
    In the Matter of the Claim of Relly Adler, Appellant, v Guild Electronics et al., Respondents. Workers' Compensation Board, Respondent.
   Appeal from a decision of the Workers’ Compensation Board, filed July 1,1982. Claimant contends that the record lacks substantial evidence to support the board’s decision finding no causal relationship between decedent’s employment and the disease which resulted in his death. It is undisputed that decedent’s death was caused by immunoblastic lymphoma, a rare form of cancer affecting the lymphatic and immunological systems. Claimant’s expert testified that the disease was directly related to claimant’s exposure to certain toxic substances during his work for the employer. Both the employer’s expert and the impartial specialist were of the opinion that there was no causal relationship between the disease and decedent’s employment since the limited medical research conducted after the disease was defined revealed no connection between the disease and the toxic substances to which decedent was allegedly exposed. The board herein was presented with a case of conflicting medical expert opinions which merely raised a factual issue for the board to resolve (Matter of Slater v Eastman Kodak Co., 78 AD2d 756). Questions of credibility, reasonableness and weight of medical evidence are for the board to decide (Matter ofRothstein v Consolidated Elec. Constr. Co., 84 AD2d 594,595). Cases relied upon by claimant to support her contention that the board erred in finding no causal relationship are inapposite, for in those cases the board resolved the factual issue created by conflicting medical proof in claimant’s favor and found a causal relationship. Here, however, the board resolved the factual issue created by conflicting medical evidence against the claimant, finding no causal relationship. Since the board’s decision is supported by substantial evidence, it must be affirmed. Decision affirmed, without costs. Sweeney, J. P., Kane, Casey, Weiss and Levine, JJ., concur.  