Sprague-Dawley rats were given various treatments of 10 ppm fluoride,
25 ppm fluoride, 25 ppm benzene hexachloride (BHC), 10 ppm fluoride 25 ppm BHC, or 25 ppm fluoride + 25 ppm BHC for 16 weeks ad libitum. R
ats showed a decrease in body weight gain, which could be attributable
to BHC alone. A synergistic effect of fluoride and BHC was seen only
in females given 25 ppm fluoride + 25 ppm BHC: a decrease in red blood
cells (RBC) and relative weight of the ovary. Females were more susce
ptible to the toxicity of fluoride and BHC than males.