Citation Nr: 21007825 Decision Date: 02/10/21 Archive Date: 02/10/21 DOCKET NO. 12-34 966 DATE: February 10, 2021 ORDER Entitlement to service connection for the cause of the Veteran's death is denied. FINDINGS OF FACT 1. The Veteran served in the Republic of Vietnam during the Vietnam Era and is presumed to have been exposed to herbicides during service; and, service connection was established prior to his death for prostate cancer as associated with herbicide exposure. 2. The Veteran is shown to have been exposed to ionizing radiation during active service that was not the result of participation in a radiation-risk activity. 3. The Veteran died in April 2005 of gastric cancer with contributing factors of lung metastases and pneumonia. 4. The evidence does not demonstrate that the Veteran’s death from gastric cancer was caused as a result of service nor that a service-connected disability caused or materially contributed to his death. CONCLUSION OF LAW The criteria for entitlement to service connection for the cause of the Veteran's death have not been met. 38 U.S.C. §§ 1110, 1112, 1113, 1116, 1131, 1137; 38 C.F.R. §§ 3.302, 3.303, 3.307, 3.309, 3.311, 3.312. REASONS AND BASES FOR FINDINGS AND CONCLUSION The appellant is the surviving spouse of the Veteran who served on active duty from June 1953 to June 1973. The Veteran died in April 2005. This matter comes before the Board of Veterans’ Appeals (Board) on appeal from a January 2011 rating decision by the Jackson, Mississippi, Regional Office (RO) of the Department of Veterans Affairs (VA). In February 2014, the Veteran testified at a personal hearing before the undersigned Veterans Law Judge. The transcript is of record. The case was remanded for additional development in January 2015 and December 2016. 1. Entitlement to service connection for the cause of the Veteran's death. A veteran’s surviving spouse is eligible for Disability Indemnity Compensation (DIC) benefits when a qualifying veteran dies from a service-connected disability. 38 U.S.C. § 1310; 38 C.F.R. § 3.5(a). The service-connected disability may be either the principal or a contributory cause of death. 38 C.F.R. § 3.312(a). It is the principal cause if it was the immediate or underlying cause of death or was etiologically related to the death. 38 C.F.R. § 3.312(b). It is a contributory cause if it contributed substantially or materially to the cause of death, combined to cause death, or aided or lent assistance to the production of death. 38 C.F.R. § 3.312(c)(1). In order to be a contributory cause of death, it must be shown that there were debilitating effects due to a service-connected disability that made the veteran materially less capable of resisting the effects of the fatal disease or that a service-connected disability had material influence in accelerating death, thereby contributing substantially or materially to the cause of death. See Lathan v. Brown, 7 Vet. App. 359 (1995). VA has a duty to make reasonable efforts to assist a claimant in obtaining evidence necessary to substantiate DIC claims and to provide a medical opinion where a reasonable possibility exists that such assistance would in fact aid in substantiating the claim. See Wood v. Peake, 520 F.3d. 1345, 1348 (Fed. Cir. 2008). Under the relevant laws and regulations, service connection may be granted for a disability resulting from disease or injury incurred in or aggravated by active service. 38 U.S.C. §§ 1110, 1131. Generally, the evidence must show: (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. Shedden v. Principi, 381 F.3d 1163, 1166-67 (Fed. Cir. 2004). Diseases subject to presumptive service connection, including cancers of the stomach and lung, shall be service-connected if they become manifest in a radiation-exposed veteran. This presumption is rebuttable by affirmative evidence to the contrary. 38 U.S.C. §§ 1112, 1113; 38 C.F.R. §§ 3.307, 3.309(d). The term radiation-exposed veteran means either a veteran who while serving on active duty, or an individual who while a member of a reserve component of the Armed Forces during a period of active duty for training or inactive duty training, participated in a radiation-risk activity. 38 C.F.R. § 3.309(d)(3)(i). The term radiation-risk activity means: (A) Onsite participation in a test involving the atmospheric detonation of a nuclear device. (B) 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. (C) Internment as a prisoner of war in Japan (or service on active duty in Japan immediately following such internment) during World War II which resulted in an opportunity for exposure to ionizing radiation comparable to that of the United States occupation forces in Hiroshima or Nagasaki, Japan, during the period beginning on August 6, 1945, and ending on July 1, 1946. (D) (1) Service in which the service member was, as part of his or her official military duties, present during a total of at least 250 days before February 1, 1992, on the grounds of a gaseous diffusion plant located in Paducah, Kentucky, Portsmouth, Ohio, or the area identified as K25 at Oak Ridge, Tennessee, if, during such service the veteran: (i) Was monitored for each of the 250 days of such service through the use of dosimetry badges for exposure at the plant of the external parts of veteran’s body to radiation; or (ii) Served for each of the 250 days of such service in a position that had exposures comparable to a job that is or was monitored