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Ujwal P, Yashodhara I, Sudeep Kumara K, Ravi PM, Karunakara N. Environmental transfer parameters of strontium for soil to cow milk pathway for tropical monsoonal climatic region of the Indian subcontinent. Sci Rep 2022; 12:7528. [PMID: 35534517 PMCID: PMC9085734 DOI: 10.1038/s41598-022-11388-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 04/22/2022] [Indexed: 11/09/2022] Open
Abstract
The radionuclide transfer between compartments is commonly described by transfer parameters representing the ratio of concentrations of an element in two compartments for equilibrium conditions. This is a comprehensive study on the soil-to-grass transfer factor (Fv) and grass-to-cow milk transfer coefficient (Fm) for stable strontium (Sr) for soil-grass (pasture)-cow (Bos taurus) milk environmental pathway under field conditions for a high rainfall tropical monsoonal climatic region of the Indian subcontinent. The study was conducted in the vicinity of the Kaiga nuclear power plant (NPP), situated ~ 58 km inland of the West Coast of the Indian subcontinent. A grass field was developed exclusively for this study, and two cows of the native breed were raised to graze on it. The soil, grass, and milk were analyzed to evaluate the Fv and the Fm values for the stable Sr. For comparison, several pasture lands and the cows raised by the villagers and a dairy farm were also studied. The Fv values were in the range 0.18-8.6, the geometric mean (GM) being 1.8. The correlations of Fv values with a range of physicochemical parameters are presented. The GM values for Fm were 2.2 × 10-3 d L-1 and 7.2 × 10-3 d L-1 for the two cows raised for this study, 2.6 × 10-3 d L-1 for those raised by the villagers, and 4.2 × 10-3 d L-1 for the dairy farm. The site-specific Fm value for the region was determined as 3.2 × 10-3 d L-1. The concentration ratio (CR), defined as the ratio of Sr concentration in milk to that in feed under equilibrium conditions, exhibited less variability (1.8 × 10-2-5.4 × 10-2) among the three categories of cows.
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Affiliation(s)
- P Ujwal
- Centre for Advanced Research in Environmental Radioactivity (CARER), Mangalore University, Mangalagangothri, 574199, India
- Department of Science and Humanities, Rajarambapu Institute of Technology, Sangli, Maharastra, 415414, India
| | - I Yashodhara
- Centre for Advanced Research in Environmental Radioactivity (CARER), Mangalore University, Mangalagangothri, 574199, India
| | - K Sudeep Kumara
- Centre for Advanced Research in Environmental Radioactivity (CARER), Mangalore University, Mangalagangothri, 574199, India
| | - P M Ravi
- Centre for Advanced Research in Environmental Radioactivity (CARER), Mangalore University, Mangalagangothri, 574199, India
| | - N Karunakara
- Centre for Advanced Research in Environmental Radioactivity (CARER), Mangalore University, Mangalagangothri, 574199, India.
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Nayak S R, D'Souza RS, Mohan MP, Bharath S, Kamath SS, Dileep BN, Ravi PM, N K. NE-OBT and TFWT activity concentrations in wild plants in the vicinity of the PHWR nuclear power plant and control regions of the tropical monsoonal climatic region of the Indian subcontinent. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2021; 240:106740. [PMID: 34592534 DOI: 10.1016/j.jenvrad.2021.106740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 09/02/2021] [Accepted: 09/13/2021] [Indexed: 06/13/2023]
Abstract
The results of the first detailed study, involving a large number of samples, on water equivalent factor (WEQp), non-exchangeable organically bound tritium (NE-OBT) and tissue free water tritium (TFWT) activity concentrations in predominant plant species of the tropical monsoonal climatic region, are presented. A total of 369 samples from the vicinity of the PHWR nuclear power plant (NPP) at Kaiga, West Coast of India, and 47 samples of the control region (region not affected by local anthropogenic sources) were analysed. The WEQp varied in the range of 0.347-0.666 L kg-1 with an overall mean value of 0.540 ± 0.045 L kg-1. The NE-OBT activity concentration varied in the range of <9.8-60.9 Bq L-1 of combustion water (mean = 24.6 ± 11.5 Bq L-1) and that of TFWT in the range of 9.2-60.5 Bq L-1 (mean = 30.7 ± 10.9 Bq L-1) in the vicinity of the NPP. Rigorous statistical analysis of the data confirmed that (i) the activity concentrations of both forms of tritium decreased with the increase in the distance between the sampling location and NPP, and beyond 10 km, it was similar to that of the control region, (ii) the incorporation of tritium released from the NPP into wild plant leaves is not species-dependent, (iii) the NE-OBT activity concentration in the 5-10 km zone exhibited a dependence on the prevailing wind regime with respect to the NPP, but not in the 2.3-5 km zone which suggests that the transport of tritium, released into the atmosphere as the gaseous effluent, through diffusion is a dominating factor governing its activity concentration in the 2.3-5 km zone. The NE-OBT to TFWT specific activity concentration ratio (R-value) had a mean value of 0.82 ± 0.27 (range: 0.38-1.64) for samples collected from the vicinity of the NPP and 1.93 ± 0.50 (range: 1.35-3.19) for the control region. Recording higher NE-OBT activity concentration and R-value at the control region highlights the necessity of detailed studies to understand the mechanism of NE-OBT partitioning in the terrestrial environment.
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Affiliation(s)
- Rashmi Nayak S
- Centre for Advanced Research in Environmental Radioactivity (CARER), Mangalore University, Mangalagangothri, 574199, India
| | - Renita Shiny D'Souza
- Centre for Advanced Research in Environmental Radioactivity (CARER), Mangalore University, Mangalagangothri, 574199, India
| | - M P Mohan
- Centre for Advanced Research in Environmental Radioactivity (CARER), Mangalore University, Mangalagangothri, 574199, India
| | - S Bharath
- Centre for Advanced Research in Environmental Radioactivity (CARER), Mangalore University, Mangalagangothri, 574199, India
| | - Srinivas S Kamath
- Centre for Advanced Research in Environmental Radioactivity (CARER), Mangalore University, Mangalagangothri, 574199, India
| | - B N Dileep
- Formerly with Environmental Survey Laboratory, Kaiga Generating Station, Kaiga, 581 400, India
| | - P M Ravi
- Centre for Advanced Research in Environmental Radioactivity (CARER), Mangalore University, Mangalagangothri, 574199, India; Formerly with Health Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400 085, India
| | - Karunakara N
- Centre for Advanced Research in Environmental Radioactivity (CARER), Mangalore University, Mangalagangothri, 574199, India.
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