{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,23]],"date-time":"2026-10-23T20:05:40Z","timestamp":1792785940008,"version":"4.5.0"},"reference-count":31,"publisher":"Oxford University Press (OUP)","issue":"5","license":[{"start":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T00:00:00Z","timestamp":1787011200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/academic.oup.com\/pages\/standard-publication-reuse-rights"}],"funder":[{"name":"Agency for the Environment and Energy Management"},{"name":"Agence de l\u2019environnement et de la ma\u00eetrise de l\u2019\u00e9nergie\u2013ADEME","award":["2162D0019"],"award-info":[{"award-number":["2162D0019"]}],"id":[{"id":"https:\/\/ror.org\/05rth8x13","id-type":"ROR","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,8,18]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Despite growing evidence on the health effects of air pollution, few studies have examined its impact on COVID-19 hospitalizations and deaths, and none have explicitly accounted for preexisting comorbidities in a causal framework. This study addresses this gap by investigating the relationship between PM2.5 exposure and COVID-19 severity. We place particular emphasis on the role of comorbidities, which can increase vulnerability to COVID-19 and may interact with air pollution exposure.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>We use an exhaustive dataset covering the entire French territory over 2020\u20131, totaling more than 3.5 million weekly observations. The data include information on COVID-19 mortality and hospitalizations, disaggregated by age, sex, and municipality, along with detailed records on preexisting conditions. To address endogeneity, we employ a two-stage least squares approach, using wind direction as an instrument for local PM2.5 concentrations.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>We find no significant effect of PM2.5 exposure on COVID-19 mortality or hospitalizations among individuals without preexisting conditions. However, when accounting for comorbidities, a 10 \u03bcg\/m3 increase in PM\u00a02.5 was associated with higher COVID-19 mortality rates (1.5 per 100\u2009000, 95% CI: 0.8\u20132.2), particularly among patients with respiratory (0.9 per 100\u2009000, 95% CI: 0.4\u20131.4), and cardiovascular diseases (0.6 per 100\u2009000, 95% CI: 0.1\u20131.1).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>These findings underscore the importance of incorporating comorbidities when assessing the health effects of air pollution during a pandemic. Our results also show that the effects of PM2.5 are driven by the oldest age groups, who are both more vulnerable to COVID-19 and more likely to have comorbidities.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1093\/ije\/dyag152","type":"journal-article","created":{"date-parts":[[2026,8,1]],"date-time":"2026-08-01T12:03:00Z","timestamp":1785585780000},"source":"Crossref","is-referenced-by-count":0,"title":["When air pollution meets comorbidities: evidence on the causal effect of PM2.5 on COVID-19 hospitalizations and deaths"],"prefix":"10.1093","volume":"55","author":[{"ORCID":"https:\/\/orcid.org\/0009-0001-2806-5100","authenticated-orcid":false,"given":"Carla","family":"Morvan","sequence":"first","affiliation":[{"name":"Faculty of Economics, University of Montpellier, CNRS, INRAe, Institut Agro CEE-M, , Montpellier,","place":["France"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Johanna","family":"Lepeule","sequence":"additional","affiliation":[{"name":"University Grenoble Alpes, Inserm U1209, CNRS UMR 5309, Institut pour l'Avanc\u00e9e des Biosciences, Team of Environmental Epidemiology Applied to Development and Respiratory Health , Grenoble,","place":["France"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Emmanuelle","family":"Lavaine","sequence":"additional","affiliation":[{"name":"Faculty of Economics, University of Montpellier, CNRS, INRAe, Institut Agro CEE-M, , Montpellier,","place":["France"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2026,8,25]]},"reference":[{"key":"2026092402423951100_dyag152-B1","doi-asserted-by":"publisher","first-page":"965","DOI":"10.1289\/ehp.1104660","article-title":"Chronic exposure to fine particles and mortality: an extended follow-up of the Harvard Six Cities Study from 1974 to 2009","volume":"120","author":"Lepeule","year":"2012","journal-title":"Environ Health Perspect"},{"key":"2026092402423951100_dyag152-B2","doi-asserted-by":"publisher","first-page":"217","DOI":"10.1146\/annurev-resource-100913-012610","article-title":"What do we know about short- and long-term effects of early-life exposure to pollution?","volume":"6","author":"Currie","year":"2014","journal-title":"Annu Rev Resour Econ"},{"key":"2026092402423951100_dyag152-B3","doi-asserted-by":"crossref","first-page":"367","DOI":"10.1038\/nature15371","article-title":"The contribution of outdoor air pollution sources to premature mortality on a global scale","volume":"525","author":"Lelieveld","year":"2015","journal-title":"Nature"},{"key":"2026092402423951100_dyag152-B4","doi-asserted-by":"publisher","first-page":"4178","DOI":"10.1257\/aer.20180279","article-title":"The mortality and medical costs of air pollution: evidence from changes in wind direction","volume":"109","author":"Deryugina","year":"2019","journal-title":"Am Econ Rev"},{"key":"2026092402423951100_dyag152-B5","doi-asserted-by":"crossref","first-page":"eabo3381","DOI":"10.1126\/sciadv.abo3381","article-title":"How low can you go? 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