[1] Univ Manchester, Sch Chem Engn & Analyt Sci, Manchester M13 9PL, Lancs, England
[2] Univ London London Sch Hyg & Trop Med, Publ & Environm Hlth Res Unit, London WC1E 7HT, England
[3] Hlth Protect Agcy, Ctr Radiat Chem & Environm Hlth Hazards, Didcot OX11 0RQ, Oxon, England
[4] Sheffield City Council, Environm Strategy Grp, Sheffield S9 2DB, S Yorkshire, England
[5] Univ Sheffield, Dept Chem & Proc Engn, Waste Incinerat Ctr, Sheffield S1 3JD, S Yorkshire, England