In a linear, non-threshold dose-effect curve, where does the curve intersect the abscissa?

In a linear, non-threshold dose-effect curve, the curve intersects the abscissa at the origin. This means that even at zero dose, there is a potential for an effect, indicating that any dose, no matter how small, has the potential to cause some harm or biological effect. This characteristic is essential in radiation protection and risk assessment because it implies that there is no safe level of exposure; any amount could theoretically contribute to an increased risk of negative health outcomes.

The concept of a non-threshold curve emphasizes that risk accumulates linearly with exposure, reinforcing the need for minimizing radiation doses. It contrasts with threshold models where a specific dose must be reached before any effect is observed. Therefore, the intersection at the origin signifies that the potential for harm begins from the very first exposure, reinforcing the importance of stringent safety protocols in radiography practices.