through the use of dosimetry badges; or (2) Service before January 1, 1974, on Amchitka Island, Alaska, if, during such service, the veteran was exposed to ionizing radiation in the performance of duty related to the Long Shot, Milrow, or Cannikin underground nuclear tests. (3) For purposes of paragraph (d)(3)(ii)(D)(1) of this section, the term “day” refers to all or any portion of a calendar day. (E) Service in a capacity which, if performed as an employee of the Department of Energy, would qualify the individual for inclusion as a member of the Special Exposure Cohort under section 3621(14) of the Energy Employees Occupational Illness Compensation Program Act of 2000 (42 U.S.C. 7384l(14)). (iii) The term atmospheric detonation includes underwater nuclear detonations. (iv) The term onsite participation means: (A) During the official operational period of an atmospheric nuclear test, presence at the test site, or performance of official military duties in connection with ships, aircraft or other equipment used in direct support of the nuclear test. (B) During the six month period following the official operational period of an atmospheric nuclear test, presence at the test site or other test staging area to perform official military duties in connection with completion of projects related to the nuclear test including decontamination of equipment used during the nuclear test. (C) Service as a member of the garrison or maintenance forces on Eniwetok during the periods June 21, 1951, through July 1, 1952, August 7, 1956, through August 7, 1957, or November 1, 1958, through April 30, 1959. (D) Assignment to official military duties at Naval Shipyards involving the decontamination of ships that participated in Operation Crossroads. 38 C.F.R. § 3.309(d)(3)(ii). VA regulations, however, also provide that all claims in which it is established that a radiogenic disease first became manifest after service and was not manifest to a compensable degree within any applicable presumptive period as specified in § 3.307 or § 3.309, and it is contended the disease is a result of exposure to ionizing radiation in service, an assessment will be made as to the size and nature of the radiation dose or doses. When dose estimates provided pursuant to paragraph (a)(2) of this section are reported as a range of doses to which a veteran may have been exposed, exposure at the highest level of the dose range reported will be presumed. 38 C.F.R. § 3.311(a)(1). Where necessary pursuant to paragraph (a)(1) of this section, dose information will be requested as follows: (i) Atmospheric nuclear weapons test participation claims. In claims based upon participation in atmospheric nuclear testing, dose data will in all cases be requested from the appropriate office of the Department of Defense. (ii) Hiroshima and Nagasaki occupation claims. In all claims based on participation in the American occupation of Hiroshima or Nagasaki, Japan, prior to July 1, 1946, dose data will be requested from the Department of Defense. (iii) Other exposure claims. In all other claims involving radiation exposure, a request will be made for any available records concerning the veteran’s exposure to radiation. These records normally include but may not be limited to the veteran’s Record of Occupational Exposure to Ionizing Radiation (DD Form 1141), if maintained, service medical records, and other records which may contain information pertaining to the veteran’s radiation dose in service. All such records will be forwarded to the Under Secretary for Health, who will be responsible for preparation of a dose estimate, to the extent feasible, based on available methodologies. 38 C.F.R. § 3.311(a)(2). When necessary to reconcile a material difference between an estimate of dose, from a credible source, submitted by or on behalf of a claimant, and dose data derived from official military records, the estimates and supporting documentation shall be referred to an independent expert, selected by the Director of the National Institutes of Health, who shall prepare a separate radiation dose estimate for consideration in adjudication of the claim. For purposes of this paragraph: (i) The difference between the claimant’s estimate and dose data derived from official military records shall ordinarily be considered material if one estimate is at least double the other estimate. (ii) A dose estimate shall be considered from a “credible source” if prepared by a person or persons certified by an appropriate professional body in the field of health physics, nuclear medicine or radiology and if based on analysis of the facts and circumstances of the particular claim. 38 C.F.R. § 3.311(a)(3). When it is determined that a veteran was exposed to ionizing radiation as a result of “other activities as claimed” and subsequently developed a radiogenic disease within the period specified by regulation before its adjudication the claim will be referred to the Under Secretary for Benefits for further consideration. 38 C.F.R. § 3.311(b)(1). For purposes of this section the term “radiogenic disease” means a disease that may be induced by ionizing radiation and shall include the following: (ix) Stomach cancer and (xxiv) Any other cancer. 