Infant powdered milk (i.e., infant formula) is a rich and convenient source of nutrients, substituting for human breast milk in many countries. Moreover, it is the basic foodstuff for the infants because of its minerals and proteins, which are essential for their growth and development. However, there are still limited data on radioactivity levels in infant powdered milk around the world, including Malaysia, for radiological health risk assessment. Thus, it is very important to assess the radioactivity levels and the associated dose in the widely consumed powered infant milk. As a result, activity concentrations of 226 Ra, 232 Th, 40 K, and 137 Cs were determined in only 14 brands of powdered milk consumed by Malaysian infants, which are imported from various regions around the world for a cross-sectional survey. The obtained mean activities of 226 Ra, 232 Th, 40 K, and 137 Cs are 3.05 -1.84, 2.55 -2.48, 99.1 -69.5, and 0.27 -0.19 Bq/kg, respectively. Among the analyzed milk samples, the brand from Philippines (Lactogen) showed low level of radioactivity, while a Singaporean brand (S26 SMA Gold) showed the highest. The artificial radionuclide, 137 Cs, is virtually not detected in most of the investigated brands. The estimated mean annual effective doses due to the consumption of powdered milk are 635.13 and 111.45 lSv/year for infants £1 year and infants 1-2 years old, respectively. The obtained dose value is significantly higher (in case of infants £1 year old) and lower (in case of infants 1-2 years old) compared with the UNSCEAR reported value (290 lSv/year) for the general population. In general, values are lower than the FAO/WHO and ICRP recommended limit of 1.0 mSv/year for all ages.

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Owing to population growth, there has been high demand for food across the world, and hence, different agricultural activities such as use of phosphate fertilizers, recycling of organic matters, etc, have been deployed to increase crop yields. In Malaysia, a total of nine composite corn advance lines have been developed at the Institute of Biological Sciences, University of Malaya and are being grown under different conditions with a bid to meet the average daily human need for energy and fiber intake. To this end, the knowledge of radioactivity levels in these corn advance lines are of paramount importance for the estimation of possible radiological hazards due to its consumption. Hence, the radioactivity concentrations of 226 Ra, 228 Ra and 40 K in the corn have been determined using HPGe γ-ray spectrometry. The activity concentrations in the corn ranged from 0.05 to 19.18 Bq kg −1 for 226 Ra, from 0.10 to 3.22 Bq kg −1 for 228 Ra and from 26.4 to 129 Bq kg −1 for 40 K. In order to ascertain the radiological safety of the population regarding maize consumption, the daily intakes of these radionuclides as well as the annual effective dose were estimated. The total effective dose obtained due to the ingestion of radionuclides via maize consumption is 15.39 μSv y −1 , which is less than the international recommendations.

Milk is the basic food stuff for the infants because they generally consume more milk on a daily basis as its minerals and proteins are essential for their growth and development, therefore, it is very important to assess the natural radioactivity levels and the associated dose in the widely consumed powered infant's milk. As a result, 14 brands of infant's powdered milk were collected from different supermarkets around Selangor, Malaysia and analysed for 226 Ra, 232 Th and 40 K activities. The obtained mean activity of 226 Ra, 232 Th and 40 K are 3.05±1.84, 2.55±2.48 and 99.1±69.5 Bqkg-1 , respectively. Among the analysed milk samples, the brand from Philippines (Lactogen) showed low level of radioactivity while Singaporean brand (S26 SMA Gold) showed the highest. The estimated mean annual effective doses due to the ingestion of natural radionuclides in the sampled milk are 635 and 111 µSv for infant ≤ 1y and infant 1-2y, respectively. The obtained dose value does not yet pose any significant radiological hazards to the population under investigation comparing with the 1.0 mSvy-1 recommended by ICRP for all ages.