Citation Nr: 1301666 Decision Date: 01/15/13 Archive Date: 01/23/13 DOCKET NO. 08-13 817 ) DATE ) ) On appeal from the Department of Veterans Affairs (VA) Regional Office (RO) in Roanoke, Virginia THE ISSUE Entitlement to service connection for a respiratory disorder, to include as due to exposure to herbicides and/or asbestos. REPRESENTATION Appellant represented by: Virginia Department of Veterans Services ATTORNEY FOR THE BOARD J. N. Moats, Counsel INTRODUCTION The Veteran served on active duty in the United States Air Force from September 1963 to August 1971. This appeal to the Board of Veterans' Appeals (Board) arose from an August 2007 rating decision in which the RO, inter alia, denied service connection for asthma and bilateral apical thickening of the lungs. In October 2007, the Veteran filed a notice of disagreement (NOD). The RO issued a statement of the case (SOC) in April 2008, and the Veteran filed a substantive appeal (via a VA Form 9), Appeal to the Board in May 2008. In October 2009 and April 2011, the Board remanded the matter on appeal (first characterized as a lung disorder, then characterized more broadly as a respiratory disorder) to the RO, via the Appeals Management Center (AMC) in Washington, DC, for further action, to include additional development of the evidence. After accomplishing further action, the RO/AMC continued to deny the claim. In November 2012, this matter was returned to the Board for further appellate consideration. As a final preliminary matter, the Board notes that, in addition to the paper claims file, there is a paperless, electronic (Virtual VA) claims file associated with the appellant's claim. The Veteran's Virtual VA electronic claims folder was reviewed in connection with this claim FINDINGS OF FACT 1. All notification and development actions needed to fairly adjudicate the claim herein decided have been accomplished. 2. While the Veteran served in Vietnam during the Vietnam era, and is, thus, presumed to have been exposed to herbicides during service, the Veteran has not been diagnosed with a disability recognized by VA as etiologically related to herbicide exposure. 3. The Veteran does not contend, and the evidence does not indicate, that a respiratory disorder, to include chronic obstructive pulmonary disorder (COPD), was present in service or for years thereafter, and there is no competent evidence or opinion that there exists a medical nexus between any current respiratory disorder and service, to include any herbicide (Agent Orange) or asbestos exposure therein. CONCLUSION OF LAW The criteria for service connection for a respiratory disorder, to include as due to exposure to herbicides (Agent Orange) and/or asbestos, are not met. 38 U.S.C.A. §§ 1101, 1110, 1113, 1116, 1131, 5103, 5103A, 5107 (West 2002 & Supp. 2012); 38 C.F.R. §§ 3.159, 3.303, 3.307, 3.309, 3.313 (2012). REASONS AND BASES FOR FINDINGS AND CONCLUSION I. Due Process Considerations The Veterans Claims Assistance Act of 2000 (VCAA), Pub. L. No. 106-475, 114 Stat. 2096 (Nov. 9, 2000) (codified at 38 U.S.C.A. §§ 5100, 5102, 5103, 5103A, 5106, 5107, and 5126 (West 2002 & Supp. 2012)) includes enhanced duties to notify and assist claimants for VA benefits. VA regulations implementing the VCAA were codified as amended at 38 C.F.R. §§ 3.102, 3.156(a), 3.159, and 3.326(a) (2012). Notice requirements under the VCAA essentially require VA to notify a claimant of any evidence that is necessary to substantiate the claim(s), as well as the evidence that VA will attempt to obtain and which evidence he or she is responsible for providing. See, e.g., Quartuccio v. Principi, 16 Vet. App. 183 (2002) (addressing the duties imposed by 38 U.S.C.A. § 5103(a) and 38 C.F.R. § 3.159(b)). As delineated in Pelegrini v. Principi, 18 Vet. App. 112 (2004), after a substantially complete application for benefits is received, proper VCAA notice must inform the claimant of any information and evidence not of record (1) that is necessary to substantiate the claim(s); (2) that VA will seek to provide; (3) that the claimant is expected to provide; and (4) must ask the claimant to provide any evidence in her or his possession that pertains to the claim(s), in accordance with 38 C.F.R. § 3.159(b)(1). The Board notes that, effective May 30, 2008, 38 C.F.R. § 3.159has been revised, in part. See 73 Fed. Reg. 23,353 -23,356 (April 30, 2008). Notably, the final rule removes the third sentence of 38 C.F.R. § 3.159(b)(1), which had stated that VA will request that a claimant provide any pertinent evidence in his or