the impact of exposure to pesticides on the risk of gastrointestinal cancer among pistachio farmers; a case-control study

background: gastrointestinal cancers are among the most common cancers in different communities. gastrointestinal tract cancer is the most common cancer among iranian men and the second common cancer among iranian women. due to the impact of environmental factors on the risk of gastrointestinal cancer and the increasing use of agricultural pesticides, this study aimed to investigate the effects of exposure to pesticides on gastrointestinal cancer among  pistachio farmers, rafsanjan, iran materials and methods: in this case-control study, 79 patients with gastrointestinal cancer (cases) and 143 healthy people (controls) were studied. for each case, two people were selected as controls for each case  from  their neighbors and relatives. data were  collected  using the study checklist which included demographic  information and specific items related to their exposure. data were  analyzed using independent t-test, chi-square test, fisher’s exact test, and logistic regression.  results: the risk of gastrointestinal cancer after controlling some confounding factors among individuals who were exposed to  spraying pesticides  for less than 10 days per year was 1.38 (ci: 0.70-2.71), and in individuals who were exposed to it for between 10 to 20 days per year was 1.71 (ci: 0.79-3.7). the difference was not statistically significant . however, for individuals who had this exposure for more than 20 days per year, the risk was increased to 8.53 (ci: 2.1-34.7) which was statistically significant (p = 0.004). unexpected exposure to agricultural pesticides and living close to pistachio gardens, both significantly (p < 0.05) increased the risk of gastrointestinal cancers by 8.67 (ci: 1-75.71) and 2.7 (ci: 1.43-5.1), respectively. among subjects who used  protective equipment, the risk of gastrointestinal cancer was statistically lower (or = 0.18, 95%ci: 0.042-0.85) than this risk among people who did not use this equipment (p = 0.03). conclusions: our findings showed that exposure to pesticides, in particular for long time, increased the risk of gastrointestinal cancer among pistachio farmers. further studies in this area are recommended.