“…Indeed, exposure to farm animals, pesticides, organic chemicals, and petrol or diesel fuel have been found to be positively associated with HCL (Oleske et al, 1985;Clavel et al, 1995Clavel et al, , 1996Nordstrom et al, 1998). Similar to other studies (Bernstein et al, 1990;Staines & Cartwright, 1993;Groves et al, 1998;Au et al, 2000;Kristinsson et al, 2002;Morton et al, 2006;Paltiel et al, 2006), we demonstrated that HCL predominates in men and also showed that age-specific incidence and age distributions-at-diagnosis differed significantly from those in women. Distinct exposures, timing of exposures and associated latency periods, and/or gene-environment interactions could account for the gender differences we observed in the age distribution patterns of HCL.…”