her possession. VA's notice requirements apply to all five elements of a service connection claim: veteran status, existence of a disability, a connection between a veteran's service and the disability, degree of disability, and effective date of the disability. Dingess/Hartman v. Nicholson, 19 Vet. App. 473 (2006). VCAA-compliant notice must be provided to a claimant before the initial unfavorable decision on a claim for VA benefits by the agency of original jurisdiction (in this case, the RO, to include the AMC). Id.; Pelegrini, 18 Vet. App. at 112. See also Disabled American Veterans v. Secretary of Veterans Affairs, 327 F.3d 1339 (Fed. Cir. 2003). However, the VCAA notice requirements may, nonetheless, be satisfied if any errors in the timing or content of such notice are not prejudicial to the claimant. Id. In this appeal, in an April 2007 pre-rating letter, the RO provided notice to the Veteran explaining what information and evidence was needed to substantiate his claim for service connection, as well as what information and evidence must be submitted by the appellant, and what information and evidence would be obtained by VA. This letter also provided the Veteran with general information pertaining to VA's assignment of disability ratings and effective dates, as well as the type of evidence that impacts those determinations. The August 2007 rating decision reflects the initial adjudication of the claims after the issuance of this letter. Hence, the April 2007 letter-which meets the content of notice requirements described in Dingess/Hartman and Pelegrini-also meets the VCAA's timing of notice requirement. The record also reflects that VA has made reasonable efforts to obtain or to assist in obtaining all relevant records pertinent to the matter herein decided. Pertinent medical evidence associated with the claims file consists of service personnel records, service treatment records, VA and private treatment records, and the reports of May 2010 and May 2012 VA examinations. Also of record and considered in connection with the claims are various written statements provided by the Veteran and by his representative, on his behalf. The Board finds that no additional RO action to further develop the record in connection with the claim for service connection, prior to appellate consideration, is required. As noted, the Board sought further development of the claim in October 2009 and April 2011. In October 2009, the Board instructed the RO/AMC to obtain any VA and/or private treatment records as well request information from the Veteran regarding pre-service and post-service exposure to asbestos. Thereafter, the RO/AMC was directed to arrange for the Veteran to undergo VA examination after all the pertinent records were associated with the claims file. In April, 2011, the RO/AMC was again instructed to obtain all VA and/or private treatment records, to specifically include requesting VA treatment records prior to May 11, 2006, and from May 27, 2007, as well as again request information from the Veteran concerning his asbestos exposure. Subsequently, the RO/AMC was directed to obtain a CT scan of the lungs and then provide the results to the same examiner, if possible, who conducted the May 2010 examination for an addendum opinion. A remand by the Board confers upon the veteran, as a matter of law, the right to compliance with the remand instructions, and imposes upon the VA a concomitant duty to ensure compliance with the terms of the remand. See Stegall v West, 11 Vet. App. 268, 271 (1998). In January 2010, the RO/AMC sent a letter to the Veteran requesting information concerning medical treatment as well as his pre-service and post-service asbestos exposure, to which the Veteran did not respond. The Veteran was also afforded a VA examination in May 2010. After the April 2011 remand, the RO/AMC sent another letter to the Veteran in May 2011 requesting information concerning medical treatment. In April 2012, the RO/AMC again requested information concerning the Veteran's asbestos exposure. Again, the Veteran did not respond to these requests. The RO obtained VA treatment records from May 2007 until April 2012, which have been associated with the Veteran's electronic record. The RO also requested VA treatment records from the VA Medical Center (VAMC) prior to May 2006. However, despite these requests, the only VA treatment records submitted by the VAMC are from May 2006. In August 2012, the RO/AMC informed the Veteran that he had not been able to obtain VA treatment records prior to May 