Richard Edwards1
, Christian P Hasselholdt2
, Kim Hargreaves3
, Claire Probert4
, Richard Holford5
, Judy Hart6
, Martie Van Tongeren7
and Adrian FR Watson2 
1Department of Public Health, Wellington School of Medicine and Health Sciences, University of Otago, Wellington, New Zealand
2Department of Environmental & Geographical Sciences, Manchester Metropolitan University, Oxford Rd, Manchester, UK
3East Lancashire Public Health Network, Eagle St, Accrington, UK
4North West ASH, Silver St, Bury, UK
5Manchester Public Health Development Service, Victoria Mill, Lower VickersStreet, Manchester, UK
6Evidence for Population Health, Division of Epidemiology and Health Sciences, University of Manchester, Oxford Rd, Manchester, UK
7Centre for Occupational and Environmental Health, Division of Epidemiology and Health Sciences, University of Manchester, Oxford Rd, Manchester, UK