Iron lung was used for the first time in 1928 in a Boston hospital. During the 1940’s and 1950’s, when polio outbreaks were at their worst, some children with polio could not breathe on their own. They were put into iron lungs, and the apparatus used negative pressure to help them breathe. Over 1,200 people needed to use an iron lung. In 1954 mass polio inoculations began to take place. Fewer and fewer people contracted polio, so the need for iron lungs decreased. Today the United States is just about polio-free. Also, newer inventions help people breathe easier and with more mobility. The iron lung is seldom used today.