Rationale, design and preliminary results of a panel study investigating six health effects of airborne pollen: the EPOCHAL study

Abstract

BACKGROUND AND AIM: While airborne pollen is widely recognized as a seasonal cause of sneezing and itchy eyes, its systemic health effects on pulmonary function, cardiovascular health, sleep quality, and cognitive performance are less well-established. Further, it is likely that the public health impact of pollen may increase in the future due to two trends in the last decades: higher population prevalence of pollen sensitization as well as earlier, longer, and more intense pollen seasons, attributed to climate change. No observational study in adults has studied dose-response relationships between pollen concentration and health yet. Most studies did not confirm allergy status objectively, lacked statistical power, or were highly restrictive in their inclusion criteria, and therefore not representative of the real-world allergic population. METHODS: This work describes an overview of epidemiological research on pollen and health so far, outlining the rationale and research design of the EPOCHAL study (Effects of Pollen on Cardiorespiratory Health and ALlergies). EPOCHAL aims to relate ambient concentrations of different pollen species to six specific health outcomes. In a panel of 400 allergic and non-allergic individuals, heart rate variability and blood pressure (cardiovascular outcomes), lung function and airway inflammation (pulmonary outcomes), performance in various cognitive domains, allergic symptom severity as well as sleep and health-related quality of life are being measured repeatedly (6-16 times) over 6 weeks. RESULTS:Participant recruitment has started in March 2021 and preliminary results will be available. We aim to uncover and characterize dose-response relationships between different allergenic species of pollen and health, while evaluating concentration thresholds, linearity and plateaus. We will further explore vulnerable population subgroups, defined by sensitization profiles, demographics and comorbidities such as asthma. CONCLUSIONS:A gain of knowledge in pollen-health outcome relationships is critical to inform future environmental and health policies, provide better symptom forecasts and improve personalized prevention and medicine. KEYWORDS: Allergies, environmental epidemiology, cardiovascular diseases, respiratory outcomes, greenspace, climate