Impact of Phosphate Industry on Natural Radioactivity in Sediment, Seawater, and Coastal Marine Fauna of El Jadida Province, Morocco

Abstract

This study aims to investigate the radiological impact of phosphogypsum (PG) discharge on the marine environment along the coast of the province of El Jadida (Morocco). The specific activity of the main radionuclides present in the raw phosphates, PG, and coastal sands will be measured using gamma spectrometry. The volume activities of radon in samples of sand, seawater, and mussel type Mytilus galloprovincialis will be evaluated using passive alpha dosimetry based on the use of LR115 detectors. The analysis shows that the radioactivity of the raw phosphates was mainly attributed to the radionuclides of the uranium (238U) family that has a specific activity of approximately 1,264 Bq/kg. The results revealed that the production of phosphoric acid (H3PO4)using the wet process has caused a dramatic radioactive imbalance in the 238U family presented in the formed PG. This disequilibrium was due to a reduction in the amount of 238U radionuclides by 84% with a quantitative release of radium (226Ra) radionuclides (845 Bq/kg). Therefore, the discharge of PG into the high seas has caused the contamination of natural beach sand by 226Ra and 238U radionuclides. The specific activity of 226Ra in beach sand increased from 16 to 217 Bq/kg when approaching the industrial discharge point of the phosphates. A large variation was noticed in the volume activities of radon measured in different samples of sand, seawater, and mussel, from 174 to 7,287 Bq/m3, 11 to 354 Bq/m3, and 18 to 497 Bq/m3, respectively. This marine radioactive contamination is spreading over a large area around the PG discharge points, which has a diameter of 10 km. This radioactive pollution could damage marine and coastal ecosystems and harm the livelihood of entire communities.