After decades of repression from the government authorities, the liberationist Catholic Church in Brazil is absent of traditional centralization and encourages an increased lay participation. Faced with a severe priest shortage, much of the Brazilian Catholic Church is organized into basic ecclesial communities (CEB) in which the Mass, community spirituality programs, and community needs are led or addressed by a single clergy member or a trained lay member in either a small chapel or an individual's home. The CEBs introduced new social ideas and democratic methods which led to many participants' active involvement in popular movements of Brazil that worked for progressive social change. An example of progressive social change initiated by the CEBs is in Nova Iguaçu. A health program began there to try to organize the population in order to remedy widespread malnutrition, open sewers, and other health hazards. Eventually the neighbourhood initiative reached a national interest level where it then became a mass movement in nearly every neighbourhood. Initiatives like the health program in Nova Iguaçu illustrate how CEBs have helped the transition from military to democratic rule.