I came across this poster in a 'Pansala'.
It is traditional to welcome a distinguished guest arriving at a home of a Sinhalese, with a wicker or brass tray containing betel leaves, arecanut, dried tobacco leaves and lime. This tray was called 'Daehaeth Vattiya'. This was the equivalent of offering a cup of tea to a guest.
Arecanut, tobacco and lime are implicated in cancer of the oral cavity.
The above poster is a media campaign to eliminate these items from the tray and replace them with other spices.