38 C.F.R. § 3.311(b)(2). When a claim is forwarded for review pursuant to 38 C.F.R. § 3.311(b)(1): (1) The Under Secretary for Benefits shall consider the claim with reference to the factors specified in paragraph (e) of this section and may request an advisory medical opinion from the Under Secretary for Health. (i) If after such consideration the Under Secretary for Benefits is convinced sound scientific and medical evidence supports the conclusion it is at least as likely as not the veteran’s disease resulted from exposure to radiation in service, the Under Secretary for Benefits shall so inform the regional office of jurisdiction in writing. The Under Secretary for Benefits shall set forth the rationale for this conclusion, including an evaluation of the claim under the applicable factors specified in paragraph (e) of this section. (ii) If the Under Secretary for Benefits determines there is no reasonable possibility that the veteran’s disease resulted from radiation exposure in service, the Under Secretary for Benefits shall so inform the regional office of jurisdiction in writing, setting forth the rationale for this conclusion. (2) If the Under Secretary for Benefits, after considering any opinion of the Under Secretary for Health, is unable to conclude whether it is at least as likely as not, or that there is no reasonable possibility, the veteran’s disease resulted from radiation exposure in service, the Under Secretary for Benefits shall refer the matter to an outside consultant. (3) For purposes of paragraph (c)(1) of this section, “sound scientific evidence” means observations, findings, or conclusions which are statistically and epidemiologically valid, are statistically significant, are capable of replication, and withstand peer review, and “sound medical evidence” means observations, findings, or conclusions which are consistent with current medical knowledge and are so reasonable and logical as to serve as the basis of management of a medical condition. 38 C.F.R. § 3.311(c). Factors to be considered in determining whether a veteran’s disease resulted from exposure to ionizing radiation in service include: (1) The probable dose, in terms of dose type, rate and duration as a factor in inducing the disease, taking into account any known limitations in the dosimetry devices employed in its measurement or the methodologies employed in its estimation; (2) The relative sensitivity of the involved tissue to induction, by ionizing radiation, of the specific pathology; (3) The veteran’s gender and pertinent family history; (4) The veteran’s age at time of exposure; (5) The time-lapse between exposure and onset of the disease; and (6) The extent to which exposure to radiation, or other carcinogens, outside of service may have contributed to development of the disease. 38 C.F.R. § 3.311(e). The determination of service connection will be made under the generally applicable provisions of this part, giving due consideration to all evidence of record, including any opinion provided by the Under Secretary for Health or an outside consultant. See 38 C.F.R. § 3.311(f). Veterans diagnosed with an enumerated disease who served in the Republic of Vietnam on active service during the period beginning on January 9, 1962, and ending on May 7, 1975, shall be presumed to have been exposed to an herbicide agent, unless there is affirmative evidence to establish that the veteran was not exposed to any such agent during that service. 38 U.S.C. § 1116; 38 C.F.R. § 3.307(a)(6)(iii). Certain disorders, including cardiovascular disease, type II diabetes mellitus, prostate cancer, and respiratory (lung) cancers, if manifest to a degree of 10 percent or more for an herbicide exposed veteran may be presumed service connected. 38 U.S.C. § 1116; 38 C.F.R. §§ 3.307, 3.309. The National Academy of Sciences (NAS) report titled: Veterans and Agent Orange: Update 2012, however, found inadequate or insufficient evidence to determine whether an association exists between herbicide exposure and cancers of the digestive organs (including stomach cancer). 79 Fed. Reg. 20308, 20312 (Apr. 11, 2014). Even though a disease is not included on the list of presumptive diseases, a nexus between the disease and service may nevertheless be established on the basis of direct service connection. Stefl v. Nicholson, 21 Vet. App. 120 (2007). When a claimed disability is not included as a presumptive disability, direct service connection may nevertheless be established by evidence demonstrating that the disability was in fact incurred during service. Combee v. Brown, 34 F.3d 1039 (Fed. Cir. 1994). The Board has the authority to discount the weight and probity of evidence in light of its own inherent characteristics and its relationship to other evidence. Madden v. Gober, 125 F.3d 1477 (Fed. Cir. 1997). VA may favor one medical opinion over another, provided an adequate basis is provided. Owens v. Brown, 7 Vet. App. 429 (1995). It is the policy of VA to administer the law under a broad interpretation, consistent with the facts in each case, with all reasonable doubt to be resolved in favor of the claimant. 