Radioactivity concentration of 14C in the air of 14C urea breath test rooms and the resulting internal dose to medical staff

Abstract

Objective

To monitor the radioactivity concentration of ¹⁴C in the air of rooms used to perform ¹⁴C urea breath tests, and evaluate the contamination status of ¹⁴C released during such tests, and assess the occupational health risk to medical staff working in such areas.

Methods

¹⁴CO₂ in air was absorbed from the air and turned into calcium carbonate through a chemical reaction. Then, calcium carbonate was prepared into a suspension in a low-potassium glass vial. The sample was analyzed using a low-background liquid scintillation counter.

Results

The radioactivity concentrations of ¹⁴C in air of the breath-test rooms in hospitals and physical examination institutions range from 1.35 to 18.41 Bq/m³. The annual committed dose for medical staff was estimated to be between 2.01 × 10⁻² and 2.74 × 10⁻¹ μSv.

Conclusions

Our results reveal a significant increase of ¹⁴C radioactivity concentration in the air of breath-test rooms, but the resulting committed dose is much lower than the limits prescribed by the International Commission on Radiological Protection (ICRP). However, the potential risk of long-term exposure to low-dose radiation should be paid more attention.