What does turbidity measure in water?

Turbidity is a measure of the cloudiness or haziness of water, which is caused by the presence of suspended particles such as sediments, organic matter, and microorganisms. When these particles are suspended in water, they scatter light, making the water appear cloudy or murky. Turbidity is important in water quality assessments because it can affect aquatic ecosystems, water treatment processes, and overall water clarity. Higher turbidity levels can indicate pollution or disturbance in a water body, leading to potential negative impacts on aquatic life and human health.

In contrast, the other options describe different aspects of water quality that do not relate to turbidity. Temperature variations concern thermal stratification, dissolved gases pertain to oxygen and gas levels in water, and pollutant levels are related to specific harmful substances, none of which directly measure the cloudiness caused by suspended particles.