Natural and artificial radioactivity in leafy vegetables cultivated in Singapore and assessment of radiological health risk

The acquisition of radioactivity data in domestically grown vegetables is valuable for the evaluation of radiation exposure to the public from consumption of domestic vegetable produce as Singapore plans to increase its local production of vegetables to enhance food security and reduce the reliance of food imports. In this study, we evaluated the activity concentrations of natural and artificial radionuclides in leafy vegetables cultivated in Singapore using gamma and alpha spectrometry. The mean activity concentrations of ²²⁸Ra, ²²⁶Ra, ⁴⁰K, ¹³⁷Cs and ²¹⁰Po in locally grown leafy vegetables were determined to be 0.124 Bq kg⁻¹, 0.082 Bq kg⁻¹, 164 Bq kg⁻¹, 0.033 Bq kg⁻¹ and 0.098 Bq kg⁻¹ respectively. Assessment of the annual committed effective dose and excess lifetime cancer risk showed that the consumption of domestically grown leafy vegetables constitutes negligible radiological health risk to the Singapore population.