HEALTH RISK RELATED TO URANIUM-238 INTAKE IN MAIZE

The regular use of phosphate fertilizer in maize crops may increase 238U, the long-lived radionuclide, in agricultural soils. Maize simply accumulated 238U during growth and development. In this study, 238U concentrations were determined in sweet corn or yellow maize (Zea mays saccharata) and flour corn or white maize (Zea mays amylocea) using radioanalytical technique and alpha spectrometry. Samples were collected from maize fields in Mae Ramat district, Tak province in 2018-2019. Health risk of children, juvenile and adults as consumers related to radiation dose and risk of fatal and illness cancer were evaluated. Concentrations of 238U in all investigated samples were found to be generally low, range from 4.98 to 7.47 Bq.kg-1 ww. in sweet corn and from 6.41 to 10.29 Bq.kg-1 ww. in flour corn which was below the average world value for 238U in all food types of 35 Bq.kg-1. Annual committed effective doses due to 238U intakes as a result of sweet corn and flour corn consumption for children, juveniles, and adults were 13.91 ± 1.47, 78.18 ± 3.48, and 34.05 ± 2.29 µSv.y-1, respectively. These individual doses were below the UNSCEAR recommended limit of 120 µSv.y-1. The lifetime cancer risks varied from 1.05 × 10-5 to 2.18 × 10-5 for fatal cancer and 1.61 × 10-5 to 3.34 × 10-5 for illness cancer. These were relatively low compared with the ICRP recommendation risk of 2.5 × 10-3. Results presented herein suggest no health risk effect to consumers related to the intake of 238U from sweet corn and flour corn.