Japan Fighting Her Biggest Oil Spill
biggest oil spill in Japan's history spreads through Inland Sea, polluting area more than 80 miles long and 20 miles wide; spill started on Dec 19 at Mitsubishi oil refinery at Mizushima and is believed to involve some 11-million gals of oil; damage to fisheries, seaweed indus and beaches is estimated at $20-million; criticism of environmental damaged caused by Mizushima indus complex noted; map (M)