The Dow Jones Industrial index plunged 212.36 points today, a fall of 1.86%, on fears that booming inflation will translate into higher interest rates. The index fell 100 points in the first hour of trading after the Labor Department reported that the Consumer Price Index jumped 0.6% in April. Higher gasoline, clothing and health-care costs were blamed for the steep increase. The S&P 500 fell 21.47 points, or 1.66%, and the Nasdaq composite was off by 32.63 points, or 1.46%. All market figures are preliminary.