authors did not state how they got the information and why 115 days was set as the threshold.
An ecologic study by Mills (1998) found no correlation between age-adjusted incidence of testicular cancer and specific pesticide use, including diazinon, in California.
Rapiti and colleagues (1997) studied risk factors for a number of cancers in a cohort of 505 male workers at an Italian chemical production plant. A worker was considered exposed to insecticides if he had ever worked in the insecticide production process. On the basis of three exposed cases of bladder cancer, an SMR of 3.53 (90% CI=0.96–9.12) was observed for exposure to insecticides. The extremely small number of exposed cases and the lack of verifiable individual exposure data limit the value of the findings of this study and do not provide the committee with evidence of an association.
Mellemgaard and colleagues (1994) conducted a case-control study on the possible occupational risk factors associated with kidney cancer. Histologically confirmed cases (n=365) were identified through the Danish Cancer Registry and matched on sex and age to controls (n=396) from the Central Population Register. Study participants were interviewed in their homes to determine lifetime occupation and exposure histories. Risk of kidney cancer was increased in men (OR=2.2, 95% CI=0.8–6.3) and women (OR=5.7, 95% CI =0.6–58) who reported insecticide exposure of at least 1 year’s duration occurring 10 years or more earlier. An increased risk of kidney cancer—adjusted for age, body mass index, and smoking—was observed among men who reported exposure to insecticides or herbicides for less than 20 years (OR=1.3, 95% CI=0.4–4.1) and for 20 years or more (OR=3.9, 95% CI=1.0–15.0). The authors indicated that the potential for recall bias was negligible. The risk of kidney cancer was increased with increasing years of exposure to insecticides or herbicides, on the basis of a small number of exposed cases; however, the exposures included exposure to herbicides, which cannot be separated from insecticide exposure.
Several studies examine the relationship between pesticide exposure and urologic cancers. These studies did not contribute substantially to the committee’s conclusions because of the lack of specificity of exposure to insecticides and the use of job title as a surrogate of exposure. The studies on pesticide exposure and the risk of urologic cancers include: Alavanja et al., 1987; Aronson et al., 1996; Cantor and Booze, 1991; Dich and Wiklund, 1998; Fincham et al., 1992; Fleming et al., 1999a,b; Schlehofer et al., 1995; Sharpe et al., 2001; Viel and Challier, 1995; Wang and MacMahon, 1979; Wesseling et al., 1999; and Wiklund et al., 1989.
The body of literature on individual urologic cancers and exposure to insecticides is small and mostly includes studies of exposure to insecticides in general. Only one study focused on a specific product, the insect repellent DEET. Furthermore, for each urologic cancer, there is no more than one study that provides primary evidence for a conclusion, and