Assessment of heavy metals and radionuclides in groundwater and associated human health risk appraisal in the vicinity of Rooppur nuclear power plant, Bangladesh

Abstract

This study was carried out to assess the groundwater quality through estimating trace and heavy metal concentration and radionuclide levels in the vicinity of the Rooppur Nuclear Power Plant (RNPP) sites. Twenty-six (26) parameters, including major cations (K, Na, Mg, Ca) and anions (SO4−2, NO3−), trace and heavy metals (Mn, Fe, Zn, Ni, Co, Pb, Cd, As, Hg, Cu, Li, Be, B, V, Ga, Sr, Ag, Ba) and radionuclides (137Cs, 226Ra, 228Ra, and 40K) were estimated in water samples in the study area. This study revealed that the concentration values (μg/L) of Mn (667.091 ± 7.481), Fe (191.477 ± 3.756), Sr (105.218 ± 13.424), and Zn (23.493 ± 1.134) were the dominant metals in the study area. Different pollution evaluation indices (i.e., HPI, HEI, NI, Cd) data revealed that the study area was under a low to medium level of pollution due to the presence of metals in water. Subsequently, non-carcinogenic and carcinogenic health risks assessments for both adults and children were conducted, which indicated that health risk for the carcinogenic metals were below the threshold level except As through oral exposure for both adult and children. The activity concentrations of 226Ra, 228Ra, and 40K were measured to demonstrate probable radioactivity pollution using Gamma-ray spectrometry (High-resolution HPGe detector). The highest activity concentration of 226Ra, 228Ra, and 40K in groundwater samples were 4.9 ± 1.24 Bq/L (RNPP-15), 1.71 ± 0.43 Bq/L (RNPP-15), and 15.43 ± 3.08 Bq/L (RNPP-15). Among the three studied radionuclides, 40K has the highest average activity concentration. The radiological indicators referred to the annual effective dose (AED) is 0.4273 mSv yr-1, which implies no significant cause of radiological risks and hazards (UNSCEAR guideline value). This study provides a baseline of trace and toxic metal contamination, radioactivity, and radiation levels in the groundwater of the nuclear power plant (being built) area.