Footnotes

• HW and MNP are joint first authors.

• Collaborators Chinthika S Perera (Centre for Combating Tobacco), WGS Madhushanka Lakmal (Alcohol and Drug Information Centre (ADIC) Sri Lanka).

• Contributors HW and MNP drafted the article. GDS, PRV, DP, SL and IBF did the investigation, obtained photographs and developed the content. MR reviewed and edited the final document. All authors reviewed and approved the publication.

• Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

• Competing interests None declared.

• Patient consent for publication Not required.

• Provenance and peer review Not commissioned; externally peer reviewed.