2006. Importantly, treatment records dated in May 2006 indicate that it was the Veteran's initial visit to the VAMC. In other words, it does not appear that he received treatment at the VAMC prior to this date and all of his records have been associated with the claims file and electronic record. Moreover, the Veteran was afforded a CT scan in April 2012 and then another VA examination in May 2012. It appears that the May 2012 VA examination was performed by a different examiner. Nevertheless, the examiner exhibited sufficient medical expertise to perform the examination and the examination is adequate for appellate review. Accordingly, the Board finds that the RO/AMC have substantially complied with the Board's remand directives. See Dyment v. West¸ 13 Vet. App. 141, 146-47 (1999) (remand not required under Stegall, 11 Vet. App. 268 where Board's remand instructions were substantially complied with); see also D'Aries v. Peake, 22 Vet. App. 97, 105-106 (2008) (finding that substantial compliance, rather than strict compliance, with the terms of a Board engagement letter requesting a medical opinion is required). In summary, the duties imposed by the VCAA have been considered and satisfied. Through various notices of the RO/AMC, the Veteran has been notified and made aware of the evidence needed to substantiate these claims, the avenues through which he might obtain such evidence, and the allocation of responsibilities between himself and VA in obtaining such evidence. There is no additional notice that should be provided, nor is there any indication that there is additional existing evidence to obtain or development required to create any additional evidence to be considered in connection with the claim. Consequently, any error in the sequence of events or content of the notice is not shown to prejudice the Veteran or to have any effect on the appeal. Any such error is deemed harmless and does not preclude appellate consideration of the matter herein decided, at this juncture. See Mayfield, 20 Vet. App. at 543 (rejecting the argument that the Board lacks authority to consider harmless error). See also ATD Corp. v. Lydall, Inc., 159 F.3d 534, 549 (Fed. Cir. 1998). II. Analysis The Veteran is seeking service connection for a respiratory disorder. In statements of record, he has asserted being exposed to asbestos during the course of his duties as an aircraft mechanic. In the alternative, he has also claimed that his respiratory disorder is due to exposure to herbicides while stationed in Vietnam. Service connection may be granted for disability resulting from disease or injury incurred in or aggravated by service. 38 U.S.C.A. §§ 1110, 1131; 38 C.F.R. § 3.303. Such a determination requires a finding of current disability that is related to an injury or disease in service. Watson v. Brown, 4 Vet. App. 309 (1993); see also Brammer v. Derwinski, 3 Vet. App. 223, 225 (1992); Rabideau v. Derwinski, 2 Vet. App. 141, 143 (1992). Service connection may be granted for any disease diagnosed after discharge from service when all the evidence, including that pertinent to service, establishes that the disease was incurred in service. 38 C.F.R. § 3.303(d). Additionally, absent affirmative evidence to the contrary, there is a presumption of exposure to herbicides (to include Agent Orange) for all veterans who served in Vietnam during the Vietnam Era (the period beginning on January 9, 1962, and ending on May 7, 1975). 38 U.S.C.A. § 1116(f) and 38 C.F.R. 3.307(a)(6). Furthermore, if a veteran was exposed to an herbicide agent (to include Agent Orange) during active military, naval, or air service, certain diseases, including respiratory cancers, shall be service-connected if the requirements of 38 C.F.R. § 3.307(a)(6) are met, even if there is no record of such disease during service, provided further that the rebuttable presumption provisions of 38 C.F.R. § 3.307(d) are also satisfied. 