As part of the Franche-Comté Regional Air Quality Plan, an assessment of the health impacts of urban air pollution was planned for the Montbéliard metropolitan area, which is particularly affected by this issue. The methodology for Health Impact Assessments (HIAs), defined by the InVS, is based on certain assumptions that must be verified before it can be applied. A feasibility study for an EIS was therefore undertaken, concluding that the Montbéliard metropolitan area does not fully meet these conditions. The primary obstacle to conducting such a study is the presence of major point sources of pollution, which prevent the criterion of homogeneous population exposure from being met. Furthermore, the metropolitan area does not have any true "background" monitoring stations. Given the changes implemented in recent years in the metropolitan area—namely, a reduction in emissions from point sources of pollution and a relocation of air pollution monitoring stations—an EIS could certainly be considered in the coming years. (R.A.)