Indigenous groups who speak little or no Spanish present special challenges [Bade, 1994b; Holmes, 2006]. It is possible that workers among these Mexican migrants may have been disproportionately represented among the
30 CAWHS PE Sample participants who refused the blood draw. A folk belief among some Mexican immigrants is that blood drawn from the body is irreplaceable and that drawing it leads to fatigue and other adverse health outcomes. Some indigenous Mexican workers further believe that the blood taken can be used against them or can be sold for malicious purposes [Bade, 1994a,b].