Which measurement unit is not typically associated with concentration levels in environmental health?

The measurement unit that is not typically associated with concentration levels in environmental health is liters per hour (L/h). Concentration is a way to express the amount of a substance within a specific volume of solution or environment, which is why units like parts per billion (ppb) and milligrams per liter (mg/L) are commonly used. These units directly describe how much of a contaminant is present in a given volume of air, water, or soil, making them vital for assessing exposure and risk in environmental health.

In contrast, liters per hour (L/h) is a unit of flow rate, which measures how quickly a volume of liquid passes a point in a system. While flow rate can be important in certain contexts within environmental health, it does not address concentration directly, as it does not provide information about the amount of substance relative to the volume being measured. Similarly, milliliters per second (mL/s) also indicates a rate, but it is not used for concentration measures either. Thus, these flow rate units stand apart from the concentration metrics vital for environmental health assessments.