Radiological safety of hair creams sold in Nnewi metropolis based on natural radionuclide content

Background: The increasing use of cosmetic hair creams has raised concerns regarding the possible presence of Naturally Occurring Radioactive Materials (NORMs) originating from mineral-based and petroleum-derived ingredients used during production. Continuous exposure to radionuclides in cosmetic products may constitute a potential radiological health risk to consumers, thereby necessitating routine assessment of such products.
Objective: This study assessed the activity concentrations of selected radionuclides in commonly used hair creams sold in Nnewi Metropolis, Nigeria, and evaluated their potential radiological hazards to consumers.
Methods: A prospective spectrometric analytical study design was employed. Ten commonly used hair cream products were selected using convenience sampling and analyzed using calibrated gamma spectrometry techniques. The activity concentrations of potassium-40 (40K), radium-226 (226Ra), and thorium-232 (232Th) were determined and expressed in becquerels per kilogram (Bq/kg). Data obtained were analyzed using descriptive statistical methods.
Results: The results showed that 40K had the highest activity concentration among the radionuclides analyzed, ranging from 79.488 ± 4.805 Bq/kg to 138.321 ± 10.992 Bq/kg, with a mean value of 112.0995 ± 8.3864 Bq/kg. The activity concentration of 226Ra ranged from 2.316 ± 0.0806 Bq/kg to 8.836 ± 1.8432 Bq/kg, with an average value of 5.43060 ± 0.77416 Bq/kg, while 232Th ranged from 0.899 ± 0.2189 Bq/kg to 1.878 ± 1.1059 Bq/kg, with a mean concentration of 1.4206 ± 0.60596 Bq/kg. Variations in radionuclide concentrations among the hair cream products were attributed to differences in raw material composition, geographical origin of ingredients, and manufacturing processes. The measured activity concentrations were below internationally recommended radiological safety limits for consumer products, indicating minimal radiological risk associated with the routine use of the investigated hair creams.
Conclusion: The investigated hair cream products sold in Nnewi Metropolis have measured radionuclide concentrations below internationally recommended safety limits. However, periodic radiological monitoring and regulatory surveillance of cosmetic products are recommended to ensure continued public safety and compliance with radiation protection standards.