Recent reports reveal that 64 million pounds of chemical agents were secretly dumped into the ocean at more than two dozen sites near Hawaii and 10 other states and that the Army can pinpoint only half of them.

At least 16,000 mustard-filled bombs were thrown into the ocean as close as five miles off Oahu. In 1976, a Hawaii fisherman was burned when he brought up a mortar round filled with mustard gas, showing how dangerous such materials can be decades after disposal.

In his letter to the secretary of the Army, Abercrombie lists other toxic materials that might have been dumped, including Lewisite, cyanogen and hydrogen cyanide, agents that are harmful to respiratory, cardiovascular and digestive systems.

Abercrombie points out that a cleanup effort might reach the "magnitude of Kahoolawe," the island that had been used as a military target and required more than $400 million to remove unexploded ordnance.

The Army maintains that the inaccessibility of the dump sites mitigates risks, but the effects of ocean disposal have never been studied and there has been no monitoring to gauge deterioration of metals or release of harmful substances. The Army bears a responsibility to attempt rectify the problem.