What is acute myeloid leukemia (AML) and what causes it?

Expert Dr. David Steensma describes acute myeloid leukemia (AML), a blood and bone marrow cancer that happens when a person has too many of a certain type of abnormal cells called blasts. While AML is most common in people over 60, it can happen at any age. People who have had radiation or certain types of chemotherapy for cancer, have a disorder called myelodysplastic syndrome (MDS), smoke or work with certain chemicals have a higher risk of AML.

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What are the specific chemicals known to increase the risk of AML?