38 C.F.R. § 3.102. The appellant contends, in essence, that the Veteran’s death was due to or a result of active service or that a service-connected or service-related disability caused or materially contributed to his death. She asserts that the Veteran developed cancers, including gastric/stomach and lung cancer, as a result of chronic gastritis, Helicopter pylori (H. pylori) and other bacteria exposure, herbicide (Agent Orange) exposure, and ionizing radiation exposure during service. She further maintains that service-connected disabilities had materially contributed to his cause of death, including that his prostate cancer may have metastasized to the lung. In a December 2010 statement, the appellant asserted that the Veteran had been exposed to radiation while transporting certain radioactive materials to airplanes and in the form of X-ray diagnostic testing during active service. She also stated that he had symptoms of prostate cancer as early as 1999 and that his gastric cancer diagnosed in 2001 could have been caused by metastasis of his prostate cancer. In March 2011, she stated his gastric cancer was related to his having lived in a barracks with asbestos, to his exposure to herbicides in Vietnam, to his having been exposed to radiation while loading radioactive materials on airplanes, and to having been exposed to bacteria due to unsanitary conditions in Vietnam. The appellant submitted copies of medical literature in June 2012 in support of her claim. An article from the National Digestive Disease Information Clearinghouse (NDDIC) noted that atrophic gastritis can lead to cancer and that untreated H. Pylori infections can cause cancer. Service treatment records show the Veteran was treated for stomach pain and nausea, including in January 1965 and July 1967. A record of exposure to ionizing radiation with an entry dated August 15, 1956, noted a “DT 60” reading of “7r.” In an April 1968 report of medical history, the Veteran noted he had worked with radioactive substances loading them on aircrafts. Service records show the Veteran’s duties included supply clerk, supply specialist, and air freight specialist. His November 1972 retirement examination revealed an abnormal abdomen and viscera clinical evaluation. It was noted he had occasional indigestion and a history of hospital treatment in 1965 for nausea and stomach cramps. Records show he served in the Republic of Vietnam from July 1966 to July 1967. His duties are shown to have included tool crib supply clerk, organization supply clerk, organization maintenance supply specialist, materiel facilities specialist, and air freight specialist. Service connection was established for prostate cancer associated with herbicide exposure in the Republic of Vietnam. See February 2003 rating decision. It was noted that the evidence did not show the Veteran had undergone prostate surgery or any other type of treatment for this cancer and that the decided course of treatment indicated was monitoring of the disease. The Veteran’s death certificate reported he died in April 2005 of gastric cancer. A September 2005 amendment to the certificate indicates factors contributing to death of lung metastases and pneumonia. VA examination in December 2002 included diagnoses of gastric cancer or poorly-differentiated adenocarcinoma of the lesser curvature of the stomach, status post surgery, and prostate cancer. It was noted that there was no relationship between the two cancers and that his prostate cancer would simply be monitored because his gastric cancer was a more serious life-threatening condition. Private treatment records include a March 4, 2005, report noting the Veteran’s diagnoses including atherosclerotic coronary vascular disease, prostate cancer, diabetes mellitus, and lung cancer. Records associated with his period of hospitalization from March 5, 2005, to March 25, 2005, noted diagnoses at discharge including pneumonia and metastatic gastric cancer. An associated emergency room note reported a history of recurrent carcinoma of the stomach that had metastasized to his lung. VA medical opinion in September 2012 found that the Veteran’s cause of death from gastric cancer was less likely related to an in-service condition for which he sought treatment. The examiner summarized the Veteran’s pertinent service treatment records as to gastrointestinal disorders from 1953 to 1972, as well as, post-service reports beginning in 2001 with a diagnosis of poorly differentiated adenocarcinoma of the lesser curvature of the stomach and incidental findings of H. pylori positive. It was further noted that records dated in 2004 revealed metastasis in the lung and that he died in April 2005 from complications (pneumonia) of the lung cancer, which was metastasis from the stomach cancer. The examiner stated that, although it was known that H. pylori had been strongly associated with gastric cancer, there was no evidence the Veteran had infection with H. pylori in service. All of his abdominal symptoms in service were nonspecific and could have been gastroesophageal reflux disease (GERD) of peptic ulcer disease related but were not diagnosed and he had documented gallbladder disease which could explain all of his symptoms in service. It was noted his gallbladder disease was not related to his gastric cancer and that his H. pylori infection could have happen any time during the 30 years between his separation from service and the gastric cancer diagnosis. The examiner found it was unlikely he had the H. pylori infection in service. An April 2016 VA medical opinion found that the gastric symptomatology experienced by the Veteran in service less likely caused or contributed to the gastric cancer that caused his death. The examiner noted he had several isolated complaints of nonspecific abdominal symptoms during service, with no diagnosis of a stomach problem. The in-service complaints of nausea and stomach pain were attributed to gallstones. There was no