| Untreated | Vehicle | DWCNT 0.125 mg/rat | DWCNT 0.250 mg/rat | DWCNT 0.500 mg/rat | MWCNT 0.500 mg/rat |
---|---|---|---|---|---|---|
Rats examined | 21 | 25 | 25 | 26 | 24 | 9a |
Bronchiolo-alveolar hyperplasia (BAH) | 4 | 4 | 1 | 4 | 0 | 1 |
Bronchiolo-alveolar adenoma (BAA) | 1 | 1 | 3 | 2 | 3 | 1 |
Bronchiolo-alveolar adenocarcinoma (BAC) | 0 | 0 | 1 | 2 | 4 | 2 |
BAA + BAC | 1 | 1 | 4 | 4 | 7* | 3* |
Malignant pleural mesothelioma | 0 | 0 | 0 | 1b | 1b | 0 |
Malignant peritoneal mesothelioma | 0 | 0 | 1 | 0 | 1 | 0 |