“…The first one is linked to the type of relationship among health expenditures, environmental degradation, and the population’s health status. Most prior works have examined either the incidences of CO2 emissions on health outcomes [e.g., ( 4 , 9 , 10 , 19 )], effects of health expenditure on health status [e.g., ( 13 , 14 , 16–18 )], or the nexus between health expenditure and environmental quality [e.g., ( 15 , 20–22 )]. However, to the knowledge of the authors, no earlier study has considered these concepts in one study.…”