38 C.F.R. § 3.309(e). Thus, a presumption of service connection arises for these veterans (presumed exposed to Agent Orange) or, alternatively, a veteran without appropriate service (as described above) but with competent evidence of herbicide exposure, who develops one of the identified diseases. In regards to asbestos exposure, there is no specific statutory or regulatory guidance with regard to claims for service connection for asbestos-related diseases. However, in 1988, VA issued a circular on asbestos-related diseases that provided guidelines for considering asbestos compensation claims. See Department of Veterans Benefits, Veterans' Administration, DVB Circular 21- 88-8, Asbestos-Related Diseases (May 11, 1988). The information and instructions contained in the DVB Circular have since been included in VA's Adjudication Procedure Manual, M21-MR, Part IV.ii.2.C.9 (Dec. 13, 2005) and Part IV.ii.1.H.29.a (Sept. 29, 2006). Also, an opinion by VA's Office of General Counsel discussed the development of asbestos claims. See VAOPGCPREC 4-00. VA must analyze the Veteran's claim of entitlement to service connection for asbestos-related disease under these administrative protocols using the following criteria. Ennis v. Brown, 4 Vet. App. 523, 527 (1993); McGinty v. Brown, 4 Vet. App. 428, 432 (1993). The Adjudication Manual contains guidelines for the development of asbestos exposure cases. They indicate that inhalation of asbestos fibers can result in fibrosis and tumors, and produce pleural effusions and fibrosis, pleural plaques, mesotheliomas of the pleura and peritoneum, and cancer of the lung, gastrointestinal tract, larynx, pharynx and urogenital system (except the prostate), with the most common resulting disease being interstitial pulmonary fibrosis (asbestosis). Also noted is that the latent period varies from 10 to 45 or more years between first exposure and development of disease. Also of significance is that the exposure to asbestos may be brief (as little as a month or two) or indirect (bystander disease). The Adjudication Manual provides that VA must determine whether military records demonstrate evidence of asbestos exposure in service; whether there is pre-service and/or post-service evidence of occupational or other asbestos exposure; and then make a determination as to the relationship between asbestos exposure and the claimed diseases, keeping in mind the latency and exposure information pertinent to the Veteran. See also VAOPGCPREC 4- 2000 (April 13, 2000); Ashford v. Brown, 10 Vet. App. 120, 123-24 (1997) (while holding that the Veteran's claim had been properly developed and adjudicated, the Court indicated that the Board should have specifically referenced the DVB Circular and discussed the RO's compliance with the Circular's claim-development procedures). The Board also points out that the pertinent parts of the Manual guidelines on service connection in asbestos-related cases are not substantive rules, and that there is no presumption that a veteran was exposed to asbestos in service. See Dyment v. West, 13 Vet. App. 141 (1999), aff'd, Dyment v. Principi, 287 F.3d 1377 (Fed. Cir. 2002); VAOPGCPREC 4-2000. Considering the record in light of the above-noted legal authority, the Board finds that service connection for a respiratory disorder is not warranted The Veteran's service treatment records have been reviewed and are silent with respect to any respiratory complaints or diagnosis of a respiratory disorder. A December 1968 chest x-ray was within normal limits. Moreover, an April 1971 service examination prior to discharge showed that the Veteran's lungs and chest were clinically evaluated as normal. Importantly, in his contemporaneous medical history, the Veteran expressly denied any asthma, shortness of breath, pain or pressure in chest, or chronic cough. Again, an August 1973 reserve enlistment examination, over two years after discharge, showed that the lungs and chest were clinically evaluated as normal. The Veteran again denied any asthma, shortness of breath, pain or pressure in chest, or chronic cough in his contemporaneous medical history. The Veteran's service personnel records reflect that he served in the United States Air Force and his military occupational specialty (MOS) was listed as an aircraft mechanic. His duties included inspection and maintenance of the aircrafts' landing gear, flight controls, dock systems, and fuel systems. The Veteran's duties also included assisting in the removal and reclamation of crash damaged aircrafts. As noted in the Board's prior October 2009 remand, the Veteran's MOS indicates that he would likely have some degree of asbestos exposure during service. These records also reflect that the Veteran had several temporary duty assignments to Vietnam. The first post service medical evidence of any respiratory disorders is a private September 2003 chest x-ray, which showed biapical scarring, likely reflecting granulomatous disease, but no radiographic evidence of an acute pulmonary process. A December 2003 computed tomography (CT) scan showed extensive mediastinal hilar and also bilaterally axillary adenopathy. There were also multifocal ground-glass