The lungs of Indians, Congolese and Bangladeshis are in worse condition than those of a person who has smoked for years. The UN wants to create a global fund to combat an issue that has become the world’s biggest public health problem
The epicenter is not the center; it's a point above the center. It's from seismology. An earthquake's origin is beneath the earth's surface. The epicenter is the point on the surface that's directly above the origin point.
Yes, it is used like that. However, not just in english, but in many languages, epicentre is sometimes used with the meaning of "centre of something". Moreover, the surface of the Global South is still the Global South, so it is irrelevant.