Reversed and remanded by published opinion. Judge WILLIAMS wrote the majority opinion, in which Judge LUTTIG joined. Senior Judge BUTZNER wrote a dissenting opinion.
OPINION
WILLIAMS, Circuit Judge:
In this appeal we consider whether a coal miner, affected by simple pneumoconiosis1 but disabled by an unrelated respiratory condition, is “totally disabled due to pneumoconi-osis” within the meaning of 30 U.S.C. § 901(a) (1988). An administrative law judge (ALJ) determined that Laymond Ballard suffered from a totally disabling respiratory condition, but denied him black lung benefits because the ALJ credited several medical opinions that Ballard’s disability was not due to his coal mine employment. The Benefits Review Board (BRB) reversed and awarded benefits to Ballard on the ground that the medical opinions relied upon by the ALJ lacked probative value. Dehue Coal Company (Dehue) petitions for review of the BRB’s decision and order. After careful consideration of the record before the ALJ and the BRB, we reverse the decision of the BRB and remand for entry of an appropriate order denying benefits to Ballard.
I.
Ballard was born on November 13, 1938, and completed schooling through the eleventh grade. He was a coal miner for approximately sixteen years, working for Dehue from 1970 to 1985. In his last position, Ballard worked as an electric repairman, troubleshooter, and general underground laborer. On or about May 27, 1990, he left the coal mines shortly after the removal of his left lung due to cancer.
Prior to the lung surgery, Ballard had never missed work due to breathing problems, although he had smoked approximately one pack of cigarettes per day for more than thirty years. It was not until the period [1192] immediately preceding his lung surgery that Ballard noticed any breathing difficulties. On May 8,1990, Ballard underwent a routine physical examination by his family physician, Dr. Harry Fortner. At this initial office visit, Ballard complained of a recent twenty-pound weight loss and pain in his chest and left arm of about one-month duration, but denied any shortness of breath. Dr. Fortner ordered a chest x-ray which revealed a mass in the upper lobe of Ballard’s left lung. He then referred Ballard to Dr. George Zaldivar, a pulmonologist who evaluated him, administered pulmonary function tests, and sent him to Dr. Sampath, who performed a pneumo-nectomy on Ballard.2
On July 17, 1990, Ballard applied for benefits pursuant to the Black Lung Benefits Act, 30 U.S.C. §§ 901-945 (the Act). During the administrative consideration of Ballard’s claim, the Department of Labor identified Dehue as the responsible operator liable for payment of benefits under the Act.3 Dehue disputed Ballard’s claim and requested a hearing before an ALJ.
After conducting a hearing on the matter, the ALJ denied Ballard’s claim for benefits on May 10, 1993. Based upon his review of the opinions of at least ten physicians and his review of x-ray, biopsy, and pulmonary function evidence, the ALJ concluded that Ballard suffered from simple pneumoconiosis and that he had a totally disabling respiratory condition. The ALJ further accorded Ballard the rebuttable presumption, as provided in 20 C.F.R. § 718.203(b) (1994), that his pneumoconiosis arose out of his coal mine employment. Nevertheless, the ALJ found Ballard ineligible for benefits because the record did not support the conclusion that his total disability was due to the pneumoconio-sis. See 20 C.F.R. § 718.204. In particular, the ALJ observed:
I find the medical evidence, taken as a whole, establishes that although Claimant may have minimal, simple pneumoconiosis, it caused little, if any, respiratory impairment- Furthermore, even if pneumo-coniosis might have played a minimal role in Claimant’s wore-disabling respiratory condition, it is wholly unrelated to Claimant’s totally disabling condition, which was caused by the pneumonectomy necessitated by Claimant’s cigarette-induced lung cancer. These conclusions are not only supported by the better reasoned medical opinions, but are buttressed by the precipitous drop recorded on the pulmonary function studies, Claimant’s work history, as well as Claimant’s testimony.
(J.A. 51.) The ALJ, therefore, concluded that pneumoconiosis was not a contributing factor in Ballard’s total disability and denied his request for benefits.
