Geography
How Altitude Affects Human Physiology and Settlement
Quick fact
The highest permanent settlement, La Rinconada in Peru, sits at 5,100 meters (16,700 feet) above sea level, where the partial pressure of oxygen is roughly half that at sea level.
Why this is interesting
You know that climbing a mountain makes you breathe harder, but did you know that entire cities exist above 4,000 meters where the air has 40% less oxygen than at sea level? How do millions of people live there every day?