The military is plowing through old records to find any and all information on the Army's ocean dumping of chemical weapons decades ago, a high priority effort to determine where they all are located and what danger they pose today.

The Army hopes to finish its record search by the end of March, said Addison Davis, an assistant secretary of the Army.

"What we're conducting right now is probably the most comprehensive search on records ... that has ever been done," he said. "Our goal is to compile the best, most comprehensive, up-to-date information possible."

An order from the highest levels of the Pentagon has gone out to all branches of the military to search for all ocean dumping records, not just of chemical weapons but of conventional ordnance as well, Davis said.

The Army is most interested in discovering where it dumped all its chemical weapons into the sea from World War I until 1970, when the practice was halted.

Officials want to know exactly where they are located and what type of chemical weapons - as well as how many - are in each dumpsite.

Then the Army will be better able to assess the risk each site poses to fishermen or the environment, Davis said.

The records search was prompted by a Daily Press investigation published in October - based on never-before released Army reports covering 1944 to 1970 - that revealed the military dumped at least 64 million pounds of chemical weapons into the ocean in dozens of locations that virtually ring the country.

The dumpsites - mostly containing mustard and nerve gases and some radioactive waste - are off the coastlines of at least 11 states. Additional dumpsites are off the coasts of 16 other countries. The sites were created when the U.S. Army dumped its overseas stockpiles of chemical weapons at the close of World War II.

The Army knows where only half the dumpsites off the U.S. coast are, because the known surviving records are vague and others have been destroyed.

More dumpsites likely exist, because the Army only now is reviewing chemical weapons dumping in the World War I-era, when it was common to throw the weapons over the side of ships in relatively shallow water.

Some scientific evidence suggests the weapons may be slowly leaking after decades of saltwater corrosion.

In the wake of the newspaper's investigation, the Army has begun a military-wide records search which includes a review of ship manifests, a look at historical nautical charts, and perusal of old chemical weapons shipments kept at a variety of Army bases.

The Army also has collected scientific research on long-known dumpsites overseas of chemical weapons. It briefed at least eight federal lawmakers who demanded data about the dumping.

"We've tried to be very responsive in replying to questions on the Hill," said Davis, a civilian near the top of the Army's chain of command. "That I personally did the briefing sends a signal of the importance I place on this."

The Army also has been busy researching the stories of individuals who came forward to report health effects they said are related to their participation in dumping operations long ago.

Davis said the Army has learned that safety measures were taken at the time to ensure that military personnel were not casually exposed to chemical agents or radioactive waste.

Medical records of one former serviceman who helped dump radioactive waste off the coast of Virginia in 1960 show that he was exposed only to the equivalent of eight chest X-rays, Davis said.

No new chemical weapons dumpsites have been identified since the record search began at the end of October.

But if others are found, Davis promised that information would be promptly released to Congress and the news media. He also vowed to give Congress progress reports, as the paperwork search continues and as discussions begin on what to do about the weapons that were dumped.

There is no easy answer for handling the weapons, once all the dumpsites are identified and their contents are catalogued.

Most, but not all, are in deep water far from shore, according to Army reports completed in 1989 and 2001, and released to the Daily Press this summer.

Some of the weapons may have released their deadly contents long ago, causing an unknown environmental impact.

Others likely remain intact where they were dumped, barnacle-encrusted and too unstable after all these years in the ocean to haul up from the ocean floor.

Shells corrode at different rates, depending on their thickness and the temperature of the water, and some may already be leaking - an extreme danger to any recovery effort.

A 2002 study by Norwegian scientists who studied chemical weapons dumped off that country's coast by the U.S. or British military after World War II revealed that some shells have leaked. Others are slowly corroding, and some seem to be undamaged, so far, by the saltwater.

Some scientists estimated the weapons pose a continuous risk of leaking over the next 100 years.

"We believe it is highly unlikely any of this stuff is in danger of washing up on shore," Davis said. "But we're putting a full-court press on this issue."