Ballard appealed to the BRB, which reversed the ALJ’s decision on September 28, 1994, and awarded benefits to Ballard. Relying upon our decision in Grigg v. Director, OWCP, the BRB concluded that the ALJ erred in lending any credence to the opinions of physicians who failed to diagnose pneumo-coniosis. See Grigg v. Director, OWCP, 28 F.3d 416, 419-20 (4th Cir.1994) (observing that interim presumption that pneumoconio-sis caused disability cannot be rebutted by medical report finding “no respiratory or pulmonary impairment” if physician erroneously assumed miner had no pneumoconiosis). Discounting the credibility of the physicians’ opinions relied upon by the ALJ, the BRB focused on the remaining medical opinions in holding that Ballard’s pneumoconiosis was a contributing cause of his total disability. See Hobbs v. Clinchfield Coal Co., 917 F.2d 790 (4th Cir.1990) (Hobbs I); Robinson v. Pickands Mather & Co., 914 F.2d 35 (4th Cir.1990) (holding claimant must show by preponderance of evidence that pneumoconiosis was contributing cause of totally disabling respiratory impairment). The BRB therefore reversed the ALJ’s decision and ordered entry of an award of benefits.
[1193] Dehue asserts that the ALJ’s determination that pneumoconiosis was not a contributing cause of Ballard’s disability was supported by substantial evidence in the record and was in accordance with law. Dehue therefore contends that the BRB erred in awarding Ballard black lung benefits. We agree.
II.
The BRB reviews the ALJ’s findings of fact to determine if they are supported by substantial evidence in the record. Doss v. Director, OWCP, 53 F.3d 654, 658 (4th Cir.1995). We review the BRB’s decision for errors of law and to ensure the BRB’s decision adhered to its statutory standard of review. Id. To that end, we undertake an independent review of the record, as in the place of the BRB, to determine whether the ALJ’s factual findings were based upon substantial evidence in the record. Toler v. Eastern Associated Coal Co., 43 F.3d 109, 114 (4th Cir.1995). We review the BRB’s legal conclusions de novo, considering first the BRB’s reading of our precedent in Grigg. Scott v. Mason Coal Co., 60 F.3d 1138, 1140 (4th Cir.1995).
A.
Ballard urges us to affirm the BRB’s reasoning that our decision in Grigg compelled it to discount the probative value of the opinions of those physicians who did not diagnose pneumoconiosis in Ballard. The BRB, however, construed our decision in Grigg without the benefit of our most recent decision in Hobbs v. Clinchfield Coal Co., 45 F.3d 819 (4th Cir.1995) (Hobbs II). Evaluating Ballard’s claim in the light of Hobbs II, we must reject his arguments because the physicians’ opinions regarding the cause of Ballard’s undisputed pulmonary impairment were probative evidence warranting due consideration by the ALJ.
Unlike Hobbs or Ballard, Grigg enjoyed an interim presumption under Part 727 of the regulations that he was “totally disabled due to pneumoconiosis.” Grigg, 28 F.3d at 418 (noting invocation of presumption under 20 C.F.R. § 727.203(a)(1) based on x-ray evidence). To rebut the presumption, medical reports were submitted stating that Grigg had “no respiratory or pulmonary impairment.” In Grigg, we observed that when a physician premises such an opinion on the assumption that the miner has no pneumoco-niosis, it is “not worthy of much, if any, weight.” Id. at 419. In that instance, the physician’s opinion simply contradicts the established presumption that the miner is disabled without offering rebuttal evidence regarding the cause of the miner’s disability. See also Warth v. Southern Ohio Coal Co., 60 F.3d 173, 175 (4th Cir.1995) (vacating order denying benefits where ALJ improperly credited physicians’ opinions of no pneumoco-niosis based on erroneous assumptions).
In Hobbs II, we confronted a slightly different context than that in Grigg. Whereas Grigg enjoyed a presumption, Hobbs bore the burden of establishing that pneumoconiosis caused his total disability. 20 C.F.R. § 718.204. We held in Hobbs II that once an ALJ has found that a miner suffers from some form of pneumoconiosis, a physician’s opinion premised on an understanding that the miner does not suffer from coal workers ’ pneumoconiosis may hold probative value. 45 F.3d at 821. To begin, the physician’s finding that the miner does not have coal workers’ pneumoconiosis is not necessarily inconsistent with the ALJ’s decision that the miner suffers from pneumoconiosis as it is defined in 20 C.F.R. § 718.201. Both conclusions may be accurate because “the legal definition of pneumoconiosis contained in § 718.201 is significantly broader than the medical definition of coal workers’ pneumoconiosis.” Id. Moreover, a medical opinion that acknowledges the miner’s respiratory or pulmonary impairment, but nevertheless concludes that an ailment other than pneumoconiosis caused the miner’s total disability, is relevant because it directly rebuts the miner’s evidence that pneumoconiosis contributed to his disability. See id. (noting physicians acknowledged that miner suffered respiratory impairment attributable to coal dust, but concluded that skeletal problems, obesity, and arthritis caused miner’s total disability); cf. Grigg, 28 F.3d at 419 (medical reports refuting existence of impairment hold little probative value on issue of causation).
