The trial court erred in granting defendant’s in limine motions to exclude plaintiff’s expert’s testimony that his employment-related exposure to diesel fuel fumes and particulate matter was a substantial factor in causing his non-Hodgkins lymphoma.  To testify regarding causation, the experts did not have to rely on published epidemiological studies liking diesel fuel exposure to lymphoma.  There are many reasons why there may be no publications yet on a subject, but that can’t preclude testimony or recovery by the first few victims.  Also, the trial court erred in thinking there was too great a logical leap between the studies showing that diesel fuel fumes and particulates cause increased risk of cancers in general and the fumes and particulates causing lymphoma in particular.  The experts used accepted scientific studies and methods in reaching their conclusions.  Causation is a matter of scientific judgment and even if disputed is not for the court to decide as a matter of law.