Poor air quality is a major problem worldwide. Exposure to air pollution is linked to the premature deaths of an estimated 6.5 million people every year. This makes air pollution the fourth largest threat to human health, trailing only high blood pressure, dietary risks, and smoking.
According to a new report from the U.S. Geological Survey, millions of people living in Oklahoma and parts of Kansas face significant potential for damaging earthquakes this year as a result of human activity. The only other part of the continental United States facing a similar danger is California, which has natural faults lines slicing through the state.