[1194] Here the physicians’ opinions that Ballard’s pneumonectomy, necessitated by smoking-induced lung cancer, caused his total disability were highly relevant to the question of whether pneumoconiosis was a contributing cause of Ballard’s total disability. None of the physicians’ opinions refuted the ALJ’s finding that Ballard suffered from a disabling respiratory condition following his pneumonectomy. Rather, Drs. Zaldivar, Fino, Hansbarger, Caffrey, and Crisalli simply concluded that Ballard’s coal mine employment was not causally related to his disability. Drs. Sampath and Chang merely reported on the characteristics of Ballard’s carcinoma, without offering an opinion as to causation.4 Consistent with both Grigg and Hobbs II, these opinions are probative and warranted the close attention the ALJ accorded to them.
Dr. Zaldivar, a board-certified pulmonary specialist who examined Ballard and administered pulmonary function tests before the pneumonectomy, stated that Ballard was not disabled prior to the surgery, an opinion completely in accord with the ALJ, who found “minimal, if any, respiratory or pulmonary impairment” prior to the surgery. (J.A. 44.) Moreover, Dr. Zaldivar did not evaluate Ballard for pneumoconiosis and thus drew no conclusions contrary to the ALJ’s further finding that, after the surgery, Ballard suffered from a totally disabling respiratory condition. Because Dr. Zaldivar’s express assumptions were consistent with the ALJ’s findings, the ALJ properly credited Dr. Zal-divar’s opinion that Ballard’s lung cancer, eaused by smoking, was wholly unrelated to coal mine employment.
In their reports, Drs. Fino, Hansbarger, Caffrey, and Crisalli recognized that Ballard had respiratory or pulmonary impairment, concluded that coal workers ’ pneumoconiosis did not cause it, and determined that the pneumonectomy necessitated by smoking-induced lung cancer was the cause of Ballard’s total disability. Their opinions are not inconsistent with the ALJ’s dual findings that Ballard is totally disabled and has simple pneumoconiosis. Dr. Fino, board-certified in internal medicine with a subspeeialty in pulmonary disease, acknowledged that Ballard developed a pulmonary disability due to his pneumonectomy, but concluded that coal workers’ pneumoconiosis played no role in the cancer that necessitated the pneumonec-tomy. Similarly, Dr. Hansbarger, a board-certified pathologist who reviewed all of the materials in Ballard’s file, found no evidence of coal workers’ pneumoconiosis and attributed Ballard’s disability entirely to the pneu-monectomy necessitated by lung cancer. Dr. Hansbarger found that “[a]ny respiratory difficulty, or pulmonary impairment in [Ballard] cannot be ascribed to ... his coal mine employment.” (J.A. 194.) Likewise, Dr. Caffrey, a board-certified pathologist, identified mild chronic bronchitis, eentrilobular emphysema, and carcinoma, but associated them with cigarette smoking rather than pneumoconiosis. Finally, Dr. Crisalli, a board-certified internist who examined Ballard and reviewed his history, also testified that Ballard’s postoperative pulmonary impairment was related to his smoking rather than coal dust exposure.5
[1195] Thus, the opinions of Drs. Fino, Hansbar-ger, Caffrey, and Crisalli were not inconsistent with the ALJ’s finding that Ballard suffered from a “totally disabling respiratory condition.” (J.A. 44.) Whereas the physicians in Grigg denied the miner’s respiratory impairment, Drs. Fino, Hansbarger, Caffrey, and Crisalli acknowledged Ballard’s impairment but attributed it to his pneumonectomy rather than pneumoconiosis. Cf. Hobbs II, 45 F.3d at 821 (noting that although physicians found that miner “suffers from respiratory problems arising out of coal mine employment, they both concluded that his total disability was caused by obesity and arthritis, but not by pneumoconiosis”).
