Neighborhood environmental exposures and incidence of attention deficit/hyperactivity disorder: A population-based cohort study

Weiran Yuchi; Michael Brauer; Agatha Czekajlo; Hugh W Davies; Zoë Davis; Martin Guhn; Ingrid Jarvis; Michael Jerrett; Lorien Nesbitt; Tim F Oberlander; Hind Sbihi; Jason Su; Matilda van den Bosch

doi:10.1016/j.envint.2022.107120

Neighborhood environmental exposures and incidence of attention deficit/hyperactivity disorder: A population-based cohort study

Environ Int. 2022 Mar:161:107120. doi: 10.1016/j.envint.2022.107120. Epub 2022 Feb 7.

Authors

Affiliations

¹ School of Population and Public Health, Faculty of Medicine, The University of British Columbia, 2206 East Mall, Vancouver, British Columbia, Canada.
² Department of Forest Resource Management, Faculty of Forestry, The University of British Columbia, 2424 Main Mall, Vancouver, Canada.
³ Department of Forest and Conservation Sciences, Faculty of Forestry, The University of British Columbia, 2424 Main Mall, Vancouver, Canada.
⁴ Fielding School of Public Health, University of California at Los Angeles, 650 Charles E. Young Drive South, Los Angeles, CA, the United States.
⁵ School of Population and Public Health, Faculty of Medicine, The University of British Columbia, 2206 East Mall, Vancouver, British Columbia, Canada; Department of Pediatrics, The University of British Columbia, 4480 Oak St. Vancouver, Canada.
⁶ School of Population and Public Health, Faculty of Medicine, The University of British Columbia, 2206 East Mall, Vancouver, British Columbia, Canada; BC Centre for Disease Control, Vancouver, Canada.
⁷ School of Public Health, University of California at Berkeley, 2121 Berkeley Way West, Berkeley, CA, the United States.
⁸ School of Population and Public Health, Faculty of Medicine, The University of British Columbia, 2206 East Mall, Vancouver, British Columbia, Canada; Department of Forest and Conservation Sciences, Faculty of Forestry, The University of British Columbia, 2424 Main Mall, Vancouver, Canada; ISGlobal, Parc de Recerca Biomèdica de Barcelona, Doctor Aiguader 88, 08003 Barcelona, Spain; Universitat Pompeu Fabra, Plaça de la Mercè, 10-12, 08002 Barcelona, Spain; Centro de Investigación Biomédica en Red Instituto de Salud Carlos III, Calle de Melchor Fernández Almagro, 3, 28029, Madrid, Spain. Electronic address: matilda.vandenbosch@isglobal.org.

PMID: 35144157
DOI: 10.1016/j.envint.2022.107120

Abstract

Background: Emerging studies have associated low greenspace and high air pollution exposure with risk of child attention deficit/hyperactivity disorder (ADHD). Population-based studies are limited, however, and joint effects are rarely evaluated. We investigated associations of ADHD incidence with greenspace, air pollution, and noise in a population-based birth cohort.

Methods: We assembled a cohort from administrative data of births from 2000 to 2001 (N ∼ 37,000) in Metro Vancouver, Canada. ADHD was identified by hospital records, physician visits, and prescriptions. Cox proportional hazards models were applied to assess associations between environmental exposures and ADHD incidence adjusting for available covariates. Greenspace was estimated using vegetation percentage derived from linear spectral unmixing of Landsat imagery. Fine particulate matter (PM_2.5) and nitrogen dioxide (NO₂) were estimated using land use regression models; noise was estimated using a deterministic model. Exposure period was from birth until the age of three. Joint effects of greenspace and PM_2.5 were analysed in two-exposure models and by categorizing values into quintiles.

Results: During seven-year follow-up, 1217 ADHD cases were diagnosed. Greenspace was associated with lower incidence of ADHD (hazard ratio, HR: 0.90 [0.81-0.99] per interquartile range increment), while PM_2.5 was associated with increased incidence (HR: 1.11 [1.06-1.17] per interquartile range increment). NO₂ (HR: 1.01 [0.96, 1.07]) and noise (HR: 1.00 [0.95, 1.05]) were not associated with ADHD. There was a 50% decrease in the HR for ADHD in locations with the lowest PM_2.5 and highest greenspace exposure, compared to a 62% increase in HR in locations with the highest PM_2.5 and lowest greenspace exposure. Effects of PM_2.5 were attenuated by greenspace in two-exposure models.

Conclusions: We found evidence suggesting environmental inequalities where children living in greener neighborhoods with low air pollution had substantially lower risk of ADHD compared to those with higher air pollution and lower greenspace exposure.

Keywords: ADHD; Air pollution; Green space; Linear spectral unmixing; Satellite remote sensing; Vegetation percentage.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Air Pollutants* / analysis
Air Pollution* / adverse effects
Air Pollution* / analysis
Attention Deficit Disorder with Hyperactivity* / epidemiology
Child
Cohort Studies
Environmental Exposure / adverse effects
Environmental Exposure / analysis
Humans
Incidence
Particulate Matter / adverse effects
Particulate Matter / analysis

Substances

Air Pollutants
Particulate Matter

Grants and funding

156152/CIHR/Canada