documentation of gastric complaints for more than 30 years and oncology documents noted he started having symptomatology of intermittent dyspepsy a few years before his diagnosis of cancer, which put the onset decades after separation. The examiner stated it was unlikely that symptoms in service were related to the gastric cancer in 2001. The examiner also found that the symptoms in service did not reflect the presence of H. pylori. It was noted that symptoms produced for H. Pylori are persistent, and typical of GERD, which were not the symptoms the Veteran had in service. It was acknowledged that his service was before the recognition of H. pylori, but that the symptoms of GERD were known at that time and they were not the ones the Veteran reported. There was also no persistence or continuity after separation. Although the Veteran could have had an asymptomatic infection in service (noting most H. pylori infections are asymptomatic), the examiner stated that this could not be stated without speculation, in the absence of typical symptoms of GERD. The examiner reiterated that based upon the available evidence it was unlikely he had H. pylori infection in service. The examiner further found that the Veteran’s service-connected prostate cancer, or his treatment thereof, did not contribute to or hasten the Veteran’s death. It was noted that the Veteran first had gastric cancer and then developed prostate carcinoma. The examiner noted gastric cancer was one of the most aggressive, which was acknowledged by the Veteran’s oncologist in his notes. The examiner noted that a decision had been made to take a watchful form of treatment for prostate cancer because of the gastric cancer, not the reverse. Prostate cancer was not being treated; therefore, there was no contribution of treatment for prostate cancer to the Veteran’s death. As documented in multiple notes, his prostate cancer was stable and asymptomatic. The examiner found that the Veteran’s gastric cancer had metastasized to the lung, and that this together with his treatment for metastatic gastric cancer lead to his death. This treatment involved chemotherapy that produced neutropenia leading to severe infection with further deterioration of health and death. A September 2016 clarifying medical opinion found that the Veteran’s cause of death of gastric cancer was less likely related to in-service conditions for which he sought treatment. The examiner noted it was known that H. pylori had been strongly associated with gastric cancer, but that there was no evidence the Veteran had infection with H. pylori in service. All the abdominal symptoms reported were nonspecific and, although they could be due to GERD or PUD, this was never diagnosed. Instead, the records documented gallbladder disease, which could explain all the symptoms in service. The examiner stated it was unlikely he had the infection in service. A January 2020 service department report noted that a search of the occupational radiation exposure monitoring records (MBER) for the Veteran revealed no external or internal radiation exposure data. The MRER was noted to be the single repository for occupational radiation exposure monitoring for its personnel. These records show the Veteran was exposed to 7r or radiation on August 15, 1956, and referred to the DT-60/PD badge. The service department indicated that many personnel at nuclear capable units were issued DT-60 accident dosimeters to for medical readiness purposes to measure exposures in unlikely occurrence of a high radiation exposure, e.g. nuclear criticality. The devices were only capable of recording high exposures and were not sensitive to occupational exposures. It was further noted that the Air Force Safety Center (AFSEC) was unaware of any event where these devices were used to establish radiation exposure for individuals. Since the United States has never experienced high radiation exposure from a fielded nuclear weapon, records recorded by these devices were considered to be of no benefit today. It was additionally noted that the AFSEC had reviewed the Veteran’s personnel records and did not find evidence of duties that would have involved working directly with nuclear weapons systems or component. The service department found that since his duties did not require prolonged, close-proximity contact with nuclear weapons, occupational-level exposures were not possible and that no dose estimate was given for this Veteran. A duplicate report dated in August 2020 was subsequently provided. A November 2020 memorandum prepared by a VA health physicist and reviewed by the Director of VA’s Post 9-11 Environmental Health Program summarized the pertinent evidence of record and concluded that since the Veteran’s assigned lifetime total radiation dose (7.0 rem) did not exceed 100 mSv (10 rem) above natural background it is unlikely that gastric cancer was caused by exposure to ionizing radiation during military service. It was noted that the Veteran was 23 years old when he was exposed to ionizing radiation during service and that records indicate he was diagnosed with gastric cancer in 2001, at age 68, approximately 45 years after his exposure to ionizing radiation. The medical records indicated he was an African American male, a former smoker, who had no reported family history of cancer, and had no reported additional radiation exposure before or after military service. It was additionally noted that “[g]astric