Harrison v. Principi — BVA denial of radiation/chemical service connection affirmed where record provided a plausible factual basis

The veteran served in Nagasaki after the atomic bombing and later developed right lung carcinoma. He sought service connection on theories of radiation exposure and exposure to DDT used in decontaminating prisoners of war. The Board denied the claim, relying on dose information from military sources, the lack of a veteran-submitted dose estimate, the regulatory framework governing radiogenic diseases, and the absence of clinical evidence supporting a chemical-exposure theory. The Board also considered other carcinogenic factors, including the veteran’s heavy smoking history.

On appeal, the Court reviewed the Board’s causation finding under the clearly erroneous standard and held that the record supplied a plausible basis for the Board’s conclusion that the cancer was not caused by radiation or toxic chemicals. The Court further held that the Board satisfied the statutory reasons-or-bases requirement and properly applied the benefit-of-the-doubt doctrine. The decision is useful for showing the limited scope of appellate review where the Board has a record-supported factual basis and has addressed the claimant’s main theories of entitlement.

A Board factual finding on service-connection causation will be upheld if the record provides a plausible basis for the finding and the Board has adequately explained its reasoning.

When the Board assembles a record-supported dose and causation analysis, the Court will generally not reweigh the evidence or substitute its judgment. Advocates must therefore focus on developing competent exposure and nexus evidence to overcome the Board’s factual findings.

Harrison is a useful precedent on deferential review of Board factual findings in radiation-related service-connection cases. It also confirms that the Board’s discussion of alternate exposure theories, competing carcinogenic factors, and benefit of the doubt can be enough to withstand appellate review.

Failure to Address Alternate Theory

A veteran with a later cancer diagnosis argues that in-service exposure to radiation or a toxic substance caused the disease, but the record contains dose estimates and no competent evidence supporting the claimed chemical-exposure theory. The Board denies the claim with an explanation tied to the evidence. Harrison supports affirmance if the Board’s factual finding is plausible and adequately reasoned.

Use this case to frame the high threshold for overturning Board causation findings on appeal and to emphasize the need for competent dose, exposure, or nexus evidence before challenging a denial.

Gilbert v. Derwinski, Lovelace v. Derwinski