Betel nut powder has been shown by a recent study to cause cancerous tumours in lab mice, and scientists are now concerned that it could have the same effect in human consumers. An immensely popular snack food throughout India, over 50 brands of betel nut powder are marketed as "paan masala", and serve as a convenient format of the traditional post-meal chew. Sales of over 50 brands of the powder amount to a US$200m industry.