Radiotoxic concentrations and risk levels along the world's coastlines during the quarter of a century

The radioactivity contamination of marine environments polluted by natural and anthropogenic radionuclides has been discussed for decades worldwide. However, there is a lack of data on the current situation and trends in this research field. For this reason, this is the first study to report an integrated data statistical analysis of radioactivity concentration mapping and systematic review using the published database from 2000 to date. The study encompassed five continents: Asia, Africa, Oceania, Europe, and America. The primary sources of natural radioactivity were ²²⁶Ra, ²³²Th, and ⁴⁰K, which are associated with geological features such as coastal structures and the seabed. Also, the contamination of anthropogenic radionuclide ¹³⁷Cs is reported in some places that are released by nuclear reactions. The annual dose rate was proved to be the basis for assessing the radiation risk of natural radioactivity. This research outcome is useful for pointing out the need for future research and supporting the development of this topic.