Development of Analytical methods for the evaluation of the impact of phosphate fertilizer industry on marine environment

Phosphate industries are considered an important potential source of natural radionuclides and heavy metals contamination in the environment. The objective of this work was to assess the marine environmental metallic and radiological pollution and the toxicological impact caused by a large production plant of phosphate fertilizer located on the eastern coast of the Mediterranean Sea, 40 km north of the capital of Lebanon: Beirut. Since 1957 this industry has been producing a large set of phosphate based fertilizers. Phosphogypsum, by-product resulting in the industrial procedure, is released directly in the marine environment. Natural radionuclides (238U, 235U, 226Ra, 232Th, 210Po, 210Pb, and 40K) and anthropogenic 137Cs were measured by alpha and gamma spectrometry in seawater, sediment, coastal sediment and biota. An alpha spectrometer with a passive ion implanted silicon detector was used for the determination of 238U, 234Uin sea water and 210Poin biota samples. 238U, 235U, 232Th, 226Ra,210Pb,137Cs and 40Kin biota and sediments were analyzed by a gamma spectrometer from Canberra, equipped with an extended range low-level coaxial high purity germanium detector with beryllium window.In addition, the radiation exposure of the population surrounding the industrial plant and the internal exposure and potential risks to human due to 210Poand 210Pbassociated with the consumption of fish have been estimated. The internal exposure due to the consumption of fish is important from the radioecology and radioprotection perspectives, and the data for most species studied, are reported for the first time in Lebanon. A multi-elemental method for simultaneous determination of trace elements in seaweeds based on the use of the new approach of collision reaction interface for the ICP-MS determination was optimized. The performance characteristics including linearity, limits of detection and quantification, repeatability, accuracy and truenesswere evaluated. Investigations on the accumulation of metals,including U, Th, Cr, V, Mn, Ni, Co, Cu, As, Cd and Pb were carried out in the gill, liver and kidney of five common fish species, crabs, mussels and Patella using an inductively coupled plasma mass spectrometer (ICP-MS), fitted with an octopole reaction-collision cell. In order to get a deeper insight into the distribution and bioavailability of the studied elements, the cytosolic distribution of heavy metals was analyzed by size exclusion chromatography (SEC) coupled with ICP MS. (author)