Health risk assessment of natural radionuclides through the consumption of fish species in Pazhaverkadu Lagoon, Southeast Coast of India

Radionuclides can bioaccumulate in the bodies of aquatic creatures, albeit to trace amounts in the surrounding water. Due of its importance as a fishing destination in South India, the current study is being conducted in the Pazhaverkadu lagoon. For 20 distinct edible fish species, the average fish bone gross alpha and beta activity were 13.25 Bq/kg and 33.10 Bq/kg. The mean values of gross alpha and gross beta activity of fish muscle were 21.98 and 63.56 Bq/kg respectively. Using the alpha and beta emitters, the Annual Effective Dose Equivalent (AED) of 0.52 mSv/y was calculated; this value is below the recommended limit. The mean values of the radiological risk metrics Excessive lifetime cancer risk (ELCR) and Annual Gonadal Dose Equivalent (AGDE) are 0.001 μSv/y and 0.22 μSv/y, respectively. The bioaccumulation of ²¹⁰Po and ²¹⁰Pb for more than 20 fish species was investigated. The mean activity in water samples is therefore 1.42 mBq/l and 2.44 mBq/l, respectively. In contrast, sediment samples have average activity values of 6.51 Bq/kg and 3.16 Bq/kg, respectively. Fish muscle had mean ²¹⁰Po and ²¹⁰Pb activities of 41.58 and 2.61 Bq/kg, respectively, whereas bone had mean activities of 3.005 and 4.51 Bq/kg. The committed effective dose equivalent (CEDE) values for the ²¹⁰Po and ²¹⁰Pb samples in this study varied from 0.04 to 0.22 mSv/y and 0.003–0.027 mSv/y and 8.82 mSv/y, respectively. Fish bones had a concentration ratio of 2.9 × 10³ to 6.5 × 10³ and muscles 1.9 × 10⁴ to 5.2 × 10⁴; similarly, for ²¹⁰Pb, the range was 1.5 × 10³ to 4.0 × 10³ and 1.6 × 10³ to 3.5 × 10³. The results of this investigation show that the values are below the global average and that there is no assessment of the radiological risk to the fish consumers in the Pazhaverkadu lagoon.