Question

A factory uses lake water as a system coolant, then returns the water, causing thermal pollution. Why is this a problem?A. The water returning to the lake carries chemicals from the factory.B. The water returning to the lake carries coolant toxins with it.C. The water returning to the lake carries pathogens from the factory.D. The water returning to the lake reduces oxygen levels in the lake.

Answer 1

Thermal pollution directly affects only the temperature of the lake. Hence, neither chemicals, toxins nor pathogens are added to the lake by the factory. However, high temperatures may deacrease the amount of dissolved oxygen in the water. Thus, the correct answer is D.