Beyond seasonal suffering: Effects of Pollen on Cardiorespiratory Health and Allergies

Project Information

EPOCHAL

Grant agreement ID: 853568

DOI

10.3030/853568

Project closed

EC signature date 19 December 2019

Start date 1 August 2020

End date 31 July 2025

Funded under

• EXCELLENT SCIENCE - European Research Council (ERC)

Total cost

€ 1 381 931,50

EU contribution

€ 1 381 931,50

Coordinated by

SCHWEIZERISCHES TROPEN UND PUBLIC HEALTH INSTITUT
Switzerland

Periodic Reporting for period 3 - EPOCHAL (Beyond seasonal suffering: Effects of Pollen on Cardiorespiratory Health and Allergies)

Reporting period: 2023-08-01 to 2025-01-31

Summary of the context and overall objectives of the project

Climate change changes the onset, duration and intensity of the pollen season. At the same time, allergies to airborne pollen are increasingly common in Europe. Yet, it is not well recognized that -besides the well-known sneezing and itching symptoms- pollen may have more severe impacts on human health as well. High pollen concentrations may increase respiratory and cardiovascular events, leading to mortality and excess hospitalizations. The EPOCHAL project aims to investigate how short-term exposure to ambient airborne pollen is related to mortality, hospitalization and pre-clinical symptoms, both on its own and in combination with air pollution and weather.
The EPOCHAL project will develop spatiotemporal exposure models of pollen for the years 2003-2022 based on a network of 14 pollen measurements stations in Switzerland, for which species distribution data, land-use and elevation maps, and satellite-observed greenness and weather data forms the basis.
Taking advantage of large, real-world datasets without selection bias (Swiss National Cohort) and the efficient case-crossover study design, the EPOCHAL project will investigate the population effects of pollen on daily respiratory and cardiovascular mortality and hospitalization, also accounting for variation in air pollution and weather conditions.
In order to explore individual sensitivity, I will conduct repeated measurements of pre-clinical symptoms such as lung function and airway inflammation in a dedicated panel of 400 allergic patients.
The EPOCHAL project aims to provide both environmental and personalized prevention recommendations, thereby enhancing quality of life for the allergic population. The project will for the first time derive exposure-response relationships for prevalent pollen, air pollution and weather triggers and several important pre-clinical outcomes: lung function, airway inflammation and symptom severity.
EPOCHAL utilizes available nationwide health datasets and systematic novel data collection methods (in the in-depth panel study), to better understand the role of pollen in respiratory and cardiovascular diseases at both personalized and population levels. The project will prevent and reduce health effects due to pollen, which constitute a large burden on health and economy.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

Early on in the project, we published a key paper about phenological trends in onset, duration and intensity of the pollen season in Switzerland over the last 30 years amidst climate change. This analysis concluded that the onset of the Swiss pollen season has advanced in the last decades, and that most of all the intensity (total of the annual pollen output) has increased for many highly allergenic species, with likely implications for public health.

Because we want to study the severe acute health effects of pollen exposure between the years of 2000 and 2020 (the years for which we have mortality and hospitalization data), we need to be able to estimate daily exposure going back 20 years. The project has developed a model which allows the daily prediction of pollen concentrations of five different species across Switzerland back in time with high accuracy. We chose to start with hazel, alder, birch, ash and grasses: five species whose pollen are common in Switzerland and to which many people are allergic. This model was already presented at two international scientific conferences, with expected submission for publication next month.

Within the EPOCHAL project, we have also designed and conducted a cohort study on the six pre-clinical health effects of pollen exposure, including 1) respiratory function and airway inflammation, 2) cardiac health, 3) sleep quality and duration, 4) cognitive performance, 5 self-reported symptoms and 6) health-related quality of life. We have published a paper on the rationale and study design of this cohort study, detailing the gaps in knowledge regarding airborne pollen and pre-clinical health. The paper also lays out the structure of the data collection as well as details on how data for each outcome is collected. We obtained ethical permission, reached our recruitment target of 400+ individuals, who were assessed six times each by a nurse in addition to 10 self-assessments for a selection of outcomes. We successfully completed data collection in September 2022, and are currently analyzing the data generated by this large data collection effort, developing manuscripts on each of the outcomes in parallel. Preliminary analyses show associations between airborne pollen concentration and increased pre-clinical blood pressure. This association would suggest systemic inflammation “beyond the typical itching and sneezing,” and would be the first study to show this effect on pre-clinical cardiac health.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

In addition, we have a visiting PhD student from China who has joined the project with own funding. Within this collaboration, we are conducting a systematic review into the cardiovascular health effects of airborne pollen exposure and intermittent allergic rhinitis is in progress. The review protocol has been registered in PROSPERO and we have published the systematic review protocol and related documents ahead of the manuscript on Zenodo. We will then proceed to data extraction and manuscript completion by fall 2023.

While the EPOCHAL cohort study had initially only proposed to measure respiratory health outcomes (lung function and airway inflammation) and self-reported symptoms, we expanded the range of health outcomes to include cardiac health (blood pressure, heart rate variability), cognitive performance (concentration, ) health-related quality of life (fatigue, ability to concentrate, mood, etc), sleep (quality and duration), thereby assessing a broader range of systemic health effects. This will allow us to ultimately present a more comprehensive picture of pre-clinical health as affected by airborne pollen exposure.

As a further next step, we will apply the spatiotemporal pollen model to estimate exposure for the Swiss National Cohort and national hospitalization statistics, in order to study the effects on mortality and hospitalization for cardiovascular and respiratory outcomes, in association with exposure to airborne pollen estimated at the individual address level.

Our team has been approached by multiple media (including popular television, radio, newspapers, professional magazines) to contribute research findings. Recently, we were approached by the popular Swiss television show SRF Puls, which is focused on health, and featured our EPOCHAL study in its 20 March 2023 episode. We also presented our research at five different conferences (in person and online, due to covid-19). The ISEE Young 2021 conference, which was hosted from Basel and co-organized by the grant holder Marloes Eeftens was a highlight. PhD student Alexandra Bürgler won 1st prize for “best speed talk” for her contribution “Effects of Pollen on Cardiorespiratory Health, Cognitive Performance and Allergic Symptoms”. Principal investigator, Marloes Eeftens has been invited to give talks to local Basel doctors association, the Swiss federal office for the environment, the World Health Organization, Public Health Zurich, Imperial College London, the Institute for Social and Preventive Medicine in Bern, and several others, which has generated quite some interest in the study.

Hazel pollen being emitted from a catkin by strong wind

EPOCHAL spatiotemporal modelling process for pollen