Topic: News article from India on Areca nut - Betel nit
"Why are they dangerous?
It is postulated that areca nut-specific N-nitroso compounds converted from alkaloids are responsible for oral and pharyngeal cancer. There are several other reports that have linked areca nut chewing (with or without tobacco) to hepatocellular carcinoma, cholangiocarcinoma, cancers of the larynx, stomach, lung and cervix in humans. Animal Research has shown that Pan Masala in the diet led to tumours in various organs, most frequently adenocarcinoma of the lung."