The issue focused on the evidence that there is a role for local risk factors in the development of environmental changes. The results of the study were based on a review of the scientific literature. The review used a broad approach to assess the evidence in an attempt to address the following questions: 1) How does the evidence support the role of local risk factors in the development of environmental changes? 2) How do the results of the review address the question of how this evidence can be used to inform current public health policy? The