cancer is not specifically listed as a “radiogenic disease” under 38 C.F.R. § 3.309(d) or 38 C.F.R. § 3.311.” The memorandum noted that radiation dose is the prime factor to consider when determining causation of radiation induced disease. Being in the vicinity of a radiation source does not necessarily mean a significant exposure occurred. Where presumption does not exist under the provisions of 38 C.F.R. § 3.309(d), the dose must be determined through direct measurement or reconstruction methodology. Once the dose is determined, the issue of disease causation can be addressed. It was noted that in this case the radiation dose is questionable, as the USAF doubts the validity of the DT-60 reading. The memorandum further noted that “[w]e also doubt the validity of the reading as an actual dose, but we will allow it for purposes of this advisory medical opinion.” The radiation dose assigned for the Veteran of “7 rem” was found to give the Veteran the benefit of doubt versus the USAF’s lack of dose monitoring records. The memorandum also noted that the Health Physics Society, in their position statement PS010-4, Radiation Risk in Perspective, revised in February of 2019, stated that: “The average annual effective dose from natural background radiation in the United States is about 3 mSv [0.3 rem]. A person might accumulate an effective dose from natural background radiation of about 50 mSv [5 rem] in the first 17 years of life and about 250 mSv [25 rem] during an average 80-year lifetime. Substantial and convincing scientific data show evidence of health effects following high-dose exposures (many multiples of natural background). However, below levels of about 100 mSv [10 rem] above background from all sources combined, the observed radiation effects in people are not statistically different from zero.” In a November 2020 advisory opinion for radiation exposure under 38 C.F.R. § 3.311 the director of VA’s Compensation Service summarized the pertinent evidence and noted the opinion was based upon the scientific evidence referenced in the memorandum from the VA Under Secretary for Health and a review of the evidence in its entirety. It was the opinion of the director that it was unlikely that the Veteran’s gastric cancer was caused by exposure to ionizing radiation during military service. As an initial matter, the Board notes that the appellant asserts that statements of the case had noted that gastric cancer was not included on the presumptive list for radiation exposure. Credible internet source reference was provided indicating that stomach cancer and gastric cancer were synonymous terms. Any such error or oversight was non-prejudicial. Notably, the Board finds that there is no evidence the Veteran participated in a radiation-risk activity as defined for VA presumptive service connection purposes. The presumptive list and any erroneous references to it are considered to be harmless errors as the applicable regulations in this case under 38 C.F.R. § 3.311 include stomach cancer and any other cancer as radiogenic diseases. The appellant specifically contends that the Veteran was exposed to radiation in his duties loading radiation material on aircraft. Such is not an activity within the applicable regulatory definition of 38 C.F.R. § 3.309(d)(3)(ii). It is additionally noted that, while the November 2020 VA memorandum’s reference that gastric cancer is not specifically listed as a “radiogenic disease,” 38 C.F.R. § 3.311 may be similarly confusing. A comprehensive review of the provided opinions demonstrates substantial compliance with the applicable regulatory provisions for any diagnosed cancer. It is further noted that the appellant argues that the November 2020 advisory opinion erroneously considered the time-lapse between exposure and onset of the disease and erroneously considered limitations in the dosimetry devices employed. There is no merit to these arguments as the matters are specifically included as factors for consideration under the provisions of 38 C.F.R. § 3.311(e). An additional contention raised by the Veteran, that the advisory opinion failed to consider the incremental effects of radiation exposure from treatment for a service-connected prostate cancer disability, is found to have no merit in the absence of evidence indicating the Veteran underwent radiation treatment for his prostate cancer. The available VA medical opinions in this case did not specifically address whether the Veteran’s gastric cancer developed as a result of his presumed herbicide exposure in Vietnam. However, the Board finds there is no reasonable possibility that an additional medical opinion as to the matter would aid in substantiating the claim on a direct service connection basis. It is noted that VA has acknowledged that the NAS in Veterans and Agent Orange: Update 2012 found there was inadequate or insufficient evidence to determine whether an association exists between herbicide exposure and cancers of the digestive organs (including stomach cancer). 