Associations between greenness and predicted COVID-19-like illness incidence in the United States and the United Kingdom

Kelly Chen; Jochem O Klompmaker; Charlotte J Roscoe; Long H Nguyen; David A Drew; Peter James; Francine Laden; Daniela Fecht; Weiyi Wang; John Gulliver; Jonathan Wolf; Claire J Steves; Tim D Spector; Andy T Chan; Jaime E Hart

doi:10.1097/EE9.0000000000000244

Associations between greenness and predicted COVID-19-like illness incidence in the United States and the United Kingdom

Environ Epidemiol. 2023 Feb 7;7(1):e244. doi: 10.1097/EE9.0000000000000244. eCollection 2023 Feb.

Authors

Kelly Chen¹, Jochem O Klompmaker^{1

2}, Charlotte J Roscoe¹, Long H Nguyen³, David A Drew^{3

4}, Peter James^{1

5}, Francine Laden^{1

2}, Daniela Fecht⁶, Weiyi Wang⁶, John Gulliver⁷, Jonathan Wolf⁸, Claire J Steves⁹, Tim D Spector⁹, Andy T Chan^{3

4

10}, Jaime E Hart^{1

2}

Affiliations

¹ Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts.
² Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts.
³ Clinical & Translational Epidemiology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts.
⁴ Division of Gastroenterology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts.
⁵ Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts.
⁶ MRC Centre for Environment and Health, School of Public Health, Imperial College London, London, United Kingdom.
⁷ Centre for Environmental Health and Sustainability, George Davies Centre, University of Leicester, Leicester, United Kingdom.
⁸ ZOE Global, London, United Kingdom.
⁹ Kings College Department of Twin Research and Genetic Epidemiology, King's College London, London, United Kingdom.
¹⁰ Department of Immunology and Infectious Disease, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.

Abstract

Green spaces may be protective against COVID-19 incidence. They may provide outdoor, ventilated, settings for physical and social activities and therefore decrease transmission risk. We examined the association between neighborhood greenness and COVID-19-like illness incidence using individual-level data.

Methods: The study population includes participants enrolled in the COVID Symptom Study smartphone application in the United Kingdom and the United States (March-November 2020). All participants were encouraged to report their current health condition and suspected risk factors for COVID-19. We used a validated symptom-based classifier that predicts COVID-19-like illness. We estimated the Normalized Difference Vegetation Index (NDVI), for each participant's reported neighborhood of residence for each month, using images from Landsat 8 (30 m²). We used time-varying Cox proportional hazards models stratified by age, country, and calendar month at study entry and adjusted for the individual- and neighborhood-level risk factors.

Results: We observed 143,340 cases of predicted COVID-19-like illness among 2,794,029 participants. Neighborhood NDVI was associated with a decreased risk of predicted COVID-19-like illness incidence in the fully adjusted model (hazard ratio = 0.965, 95% confidence interval = 0.960, 0.970, per 0.1 NDVI increase). Stratified analyses showed protective associations among U.K. participants but not among U.S. participants. Associations were slightly stronger for White individuals, for individuals living in rural neighborhoods, and for individuals living in high-income neighborhoods compared to individuals living in low-income neighborhoods.

Conclusions: Higher levels of greenness may reduce the risk of predicted COVID-19-like illness incidence, but these associations were not observed in all populations.

Keywords: Built Environment; COVID; Green space; Natural environment.

Abstract

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