Sir: We need a strong and concentrated campaign to curb paan (betel) spitting on the streets and walls. Educating people on the menace of paan eating would help curtail this anti-social behaviour. Imposing a fine of Rs 500 or more could also register the enormity of the filth paan spit spreads in the environment. We need our municipal staff to get involved, patrolling areas with the local police, to resolve this issue. SANA SARFARAZ Karachi