Mechanical contamination - this dust and debris. Physical pollution is associated with changes in physical parameters: heat, light, electromagnetic, acoustic, radiation. Thermal pollution due to industrial emissions of warm water and gases. Any sounds generated by non-natural sources, can be considered as noise since no period in human evolution. Noise pollution reduces life expectancy by 8-12 years. Examples of chemical contamination is pesticides, heavy metals, spills negrti. Biological pollution - it's penetration into the ecosystem of alien animals, plants and microorgani sms.