For worker exposure, what is the assumed Equilibrium Ratio?

The assumed Equilibrium Ratio for worker exposure is typically set at 1.0 or 100%. This indicates that the concentration of radon in the air is the same as the concentration of radon in the material (e.g., soil or building materials) leading to the air, representing a state of equilibrium. In this scenario, the assumption is that all radon present in the ground or surrounding materials is released into the air, and thus the exposure potential is maximized.

This assumption is critical for risk calculations and modeling because it helps in establishing the potential for radon accumulation in indoor environments. A ratio of 1.0 simplifies assessments regarding protective measures and mitigation strategies needed to reduce worker exposure to radon.

Other ratios, like 0.5 or 50%, 0.3 or 30%, or 0.8 or 80%, suggest varying levels of atmospheric equilibrium that do not reflect the full exposure risk typically assumed for indoor air scenarios unless there are specific conditions that would warrant such lower ratios. In standard practice, the assumption of 1.0 provides a clear and straightforward baseline for evaluating radon exposure risks.