This article reflects on the key findings and insights offered by recent work on public understandings of air pollution, which has begun to adopt some of the concepts and methodologies associated with social constructionism. We begin with a brief discussion of debates in the social sciences generally, and human geography specifically, regarding the precepts of 'social constructionism', before setting out the 'heterogeneous' mode that we adopt in this paper. In this light, we trace briefly the fairly narrow empirical, methodological and conceptual preoccupations of early air pollution perception work. These accounts usefully situate the remainder of the paper, which focuses on the recent body of research that explores public understandings of air pollution, with quite different approaches to theory and data collection to that which has gone before. The argument we develop asserts that a constructionist interpretation, in revealing 'complexity' and the entangled interaction of society-environment-technology, raises serious questions about the dominant political discourse of air pollution and the policy responses which it legitimates. The issues raised by this review, we believe, offer a fresh perspective and the potential to progress not only our understanding and management of air pollution risks but also the contribution of geographers to a challenging research terrain.