There is inadequate evidence that t

There is inadequate evidence that the habit of chewing betel quid without tobacco is carcinogenic to humans.

The Working Group also concluded that, while there is sufficient evidence that the combined habits of smoking tobacco and chewing betel quid without tobacco cause oral and pharyngeal cancer, the evidence considered here does not allow an assessment of the possible contribution of betel quid without tobacco to this carcinogenic risk.

There is limited evidence that aqueous extracts of betel quid with and without tobacco are carcinogenic to experimental animals.

There is limited evidence that areca nut with and without tobacco is carcinogenic to experimental animals.

The data are inadequate to allow an evaluation of the carcinogenicity of betel leaf or arecoline to experimental animals.

For definition of the italicized terms