The 'Land of Fires' is a district in Italy characterized by illegal waste disposal, waste burning, and citizen protests over contamination. This study investigates the relevance of several psycho-social factors that predict citizens' intention to protest, taking into account different research traditions. In addition, we hypothesize the effect of protest antecedents to be moderated by past participation behaviour (i.e. the level of activism). Hence, our study is a first attempt to explore the effect of protest antecedents as a function of the individual level of activism through a cross-sectional survey study (N = 306). The results show significant effects of collective identity, sense of injustice, costs of protest, and perceived risk (cognitive dimension) on intention to protest. The effects of collective efficacy and perceived risk (affective dimension) are moderated by participants' level of activism, and these effects are significant only for non-activists. The relevance of this new approach is discussed, as well as practical implications and possible further developments.