| 4 month study |
Chronic (>90 days) |
Group 1 was given a standard laboratory diet to which had been added 150 ppm of NaF (68 ppm of F), Group 2 received the same diet with 15 ppm of added NaF (6.8 ppm of F) and Group 3, the control group, received the standard diet without any added fluoride. The concentrations of NaF added to the diets were the same as those reported by Lu et al. (1961). The concentration of fluoride in drinking water was well below 1 ppm.; 45 male hooded rats were divided into three equal groups at the age of 42 days… Food and water were available ad libitum, except for some weeks before and during the maze experiment, when food was rationed. The daily intake of food was recorded and the animals were weighed at weekly intervals. All the rats were housed in individual cages and kept in an air conditioned room maintained at 72-78 deg F. |