1. Note regarding URLs: References in this paper rely extensively on Internet URLs (Universal Resource Locators), which can cease to function for any number of reasons. To locate information on web pages no longer accessible, an archive service as the“Internet Archive Wayback Machine” (http://www.archive.org) can be useful. Other information regarding non-functional URLs can be located at: http://www.epa.gov/ nerlesds/chemistry/ppcp/advice.htm (“Advice on Non-Functional URLs”).
2. Ayscough NJ, Fawell J, Franklin G, Young W (200o) Review of human pharmaceuticals in the environment. UK Environment Agency, Rio House, Bristol (R+D Technical Report P39o, June 2000, ISBN i 85705 411 3; available at
http://www.wrcplc.com
/ea/rdreport.nsf)
3. BELLE (2003) Biological effects of low level exposures. (Web site maintained by the BELLE Advisory Committee,
http://www.belleonline.com
/)
4. Boxall ABA, Fogg L, Blackwell PA, Kay P, Pemberton EJ (2002) Review of veterinary medicines in the environment. UK Environment Agency, Rio House, Bristol (R+D Technical Report P6–002/TR, March 2002, ISBN 1–8570–5–780–5; available at http://www.webookshop.com/ea/rdreport.nsf/ cb25ea8bb5cda7ce8o2567odoo46afca/ebb7o7d23d5c38f98o256bfioo5ca749?OpenDocument) (see also series of recommendations regarding veterinary medicines: http://www.epa.gov/nerlesdi/ chemistry/pharma/vet.htm)
5. Calabrese EJ (2002) Hormesis: changing view of the dose-response, a personal account of the history and current status. Mutat Res 511:181–189