Depression increases your risk of a number of diseases and other conditions by, for example, increasing levels of stress hormones such as cortisol or adrenaline. Depression can affect the immune system, making it harder for your body to fight infection. Vaccinations are even less effective in people with depression.
The total surface area of the Earth is about 7008510000000000000â 510 million km2 (197 million sq mi). Of this, 70.8%, or 7008361130000000000â 361.13 million km2 (139.43 million sq mi), is below sea level and covered by ocean water.
There are 5,280 feet per mile, or 5,280 Ã 5,280 square feet per square mile. Thatâs 27,878,400 square feet per mile. If there are 200 million square miles, then there are 6,000,000,000,000,000 square feet of land on the earth. That leaves about 1,000,000 square feet or land per person on the earth.