RIASSUNTO
PANEL DISCUSSION OIL SPILLS ON LAND AND WATER Chairman: K. G. BRUMMAGE (U.K.) Vice-chairmen: E. C. CADRON (BELGIUM) Scientific Secretary: A. KOBAYASHI (JAPAN) W. SCHIRMER (GERMAN DEMOCRATIC REPUBLIC) The subject of oil pollution continues to be of great concern to governments and to the oil industry. Both recognise that the first essential is to avoid spillage of oil, which depends on the proper and safe design and use of equipment in all types of industry operations. Many of the presentations during the Congress dealt with such subjects and hence indirectly with the avoidance of spillage and pollution. Oil nevertheless does enter the environment both during normal operations and as a result of accidents. To set rational limits to the former and to deal with the latter knowledge of the behaviour and effects of oil on land and water is essential and this is the task to which the members of this Panel addressed themselves. In his paper E. H. HUBBARD described the results of work on the migration of oil spilled on soil, showing that little sideways movement occurs unless the oil impinges on a water table. If it does, it spreads out above the water level preferentially in the downstream direction of the water flow. Rain can subsequently leach some components from the oil and carry them into the ground water. Much remains to be learnt about the subsequent fate of these components par- ticularly in anaerobic conditions. Aerobic oil degrada- tion products nearer the surface of the ground can provide a source of carbon for plant life and in the presence of fertilisers the oil can even have a beneficial effect. He illustrated this by describing experiments with helm grass in the Netherlands. He also dealt with the rapid spread of oil spilled on water and its various effects such as taste and odour, toxicity and oxygen depletion. The paper by P. J. AGIUS, H. JAGGER, D. R. FUSSELL and G. L. JOHNES, presented by Dr P. J. AGIUS, dealt with the clean-up of inland oil spills, emphasising the need for quickly confining oil spilt on land or water to minimise the problems of removal. The clean-up method selected will depend on the particular circumstances of each spill, including the type of oil, the surface on which it occurs, the soil and sub-soil, weather conditions and the sensitivity of the site to oil pollution. The organisation in the UK for cleaning up inland oil spills was also described including the co-operation between local government authorities and the oil industry. L. P. HAXBY, in presenting the paper by E. W. MERTENS and himself, summarised the result of a four-year API-sponsored research programme on the fate and biological effects of oil in the sea. They con- cluded that an oil spill seldom causes even temporary damage to marine life; only rarely is damage sustained which persists as much as a year. Marine organisms subjected to sub-lethal concentrations of oil accumulate petroleum hydrocarbons, but they rapidly eliminate these materials