Abstract
WHAT IS ALREADY KNOWN ON THIS TOPIC? Healthcare workers in (131)I treatment facilities face potential occupational internal exposure through inhalation of volatile radioiodine, in addition to external exposure. WHAT IS ADDED BY THIS REPORT? This study presents the first comprehensive national monitoring data on internal exposure among Chinese nuclear medicine (NM) workers. Approximately one-fifth of personnel working at radioiodine treatment sites showed detectable levels of (131)I in their thyroid tissue. WHAT ARE THE IMPLICATIONS FOR PUBLIC HEALTH PRACTICE? These findings provide essential baseline data for enhancing radiation protection protocols in NM facilities and optimizing national internal exposure monitoring.