It is amazing to me as an American that there are people who do not have access to clean drinking water. In countries all over the world people drink ground water (lakes, rivers and ponds) every day. This makes people sick and they die. This poster presents some of the statistical data in a unique way.
I like the treatment of the text here. I like how it follows the form of the person carrying water in a vessel on their head. I believe the goal of the poster is to get people to think about the problem and it is hard to do that with just boring statistical data. By presenting the information in this way they are drawing people in with presentation and getting them interested in reading the information. It is very clever.
The information is not easy to read because of how they have formatted the text but that was obviously not the goal. They wanted to use the information in a way that would humanize the problem. They could have done this in different ways like using a handwriting style typography but instead they presented the information in the form of the person. I feel like since they went with this design the font they chose was great. It is a simple sans serif font that is easy to read. Since there are already so many other challenges in reading it I feel like the font was a good choice. It is good idea If you are going to go this route keep the font clean and simple.