The Biological Oxygen Demand (BOD) test measures what?

The Biological Oxygen Demand (BOD) test specifically measures the amount of dissolved oxygen that aerobic microorganisms will consume while decomposing organic matter in a water sample over a specified period, typically five days. This is an important metric for understanding the level of organic pollution in a body of water. A higher BOD indicates a greater amount of organic material, which can lead to reduced oxygen levels in the water and, subsequently, adverse effects on aquatic life. Therefore, this test is essential for assessing the potential impact of wastewater and other discharges on aquatic ecosystems, making it closely tied to the oxygen consumption by aquatic life.

The other options do not accurately describe what the BOD test measures. While they may relate to water quality, they focus on other factors, such as chemical toxicity, nutrient levels, or pollutants in drinking water, rather than the specific biological activity linked to oxygen consumption.