TY - JOUR
AU - Benmhammed, A
AB - Abstract In this work, we considered the concentrations of natural and anthropogenic radionuclides (namely the 40K, 210Pb, 226Ra, 137Cs, 234Th, 228Th and 228Ra) in sediments from Moroccan coast areas by considering estuaries (Sebou and Loukkos) and marine ecosystems (M’diq Bay and three Lagoons: Moulay Bousselham, Sidi Moussa and Oualidia). Sediment samples were analyzed using Gamma spectrometry. The objective was to establish radioactivity levels in Moroccan coastal areas as well as radiological risk assessment by using the ERICA tool. The software allows the estimation of dose rates to biota (a set of reference organisms by default). The highest activity concentrations were found in sediment samples of Sidi Moussa Lagoon, possibly due to the anthropogenic activities, while the lowest levels were reported in Sebou estuary, attributed most probably to a flooding event that occurred in the same year of sampling. Also, 210Pb and 40K have the most significant concentrations, while 137Cs has the lowest concentrations with a great resemblance with similar works. The World Wide Average concentration of 226Ra was exceeded in the three lagoons and that of 40K only exceeded at Sidi Moussa Lagoon. The application of ERICA tool allowed the assessment of total dose rates that are mainly due to internal exposure with strong contribution of 226Ra mainly for phytoplankton in the case of marine ecosystems and insect larvae, mollusc-bivalve, mollusc-gastropod and zooplankton for estuary ecosystems. The total dose rates were far lesser than the admissible dose rate proposed by ERICA tool (10 μGy h−1) and, therefore, unlikely to cause harmful effects to organisms. INTRODUCTION Sediment is any deposit mixture of insoluble material, rock and soil particles, which is transported, by different factors, from land areas to the coastal environment(1). Sediments have an important role to play in the ongoing monitoring of the environment. They act then as both sinks and sources of radionuclides in this environment(2). Knowledge of radionuclide concentrations in the marine environment is important for assessing acceptable levels of radioactivity(3). They are also widely used for radiological risk assessment on human exposure(4–8). However, these works did not address any study of radiological risk assessment for aquatic organisms. In this study, we are interested in Moroccan coastal ecosystems. The latter, with their highly diverse ecosystems, play an important role in the national economy in terms of fishing, tourism, exploitation of salts, aquaculture, irrigated agriculture, tourism etc. Unfortunately, these coasts are the seat of many disturbances caused by human activities such as urbanization, industry, transportation etc.(9, 10). In recent years, several studies have focused on the evaluation of metal pollution and the dating of sediments along Moroccan coastal ecosystems(11–21). So, the objective of this study is focused on determination of activity concentrations of natural (40K, 210Pb, 226Ra, 234Th, 228Ra and 228Th,) and anthropogenic (137Cs) radionuclides, as well as the assessment of the radiological impact due to these radionuclides. MATERIALS AND METHODS Description of the study area For compilation of radionuclide concentrations, we have relied on scientific publications as well as on our own results. So, data were gathered in two estuaries (Sebou and Loukkos) and four marine ecosystems (M’diq Bay and three Lagoons: Moulay Bousselham, Sidi Moussa and Oualidia), in Moroccan coast areas (Figure 1) covering the period from 1997 to 2014. Sebou estuary is located in the northwest of Morocco on the Atlantic coast (34°16′N, 6°34′W). It is one of the largest Moroccan rivers, draining approximately 40 000 km2 and stretches about 600 km from its source in the Middle Atlas to the Atlantic Ocean(22–24). Sebou estuary is a zone of great socioeconomic importance, with the existence of agricultural areas not far from