Risk Assessment for Natural Uranium in Subsurface Water of Punjab State, India

ABSTRACT

Traces of uranium were measured by laser fluorimeter in 235 subsurface water samples collected from four districts of Punjab state in India. The concentration of U in water samples ranged between <2–644 μg/L with a mean value of 73.1 μg/L. The radiological risk was observed to be in the range of 5.55 × 10⁻⁶–1.78 × 10⁻³ with a mean value of 2.03 × 10⁻⁴, which is around 22% more than the maximum acceptable level (l.67 × 10⁻⁴) as per guidelines of India's Atomic Energy Regulatory Board. The mean of chemical toxicity risk, expressed as life time average daily dose (LADD) was worked out to be 5.56 μg/kg/day with a range of 0.15–48 μg/kg/day by considering a bodyweight of 51.5 ± 8.5 kg, water ingestion rate of 4.05 L/d, and life expectancy of 63.7 yrs for an adult Indian reference man and compared with the reference dose (4.53 μg/kg/day). The average exposure level of U was comparatively high and the chemical toxicity was expected to be more. The mean of hazard quotient (LADD/ RfD) for all four districts was found to be greater than 1, indicating that groundwater may not be suitable for consumption from a chemical toxicity point of view.

Key Words:

• groundwater
• uranium
• laser fluorimeter
• radiological risk
• chemical risk

This article is referred to by:

Letter to HERA's Editor Concerning the Article “Risk Assessment for Natural Uranium in Subsurface Water of Punjab State, India” (Kumar et al. 2011a)

ACKNOWLEDGMENTS

The authors sincerely acknowledge the guidance and help provided by Dr. P.K. Sarkar, Head, Health Physics Division, BARC, Trombay, Mumbai, and Dr A.G. Hegde, Head, Evironmental Studies Section, BARC, Mumbai. The authors thank Professor B.S. Bajwa, HOD, Department of Physics, Guru Nanak Dev University (GNDU), Amritsar, Prof. Lakhwant Singh, Department of Physics, GNDU, Amritsar, for providing necessary facilities, good hospitalities, help in sampling, and for encouragement. The authors are also grateful for financial support given by the Board of Research in Nuclear Science (BRNS), Mumbai, under the memorandum of understanding (MOU) between GNDU, Amritsar, Punjab and the Bhabha Atomic Research Centre, Trombay, Mumbai.