Community-level risk factors for temperature-related mortality in France

Area of Science:

• Environmental epidemiology
• Public health
• Climate change adaptation

Background:

• Geographical variations in temperature vulnerability are not well understood.
• Contextual factors driving spatial differences in heat and cold mortality risk require investigation.

Purpose of the Study:

• To identify community-level characteristics influencing geographical disparities in heat-related and cold-related mortality risk in France.
• To assess the role of contextual factors in modifying temperature-mortality associations.

Main Methods:

• Country-wide analysis of mortality, temperature, and contextual data in France (2004-2019).
• Time-series quasi-Poisson regression with distributed lag nonlinear models to estimate temperature-mortality associations.
• Multivariate meta-regression to evaluate effect modification by contextual factors.

Main Results:

• High temperatures increased mortality risk by 11.0% (95% CI = 9.4, 15.5).
• Low temperature mortality risk was not modified by any contextual factors.
• High temperature mortality risk was independently modified by nitrogen dioxide (NO2) pollution; urban areas with high NO2 had increased heat mortality risk.

Conclusions:

• Urban areas in France exhibit greater vulnerability to heat compared to rural areas.
• Air pollution (NO2) and urban heat island effects likely drive this disparity.
• Mitigation of air pollution and urban heat islands are crucial for heat-related health adaptation strategies.