This bill requires the Department of Defense to publish a comprehensive report within one year of enactment, then every three years afterward, examining toxic exposures in Guam between August 1958 and July 1980. The reports must review scientific literature on illnesses and conditions linked to toxic substance exposure among people who spent more than 30 days in Guam during that period, and must specifically document any transfer and storage of Agent Orange on the island during those years. The Department of Defense will coordinate with the Department of Health and Human Services and the Agency for Toxic Substances and Disease Registry to categorize the strength of evidence showing whether toxic exposure caused specific illnesses, ranging from sufficient evidence to limited evidence. The bill also requires periodic updates to these reports as new scientific findings emerge. This legislation directly affects former residents and military personnel who were in Guam during the specified 22-year period and aims to provide transparency about potential health risks from toxic substance exposure during the Cold War era.