Solvents, electromagnetic fields, physical activity and non -Hodgkin lymphoma

Non-Hodgkin lymphoma (NHL) is a commonly diagnosed cancer and a leading cause of cancer deaths in the United States. A population based case-control study involving 601 incident cases and 717 controls was conducted among women in Connecticut from 1996-2002 to evaluate association between occupational and environmental exposures and risk of NHL. A job-exposure matrix was applied to assess occupational exposures.;The first study evaluated the role of occupational solvents exposure in the etiology of NHL. An increased risk of NHL was associated with occupational exposure to organic solvents, chlorinated solvents, and carbon tetrachloride. The risks of NHL increased with the increasing cumulative exposure intensity level of organic solvents and chlorinated solvents. Analyses by NHL subtype showed a similar risk pattern for diffuse large B-cell lymphoma as observed for overall NHL. In summary, the study results suggest occupational exposure to solvents increase the risk of NHL.;The second study evaluated the effects of occupational and residential electromagnetic fields (EMF) exposure on the development of NHL. An increased risk of NHL was found to be associated with occupational EMF exposure after excluding occupational EMF exposure with low probability. Furthermore, the risk of NHL increased with occupational exposure intensity and years of duration. In conclusion, findings of the study suggest a positive association between occupational EMF exposure and NHL.;This dissertation further evaluated association between occupational and leisure-time physical activity and the risk of NHL. The study results suggest leisure-time physical activity may reduce the risk of NHL, and occupational physical activity may not be as important as leisure-time physical activity in the development of NHL.;It is necessary for the future epidemiologic researches on NHL to develop more accurate and reliable exposure assessment tools to assess historical and current exposures, as well as explore gene-environment interactions. Further understanding of the factors that increase or decrease risk of NHL can be used to help reduce and prevent the occurrence of this disease.