Risk assessment due to ingestion of natural radionuclides and heavy metals in the milk samples: a case study from a proposed uranium mining area, Jharkhand

Abstract

Ingestion of radionuclides and heavy metals through drinking water and food intake represents one of the important pathways for long-term health considerations. Milk and milk products are main constituents of the daily diet. Radionuclides and heavy metals can be apprehended in the ecosystem of the East Singhbhum region which is known for its viable grades of uranium, copper and other minerals. For the risk assessment studies, samples of milk were collected from twelve villages around Bagjata mining area and analysed for U(nat), 226Ra, 230Th, 210Po, Fe, Mn, Zn, Pb, Cu and Ni. Analysis of the results of the study reveals that the geometric mean of U(nat), 226Ra, 230Th and 210Po was 0.021, 0.24, 0.23 and 1.08 Bq l(-1), respectively. The ingestion dose was calculated to be 12.34 μSvY(-1) which is reflecting the natural background dose via the route of ingestion, and much below the 1 mSv limit set in the new ICRP recommendations. The excess lifetime cancer risk was estimated to be 1.72×10(-4) which is within the acceptable excess individual lifetime cancer risk value of 1×10(-4). The geometric mean of Fe, Mn, Zn, Cu and Ni was 4.91, 0.29, 4.77, 0.56 and 0.48 mgl(-1), respectively; whereas the daily intake was computed to be 0.44, 0.03, 0.43, 0.05 and 0.04 mg/day, respectively. Pb was not detected in any of the samples. The hazard quotient revealed that the intake of the heavy metals through the ingestion of milk does not pose any apparent threat to the local people as none of the HQ of the heavy metals exceeds the limit of 1.

Measurement of Natural and Artificial Radioactivity in Infant Powdered Milk and Estimation of the Corresponding Annual Effective Dose

“…However, this is limited, in that the global economy necessitates the use of materials imported from all around the world. Meanwhile, the nature of the soil-plant ecosystem and particular food (e.g., silage, hay) intake by different organisms/animals (cow in this case) may influence the radioactivity level in the infant formula/milk (Pietrzak-Flis et al, 1997;Giri et al, 2011;Štrok and Smodiš, 2011). Apart from this, the method of food processing and preparation to some extent contributes to the radionuclide redistributions ( Jibiri et al, 2007); this could be another reason for the level of radioactivity in this brand of infant milk under consideration.…”

“…These pollutants may arise from the raw materials, poor quality of production process, subsequent pooling and the storage of milk, adulteration of infant foods (Fein and Falci, 1999), and through the soil-grass-cow milk pathway, especially when cows have fed on hay and silage in higher natural radioactivity areas. In the recent time, several studies have been conducted on milk and milk products consumed in different countries for adequate radiological assessment to forestall unnecessary radiation exposure to humans, particularly the infant population above the limiting index (Osibote et al, 1999;Navarrete et al, 2007;Afshari et al, 2009;Ababneh et al, 2010;Shanthi et al, 2010;Giri et al, 2011;Al-Zahrani, 2012;Alamoudi, 2013). In Malaysia, no surveys of radiation dose through the consumption of infant formula have been carried out and no baseline data of naturally occurring and anthropogenic radionuclides have been reported, considering the fact that over 90% of powdered milk consumed by Malaysian infants (<2 years old) is just being packed locally, but their origins are either Australia or New Zealand.…”

“…Therefore, the activity concentrations of some long-lived natural radionuclides ( 226 Ra, 232 Th, and 40 K) and artificial radionuclide, 137 Cs, have been measured and the annual effective dose due to the intake of radionuclides is estimated for radiological risk assessment to the Malaysian infant population. Note that other studies such as Giri et al (2011) have successfully applied such data to generate risk estimates. The values reported in this study will serve as reference data for natural and artificial radioactivity in the widely consumed powdered infant milk in Malaysia.…”

Assessment of environmental and occupational exposure to heavy metals in Taranto and other provinces of Southern Italy by means of scalp hair analysis

“…The influence of sex (male), habits (smoking), and hair pigmentation (decrement in white hair than dark, red, and light brown/ brown hair) on the heavy metal levels in human scalp hair was found (Wolfsperger et al 1994;Bertazzo et al 1996). Milk is a vector of radionuclides through the soilgrass-cow-milk chain (Licata et al 2004;Giri et al 2011). Seafood consumption is a source of organic mercury (Abe et al 1995), and human hair is recognized as the best indicator of population exposure to methyl mercury.…”

Occurrence of 210 Po and Biological Effects of Low-Level Exposure: The Need for Research

“…Concentrations can be much higher in milk from areas known to be contaminated. For example, the geometric mean 210 Po concentration in milk samples from cattle raised in a uranium-mining district in India was 1.08 Bq/L (Giri et al 2010), with a maximum of 2.94 Bq/L.…”