[1] Univ Ljubljana, Biotech Fac, Ljubljana 1000, Slovenia
[2] Wageningen Univ & Res, Environm Res, POB 47, NL-6700 AA Wageningen, Netherlands
[3] Natl Inst Publ Hlth & Environm, Antonie van Leeuwenhoeklaan 9, NL-3721 MA Bilthoven, Netherlands
[4] Norwegian Inst Water Res NIVA, Gaustadalleen 21, N-0349 Oslo, Norway