An Analysis of the Risk of B-Lymphocyte Malignancies in Industrial Cohorts

Abstract

Among numerous studies of occupational groups with varied chemical exposures (e.g., farmers, petroleum workers, and rubber workers), some have reported excess risk for non-Hodgkin's lymphoma (NHL), multiple myeloma, and other cancers of the B-lymphocyte cell line. While not conclusive, these studies raise questions about the effects of chemical exposures on the lymphocytic versus myeloid cell lines. Almost 70 occupational cohort studies were identified that addressed B-cell cancer risks in 9 major industrial categories, in order to look for common patterns across industries. This effort was substantially limited by the inconsistent nature of lymphohematopoietic (LH) classification schemes across studies and over time, and the relative paucity of B-cell-specific results in studies for any given industry. Taking these limitations into consideration, a descriptive, graphical analysis suggested a pattern of B-cell cancer elevations in the rubber and "general chemical" industries, but no consistent patterns in petroleum production/distribution or petrochemical production. The limited data sources, which lack detail about differences in hazard and exposure for different types of products/chemicals, did not allow a comprehensive look at possible common exposures associated with B-cell cancer elevations across industries. This study suggests that evaluation of possible associations between specific chemical exposures and B-cell malignancies would require additional studies with clear and common definitions of B-cell outcomes. The article concludes by giving an example of a possible common framework for categorizing NHL, the diseases for which most classification issues arise.

Acute myeloid and chronic lymphoid leukaemias and exposure to low-level benzene among petroleum workers

“…CLL is considered a subtype of non-Hodgkin lymphoma (NHL), as both are lymphoid cell malignancies ( Jaffe et al , 2001 ). A review of 68 industrial studies reported several elevated findings for lymphoid cancers (CLL, NHL, multiple myeloma) for rubber workers and cohorts exposed to multiple chemicals ( Bukowski et al , 2003 ). Possibly a more complex environment such as a refinery compared with terminals might tend to show an increased risk for lymphoid tumours such as CLL.…”

Update: cohort mortality study of workers highly exposed to polychlorinated biphenyls (PCBs) during the manufacture of electrical capacitors, 1940-1998

“…Mortality from some diseases associated with smoking and alcohol (cirrhosis of liver and respiratory diseases) was not elevated, although heart disease mortality, particularly ischemic heart disease in men, did not show a "healthy worker" effect [ 27 ]. Myeloma risk has not been associated with smoking and alcohol use [ 28 , 29 ], but it has been linked to occupational chemical exposures [ 30 , 31 ]. It is also unlikely that regional differences contributed to the observed excesses in mortality from intestinal and liver cancers or myeloma since state- and county-based SMRs (not shown) were similar to those using U.S. referent rates.…”

Childhood cancers and atmospheric carcinogens

“…Some of the human reports have decided that 1,3-butadiene and dioxins are significant human carcinogens, 13 14 while others give more cautious ''probable'' or ''possible'' verdicts [15][16][17] and yet others report doubtful or negative effects. [18][19][20][21] Two mass exposure episodes to carcinogens so far remain uninformative including the major escape of dioxins at Seveso and a possible relation between an alleged leukaemia epidemic in Basra and the Gulf war oil well fires in Kuwait and southern Iraq. These uncertainties have inhibited any consistent public health policy.…”