Radon and decay product levels, and radiological risk assessment in human teeth from the Sulaymaniyah Governorate, Iraqi Kurdistan

This research investigated alpha-emitting radionuclide concentrations (222Rn, 226Ra, 214Po, and 218Po) in teeth samples from 78 participants in Sulaymaniyah, Iraqi Kurdistan. The study examined both male and female volunteers across six age subgroups (20–25, 26–30, 31–35, 36–40, 41–45, and 46–50 years). The methodology employed CR-39 solid-state nuclear track detectors to measure radon and decay product levels. The samples were etched with 6.25 N NaOH at 70 ± 0.1°C for 6 hours, and then examined microscopically for track analysis. Mean alpha activity concentrations showed radon levels of 856 ± 688 and 129 ± 124 mBq m−3, radium levels of 10.0 ± 8.0 and 1.5 ± 1.4 mBq kg−1, radon progeny on detector surfaces of 134 ± 108 and 20.1 ± 19.4 mBq m−3, and radon progeny in chamber wall deposits of 24.2 ± 19.4 and 3.6 ± 3.5 mBq m−3 for males and females, respectively. All measured values remained substantially below the global safety standard. Gender-based analysis revealed consistently higher alpha radioactivity in male participants compared to females. Annual effective dose and excess lifetime cancer risk were evaluated for both demographic groups, and all radiological indices were found to be within global reference standards. Statistical analysis demonstrated significant positive correlations between alpha radioactivity concentrations and radiological risk factors across age categories (p- value < 0.001). The results indicate that the study region poses minimal radiological health risks to the population. These findings establish critical baseline parameters for future environmental monitoring, intervention assessment, and evidence-based policy development, with documented gender disparities warranting integration into occupational health guidelines and potentially adjusted exposure limits for high-risk demographic groups.