title: Realist review of policy intervention studies aimed at reducing exposures to environmental hazards in the United States.
abstract: Exposure to pollution is a significant risk to human health. However few studies have attempted to identify the types of policy interventions that can reduce the health risks of pollution exposure in the United States. The study objective was to conduct a realist review of policy interventions conducted or aimed at reducing chemical exposures in humans or the environment where exposure was measured.
  
  
  
  A systematic literature search identified published articles that assessed policy interventions using exposure data. Two coders independently extracted data from the studies, assessing methods, context, details of interventions, outcomes, and risks of bias. Data were analyzed iteratively and manually to identify the most effective and transferrable types of interventions. The reasons for variability in the success of different interventions were explored.
  
  
  
  The review found that regulatory interventions that eliminate point sources of pollution appeared to reduce exposure to environmental hazards. Regular monitoring to provide environmental and human exposure data helped assess compliance with the regulatory standards. Educational and economic interventions were less successful.
  
  
  
  Although some types of regulatory interventions appear to reduce exposures, our findings are limited by the nature of existing interventions, the weaknesses of the study designs used in the literature, and the lack of details on implementation. Information on contextual factors that influence implementation would assist with future reviews and could help identify effective interventions.
authors.affiliation: Department of Clinical Pharmacy, University of California, 3333 California Street Suite 420, San Francisco, CA, 94143 - 0613, USA. dorie.apollonio@ucsf.edu.
authors.forename: Dorie E
authors.identifier: 0000-0003-4694-0826
authors.initials: DE
authors.lastname: Apollonio
authors.affiliation: Department of Social and Behavioral Sciences, University of California, San Francisco, USA.
authors.forename: Nicole
authors.initials: N
authors.lastname: Wolfe
authors.affiliation: Department of Pharmacy; Charles Perkins Centre, University of Sydney, Sydney, Australia.
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Bero
mesh_terms: D004781:Environmental Exposure / Q000331:legislation & jurisprudence* / Q000517:prevention & control; D004785:Environmental Pollutants; D006801:Humans; D011640:Public Policy; D014481:United States
chemical_list: D004785:Environmental Pollutants
keywords: Environmental toxic substances; Health policy; Pollution; Systematic review