Radon Concentration Assessment and Potential Health Impact in Selected Wetlands of Warri, Delta State

Value Warri South LGA Wetlands (Present Study, 2026) 0.143–1.987 ≈0.743 ≈0.49– 4.92* 2.02 × 10−6–2.03 × 10−5* Well below reference value at all sites Bosso, Nigeria (Kolo et al., 2023) 2.8–39.2 14.3 74–104 0.10–0.13 × 10−3 Below reference value Edu, Kwara, Nigeria (Ajibola et al., 2021) 16–28 24.2 237–370 >0.29 × 10−3† Below reference value Yerevan, Armenia (Petrosyan & Perikhanyan, 2022) 2–11 7.1 <100 Below 0.29 × 10−3 Below reference value Ubon Ratchathani, Thailand (Sittitanadol et al., 2026) ≈0.4 ≈0.4 0.78–2.13 Negligible Well below reference value Saudi Arabia Bottled Water (Khan et al., 2026) 0.13–0.39 ≈0.3 1.69–9.24 Negligible Well below reference value The concentrations obtained in the present study are therefore considerably lower than those reported for these Nigerian locations. International studies, including those conducted in Yerevan, Armenia, Thailand and Saudi Arabia, have likewise reported relatively low 222Rn concentrations in water. The comparative results indicate that the Warri wetlands based on the sampled locations and corrected measurements, do not exhibit an unusually high dissolved-radon burden. Rather, the concentrations fall within the lower range of values reported in many published studies as shown in Figure 7. Figure 7 Comparative 222Rn Concentrations, Dose, and ELCR in Drinking-Water Studies Conclusion The radiological interpretation of the Warri South LGA wetlands dataset indicates that radon concentrations are lower relatively to international reference values. From a radiological perspective, all wetlands produced concentrations well below the 100 Bq/L parametric value established by Euratom (2013) and WHO (2008). The calculated annual effective doses (≈0.49– 4.92 μSv/y) are far beneath the 0.1 mSv/year reference dose level, and the excess lifetime cancer risk estimates (≈2.02 × 10−6–2.03 × 10−5) remain negligible compared to the UNSCEAR benchmark of 0.29 × 10−3. These findings indicate that wetland water in Warri South LGA does not pose a significant radiological hazard if consumed directly. This contrasts sharply with elevated risks reported in Nigerian mining regions (Ajibola et al., 2021; Kolo et al., 2023) and highlights the safer baseline observed in Warri, comparable to international studies in Armenia (Petrosyan & Perikhanyan, 2022), Thailand (Sittitanadol et al., 2026), and Saudi Arabia (Khan et al., 2026). The implications of the lower concentrations observed at Market Road, McDermott Road, and Okere are equally important. Although these values were the lowest in Warri, they still confirm the overall safe profile of the wetlands relative to international standards. This reinforces the conclusion that Warri South LGA wetlands are radiologically safe, while also emphasizing the need for continued monitoring and public awareness. References Ajibola, T. B., Orosun, M. M., Lawal, W. A., Akinyose, F. C., & Salawu, N. B. (2021). 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