When a trial commissioner does not find the claimant credible, the commissioner is entitled to conclude any medical evidence which relied on the claimant's statements was also unreliable. Beverly Herbert, employed by the Connecticut Department of Correction as a social worker for over 20 years, observed ceiling tiles become discolored in her office at the York Correctional Center on a rainy day. Herbert testified that within minutes she began experiencing symptoms of coughing and sneezing, her head and ears filled up and she felt dizzy and nervous. She left the office after approximately 30 minutes. Herbert returned the following day and experienced similar symptoms. She did not return again. Herbert sought medical treatment for respiratory symptoms which she believed were caused by toxic mold exposure and filed a claim for workers' compensation benefits. The trial commissioner dismissed the claim finding that the claimant had not carried her burden of proof that she suffered an injury due to workplace mold or toxin exposure and that the respondent's evidence was more persuasive. Herbert appealed pro se. The Compensation Review Board affirmed the dismissal. The decision was based on the commissioner's weighing and evaluation of factual evidence. As an appellate panel, the board could not reweigh the evidence. Herbert argued that the commissioner should have relied upon the numerous witnesses supporting her claims. However, it is the qualitative value of evidence that decides a contested case before a trial commissioner, not the sheer number of reports or witnesses. The commissioner found that the claimant was not a credible witness and all of the claimant's medical witnesses depended primarily on her narrative. The board could not revisit the commissioner's determination as to witness credibility. The commissioner cited the testimony of an occupational hygienist who conducted a site inspection of the office less than two weeks after the alleged mold exposure and found the presence of mold within normal limits. The hygienist testified that it would have taken about 48 hours for wet ceiling tiles to grow mold. Because the claimant testified to becoming ill shortly after observing a ceiling leak, the commissioner reasonably could conclude that Herbert had not proven that workplace mold was the cause of her ailments.