DANIA, Fla. (AP) _ Leo Polk, the most prolific blood donor on record in the United States, died Tuesday of cancer. He was 79.

Polk, who proudly kept detailed records of his many trips to blood banks, donated 320 pints of blood over nearly 60 years. He first gave blood in 1928 and last donated a pint at the dedication of Broward Community Blood Center in 1983.

The American Association of Blood Donors could find no person who had donated more blood than Polk, said Rita Cohl of the Broward Community Blood Center.

Polk, a former AFL-CIO executive from Detroit, retired to south Florida in 1974. He helped organize a number of blood drives, including one at Jackson State Prison in Michigan. For his work, he was named Michigan Man of the Year in 1951.

Blood donors now are required to wait eight weeks between donations, but more lenient rules years ago allowed Polk to give much more frequently, Ms. Cohl said.

Polk stopped donating at the age of 65 after 318 pints when the local blood bank set an upper age limit for donors. But the policy was changed in 1982 and Polk donated twice more.