its river bank and the multitude and diversity of industrial units, without forgetting the uncontrolled dumping of household waste that are the main causes of degradation of the quality of this Oued(25, 26). Sebou estuary is characterized by the presence of numerous fish, birds, mammals and bivalves molluscs(27). Concerning the salinity in this estuary, it decreased continuously upstream from the river’s mouth in the Sebou estuary. Also, salinity decreased at a faster rate during the wet season than it did during the dry season(28). In our case, samples were taken from this site in February 2009 after a period of heavy rains that caused flooding in Sebou estuary(16); i.e. during the period of decreasing salinity. Loukkos estuary is 20 km in length, located north of the Moroccan Atlantic coast (35°9′–25°14′N and 6°5′–6°3′W)(29). Loukkos estuary is surrounded by a fishing port on its left bank and sandy beaches northwest of its mouth. It is bordered by agroindustrial infrastructure encompassing many companies operational for the production, processing, packaging and storage of various agricultural products(30). This site is home to several species of plants, insects, fish, amphibians, reptiles, birds and mammals(31). The Loukkos estuary has experienced several flood events overtime(29). In order to protect adjacent regions against inundations, Loukkos estuary knew construction of two dams between 1979 and 1980(32). Those dams used also to regularize the water irrigation of the surrounding soils and to prevent the ascent of saline water from the Sea(33). However, Loukkos estuary may be described as ‘an estuary with a salt corner’ in the wet season and as ‘a partially mixed estuary’ in the dry season(34). Below, when applying Erica, we will consider the Sebou and Loukkos estuaries as fresh water. M’diq Bay is located in the southwest Mediterranean Sea (the Alboran Sea and Strait of Gibraltar) (35°47′N, 04°48′W)(35) with a length of 23 km with depth that varies between 2 and 5 m. The bay is bordered by the Mediterranean Sea to the east and the Rif chain to the west(36). M’diq is one of the most important tourist attractions and it has a port whose main activities are fishing and boating(37). It is fed by wastewater discharge(38) and it suffers from rapid urbanization(39). M’diq Bay is an area rich in shellfish, phytoplankton(40), migratory birds, fishes and the marine mammals. It is a place where the biodiversity appears extremely generous(37).— Moulay Bousselham lagoon covers 35 km2, (34°48′ and 34°53′N, 6°19′ and 6°16′W) on the Moroccan Atlantic coast(41). Moulay Bousselham lagoon has an elliptical shape, with a maximum length of 9 km, a maximum width of 5 km and a depth that varies between 0 and 2 m(42). The flora of the lagoon is estimated at 50 species and fauna is mainly composed of invertebrates and fish(42). Sidi Moussa lagoon occupies an area of 4.2 km2 (32°52′0″N, 8°51′ 05″W). It is located on the western coastal Morocco (our laboratory). This lagoon has an elongated shape. It is part of a rectangle 5.5 km long and 0.5 km wide and the maximum depth of the lagoon is around 2.5 m(42). The vegetation of Sidi Moussa combines 12 families and 27 species. The lagoon of Sidi Moussa is of major importance for the wintering and the passage of several remarkable bird species, and we can note the presence of an interesting amphibian of three Molluscs(42). Oualidia lagoon is spread over an area of 3 Km2, (32°46′N, 09°01′W) on the Atlantic coast, southern Morocco at the industrialized and urbanized El Jadida–Safi axis. The Oualidia lagoon is in the form of an authentic arm of the sea stretched out parallel to the coast, 7 km long and 0.5 km wide with a maximum depth not exceeding 5–6 m(10, 21, 42, 43) and (our laboratory). The macroflora in the lagoon consists of phanerogams, algae and halophyte vegetation. The fauna of the lagoon is made up of Echinoids, Polychaetes and Crustaceans, which are represented by Isopods, Decapods, Copepods