Population health aims to improve the health outcomes of entire groups through considering factors like air, water, and soil pollution that affect populations locally and globally. It is defined as the health outcomes within a group, including the distribution of those outcomes. The term "think globally, act locally" means that environmental factors impacting the world's health are the same as those impacting personal health, as air pollution causes lung disease, chemicals in soil enter the food chain, and water pollution harms both humanity and the planet. More information is available at the provided link.