Non-Hodgkin's Lymphoma: An Occupational Disease
Non-Hodgkin’s Lymphomas are cancers of the lymphatic system. Generally, leukemias are those cancers which occur predominantly in the bone marrow and the peripheral blood, while lymphomas occur predominantly at sites other than the bone marrow and the peripheral blood. The blood cells found in the lymph are called lymphocytes. Lymphomas may be found wherever normal lymphocytes go; they may occur in an isolated lymph node or a group of lymph nodes, in organs such as the stomach or intestine, the sinuses, bone, or any combination of these sites. Leukemias may be of lymphocytes or myelocytes, a type of blood cell that is not found in the lymphatic system.
About 23 in 100,000 people are diagnosed with non-Hodgkin’s lymphoma annually. A total of about 74,000 people are diagnosed with lymphoma in the United States each year. The median age at diagnosis is 64. Non-Hodgkin’s lymphomas are uncommonly diagnosed in people under age 50 and is rare among people under age 50.
Non-Hodgkin’s Lymphoma has been associated with occupational exposure to solvents (including benzene), pesticides, and ionizing radiation.
In 2009 the International Agency for Research on Cancer (IARC) concluded that there is “limited evidence” that benzene causes non-Hodgkin’s lymphoma. According to IARC, the designation “limited evidence” means that “a positive association has been observed between exposure to the agent and cancer for which a causal interpretation is considered . . . to be credible, but chance, bias, or confounding could not be ruled out with reasonable confidence.”
In 2010 the President’s Cancer Panel concluded that the evidence between exposure to benzene and non-Hodgkin’s lymphoma is “strong.”
Canada and Germany have recognized non-Hodgkin’s lymphoma as an occupational disease from benzene exposure, and benzene-exposed workers who develop non-Hodgkin’s lymphoma in Canada and Germany may be compensated under the occupational disease laws of those countries.