I. Applicable Law
In general, service connection may be granted for a disability resulting from disease or injury incurred in or aggravated by service. 38 U.S.C.A. §§ 1110, 1131 (West 2002); 38 C.F.R. §§ 3.303, 3.304. Service connection generally requires credible and competent evidence showing: (1) the existence of a present disability; (2) in-service incurrence or aggravation of a disease or injury; and (3) a causal relationship between the present disability and the disease or injury incurred or aggravated during service. See Davidson v. Shinseki, 581 F.3d 1313, 1316 (Fed. Cir. 2009); Hickson v. West, 12 Vet . App. 247, 253 (1999); Caluza v. Brown, 7 Vet. App. 498 (1995).
Diseases subject to presumptive service connection based on participation in a ‘radiation-risk activity‘ include lymphomas (except Hodgkin's disease). 38 C.F.R. § 3.309(d)(2) . A ‘radiation-exposed veteran‘ is defined as a veteran who while serving on active duty or on active duty for training or inactive duty training, participated in a radiation-risk activity. ‘Radiation-risk activity‘ is defined to include the occupation of Hiroshima or Nagasaki, Japan by United States forces during the period beginning on August 6, 1945, and ending on July 1, 1946. 38 C.F.R. § 3.309(d)(3)(i) .
*2 The term ‘occupation of Hiroshima or Nagasaki, Japan, by United States forces‘ means official military duties within 10 miles of the city limits of either city, which were required to perform or support military occupation functions such as occupation of territory, control of the population, stabilization of the government, demilitarization of the Japanese military, rehabilitation of the infrastructure or deactivation and conversion of war plants or materials. 38 C.F.R. § 3.309(d)(3)(vi).
Service connection may also be granted for disability shown after service, when all of the evidence, including that pertinent to service, shows that it was incurred in service. 38 C.F.R. § 3.303(d).
In making all determinations, the Board must fully consider the lay assertions of record. A layperson is competent to report on the onset and continuity of his current symptomatology. See Layno v. Brown, 6 Vet. App. 465, 470 (1994).
Lay evidence can be competent and sufficient evidence of a diagnosis or used to establish etiology if (1) the layperson is competent to identify the medical condition, (2) the layperson is reporting a contemporaneous medical diagnosis, or (3) lay testimony describing symptoms at the time supports a later diagnosis by a medical professional. Davidson, 581 F.3d at 1316; Jandreau v. Nicholson, 492 F.3d 1372, 1376-77 (Fed. Cir. 2007). When considering whether lay evidence is competent the Board must determine, on a case by case basis, whether the Veteran's particular disability is the type of disability for which lay evidence may be competent. Kahana v. Shinseki, 24 Vet. App. 428 (2011); see also Jandreau, 492 F.3d at 1376-77.
The Board is charged with the duty to assess the credibility and weight given to evidence. Madden v. Gober, 125 F.3d 1477, 1481 (Fed. Cir. 1997).
The Veteran has submitted a number of statements in the process of his appeal, where he has consistently reported that he participated in the occupation of Japan between September 22, 1945 and October 20, 1945, including travel to Nagasaki in performing duties including guard duty. He has reported that he was with the 5th Marine Division, 26th Marine Regiment, and was based at Sasebo, Japan, from whence he traveled for duty including to Nagasaki.
The Veteran's service personnel records include a U.S.M.C. Enlisted Man's Qualification Card, showing that he participated in the occupation of Japan from September 22, 1945 to October 20, 1945, and that he was a light machine gun crewman. His record of Honorable Discharge of November 1946 shows that he participated in the occupation of Japan from September 23, 1945 to October 20, 1945. Another service personnel record states that the Veteran participated in the occupation of the Sasebo area, Kyushu, Japan, while a member of the 5th Marine Division from September 23, 1945 to October 1945.
A January 2010 letter from a Commander, U.S. Navy, Nuclear Test Personnel Review, of the Defense Threat Reduction Agency (DTRA), stated the following: The Veteran's service record indicated that he was assigned to I Company, 3rd Battalion, 26th Marine Regiment, 5th Marine Division, with a military occupational specialty of Machine Gun Crewman. The Veteran arrived at Sasebo, Japan (approximately 30 miles from Nagasaki) by ship on September 22, 1945 and debarked the next day. The Veteran remained at Sasebo until October 19, 1945 when he left by ship. Muster rolls show no temporary additional duty for him to either Hiroshima or Nagasaki.
*3 In a reply to that letter, the Veteran addressed a statement in January 2010 to the RO, explaining that while still attached to the 5th Marine Division in Sasebo, Japan, he participated in guard duty and