Assessment of radioactivity levels and health hazards in welding electrodes using spectrometric and statistical methods

Abstract

Welding is a fundamental aspect of industrial development, yet it involves notable radiological hazards due to the presence of primordial radionuclides in electrodes. This study measured the radioactivity concentrations of ⁴⁰K, ²³⁸U, and ²³²Th in six types of commercially available electrodes using gamma-ray spectrometry with a NaI(Tl) detector. The analysis was complemented with a suite of statistical methods, including the Shapiro-Wilk test, ANOVA, Pearson correlation analysis, and Principal Component Analysis (PCA), to interpret patterns in radionuclide distribution, inter-variable relationships, and the multivariate structure of the dataset. The results confirmed the presence of radioactive isotopes in all electrode types, indicating potential health risks to welders, metalworkers, and the public through inhalation, skin contact, and ingestion. Activity concentrations ranged from 192.48 to 731.81 Bq kg⁻¹ for ⁴⁰K, 9.17–45.76 Bq kg⁻¹for ²³⁸U, and 17.81–34.37 Bq kg⁻¹ for ²³²Th. While electrodes coated with rutile and titanium (stainless and cast-gauge 12 types) showed levels below international averages in terms of absorbed dose, effective dose, and annual gonadal dose, thoriated electrodes exceeded these global standards. Notably, all electrode types surpassed the global threshold for excess lifetime cancer risk (ELCR). PCA revealed that over 98 % of the data variability was captured by the first component, confirming strong co-variation among radioactivity levels and associated risk indices. To reduce health risks, it is recommended that electrode packaging include radiological warnings and that welding be performed in well-ventilated or open-air environments. Optimising radionuclide levels across electrode types and implementing protective measures are essential for occupational safety.