opacities in both lungs with areas of pleural based thickening in apices. The examiner indicated that diagnostic considerations included sarcoidosis and lymphoma. The ground-glass opacities may also be due to alveolitis of nonspecific causes such a hypersensitivity pneumonitis, drug reaction or opportunistic infection. A January 2004 private pulmonary function test (PFT) revealed a minor degree of obstruction, which did not respond to bronchodilator, and a reduced diffusion capacity. Although this was not specific, it was compatible with a diagnosis of sarcoid. The finding was also compatible with a diagnosis of COPD. A January 2004 biopsy showed no evidence of cancer. A January 2004 private letter indicated that the Veteran had quit smoking about two months prior although he had never smoked a lot. The Veteran denied shortness of breath at the time he quit smoking, but the examiner felt that he was starting to notice shortness of breath at that time. He indicated that the CT scan was compatible with a diagnosis of sarcoid, lymphoma or opportunistic infection. Another private CT in April 2004 showed interval development of pleural based abnormality in left lower lobe with solid component which was tenting the inferior oblique fissure on the left. The technician could not exclude developing malignancy. However, there was remarkable improvement in focal ground glass opacities and adenopathy when compared to December 2003 scan. The findings needed to be clinically correlated. There was a question of whether there was a history of sarcoidosis. It was also observed that other consideration would include recurrent hypersensitivity pneumonitis or unusual opportunistic infection. VA treatment records document that, in May 2006, the Veteran reported for an initial visit. He reported a history of wheezing since September 2003 when he had shortness of breath and was sent to the emergency room. The examiner diagnosed bronchial spasm although there was no wheezing or shortness of breath at that time. At an Agent Orange examination that same month, the Veteran provided that he believed his respiratory problems were due to Agent Orange exposure. He again, indicated that he had breathing problems since September 2003. It was observed that there was no evidence of Agent Orange related illnesses. The Veteran was diagnosed with asthma-like syndrome since 2003. A June 2006 chest x-ray shoed no evidence of cardiomegaly or pulmonary infiltrate. In a January 2007 VA Environmental Health General Progress Note, which was a follow-up note to a previous Agent Orange exposure examination, the VA nurse practitioner indicated that bilateral apical thickening may be related to asbestos exposure. Follow up VA treatment records continued to show active problems of asthma or bronchospasm. An April 2010 PFT showed moderate obstructive airway disease which improved with inhaled bronchodilators. A May 2010 chest x-ray showed no acute findings. The Veteran was afforded a VA examination in May 2010. The claims file was reviewed in conjunction with the examination. The Veteran reported that his breathing problems began in 2001 when he experienced shortness of breath and had to go to the emergency room. He indicated that he had breathing problems for years and shortness of breath. He was currently on three different medications for breathing problems. Veteran reported that he was an airline mechanic and was also exposed to Agent Orange while in the Air Force. After examining the Veteran and reviewing the claims file, the examiner diagnosed restrictive lung disease, COPD, moderate in severity and with a reversible component. The examiner opined that this condition was more likely than not related to 30+ years of cigarette smoking. It was noted that the Veteran stopped smoking in 2003. The examiner continued that the Veteran's COPD was not caused by or the result of military service, including exposure to Agent Orange or asbestos. The examiner rationalized that the Veteran was diagnosed with restrictive lung disease and x-ray evaluation from 2006 and 2010 does not indicate any signs of asbestosis. In addition, the only lung diseases related to Agent Orange exposure are lung cancer. Therefore, the Veteran does not have any lung condition that can be connected to asbestos exposure or Agent Orange. The report of a May 2010 pulmonary consultation report that was performed in conjunction with the VA examination indicates that the Veteran reported the same history of Agent Orange and asbestos exposure. He was currently employed as a building