Sri Lanka faces 30 thousand cases of dengue fever a year. A local paper decided to take action and produced a newspaper and associated street advertising with mosquito repellent citronella introduced into the ink. So every letter of every word stopped mosquitos.

1. http://www.youtube.com/watch?v=rMN0_6ytY9I
http://www.themalaymailonline.com/features/
article/the-newspaper-that-repels-mosquitoes
http://en.wikipedia.org/wiki/Citronella_oil
Over 15,000 people have been
infected with dengue fever in Sri
Lanka in the past 6 months alone.
Mawimba, a local newspaper
company, wanted to do something
about this and engaged with Leo
Burnett to create a newspaper
printed with mosquito-repellent ink.
The idea was prompted by people
typically reading newspapers in the
early morning and in the evening,
when dengue mosquitoes are most
likely to strike.
The designers
introduced citronella,
a natural mosquito
repellent, into the
paper’s ink.
Despite an increased print run for the occasion, the paper
had sold out by 10 am and its readership increased by 30%.
See the Video
http://www.springwise.com/newspaper-printed-ink-repels-mosquitoes/