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.
miles are pretty much only used in the US but many there consider that to be the world (calling George Bush the leader of the world and other idiotic statements of the like) America has land borders of 12,034km and coastlines 19,924km. So if this is your world then it there are 19858 miles around it.