A review on working time aspects available which Friedhelm Nachreiner and collegeaus did for the European Commission. The review on health, safety and some social effects (Annex 1)  can be found under http://ec.europa.eu/social/BlobServlet?docId=6423&langId=en
and the full report (from Deloitte), covering some more aspects under
http://ec.europa.eu/social/BlobServlet?docId=6421&langId=en