to testify about causation. See, e.g., Hardyman v. Norfolk & W. Ry., 243 F.3d 255, 262 (6th Cir.2001) (reversing trial court’s ruling that plaintiff could establish causation only by showing a “dose/response relationship” between exposure levels and risk of disease); Wilson v. CSX Transp., Inc., No. E2002-00291-COA-R9-CV, 2003 WL 1233536, at *8 (Tenn.Ct.App. Mar. 18, 2003) (allowing admission of expert’s opinion that “occupational exposures caused, or contributed to the cause,” of the plaintiffs cancer, even though the expert “admitted in his deposition that he did not have any quantitative information about the amount of exposure or dosage [the plaintiff] had to the various chemicals at issue,” including diesel exhaust); accord Ambrosini v. Labarraque, 101 F.3d 129, 135 (D.C.Cir.1996) (<HOLDING>). In fact, some courts have pointed out why it
holding that experts medical opinion constituted no evidence because it was based upon speculation and surmise rather than reasonable medical probability holding even though experts are permitted to give an opinion they may not offer an opinion regarding the credibility of others holding that an experts opinion does not warrant exclusion simply because it fails to establish the causal link to a specified degree of probability holding that an experts opinion must be based on facts in evidence or within his or her knowledge and that the admission of an experts opinion is reviewed for an abuse of discretion holding that it is not the courts role to decide whether an experts opinion is correct