inspector. The assessment again was COPD, moderate in severity and with reversible component. There was no evidence of asbestosis by chest x-ray and the the VA pulmonologist recommended that a CT scan of the lungs be performed prior to ruling out a diagnosis of asbestosis. The VA pulmonologist noted that a CT scan was more sensitive than plain chest x-rays. A CT scan the following month revealed some scarring in the top part of the lungs and some in the bottom of the right lung. The examiner determined that these findings were not typical of asbestosis. A follow up July 2010 consultation observed the same findings. However, a November 2010 treatment record includes a noted observed that the radiologist noted a lesion on the left lung, and a follow up CT was recommended. A January 2011 record showed that the Veteran had an abnormal chest CT in November 2010 that showed pleural densities in the right apex and additional follow up was needed to rule out cancer. On remand, another CT scan was performed in April 2012, which showed fairly stable chronic pleural and parenchymal changes toward the lung apices. The CT scan also showed apparent progression of fibrotic changes in the lung bases, suggestive of COPD. Calcified pleural plaques typical of asbestos related changes were not seen. Subsequently, as directed by the Board, the Veteran was afforded another VA examination in May 2012. The claims file was reviewed in conjunction with the examination. The Veteran reported starting smoking one pack per month from 1965 until 1991 when he quit. He said his respiratory problems began in 2004. Prior to that time, he was fine and had no noticeable symptoms. The examiner summarized the private and VA treatment records, including the April 2012 CT scan. The examiner diagnosed COPD and restrictive lung disease. After examining the Veteran, the examiner opined that the claimed condition was likely than not due to an in-service injury, event, or illness because the Veteran did not show any problems from discharge in 1971 until 2004 when he suddenly experienced shortness of breath and a chest x-ray revealed pulmonary opacities and lymphadenopathy. He had a bronchoscopy, then bronchial wash. The Veteran was started on steroids for six months because medical personnel thought it was eosinophilic granuloma/sarcoidosis. Subsequently, the Veteran was diagnosed with COPD and pleural plaque, which per radiologist were not typical for asbestosis. He further observed that Agent Orange was thought related to lung malignancy, which the Veteran did not have. The Veteran did smoke about one pack per month so not a lot, but totalled 26 years from 1965 to 1991. The Veteran was an aircraft mechanic in service. The examiner concluded that the Veteran COPD was less likely as not caused by Agent Orange or asbestos as found in the 2010 pulmonologist consult. Initially, the Veteran's service personnel records reflect that he served in the Republic of Vietnam during the Vietnam era. Thus, the Veteran is presumed to have been exposed to herbicides, to include Agent Orange. See 38 C.F.R. § 3.307(a)(6)(iii). However, the record reflects that the Veteran has not been diagnosed with a disability recognized as associated with herbicide exposure (such as a respiratory cancer) and COPD is not among the disabilities recognized by VA as associated with herbicide exposure. See 38 C.F.R. § 3.309(e). The record does not establish a diagnosis for any respiratory disability associated with Agent Orange exposure. Hence, presumptive service connection for a respiratory disability based on the Veteran's presumed herbicide exposure, is not warranted. Notwithstanding the above, service connection for a disability claimed as due to herbicide exposure may be established by showing that a disorder resulting in disability or death was in fact causally linked to such exposure. See Brock v. Brown, 10 Vet. App. 155, 162-64 (1997); Combee v. Brown, 34 F. 3d 1039, 1044 (Fed. Cir. 1994), citing 38 U.S.C.A. § 1113(b) and 1116 and 38 C.F.R. § 3.303. Nevertheless, there is no evidence of a respiratory disability for approximately 32 years after the Veteran's discharge from service. The Board points out that the passage of many years between discharge from active service and the medical documentation of a claimed disability is a factor that tends to weigh against a claim for service connection. See Maxson v. Gober, 230 F.3d 1330, 1333 (Fed. Cir. 2000); Shaw v. Principi, 3 Vet. App. 365 (1992). The Veteran himself has asserted that his symptoms did not begin until