Uranium concentration in groundwater in Hisar city, India.

Groundwater quality of a region can influence the health of its inhabitants. A number of studies have so far been conducted on chemometric analysis of groundwater and shown that the major contaminants present in groundwater of Indian territories are salinity, fluoride, nitrates, arsenic and heavy metals.[1,2] However, some recent studies have reported the presence of natural uranium and other radionuclides, of geogenic origin, in groundwater at several places in India.[3-5]

Uranium is omnipresent and the second heaviest naturally occurring element. It is present in the earth’s crust with an average abundance of 1.8 mg/kg.[6] Natural uranium mainly consists of 238U isotope (99.27%); 235U and 234U isotopes comprising 0.72% and 0.0055%, respectively.

Uranium is present in measurable concentrations in most of the natural water sources. It has been reported that the average concentration of uranium in the ocean water is about 3.0 µg/L. Drinking water contributes to almost 85% of the total ingested uranium by human beings.[5] It has dual effect on human health due to its chemical and radioactive properties.[4] Several authors believe that the chemical toxicity of uranium is more than its deleterious radiological effects.[7] Chemical toxicity of uranium may cause damage to liver, kidneys and reproductive system; it may also induce bone cancer. Keeping this in view, the present study was undertaken to quantify the uranium concentrations in the groundwater of Hisar city, Haryana, India.

Hisar is an approximately 50-km2 wide district city situated in mid-western part of Haryana state, India (29° 09′ 51″ N, 75° 45′ 55″ E). Climate of the area is semi-arid with mean annual temperature of 28.3 °C, ranging from 2 °C in winter to 47 °C in summer. Surface moisture is very low in the region and water table varies from 4–30 m. The area has a population of 350000, ≈30% of whom use groundwater for drinking purposes. The shallow hand-pumps are extensively used by the residents to extract the groundwater from upper layers of the aquifer.

To achieve the objective of this study, 38 groundwater samples were collected from the region in 1-L pre-cleaned polyethylene bottles. Uranium analysis was performed by laser fluorimetry method as described elsewhere.[8]

The uranium concentration in the studied area had a geometric mean of 33.9 (range: 5.3–113.5) µg/L ( Fig 1). The concentration in 77% of samples was lesser than 60 µg/L—the AERB, Indian Standard. But, considering the WHO standrads, only 16% of the samples had uranium concentration within the permissible limit—equal to or lower than 15 µg/L. Considering the results, it is necessary to further study the uranium in groundwater of the region so that health policymakers can develop appropriate strategies to take proper actions.

Figure 1

Distribution of uranium concentration in groundwater in Hisar city, Haryana, India. Values are mean concentration of three readings. Error bars represent 95% CI of the mean.

Acknowledgements

Authors are thankful to Board of Research in Nuclear Science, Department of Atomic Energy, (DAE-BRNS), Mumbai, India, for providing the financial assistance for the conduction this research work.

Conflicts of Interest:

None declared.