PLoS ONE (Jan 2022)

Spatial environmental factors predict cardiovascular and all-cause mortality: Results of the SPACE study.

  • Michael B Hadley,
  • Mahdi Nalini,
  • Samrachana Adhikari,
  • Jackie Szymonifka,
  • Arash Etemadi,
  • Farin Kamangar,
  • Masoud Khoshnia,
  • Tyler McChane,
  • Akram Pourshams,
  • Hossein Poustchi,
  • Sadaf G Sepanlou,
  • Christian Abnet,
  • Neal D Freedman,
  • Paolo Boffetta,
  • Reza Malekzadeh,
  • Rajesh Vedanthan

DOI
https://doi.org/10.1371/journal.pone.0269650
Journal volume & issue
Vol. 17, no. 6
p. e0269650

Abstract

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BackgroundEnvironmental exposures account for a growing proportion of global mortality. Large cohort studies are needed to characterize the independent impact of environmental exposures on mortality in low-income settings.MethodsWe collected data on individual and environmental risk factors for a multiethnic cohort of 50,045 individuals in a low-income region in Iran. Environmental risk factors included: ambient fine particular matter air pollution; household fuel use and ventilation; proximity to traffic; distance to percutaneous coronary intervention (PCI) center; socioeconomic environment; population density; local land use; and nighttime light exposure. We developed a spatial survival model to estimate the independent associations between these environmental exposures and all-cause and cardiovascular mortality.FindingsSeveral environmental factors demonstrated associations with mortality after adjusting for individual risk factors. Ambient fine particulate matter air pollution predicted all-cause mortality (per μg/m3, HR 1.20, 95% CI 1.07, 1.36) and cardiovascular mortality (HR 1.17, 95% CI 0.98, 1.39). Biomass fuel use without chimney predicted all-cause mortality (reference = gas, HR 1.23, 95% CI 0.99, 1.53) and cardiovascular mortality (HR 1.36, 95% CI 0.99, 1.87). Kerosene fuel use without chimney predicted all-cause mortality (reference = gas, HR 1.09, 95% CI 0.97, 1.23) and cardiovascular mortality (HR 1.19, 95% CI 1.01, 1.41). Distance to PCI center predicted all-cause mortality (per 10km, HR 1.01, 95% CI 1.004, 1.022) and cardiovascular mortality (HR 1.02, 95% CI 1.004, 1.031). Additionally, proximity to traffic predicted all-cause mortality (HR 1.13, 95% CI 1.01, 1.27). In a separate validation cohort, the multivariable model effectively predicted both all-cause mortality (AUC 0.76) and cardiovascular mortality (AUC 0.81). Population attributable fractions demonstrated a high mortality burden attributable to environmental exposures.InterpretationSeveral environmental factors predicted cardiovascular and all-cause mortality, independent of each other and of individual risk factors. Mortality attributable to environmental factors represents a critical opportunity for targeted policies and programs.