79 Fed. Reg. 20308, 20312. Nor is there any indication that any subsequent medical or scientific pertinent to the matter exists. In light of the available medical/scientific evidence, the Board there is no reason to believe that an additional medical opinion based upon nonspecific herbicide exposure could adequately address the matter. The Veteran is shown to have served in Vietnam from July 1966 to July 1967; however, there is no specific information as to the extent of any actual herbicide agent exposure during service. As he is unavailable to provide any additional information, additional VA efforts to assist the appellant would be futile. With regard to the medical literature provided by the appellant, VA has “an obligation to consider and discuss potentially favorable medical text evidence that was unaccompanied by a medical opinion.” McCray v. Wilkie, 31 Vet. App. 243, 255 (2019). In the present case, the Board concludes that the information provided addressing the relationship between gastritis and gastric or stomach cancer was adequately considered by the September 2016 VA examiner. As to the appellant’s claims that the Veteran’s death was a result of asbestos and bacteria (other than H. pylori) exposure during active service, the Board finds the claims based upon such exposure, including that he lived in barracks that had asbestos and had bacteria exposure in Vietnam, to be too vague or lacking sufficient specificity to warrant further VA assistance. As the appellant has not provided such information and there is no indication of asbestos exposure or identified specific bacteria (other than H. pylori) exposure in the available record, the Board finds no additional VA assistance is warranted. Reasonable efforts were made to assist the appellant in this case in obtaining evidence necessary to substantiate claims and there is no reasonable possibility that a medical opinion as to these matters in the absence of additional specific information would, in fact, aid in substantiating the claim. The Veteran served in the Republic of Vietnam during the Vietnam Era and is presumed to have been exposed to herbicides during service. The record also establishes that that he was exposed to ionizing radiation during active service that was not the result of participation in a radiation-risk activity. The Veteran’s exposure to herbicides and radiation exposure dose estimate of 7 rem is conceded. It is also noted that VA established service connection for the Veteran’s prostate cancer as associated with herbicide agent exposure prior to his death. Finally, the Veteran is shown to have died in April 2005 of gastric cancer with contributing factors of lung metastases and pneumonia. However, the Board finds that the overall evidence does not demonstrate that the Veteran’s death from gastric cancer was caused as a result of service nor that a service-connected disability caused or materially contributed to his death. The September 2012, April 2016, September 2016, and November 2020 VA medical opinions are found to be persuasive and to have been based upon adequate rationale. See Dalton v. Nicholson, 21 Vet. App. 23 (2007). There are no competent medical opinions to the contrary. Presumptive service connection under the provisions of 38 C.F.R. § 3.309 is not warranted because gastric or stomach cancer is not included as a specific disease associated with herbicide exposure and because the Veteran’s cancer was not the result of his participation in a radiation-risk activity as defined for VA compensation purposes. The appellant has provided no medical, scientific, or other competent evidence indicating that a disease under 38 C.F.R. § 3.309(e) was the principal or a contributory cause of death. In fact, a December 2002 VA examiner found there was no relationship between the Veteran’s gastric and prostate cancers and a September 2012 VA examiner found his carcinoma of the lung was due to metastasis from his stomach cancer. The April 2016 VA medical opinion further found that the Veteran’s service-connected prostate cancer, including any treatment provided for the disorder, was less likely to have contributed to or hastened his death. It was noted that the evidence demonstrated he had gastric cancer and then developed prostate carcinoma, that gastric cancer was one of the most aggressive cancers, and that his prostate cancer was not being treated and was stable and asymptomatic at the time of death. The examiner specifically found that his gastric cancer had metastasized to the lung, and that this together with his treatment for metastatic gastric cancer lead to his death. These opinions are consistent with information recorded in the Veteran’s treatment records and with the September 2005 amended death certificate report. There is no competent evidence indicating a primary site lung or respiratory cancer caused or contributed to death nor that any other 38 C.F.R. § 3.309(e) disease, such as type II diabetes mellitus, cardiovascular disease, or prostate cancer, was a contributory cause of his death. The appellant does not assert, and the evidence does not indicate, that the Veteran ever participated in a radiation-risk activity under 38 C.F.R. § 3.309(d)(3)(ii). As such, presumptive service connection for the cause of his death is not warranted. The matters in dispute also include assertions that the Veteran’s death from gastric or stomach cancer was directly due to or a result of active service. The appellant contends, in essence, that the Veteran had gastric or stomach cancer that began in service and was manifested by gastrointestinal symptoms or that subsequently developed as a result of chronic gastritis that continued after service and/or an H. pylori infection manifest during active service. The Veteran’s service treatment records clearly show complaints and treatment for gastrointestinal