Assessing the Excess Lifetime Cancer Risk from Water in the Euphrates River, Najaf, Iraq.

Abstract

Abstract: Water is the basic element for the continuation of human life for all inhabitants, animals and plants on Earth, and water cannot be dispensed with as it is a basis of life. This study focuses on measuring radiation to assess activity levels of some radionuclides in the waters of the Euphrates River, which is the main tributary of drinking water in Najaf, Iraq, and determining whether it is safe for health in terms of radiation. The concentrations of three gamma-emitting nuclides (226Ra, 232Th, and 40K) were measured in a section of the Euphrates River using gamma-ray spectroscopy using a 3" × 3" sodium iodide scintillation detector doped with thallium and connected to software version MAESTRO-32. Twenty-nine water samples were collected at regular intervals along the Euphrates River within the administrative boundaries of Al-Najaf Al-Ashraf Governorate. The Al-Mishkab branch results showed activity concentration levels of 226Ra, 232Th, and 40K that are 3.182 ± 1.514, 1.572 ± 0.509, and 26.715 ± 17.082 Bq L-1, respectively. For Al-Qadesia branch, the activity concentrations are equal to 3.190 ± 1.350, 2.190 ± 1.082, and 37.135 ± 29.464 Bq L-1, respectively, which is within the maximum acceptable concentration levels recommended by the World Health Organization. The annual effective ingestion dose (EID) due to the specific activities of the three nuclides is equal to 0.311 ± 0.103 and 0.357 ± 0.144 mSv y-1 for the Al-Mishkab branch and the Al-Qadesia branch, respectively. The excess lifetime cancer risk (ELCR) values are 1.197 ± 0.395 and 1.373 ± 0.553 × 10-3 for the Al-Mishkab and Al-Qadesia branches, respectively. Therefore, the study concluded that radiation levels in the river water are a significant risk to public health because the concentrations of the studied nuclides are higher than what is globally permitted according to the U.S. Environmental Protection Agency.