Lämpösaastuminen

Lämpösaastuminen, also known as thermal pollution, refers to the degradation of water quality by any process that changes ambient water temperature. In most cases, thermal pollution is caused by human activities, primarily the use of water as a coolant by power plants and industrial manufacturers.

When water is used as a coolant, it is drawn from a natural body of water, used to absorb waste heat, and then discharged back into the water body at a higher temperature. This increase in water temperature can have significant negative impacts on aquatic ecosystems. Higher temperatures reduce the dissolved oxygen (DO) levels in the water, which is essential for the survival of fish and other aquatic organisms. Lower DO levels can lead to stress, reduced reproduction, and even death for many species.

Furthermore, elevated water temperatures can alter the metabolic rates of aquatic organisms, making them more susceptible to diseases and toxins. It can also disrupt spawning cycles and larval development. In some cases, thermal pollution can lead to the displacement of native species by more heat-tolerant invasive species.

Natural sources of thermal pollution include volcanic activity and geothermal springs. However, human-induced thermal pollution is far more widespread and impactful. Mitigation strategies often involve cooling towers or ponds to reduce the temperature of discharged water before it re-enters natural water bodies.