Past work exposure to benzene or any other hematological toxins;
A family history of blood dyscrasias including hematological neoplasms;
A history of blood dyscrasias including genetic hemoglobin abnormalities, bleeding abnormalities, abnormal function of formed blood elements;
A history of renal or liver dysfunction;
A history of medicinal drugs routinely taken;
A history of previous exposure to ionizing radiation and
Exposure to marrow toxins outside of the current work situation.