i do not think it was too slow. Hey it's possible and where would you go. Just think about it you can't get away. Unless you have a gas mask. In the end it's kind of freaky. Everything adapts in this world and who knows how they could adapt. I just didn't like not seeing how the mom killed herself or that more people were not affected. You see one person not being affected then you don't know if they kill themselves in the end. Not everyone would be affected by this but in the movie they were.