Pollution is the introduction of contaminants into an environment that causes instability, disorder, or harm to the ecosystem. It can take the form of chemical substances or energy such as, noise heat or light. The elements of pollution are called pollutants. The pollutants can be foreign substances or energies. They are considered contaminants when they exceed natural levels. The blacksmith institute issues a list of the worlds most polluted places annually. In 2007, most polluted places were China, Peru, Russia, Zambia, Ukraine, and Azerbaijan. A lot of pollution is caused by air pollution. Air pollution comes from both natural and man made sources. Though man made pollutants are more significant. Like construction,mining, and agriculture. Motor vehicle emissions are one of the leading causes in the air pollution. Pollution could be a consequence of natural disaster. Like hurricanes. They involve water contamination from sewage and petrochemical spills from ruptured boats and vehicles. Pollution can cause lots of damage to the environment and we need to do whatever it takes to stop it.