and Cladocerans. Upstream, we note the abundance of Molluscs: gastropods and lamellibranchs. The lagoon is also home to species of fish(42). The Moulay Bousselham, Sidi Moussa and Oualidia lagoons are protected by the Ramsar Convention, as a wetland of biological and ecological importance and an area for migratory bird protection(17, 44). Despite this, they are suffering from human activities such as agriculture, rapid urbanization and intensive exploitation of sand quarries(11, 21, 45). Sampling, preparation and analysis The collected sediment samples are the surface sediments as well as the sediment cores. These latter were sampled using a stainless steel tube with inner diameter of 10 cm, and their ends were covered with silicone tops to avoid any contact with the air. The core was sectioned into slices between 1 and 2 cm thickness. Figure 1 Open in new tabDownload slide Map of all coring and surface sediment sampling locations collected in some Moroccan coastal areas from 1997 to 2014. Figure 1 Open in new tabDownload slide Map of all coring and surface sediment sampling locations collected in some Moroccan coastal areas from 1997 to 2014. All collected sediment samples were oven dried to constant weight and finely crushed (ground). Once ground, the samples obtained were conditioned in plastic bottles closed and hermetically sealed for a minimum period of 3 weeks (to prevent escape of 222Rn gas) before being analyzed by Gamma Ray Spectrometry (the time necessary to reach a secular equilibrium between 226Ra and 214Pb; the latter was used to estimate 226Ra, i.e. supported 210Pb activity(22)). The sealed samples were then counted for 1–3 days. Gamma-emitting radionuclides were measured using hyperpure germanium detectors Gamma Ray spectrometry. More details about this technique have been reported in the scientific literature(46, 47). The measurement of the activity of 210Pb was determined by its gamma emission at 46.5 keV, and that of 226Ra was estimated from the 295 and 352 keV γ-rays emitted by its daughter isotope 214Pb. The 137Cs was measured by its emission at 662 keV. The activity of 228Th was obtained from the activity of its daughter 212Pb radionuclide at 239 keV, 228Ra from the activities of 228Ac at 338 and 911.0 keV, 234Th at 63.3 and 92.5 keV and 40K at 1460 keV(8, 22). In some cases, 210Pb concentrations in sediments were inferred by measurement of the daughter product, 210Po, by alpha spectrometry(35). In fact, 210Po is an important radionuclide that could be considered, but that it cannot be detected by gamma spectrometry, so it is not considered in this work. The activity concentrations of radionuclides in the sediment samples, namely, 40K, 210Pb, 226Ra, 137Cs, 234Th, 228Th and 228Ra expressed in Bq kg−1 dry weight (dw) are given by our laboratory as well as by Moroccan studies, where the data are accessible(21, 22, 29, 35, 41, 43, 48, 49). The low number of references considered in this work is due to the lack of data in table form in most of the articles dealing with this subject. In this study, for core sediments, we consider only the surface layer, because when applying the ERICA tool, we assumed that the reference organisms spend their time on the sediment surface. Description of ERICA tool The assessment of the radiological risk on non-human biota is carried out by the ERICA tool (version 1.2); indeed, ERICA is the abbreviation of environmental risk from ionizing contaminants: assessment and management. It is freely available software program, used to assess radiological risk to terrestrial, freshwater and marine biota, and it includes a set of default organisms and parameter values and allows at the same time to use our own organisms and parameter values if they are available. In this work, we will limit to freshwater and marine ecosystems. ERICA implements three tiered approaches: generic screening, detailed screening and probabilistic assessment capability. This approach is described in