approximately 2003 or 2004, or at the earliest 2001. He has expressly denied experiencing any pertinent respiratory symptoms since service. Importantly, the August 1973 reserve examination, over two years after discharge) found no lung or chest abnormalities and the Veteran expressly denied any symptoms at that time. Here, the lack of any evidence (or even lay assertions) of symptoms during service which have continued to the present day preponderates against awarding service connection on the basis of chronicity and continuity of symptomatology. See 38 C.F.R. § 3.303(b). Thus, in order to establish service connection, there must be some competent evidence establishing that a respiratory disorder was incurred during service. See 38 C.F.R. 3.303(d). However, there is no competent evidence or opinion even suggesting that there exists a medical nexus between a respiratory disorder diagnosed so many years after the Veteran's discharge and any incident of service. After reviewing the claims file, taking a thorough history from the Veteran, and examining the Veteran, the VA examinations performed in May 2010 and May 2012 by medical professionals clearly found that the Veteran's diagnosed COPD and restrictive airway disease were not related to service, including exposure to herbicides and asbestos, and, as discussed above, provided a detailed rationale for such finding. Importantly, there is no competent medical evidence of record to refute these findings. Moreover, CT scans also clearly showed that the Veteran does not have an asbestos related illness. The staff radiologist who performed the most CT scan in April 2012 clearly found that asbestos related changes were not seen. Although a nurse practitioner in January 2007, indicated that the bilateral apical thickening may be related to asbestos. This statement has no probative value as it is couched in speculative terms with no rationale and was not based on CT scan findings. Moreover, again this statement was made by a nurse practitioner; whereas the findings that the Veteran did not have an asbestos related illness were made by medical doctors who had experience with pulmonary disorders. The Board also notes that statements like this amount to "nonevidence," neither for nor against the claim, because service connection may not be based on speculation or remote possibility. See generally Bloom v. West, 12 Vet. App. 185 (1999) (a medical opinion based on speculation, without supporting clinical data or other rationale, does not provide the required degree of medical certainty). In turn, while the Veteran's military occupational specialty as an aircraft mechanic is indicative of possible asbestos exposure, given the lack of findings consistent with an asbestos-related disorder, there is no medical nexus (or, relationship) between any in-service asbestos exposure and any current respiratory illness. Furthermore, as for any direct assertions by the Veteran and/or his representative that there exists a medical relationship between a current respiratory disorder and service, the Board notes that the matter of the etiology of the disability is one within the province of trained professionals. See Jones v. Brown, 7 Vet. App. 134, 137-38 (1994). As the Veteran and his representative are not shown to be other than laypersons without the appropriate training and expertise, neither is competent to render a probative (i.e., persuasive) opinion on the medical matter upon which each of these claims turn. See, e.g., Bostain v. West, 11 Vet. App. 124, 127 (1998), citing Espiritu v. Derwinski, 2 Vet. App. 492 (1992). See also Routen v. Brown, 10 Vet. App. 183, 186 (1997) ("a layperson is generally not capable of opining on matters requiring medical knowledge"). Hence, on these facts, lay assertions of medical nexus have no probative value. For all the foregoing reasons, the Board finds that the claim for service connection for a respiratory disorder must be denied. In reaching the conclusion to deny the claim, the Board has considered the applicability of the benefit-of-the-doubt doctrine. However, as a preponderance of the evidence is against the claims, that doctrine is not applicable. See 38 U.S.C.A. § 5107(b); 38 C.F.R. § 3.102; Gilbert v. Derwinski, 1 Vet. App. 49, 53-56 (1990). ORDER Service connection for a respiratory disorder, to include as due to exposure to herbicides (Agent Orange) and/or asbestos, is denied. ____________________________________________ JACQUELINE E. MONROE Veterans Law Judge, Board of Veterans' Appeals Department of Veterans Affairs