area cigarettes danger direction environment health health risk no smoking no smoking in this area sign not allowed pollution prohibition sign unhealthy warning appropriate behavior appropriate behaviour no spitting not permitted penalties permission denied prohibited spit spitting no smoking sign alert appropriate-behavior appropriate-behaviour communicating communication health-risk no-smoking not-allowed not-permitted permission-denied ambulance chemist clinic cross Doctor drug drugstore help hospital medic medical pharmacy point red risk roadsign store switzerland expectorate expectorating historic-sign no-spitting old railway-platform appreciated black symbols thanks white ban banned cease cigar cigarette disease forbidden kills lungs nicotine prohibit quit smoke smokers smoking stop tobacco black-&-white gray grey greyscale