Moreover, the four physicians’ diagnoses that Ballard did not suffer from coal workers’ pneumoconiosis did not contradict the ALJ’s conclusion that Ballard had simple pneumo-coniosis within the meaning of 20 C.F.R. § 718.201.6 We emphasized in Hobbs II that “a medical diagnosis finding no coal workers’ pneumoconiosis is not equivalent to a legal finding of no pneumoconiosis” because the legal definition is significantly broader than the medical definition. 45 F.3d at 821. Drs. Fino, Hansbarger, Caffrey, and Crisalli simply stated that they found no evidence of coal workers’ pneumoconiosis, one of many ailments that would satisfy the legal definition of pneumoconiosis. In fact, Drs. Hansbarger and Caffrey expressly observed that Ballard exhibited symptoms pertaining to anthraco-sis, another of several ailments subsumed under the legal definition of pneumoconiosis. Dr. Hansbarger diagnosed anthraeosilicosis of bronchial lymph nodes. Similarly, Dr. Caffrey discerned “black pigment which is morphologically consistent with coal dust,” “a mild amount of anthracotic pigment,” and a “[m]oderate amount of anthracotic pigment identified within lung tissue and hilar lymph node tissue.” (J.A. 202.)
Because the physicians here did not premise their opinions on an “erroneous finding” contrary to the ALJ’s conclusion, as in Grigg, 28 F.3d at 419, the ALJ correctly credited their unanimous opinion that Ballard’s disability was due to the pneumonectomy rather than pneumoconiosis. Accordingly, we hold that the BRB erred as a matter of law in discounting the physicians’ opinions.
B.
Having determined that the ALJ did not err in according weight to the opinions of Drs. Zaldivar, Fino, Sampath, Chang, Hansbarger, Caffrey, and Crisalli, we now review the ALJ’s finding that pneumoconiosis was not a contributing cause of Ballard’s total disability. In so doing, we “adhere carefully to the principle that we must affirm the ALJ’s factual findings and weighing of the medical evidence where these conclusions of the ALJ are supported by substantial evidence.” Hobbs II, 45 F.3d at 820. Finding that the physicians’ opinions provided substantial evidence that the pneumonectomy, rather than pneumoconiosis, caused Ballard’s total disability, we affirm the ALJ’s decision to deny benefits.7
To receive black lung benefits, a claimant must prove by a preponderance of the evidence that he is “totally disabled due to pneumoconiosis.” 30 U.S.C. § 901(a); 20 C.F.R. § 718.204(a). Specifically, the claimant must show “that his pneumoconiosis was at least a contributing cause of his totally [1196] disabling respiratory impairment.” Robinson, 914 F.2d at 38; Hobbs I, 917 F.2d at 791-92 (same). Accordingly, we ask whether
the claimant’s coal mining [was] a necessary condition of his disability. If the claimant would have been disabled to the same degree and by the same time in his life if he had never been a miner, then benefits should not be awarded.
Robinson, 914 F.2d at 38 (emphasis added) (citing Shelton v. Director, OWCP, 899 F.2d 690, 693 (7th Cir.1990) (“A miner is not entitled to benefits if by reason of his heavy smoking or some other activity or condition of his that is not itself mining, he would have become totally disabled _”));8 see Freeman United Coal Mining Co. v. Foster, 30 F.3d 834, 838-39 (7th Cir.1994) (rejecting use of a disability unrelated to extant simple pneumoconiosis to support an award of black lung benefits), cert. denied, —— U.S. —, 115 S.Ct. 1399, 131 L.Ed.2d 287 (1995).
Thus, if the record before the ALJ contains substantial evidence to support the conclusion that Ballard’s cigarette smoking and resulting lung cancer would have disabled him to the same degree by the same time in his life had he never been a miner, he is not entitled to black lung benefits. Based upon our review of the record, the ALJ’s careful consideration of the pulmonary function and blood gas tests, Ballard’s work history and testimony, and the professional opinions of ten physicians, we conclude that substantial evidence in the record supports the ALJ’s determination that Ballard failed to establish that pneumoconiosis was a contributing factor in his total disability.
We look first to the pulmonary function studies administered prior to the pneumonec-tomy and note that they reflect minimal, if any, respiratory impairment, as the ALJ so found. Not surprisingly, following the left pneumonectomy performed by Dr. Sampath on June 8, 1990, Ballard’s tests revealed a precipitous drop in pulmonary function. This data supports the ALJ’s conclusion that the disability demonstrated by Ballard’s reduced pulmonary function was due to the pneumonectomy and not to his simple pneu-moconiosis.
Ballard’s own testimony further supports the ALJ’s conclusion that he had suffered no impairment prior to the pneumonectomy. Ballard testified that prior to his pneumonec-tomy he never missed a day of work because of breathing problems. However, he testified that he did miss work because of breathing problems after the pneumonectomy.
