized that high pollen concentrations may also have more severe and systemic impacts on our health.

The PoCHAS project aims to investigate how short-term exposure to pollen is related to respiratory and cardiovascular events. We will study mortality, hospitalization and self-reported allergic symptoms. Moreover, in light of increasing allergy prevalence, we aim to study how the relationship between pollen and health has developed over the study period, and which subpopulations might be most at risk. Moreover, combined exposure to pollen, air pollution and weather conditions could have synergistic effects, which alter the allergenicity of pollen - a research area that has been hardly explored.

We will use large, real-world datasets without selection bias: individual cause-specific mortality is available from the Swiss National Cohort (2003-2018) and hospital admissions from the hospital admission database of the Federal Office of Statistics. We will study the population effects of pollen on daily respiratory and cardiovascular mortality and hospitalization. We will investigate trends in how pollen affected each outcome over the last 16 years, as our climate and pollen exposure has been changing.

This project will help us better understand the role of pollen in self-reported symptoms, respiratory and cardiovascular diseases at the population level. This study will add substantially to the small body of scientific evidence regarding the sever health effects of airborne pollen. With these insights, we can prevent and reduce health effects due to pollen, which constitute a large burden on health and economy.

Involved Regions: Europe and Central Asia
Involved Countries: Switzerland

Glick S, Gehrig R, Eeftens M. Multi-decade changes in pollen season onset, duration, and intensity: a concern for public health?. Sci Total Environ. 2021;781:146382. DOI: 10.1016/j.scitotenv.2021.146382

Bürgler A, Glick S, Hartmann K, Eeftens M. Rationale and design of a panel study investigating six health effects of airborne pollen: the EPOCHAL study. Front Public Health. 2021;9:689248. DOI: 10.3389/fpubh.2021.689248

Valipour Shokouhi B, de Hoogh K, Gehrig R, Eeftens M. Estimation of historical daily airborne pollen concentrations across Switzerland using a spatio temporal random forest model. Sci Total Environ. 2024;906:167286. DOI: 10.1016/j.scitotenv.2023.167286

Bürgler A, Luyten A, Glick S, Kwiatkowski M, Gehrig R, Beigi M, Hartmann K, Eeftens M. Association between short-term pollen exposure and blood pressure in adults: a repeated-measures study. Environ Res. 2024;256:119224. DOI: 10.1016/j.envres.2024.119224

Luyten A, Bürgler A, Glick S, Kwiatkowski M, Gehrig R, Beigi M, Hartmann K, Eeftens M. Ambient pollen exposure and pollen allergy symptom severity in the EPOCHAL study. Allergy. 2024;79(7):1908-1920. DOI: 10.1111/all.16130

Valipour Shokouhi B, de Hoogh K, Gehrig R, Eeftens M. Spatiotemporal modelling of airborne birch and grass pollen concentration across Switzerland: a comparison of statistical, machine learning and ensemble methods. Environ Res. 2024;263(Pt 1):119999. DOI: 10.1016/j.envres.2024.119999

Corpening B, Bürgler A, Tamási B, Gehrig R, Gan K, Alonso Hellweg A, Luyten A, Glick S, Beigi M, Hartmann K, Eeftens M. Associations between ambient pollen exposure and measures of cognitive performance. Environ Epidemiol. 2025;9(2):e374. DOI: 10.1097/ee9.0000000000000374

Contact