Inequality amplifies the negative association between life expectancy and air pollution: A cross-national longitudinal study.

Ambient air pollution, in the form of fine particulate matter (PM2.5), poses serious population health risks. We estimate cross-national longitudinal models to test whether the negative relationship between life expectancy and PM2.5 concentration is larger in nations with higher levels of income inequality. The dependent variable is average life expectancy at birth, and the focal predictor variables include PM2.5 concentration, income inequality, and the two-way interaction between them. We also estimate the average marginal effects of PM2.5 concentration from low to high values of income inequality, and the predicted values of life expectancy from low to high values of PM2.5 concentration and income inequality. Results indicate that the negative relationship between life expectancy and PM2.5 concentration is larger in nations with higher levels of income inequality, and the reductions in predicted life expectancy are substantial when both PM2.5 concentration and income inequality are high. We suggest that the theoretical principles of Power, Proximity, and Physiology help explain our findings. This study underscores the importance in considering the multiplicative impacts of environmental conditions and socioeconomic factors in the modeling of population health.

The multiplicative impacts of working hours and fine particulate matter concentration on life expectancy: A longitudinal analysis of US States.

This study contributes to interdisciplinary research on the social and environmental determinants of population health, with a focus on the interaction between working hours and fine particulate matter (PM2.5) concentration. The authors estimate longitudinal models of the relationship between US state-level average life expectancy and both average working hours and PM2.5 concentration for the 2005-2014 period. Results obtained from two-way fixed effects models indicate that average life expectancy is negatively associated with both average working hours and fine particulate matter concentration. Findings also indicate clear moderating relationships: the negative association between life expectancy and working hours is amplified as PM2.5 concentration increases, and the negative relationship between life expectancy and fine particulate matter concentration is amplified when average working hours increase. The results of this study underscore the need for additional research on the multiplicative impacts of socioeconomic factors and environmental factors in the modeling of population health.