The ALJ further recognized the extensive hospital reports and medical notes regarding Ballard’s deteriorated condition post-surgery. He reviewed the written reports and depositions of Drs. Ranavaya, Zaldivar, Cinco, Ahmed, Hansbarger, CafErey, Chang, Sam-path, Crisalli, and Fino to detect any evidence of a causal connection between pneu-moconiosis and Ballard’s total disability. Three of these physicians, Drs. Ranavaya, Cinco, and Ahmed, diagnosed pneumoconio-sis. Dr. Ranavaya, who performed pulmonary function studies on Ballard shortly after his surgery and on July 17, 1992, following Ballard’s application for black lung benefits, attributed Ballard’s impairment primarily to the pneumonectomy, but suggested perhaps that pneumoconiosis had affected Ballard’s remaining lung.9 Dr. Cinco, a consulting pathologist, diagnosed coal workers’ pneumo-coniosis, but articulated no causal connection between pneumoconiosis and Ballard’s postoperative total disability.10 Finally, Dr. [1197] Ahmed, another consulting pathologist, who discerned evidence of simple pneumoconiosis in two of the fifteen slide samples he reviewed, was critical of the “grossly insufficient” amount of lung tissue sampled for the purpose of determining the presence or absence of the disease. (J.A. 437.) Relying on the same samples, he nevertheless stated that Ballard “suffered significant pulmonary impairment that was certainly aggravated by coal mine dust exposure.” (J.A. 437.)
Five of the remaining physicians expressly concluded that Ballard’s disability was caused by the pneumonectomy. In particular, Dr. Zaldivar, one of Ballard’s initial examining physicians who also performed pulmonary function studies, stated that Ballard was not disabled prior to the surgery and that the lung cancer, caused by smoking, was wholly unrelated to coal mine employment. Similarly, Dr. Hansbarger, following his review of all the materials in Ballard’s file, concluded that Ballard’s pulmonary impairment was due to the carcinoma that necessitated the pneumonectomy. Dr. Caffrey’s opinion was also unequivocal:
It is my opinion that the patient does not show the necessary findings to make a diagnosis of coal workers’ pneumoconiosis or any other occupational pneumoconiosis. The findings from this left pneumonectomy specimen, in my opinion, show a large mu-coepidermoid carcinoma which has definitely no cause and [effect] relationship with coal mine work. [Ballard’s] centrilo-bular emphysema and mild chronic bronchitis are due to his long history of smoking cigarettes, in my opinion.
(J.A. 203.) In like manner, Dr. Crisalli concluded that “Ballard has significant impairment because of his left pneumonectomy necessitated by his cancer of the lung. The lung cancer was not in any way contributed to or caused by his coal dust exposure.” (J.A. 219.) Finally, Dr. Fino similarly concluded that pneumoconiosis did not cause Ballard’s total disability:
Prior to this man’s lung surgery he had no pulmonary disability.
... Subsequent to his lung surgery he developed a pulmonary disability because the lung was removed. The lung was removed due to lung cancer, and the lung cancer was from cigarette smoking. Simple coal workers’ pneumoconiosis or coal mine dust inhalation played no role in his cancer and subsequent removal of the left lung.
... It is my opinion that this man would be as disabled as I find him now had he never stepped foot in the coal mines.
(J.A. 108.) (emphasis added).
The clearly articulated opinions of both examining and consulting physicians support the ALJ’s conclusion that “pneumoconiosis ... is wholly unrelated to [Ballard’s] totally disabling condition, which was caused by the pneumonectomy necessitated by [Ballard’s] cigarette-induced lung cancer.” (J.A. 51.) The otherwise inexplicable sharp drop in Ballard’s pulmonary function results and non-qualifying blood gas studies, as well as Ballard’s work history and testimony, also bolster the ALJ’s conclusion. We therefore conclude that the ALJ’s decision to deny Ballard black lung benefits is supported by substantial evidence in the record and is in accordance with the law.
III.
Based upon our review of the record, we conclude that the ALJ did not err in according weight to the opinions of Drs. Zaldivar, Fino, Sampath, Chang, Hansbarger, Caffrey, and Crisalli and that the ALJ’s decision finding that pneumoconiosis was not a contributing cause of Ballard’s disability is supported by substantial evidence. We therefore reverse the decision of the BRB and remand for entry of an order consistent with this opinion.
REVERSED AND REMANDED.