Tellurium and tellurium dioxide: single endotracheal injection to rats

Single endotracheal injections of tellurium and tellurium dioxide, at dosage levels sufficient to cause observable stress in rats, did not result in a progressive fibrotic tissue response after 180 days. The observation period of 180 days is insufficient to assess the lack of tumorigenic potential of these compounds and, therefore, no conclusions on this point are to be inferred.