A two-generation reproduction study in rats with methyl bromide-fumigated diets

Crj:CD(SD) rats were fed basal (control) diet or methyl bromide-fumigated diet containing 80, 200 or 500 ppm total bromine for two successive generations (18 wk for each generation). Compared with controls, food consumption was significantly lower in F1 parental females of the 500-ppm group during the second half of the dosing period, and F2 female pups of the 500-ppm group showed lower body weights throughout the lactation period. No other treatment-related changes were found at any dietary level of total bromine in either parental animals (F0, F1) or their offspring (F1, F2) for any of the parameters studied (i.e. clinical signs, oestrous cycle, sperm count and morphology, mating, fertility, gestation, parturition, litter size, pup viability, organ weights, and gross or histopathological examination). It was concluded that residues of 200 and 500 ppm total bromine in diets fumigated with methyl bromide are the no-observed-effect level and the minimum toxic level, respectively, for both parental rats and their offspring, and that bromine residues do not affect reproductive performance at dietary levels of up to 500 ppm.