Figure 1.

Experimental design. GD, gestation day (pregnancy day); PND, post natal day (days afterbirth); DAE, days after exposure. ‘Time-mated mice’ term was used for all exposed mice during gestation and when referring to results of ‘females’ and ‘dams’ together. Time-mated mice that had not given birth or had only few offspring were termed ‘females’.Time-mated females that gave birth were termed ‘dams’. PND 1 and PND 2 offspring were termed ‘newborns’. Offspring on PND 22-23 was termed ‘offspring at weaning’. Offspring on PND 50 (47) termed ‘adolescents’ had not reached sexual maturity. Time-mated mice were exposed by inhalation and intratracheal instillation to Printex 90. Time-mated mice inhaled 42 mg/m³ Printex 90 or filtered air for 1 hour/day for 11 consecutive days on GD 8-18. The daily dose would correspond to 12 hours at the Danish Occupational Exposure Limit of 3.5 mg/m³for carbon black. The total instilled doses were 0, 11, 54 and 268 (Xg/animal were distributed over four instillations on GD 7, 10, 15 and 18. The highest dose was chosen as to be similar to the estimated deposited dose in the pulmonary region from the inhalation study.