Plasma polychlorobiphenyl and organochlorine pesticide level and risk of major lymphoma subtypes

Abstract

Background: Conflicting epidemiological evidence exists about an increase in risk of non Hodgkin¡¦s lymphoma (NHL) associated with elevated blood levels of persistent organochlorine (OC) pesticides and polychlorobiphenyls (PCB). Methods: We measured the concentration of 17 OC pesticides, including hexachlorobenzene (HCB), four lindane isomers (ƒÑ-,ƒÒ-,ƒ×-, and ƒÔ-hexachlorocyclohexane (HCH), two chlordane species (heptachlor and oxy-chlordane), four cyclodiene insecticides (Aldrin, Dieldrin, Endrin, and Mirex), and six DDT isomers, and nine PCB congeners, namely congeners 28, 52, 101, 118, 138, 153, 170, 180, and 194, in a plasma sample of 377 subjects, including 174 non Hodgkin¡¦s lymphoma cases and 203 controls from France, Germany, and Spain. Risk of non Hodgkin¡¦s lymphoma and its major subtypes associated with increasing blood level of OC pesticides and PCBs was calculated using unconditional logistic regression. Results: Risk of NHL, diffuse large B cell lymphoma (DLBCL) and chronic lymphatic leukemia (CLL) did not increase with plasma level of HCB, ƒÒ-HCH, p,p¡¦-DDE, total and individual PCB, or their functional groups, in the overall study population. Substantial heterogeneity in DLBCL risk associated with immunotoxic PCBs (p = 0.03) existed between the Spanish subgroup (OR for immunotoxic PCB plasma level above the median vs below the median = 0.7, 95% C.I. 0.3, 1.6) and the French and German subgroups combined (OR = 3.2, 95% C.I. 0.9, 11.5). Conclusion: We did not find evidence of an association between NHL risk and plasma level of OC pesticides and PCBs.