title: Dose assessment to workers in a dicalcium phosphate production plant.
abstract: The production of dicalcium phosphate (DCP) uses phosphate rock (PR) as a raw material. Sedimentary phosphate rocks are enriched with relevant concentrations of natural radionuclides from the238U decay chain (around 103Bq·kg-1), leading to the need of controlling potential exposures to radiation of workers and members of the public in accordance with IAEA safety standards. Indeed, phosphate industries are classified as Naturally Occurring Radioactive Material (NORM) industries. Thus, the aim of this work is to assess the radiological risk of the workers in a DCP production plant located in the Iberian Peninsula (South-West Europe), which digests PR with hydrochloric acid. In the present study238U,230Th,222Rn,210Pb and210Po concentrations in aerosols (indoor and outdoor areas) are reported. Aerosols showed concentrations between 0.42-92 mBq·m-3for238U, 0.24-33 mBq·m-3for230Th, 0.67-147 mBq·m-3for210Pb and 0.09-34 mBq·m-3for210Po. Long-term exposure (four months) of passive222Rn detectors provided concentrations that ranged from detection limit (< DL) to 121 Bq·m-3in outdoor areas and from < DL to 211 Bq·m-3in indoor areas, similar to concentrations obtained from short-term measurements with active detectors from < DL to 117 Bq·m-3in outdoor areas and from < DL to 318 Bq·m-3in indoor places.226Ra accumulation in ebonite and pipe scales were the most important contributions to the ambient dose equivalent H*(10), resulting in 0.07 (background)-27 μSv·h-1with a median value of 1.1 μSv·h-1. Average222Rn air concentrations were lower than the 300 Bq·m-3limit and therefore, according to European Directive 2013/59/EURATOM,222Rn concentration is excluded from the worker operational annual effective dose. Thus, considering the inhalation of aerosols and the external dose sources, the total effective dose determined for plant operators was 0.37 mSv·y-1.
authors.affiliation: Institut de Tècniques Energètiques (INTE), Universitat Politècnica de Catalunya, Campus Sud - Edifici PC, E-08028, Barcelona, Spain.
authors.forename: D
authors.initials: D
authors.lastname: Mulas
authors.affiliation: Institut de Ciència i Tecnologia Ambientals (ICTA), Universitat Autònoma de Barcelona, E-08193, Bellaterra, Spain; Departament de Física, Universitat Autònoma de Barcelona, E-08193, Bellaterra, Spain. Electronic address: jordi.garcia@uab.cat.
authors.forename: J
authors.initials: J
authors.lastname: Garcia-Orellana
authors.affiliation: ETH-Zurich, Laboratory of Ion Beam Physics, HPK G26, Otto-Stern-Weg, 5, Zürich, CH-8093, Switzerland.
authors.forename: N
authors.initials: N
authors.lastname: Casacuberta
authors.affiliation: Departament de Física, Universitat Autònoma de Barcelona, E-08193, Bellaterra, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Hierro
authors.affiliation: Departament de Física, Universitat Autònoma de Barcelona, E-08193, Bellaterra, Spain.
authors.forename: V
authors.initials: V
authors.lastname: Moreno
authors.affiliation: Institut de Ciència i Tecnologia Ambientals (ICTA), Universitat Autònoma de Barcelona, E-08193, Bellaterra, Spain; Departament de Física, Universitat Autònoma de Barcelona, E-08193, Bellaterra, Spain; Oceans Institute & School of Physics, The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia; School of Natural Sciences, Edith Cowan University, 270 Joondalup Drive, Joondalup WA, 6027, Australia.
authors.forename: P
authors.initials: P
authors.lastname: Masqué
mesh_terms: D000395:Air Pollutants, Occupational / Q000032:analysis*; D000396:Air Pollutants, Radioactive / Q000032:analysis*; D000398:Air Pollution, Radioactive / Q000706:statistics & numerical data*; D001417:Background Radiation; D002130:Calcium Phosphates; D006801:Humans; D016273:Occupational Exposure / Q000706:statistics & numerical data*; D011829:Radiation Dosage; D000069079:Radiation Exposure / Q000706:statistics & numerical data*; D011834:Radiation Monitoring
chemical_list: D000395:Air Pollutants, Occupational; D000396:Air Pollutants, Radioactive; D002130:Calcium Phosphates; C485829:calcium phosphate, dibasic, anhydrous
keywords: Aerosols; Ambient dose equivalent H*(10); Dicalcium phosphate plant; NORM; Occupational effective dose; Radon