Assessing the impact of short term outdoor air pollution exposure on cardiac dyspnea: a case study of the south of France
Authors: Simoes F , Bouveyron C , Piga D , Borel D , Descombes S , Paquis-Flucklinger V , Gibelin P , Levraut J , Bottini S 
Published: November 2020

Abstract

There is a growing body of evidence that air pollution is a significant threat to health worldwide. The time exposure to air pollution leads diverse impact on the health. A short-term exposure increases hospital admission and mortality rate, causing mainly respiratory and cardiovascular diseases, including dyspnea; whereas a long-term exposure reduce life expectancy. Although the relationship between short term exposure to air pollution and several cardiovascular pathologies, such as coronaropathy, is widely established, the link regarding cardiac dyspnea is quite controversial. Nevertheless, previous studies are lead on few selected cities preventing a global overview on an entire territory.
Here, we aim to fill this gap and finally establish the impact of pollution on cardiac dyspnea, using the “Région Sud” in the south of France, as a model. We focused on the period from 2013 to 2018 for which we dispose of clinical data of people having attended one of the 47 emergency departmentss of the region with symptoms related to cardiac dyspnea, collected by the gip e-santé ORUPACA, for a total of 43,404 events. We collected pollutants (NO2, PM10 and O3) and climate (temperature and pressure) measurements on a daily basis supplied by the French agency AtmoSud. We set up a reproducible statistical framework based on a distributed lag non-linear model (DLNM) to show the relationship between short term exposure to outdoor air pollution and the incidence of cardiac dyspnoea event for each of the defined 366 areas of the region.
This study showed that each pollutant has a significant effect on triggering cardiac dyspnoea. Specifically, we found that the biggest cities of the region, with more than 300000 habitants, such as Marseille and Nice have a significant increase of 1,5 and 1,2 respectively, if the NO2 pass the threshold of 200 mg/m3, three days before the dyspnea event. In cities with habitants between 50000 and 100000, such as Avignon and Fréjus, we found that is the O3 to have the most significant effect on the cardiac dyspnea events. A peak of O3 over 180 mg/m3 in these cities, will increase of five times the number of dyspnea events after 6 days. We observed a milder effect of PM10 on dyspnea events and mainly on cities on the coast, such as Marseille, Nice and Toulon, for which the risk of dyspnea events significantly increase if the level of PM10 overcome 50 mg/m3.
Importantly, we established the impact of three different pollutants on hospital admission for cardiac dyspnea in each of the 366 areas in the South of France. Overall, we observed that each pollutant impacts the cardiac dyspnea events on different time frame between the pollution peak and the event, such as: few days for NO2, between 6 and 8 days for O3 and the same day or the day before for PM10. Finally, we developed a user-friendly web application called HEART (Health, Environment in PACA Region Tool) to easily show the results of this study.

Funding Acknowledgement
Type of funding source: Public grant(s) – EU funding. Main funding source(s): Idex UCAJEDI