symptoms and post-service records document an H. pylori infection. However, the Board finds VA medical opinions as to these matters to be persuasive. The September 2012 specifically found that the Veteran’s cause of death from gastric cancer was less likely related to an in-service condition for which he sought treatment and that it was unlikely he had his H. pylori infection in service. The opinion is shown to have been based upon a thorough and substantially accurate review of the evidence of record with adequate rationale provided. The examiner noted that H. pylori had been strongly associated with gastric cancer but found that his symptoms in service were likely related to his documented gallbladder disease. The April 2016 VA examiner also found that the Veteran’s gastric symptomatology in service was less likely caused or contributed to the gastric cancer which caused his death. It was noted he had several isolated complaints of nonspecific abdominal symptoms during service with no diagnosis of a stomach problem, that his symptoms in 1967 and 1968 were likely due to gallstones, and that his oncology treatment documented only intermittent dyspepsia a few years before his diagnosis of cancer. The examiner also found that the symptoms in service less likely reflected the presence of H. pylori at the time since they were not typical for GERD. The September 2016 clarifying medical opinion, in essence, reiterated the opinion and found that all of the Veteran’s abdominal symptoms could be explained by his documented gallbladder disease. The Veteran also claims that the Veteran’s gastric or stomach cancer developed as a result of his exposure to radiation while transporting certain radioactive materials to airplanes and in the form of X-ray diagnostic testing during active service. The medical opinions addressing this argument, most notably the November 2020 VA medical and advisory opinions, are persuasive. Although the January 2020 and August 2020 service department reports expressed doubt as to the validity of the 7-rem exposure record for the Veteran, the November 2020 medical and advisory opinions are shown to have conceded ionizing radiation exposure to this extent. It was noted that the finding was accepted for the purposes of the advisory medical opinion. The Board also finds no indication that the Veteran was exposed to abnormal or excessive radiation in service from X-ray diagnostic testing that may not reasonably be considered as included as part of the natural background exposure referenced for the opinions. In support of the provided opinion, the memorandum referenced a February 2019 Health Physics Society report noting that in the United States a person might accumulate an effective dose from natural background radiation of about 25 rem during an average 80-year lifetime and that for levels below 10 rem from all sources combined the observed radiation effects in people were “not statistically different from zero.” The November 2020 advisory opinion for radiation exposure under 38 C.F.R. § 3.311 by the director of VA’s Compensation Service that it was unlikely that the Veteran’s gastric cancer was caused by exposure to ionizing radiation during military service adequately addressed the complex medical and scientific matters at issue and is persuasive in this case. The Board acknowledges that the appellant is competent to report observable symptoms, but that there is no indication she is competent to etiologically link any such symptoms to a current diagnosis. She is not shown to possess the requisite medical training, expertise, or credentials needed to render a diagnosis or a competent opinion as to medical causation. Nothing in the record demonstrates that she received any special training or acquired any medical expertise in evaluating such disorders. See King v. Shinseki, 700 F.3d 1339, 1345 (Fed. Cir. 2012). Accordingly, the lay evidence does not constitute competent medical evidence and lacks probative value. Consideration has also been given to the appellant’s personal assertions as to matters causing or materially contributing to the Veteran’s cause of death. However, while lay persons are competent to provide opinions on some medical issues, see Kahana v. Shinseki, 24 Vet. App. 428, 435 (2011), the specific issues in this case falls outside the realm of common knowledge of a lay person. See Jandreau v. Nicholson, 492 F.3d 1372, 1377 n.4 (Fed. Cir. 2007). The chronic disabilities at issue are not matters that are readily amenable to lay diagnosis or probative comment regarding etiology. See Davidson v. Shinseki, 581 F.3d 1313 (Fed. Cir. 2009). In conclusion, the Board finds service connection for the cause of the Veteran’s death is not warranted. When all the evidence is assembled VA is then responsible for determining whether the evidence supports the claim or is in relative equipoise, with the claimant prevailing in either event, or whether a preponderance of the evidence is against the claim in which case the claim is denied. Ortiz v. Principi, 274 F.3d 1361 (Fed. Cir. 2001). The preponderance of the evidence is against the claim. MICHAEL A. HERMAN Veterans Law Judge Board of Veterans’ Appeals Attorney for the Board T. Douglas The Board’s decision in this case is binding only with respect to the instant matter decided. This decision is not precedential and does not establish VA policies or interpretations of general applicability. 38 C.F.R. § 20.1303.