Despite the fact that overall health has improved over the past few decades in most high developed countries, including the European Union, socio-economic inequalities in health persist both between Member States and between different regions within the same Member State. These inequalities could even be increasing in the near future (Marmot 2010). In most of the countries, clear differences are being observed in morbidity and mortality rate due to disorders dependent on socio-economic factors, their criterions being education, income (individual, family, material status), or employment status (Mackenbachet al. 2003). Environmental exposures also signifi cantly contribute to health inequalities and associated health disparities and diseases. Evidence shows that air pollution at current levels in European cities is responsible for a signifi cant burden of deaths, hospital admissions, and exacerbation of symptom, especially for cardiorespiratory disease in urban environments (WHO 2013b). Poor health is often made worse by the interaction between individuals and their physical environment. There are two major mechanisms that may act independently or together, through which environmental exposure may contribute to health inequalities; among the general population, disadvantaged and “higherrisk” groups are recognized as being more often exposed to sources of air pollution (differential exposure) and may also be more susceptible (differential susceptibility)

to the resultant health effects (Deguen and Zmirou-Navier 2010). WHO assessment shows that inequalities in environmental exposure can reach extreme levels, with disadvantaged populations groups often being at least fi ve times more exposed than advantaged groups (WHO 2013a). Over the past few decades, the socio-economic and environmental risk factors related to such phenomena like climate change, globalization, urbanization, economic, demographic, and health changes have signifi cant infl uence on the poorest and most vulnerable groups.