KAILUA-KONA >> The state is working to bring awareness to the dangers of unexploded ordnance left over from World War II on the northwestern part of the Big Island.

The explosive devices were used in training exercises by the U.S. Navy and Marines to prepare soldiers for combat. The Department of Defense has worked to locate and remove the ordnance from the Waikoloa Maneuver Area since the exercises stopped in 1946, but an estimated 10 percent of the munitions failed to detonate and remain there, West Hawaii Today reported .

The Hawaii Department of Health held a forum Wednesday to educate the public on safety precautions. The discussion centered on improving signage around the hazardous area and making sure people are aware of the dangers.

“Our whole purpose in bringing the forum together is . to do public outreach,” said Fenix Grange, manager of the Hazard Evaluation and Emergency Response Office at the HDOH. “(Unexploded ordnance) have been there for 40, 60 years, and they’re not like improvised explosive devices where you walk down the street and it’s going to blow you up. But if you play with it, or you carry it in the back of your pickup truck, or if you’re a child and you see something interesting and you want to bring it home, there’s a big risk.”

The munitions include artillery, mortars, grenades, rockets and tank rounds, which are scattered across areas zoned for residential, commercial and agricultural use.

Walter Nagai with the U.S. Army Corps of Engineers said a live hand grenade was found about five years ago on the soccer field at Waikoloa Elementary and Middle School. The area was being cleared for unexploded ordnance at the time of the discovery, he said.

Children and tourists have been identified as the most vulnerable to the explosive devices because of a lack of awareness. Ross Birch, executive director of the Island of Hawaii Visitors Bureau, said the agency has been trying to educate tourists about the risks they could encounter while exploring the island.

“We try to get that message to our visitors,” Birch said. “Not an alarming message, not one that’s going to make them change their plans to vacation on our island, but one that’s going to make them aware of potentials that are out there.”

Removal costs for the entire 100,000-acre Waikoloa Maneuver Area are estimated at about $720 million, but only about $10 million is budgeted for the work each year.