Erythropoietin-independent colonies of red blood cells and leukocytosis in a worker exposed to low levels of benzene.

Background: Exposure to high levels of benzene commonly results in the suppression of hemopoiesis, although cases of leukocytosis and leukocytosis with thrombocytosis have been reported. No hematologic abnormalities have generally been found with exposure to low levels of benzene.

Methods: A pipe fitter exposed to low levels of benzene (time-weighted average 0.