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.
1. Biodegradable pollutants. 2. Non-biodegradable pollutants. 1. Biodegradable pollutants : Advertisements: Those pollutants which can be broken down into simpler, harmless, substances in nature in due course of time (by the action of micro-organisms like certain bacteria) are called biodegradable pollutants.his balance of the environment may be disturbed by the entrance of some harmful and unwanted components in the environment. These unwanted, harmful components make the environment polluted. This is called pollution.