Review of Health Effects Research - Agriculture Forestry and Fishing Research at NIOSH - page 96

Mortality resulting from cancer is generally lower in AFF populations than in
the overall American population (Hanrahan et al., 1996). That may be due in part
to greater use of preventive measures and clinical screening in some AFF worker
populations than in other working populations. It could also be due to the protec-
tive effect of some AFF exposures—a phenomenon that deserves further explora-
tion (NIOSH, 2007c). The higher incidence of primary intracranial glioma among
male farmers compared to the general population led to the design and implemen-
tation of a case-control study conducted jointly by NIOSH and two extramurally
funded Ag Centers (Great Plains Center for Agricultural Health in Iowa and the
National Farm Medicine Center in Wisconsin). Results of the effort are emerging.
In general, cancer mortality in American males has declined (American Cancer
Society, 2007), so any decline attributed to occupational exposure needs to exceed
historically observed declines.