Life Expectancy Changes Between 1950 And 1970

I think the life expectancy change from 69.2 in 1950 to 78.9 in 2007 because . In 1950 America was still just getting started and they were buliding a lot of buildings which causes air pollution so people might have died from contaminated air. Also in the 1950's people were still moving to America from other places so their diseases could of spread to other people that had never had it so their body didn't know how to fight it so they died from sickness. Also they didn't have the technology to cure diseases or vaccinate them.

I think the life epectancy increased from 69.2 from 1950 to 78.9 in 2007 because. In 2007 there was not as much air pollution from bulidings because we had been settled for a while. Also there were still imigrants