Objectives. This study examined the association between non-Hodgkin's lymphoma (NHL) and farming. Methods. A series of meta-analyses of peer-reviewed studies was performed using 36 studies published between 1982 and 1997. Prior to the meta-analyses, all the studies were reviewed and evaluated for heterogeneity and publication bias. Combined relative risks (RR) were calculated using the random effect model. Results. The combined RR was 1.10 [95% confidence interval (95% CI) 1.03-1.19] for all the studies and 0.93 (95% CI 0.82-1.06) for studies involving female farmers. Significant heterogeneity was detected for study design and country of study among the studies. Significantly elevated RR values were obtained for case-referent studies (combined RR 1.19, 95% CI 1.06-1.33) and for studies conducted on farmers residing in the United States (combined RR 1.26, 95% CI 1.15-1.37). These findings were not influenced by a publication bias. Conclusions. The findings suggest that male farmers residing in the United States have a slightly elevated risk of contracting NHL. Commonly experienced exposures that might contribute to the occurrence of NHL in this group include infectious microorganisms, herbicides, and insecticides.
Financed by the National Centre for Research and Development under grant No. SP/I/1/77065/10 by the strategic scientific research and experimental development program:
SYNAT - “Interdisciplinary System for Interactive Scientific and Scientific-Technical Information”.