Economic disparities in pollution-related mortality in three municipalities of the Metropolitan Area of the Valley of Mexico

Abstract

This study explored the nature of health risks in the population of three municipalities within the Metropolitan Area of the Valley of Mexico (MAVM) by means of an empirical analysis of health effects associated with air pollution and temperature variation. Based on the environmental justice theory, we asked whether, in unequal socioeconomic municipalities of the MAVM, the association between PM₁₀ concentrations and mortality depends on socioeconomic disparities. We differ from previous studies that have established a relationship between PM₁₀ and mortality based on a state-space model instead of the Poisson regression model. The state-space model allows estimating the size of the unobserved at-risk population, its hazard rate, the life expectancy of individuals in that population, and the effect of changes in environmental conditions on that life expectancy. Our results show a lower hazard rate in a wealthy municipality, as compared to a higher hazard rate in a poor one. The lower hazard rate of the wealthy municipality extends life expectancy and enhances the likelihood of inhabitants staying long-lasting within the population at risk, thus increasing the size of that population, as compared to the population at risk in the poor municipality, whose members show a lower life expectancy. Thus, the smaller the at-risk population, the sicker its average member and the smaller the impact on long-term mortality. Our study examines how regional health disparities could provide information for public health policy initiatives which might improve living conditions among different communities.