Updated

Roadside bombs have killed nearly 3,600 military service members and wounded 34,000 more in Iraq and Afghanistan, but many of the long-term health effects are unknown for those who seemingly walked away without serious injury.

For that reason, the Institute of Medicine is calling on the Department of Veterans Affairs to create a registry of service members exposed to such bombs so the long-term consequences can be better tracked.

Medical researchers often establish disease registries to help monitor health trends in participants. For example, the VA has one for those exposed to Agent Orange in Vietnam and one for those who served during the first Gulf War. The registries serve as a giant database that researchers can review for signs of problems.

The institute panel reviewed hundreds of research papers to evaluate when service members are at increased risk of health problems because of a bomb blast. The committee concluded that there was sufficient evidence to show that the blasts contributed to the development of post-traumatic stress disorder and symptoms following a concussion, such as persistent headaches.

But there was not enough evidence to assess whether exposure to bomb blasts leads to depression, substance-abuse and chronic pain. Nor was there enough to determine the prospects for long-term hearing loss, tinnitus, vertigo or the development of muscle or bone impairment such as osteoarthritis.

Stephen L. Hauser, chairman of the committee that wrote the report, said the roadside bombs clearly have caused devastating physical and psychological injuries for thousands of U.S. military members. "But the long-term consequences are less clear, particularly for individuals who show no external signs of injury from exposure to blast waves or may not even be aware that they were exposed," said Hauser, chairman of the department of neurology of the University of California, San Francisco.

The VA asked the Institute of Medicine to conduct the study and said it would review the recommendations.

The institute is part of the National Academy of Sciences, a private organization chartered by Congress to advise the government on scientific matters.