From "This is your brain on drugs" PSAs to various obesity campaigns, public health messages take to our airwaves, radiowaves, and bus stops to grab us when we're paying attention. Messages of the past tried to draw the public's attention to epidemics like polio and other important public health issues with colorful and creative posters. I recently was browsing through some of these posters on the World Health Organization's website, and I loved the creativity and artistry that went into these posters of the past. They seem more like art than a staid government announcement, and some of them are pretty humorous as well. Check out some of my favorites in the gallery below.