1 Substance abuse. Abuse of drugs and alcohol can contribute to panic disorder.  Major life stress. Stressful events and major life transitions, such as the death of a loved one, can sometimes trigger panic attacks, which can potentially recur and go on to become panic disorder.
Zero emission refers to an engine, motor, process, or other energy source, that emits no waste products that pollutes the environment or disrupts the climate. Contents.
That almost equals the 340,000 electric cars and plug-in hybrids now on American roads. Tesla has advertised its vehicles as having zero emissions, helping fuel the mania for the fun-driving sedan, but that's not necessarily true.