RETENTION OF 7Be IN THE LUNGS FOLLOWING INTAKE BY INHALATION

Area of Science:

• Occupational health
• Radiological protection
• Environmental science

Background:

• Internal exposure to radioactive particles can occur in occupational settings.
• Beryllium-7 (7Be) is a radionuclide that may be inhaled.
• Understanding radionuclide retention is crucial for dose assessment.

Purpose of the Study:

• To quantify the retention and clearance of inhaled beryllium-7 (7Be) particles in a worker.
• To estimate the initial deposition and committed effective dose following internal exposure to 7Be.

Main Methods:

• In vivo measurements of 7Be in the thoracic region over 108 days post-exposure.
• Analysis of urine samples for 7Be concentration up to 3 days post-intake.
• Modeling of 7Be retention using a two-component exponential function.

Main Results:

• Thoracic retention of 7Be followed a two-component exponential model with half-lives of approximately 0.4 and 109 days.
• Initial thoracic deposition was estimated at 6.8 kBq.
• Urine concentrations ranged from 1 to 10 Bq/l within 3 days post-intake.

Conclusions:

• Long-term retention of 7Be in the respiratory tract was observed.
• The committed effective dose was estimated at 0.3 μSv, acknowledging uncertainties due to unknown particle characteristics.
• This study provides valuable data for internal dosimetry of 7Be exposure.