Abstract: Preface. 1: General Introduction and Overview Articles. A. Grimvall, D.B. Harper, G. Asplund, C. Gron. 2: Characterization of Organohalogens of Natural Origin. R.L. Malcolm, J.P. Croue, M. Benedicte, W.M.G.M. van Loon, J.J. Boon, B. de Groot, A.J. Bulterman, C. Johansson, H. Boren, A. Grimvall, O. Dahlman, R. Morck, A. Reimann, R.L. Malcolm, O. Hjelm, G. Asplund, K. Laniewski, S. Jonsson, L. von Sydow, P.K.G. Manninen, M. Lauren. 3: Natural Production of Organohalogens Normally Considered to be of Anthropogenic Origin. R.E. Alcock, K.C. Jones, A.E. Johnston, E.J. Hoekstra, P. Lassen, J.G.E. van Leeuwen, E.W.B. de Leer, L. Carlsen. 4: Mechanisms for the Incorporation of Halogens into Organic Substances. J.M. Bollag, J. Dec, M.D.R. Pizzigallo, P. Ruggiero, C. Crecchio, R. Mininni, P. Lassen, A. Randall, O. Jorgensen, P. Warwick, L. Carlsen, J.-H. van Pee, H.-J. Hecht, T. Haag, O. Pfeifer, R. Bantleon, H. Sobek, I. Pelletier, J. Altenbuchner, J. Hejzlar, H. Boren, A. Grimvall, J.T.G. Hamilton, O. Flynn, M.J. Larkin, D.B. Harper, J. Dolfing, W. Salomons. 5: Occurrence and Production of Organohalogens in the Terrestrial Environment. K.C. Engvild, D.B. Harper, T. Vartiainen, K. Takala, P. Kauranen, E. de Jong, J.A. Field, H.E. Spinnler, A.E. Cazemier, J.A.M. de Bont, G. Nkusi, G. Muller, K.A. Reid, R.D. Bowden. 6: Occurrence and Production of Organohalogens in the Marine Environment. R.M. Moore, R. Tokarczyk, V.K. Tait, M. Poulin, C. Geen, E. Fogelqvist, T.Tanhua, C. Wesen, H. Mu, P. Sundin, O. Ringstad, G. Odham, A. Abrahamsson, A. Ekdahl, J. Collen, M. Pedersen, E. Fahlstrom, M. Kawano, H. Yoshioka, Y. Tejima, R. Tatsukawa, S. Jonsson, I, Pavasars, C. Johansson, H. Boren, A. Grimvall, Y. Izumi, R. Wever. 7: Reactive Chlorine and Halogenated Organic Compounds in the Atmosphere. W.C. Keene, W. Behnke, V. Scheer, C. Zetzsch, S.T. Sturges, G.F. Cota, R.H.A. Brown, J.N. Cape, J.G. Farmer. 8: Policy Aspects. J.A. Wesseldijk, R.L. Stringer, P.A. Johnston, M. Bovenkerk.