EFFECT OF BIOREMEDIATION ON THE MUTAGENICITY OF OIL SPILLED IN PRINCE-WILLIAM-SOUND, ALASKA

On 24 March 1989 approximately 11 million gallons of Prudhoe Bay crude oil spilled into the waters of Prince William Sound, Alaska ultimately contaminating nearly 1000 miles of shoreline. Approximately 300 miles of contaminated beach were considered amenable to cleanup by bioremediation. To determine whether or not bioremediation would be effective in this geophysical setting and under such climatic conditions and to identify potential deleterious effects, the U.S. Environmental Protection Agency (EPA) conducted one of the world's largest in situ bioremediation field demonstration research projects. One of the methods used to assess potential health effects associated with this and similar efforts was the examination of mutagenicity associated with the oil spill and the products of bioremediation. Salmonella mutagenicity was assessed using a semi-automated plating device (spiral plater) that requires less sample than the standard assay. Both the Prudhoe Bay crude oil and its weathered counterpart collected from oil-impacted water were weakly mutagenic. The mutagenicity of samples collected from the contaminated beaches (undergoing both enhanced and natural bioremediation) declined over time.