JET, Okla. (AP) _ The Army Corps of Engineers is trying to determine what equipment to use to assess safety at Salt Plains National Wildlife Refuge.
The refuge has been closed since April after a Boy Scout digging for salt crystals found vials of chemicals used in chemical war training kits during World War Two.
The boy began coughing and suffered from burning eyes and a runny nose but officials say he has no lingering effects.
The Corps is now testing equipment that utilizes ground penetrating radar and metal detectors and so far more than 130 vials have been found.
The digging area will remain closed until the Corps completes a thorough assessment of the site.