Total natural gas rig count in the US (including conventional gas drilling) Shale gas is natural gas that is found trapped within shale formations. Shale gas has become an increasingly important source of natural gas in the United States since the start of this century, and interest has spread to potential gas shales in the rest of the world.
A stressor is a chemical or biological agent, environmental condition, external stimulus or an event that causes stress to an organism.[1]
Stress is the process by which we appraise and cope with stressors. A person may consider an event stressful and threatening but at the same time another person may consider the same event a challenge. It all depends on how we perceive the event. If we believe that we have no control over the event and there is nothing we can do to deal with the stressor, then it becomes very stressful.