that the cause or causes of death are knownto result from the type and amount ofionizing radiation received. [Veteran] was a photographer on board the [support ship] at the time of the underwater atomic test in the Pacific in 1946. However, the [ship] was not at any time during this test exposed to atomic radiation and {veteran] was not exposed to atomic radiation during the time of the test. The medical records and autopsy show, contrary to the strong feelings expressed in the contentions, that death was due to rheumatic heart disease and superimposed subacute bacterial endocarditis which are not produced by radiation; by kidney diseases due to infection and arteriosclerosis (not due to radiation), and by hemorrhagesinto the lungs and other organs, at the time of death. When hemorrhages are due to radiation (as in atomic explosions) they are produced by changes induced in the bone marrow, so that the bleeding occurs as a result of lack of normal blood elements. Since the bone marrow examined during the terminalillness and at autopsy was not abnormal it can be concluded that [veteran’s] bleeding was not due to bone marrow destruction, and therefore not a response to radiation. CASE NO.31 Type of Injury: Malignant Lymphoma. BVA’s Decision: Denial Affirmed. Date of Decision: 1966. Appellant's Allegation: That veteran’s death from malignant lymphoma wasas a result of exposure to ionizing radiation during active service. Facts: Veteran served on active duty from June 1945 until February 1949. His service records indicated that he served aboard two of the ships which participated in atom bomb tests at Bikini Atoll in July 1946. Malignant lymphoma was not present during service and was first shown in 1963, about 14 years after service. He died in March 1966 and the cause of his death was certified as broncho-pneumonia due to lymphoma. Specifically, veteran’s service records indicated that he was assigned to the USS Dawson from February 9 to August 19, 1946 when he wastransferred to the USS Bladen and. he was assigned to that ship unti! December 26, 1946. Both of these ships, among many others, participated in Operations Crossroads which involved the explosion of one atom bombin the air on July 1, 1946 and a second bomb under water on July 25, 1946. Deck logs were produced of the USS Dawson and USS Bladen which disclosed the following information: The USS Dawson was reboarded on July 2, the day after the first test, and the ship was declared safe. By July 3 the entire crew was on board, with the exception of men away from the ship on temporary duty. The crew was again evacuated from the ship prior to the July 25 test. On August 19, the date of the serviceman’s transfer to the USS Bladen, the USS Dawson was towed away andit was subsequently placed out of commission. With respect to the USS Bladen, extracts from the deck logs of this ship indicate that the crew reboarded the ship on July 2, after the first bomb test. After the second bombtest on July 25, the crew returned to the ship on July 29. Under date of August 27 it was recorded that a radiological clearance certificate had been issued after radiological monitors inspected and passed the ship as free of radioactivity. Additional information with respect to the role of the USS Sladen was obtained from an official of the Atomic Energy Commission. This ship was stationed at the outer portion of the target array in both of the bomb tests. It received only minor damagein the first test, was reboarded at H+8 hours and pronounced radiologically clear. After the second 96 97