more detail by(50–53). So tier 1 is characterized by its simplicity, and it requires a minimum of input data and allows the calculation of the Environmental Media Concentration Limits (EMCLs) to estimate the Risk Quotients (RQ), according to the following formulas: $$\begin{equation} \mathrm{EMCL}=\frac{\mathrm{SDR}}{F}. \end{equation}$$(1) $$\begin{equation} {\mathrm{RQ}}_n=\frac{M_n}{{\mathrm{EMCL}}_n}<1. \end{equation}$$(2) SDR: Screening Dose Rate (or dose rate without effect), recommended in ERICA at 10 μGy h-1(54). The 10 μGy h−1 incremental screening dose rate is the result of an analysis of chronic exposure data from among the 26 000 data on the effects of ionising radiation in non-human biota collated in the FRED effects database and covering the period 1945–2007(55); F: The maximum dose rate that an organism will receive for a unit activity concentration of a given radionuclide in an environmental medium {mGy h−1 per Bq L−1 dw in water (or per Bq kg−1 dw in sediment)}; Mn: The maximum measured activity concentration for radionuclide “n” in medium M in Bq L−1 (or kg−1). We can examine and edit most of the parameters used in the calculation such as reference organisms (Table 1), concentration ratios (CR), dose conversion coefficients (DCC), occupancy factors (OF) etc. (Figure 2) that enable us to estimate dose rates to biota from internal and external radionuclide distributions. Table 1 Reference organisms for marine and freshwater ecosystems in the ERICA methodology. Reference organism . In marine ecosystem . In freshwater ecosystem . Benthic fish Bird Crustacean Mammal Mollusc-bivalve Pelagic fish Phytoplankton Reptile Vascular plant Zooplankton Macroalgae Mollusc-gastropod Polychaete worm Insect larvae Sea anemones & true coral Amphibian Reference organism . In marine ecosystem . In freshwater ecosystem . Benthic fish Bird Crustacean Mammal Mollusc-bivalve Pelagic fish Phytoplankton Reptile Vascular plant Zooplankton Macroalgae Mollusc-gastropod Polychaete worm Insect larvae Sea anemones & true coral Amphibian Open in new tab Table 1 Reference organisms for marine and freshwater ecosystems in the ERICA methodology. Reference organism . In marine ecosystem . In freshwater ecosystem . Benthic fish Bird Crustacean Mammal Mollusc-bivalve Pelagic fish Phytoplankton Reptile Vascular plant Zooplankton Macroalgae Mollusc-gastropod Polychaete worm Insect larvae Sea anemones & true coral Amphibian Reference organism . In marine ecosystem . In freshwater ecosystem . Benthic fish Bird Crustacean Mammal Mollusc-bivalve Pelagic fish Phytoplankton Reptile Vascular plant Zooplankton Macroalgae Mollusc-gastropod Polychaete worm Insect larvae Sea anemones & true coral Amphibian Open in new tab Figure 2 Open in new tabDownload slide Underlying approach to Environment Impact Assessment in ERICA.(56) Figure 2 Open in new tabDownload slide Underlying approach to Environment Impact Assessment in ERICA.(56) So, tier 2 is based on seven parameters, to know: Distribution coefficients (Kds) is defined as the ratio between the specific activity of sediment given in Bq Kg−1 dw and that of the overlying water in Bq Kg−1: $$\begin{equation} \mathrm{Kd}=\frac{\mathrm{Concentration}\ \mathrm{per}\ \mathrm{unit}\ \mathrm{mass}\ \mathrm{of}\ \mathrm{particulate}}{\mathrm{Concentration}\ \mathrm{per}\ \mathrm{unit}\ \mathrm{mass}\ \mathrm{of}\ \mathrm{water}\ }. \end{equation}$$(3) So, if we have activity of sediment, by this formula, we can calculate the activity of water and vice versa. For sediment core, we consider the activity in the upper sediment slice. Also, Concentration ratio or Water biota concentr- ation factor (CF) is used to obtain water concentrations from those in biota given in Bq.Kg−1 wet weight (fw) and that of the overlying water in Bq.L−1 or the opposite according to this formula: $$\begin{equation} \mathrm{CF}=\frac{\mathrm{Activity}\ \mathrm{concentration}\ \mathrm{in}\ \mathrm{whole}\ \mathrm{organism}}{\mathrm{Activity}\ \mathrm{concentration}\ \mathrm{in}\ \mathrm{water}}. \end{equation}$$(4) CF values differ from one organism to another. For example, (CF) in fish differ from those in molluscs and differ from those in crustaceans etc. For water, sediment (soil) and organisms, we use our own data if they are available. In this study, we use ERICA default value. Percentage dry weight soil or sediment are fixed at 100% by TRS 422 to enable a conversion to wet weight. Radiation weighting factors represent the relative biological effectiveness of the different radiation types (alpha, beta and gamma), used to convert physical dose (Gy) to equivalent dose (Sv). $$\begin{eqnarray} \mathrm{Equivalent}\ \mathrm{dose}=\mathrm{Absorbed}\ \mathrm{dose}\ast \mathrm{Radiation}\nonumber\\ \mathrm{weighting}\ \mathrm{factor}. \end{eqnarray}$$(5) ERICA proposes 10 for alpha radiation, 1 for beta and gamma radiation and 3 for low beta radiation. The Occupancy Factor is the fraction of time of a given organism spends at a location in its habitat; it varies between 0 (absence of the organism) and 1 (presence of the organism all the time). Uncertainty Factor is used to account for uncertainties in the input data and other parameters. ERICA estimates the value 3 to provide the dose rates and risk quotients at the 95th percentile, which means that the probability that the risk quotient exceeds 1 and the dose rates exceed 10 μG.h−1 is less than or equal to 5%. And the last parameter is Dose Conversion Coeffi- cients(DCC) relating activity concentration to dose rates. They are specific to each radionuclide and depend on several factors as, the radiation types, the habitat, the size of the organism and its pathways of exposure. $$\begin{equation} \mathrm{DCC}=\frac{\mathrm{Dose}\ \mathrm{rate}}{\mathrm{Activity}\ \mathrm{concentration}}. \end{equation}$$(6) The DCC are used to derive internal dose rates by (7) and together with `occupancy factors', external dose rates for reference organisms in the exposure medium (8). $$\begin{equation} {\dot{D}}_{\mathrm{int}}^j=\sum_i{C}_i^j\cdot{\mathrm{DCC}}_{\operatorname{int},i}^j. \end{equation}$$(7) |${C}_i^j$|⁠: The average concentration radionuclide i in the reference organism j (Bq Kg−1 fw); |${\mathrm{DCC}}_{\operatorname{int},i}^j$|⁠: The radionuclide-specific dose conversion coefficient for internal exposure (μG h−1 per Bq Kg−1 fw). $$\begin{equation} {\dot{D}}_{\mathrm{ext}}^j=\sum_z{\nu}_z\ \sum_i{C}_{zi}^{\mathrm{ref}}\cdot{\mathrm{DCC}}_{\operatorname{ext}, zi}^j. \end{equation}$$(8) ν: The occupancy factor of the organism j at location z; |${C}_{zi}^{\mathrm{ref}}$|⁠: The average concentration of radionuclide i in the reference media in a given location z; |${\mathrm{DCC}}_{\operatorname{ext}, zi}^j$|⁠: The dose conversion coefficient for external exposure. Total dose rate is assessed by summing the two equations. $$\begin{equation} {\dot{D}}_{\mathrm{Tot}}^j={\dot{D}}_{\mathrm{int}}^j+{\dot{D}}_{\mathrm{ext}}^j. \end{equation}$$(9) And using with screening dose rate (SDR) to determine the RQ. $$\begin{equation} \sum \mathrm{RQ}=\frac{{\dot{D}}_{\mathrm{Tot}}^j}{\mathrm{SDR}}<1. \end{equation}$$(10) The third level (tier 3) is reserved for complex situations and will not be detailed here. This level may need to consider biological effects data in the database FREDERICA data, or undertake ecological studies. Tier 3 is a probabilistic study where the user estimates the probability occurrence and severity of radiological effects on the environment that may occur, which allows to discuss the acceptability of the risk for non-human species. RESULTS AND DISCUSSION Natural and anthropogenic radioactivity levels The results of activity concentrations due to 40K, 210Pb, 226Ra, 137Cs, 234Th, 228Th and 228Ra (Bq kg−1 dw) in sediment samples are given in Figure 3. The mathematical average (the sum of all the values divided by the number of values) and range values (the minimum value and the maximum value) are presented in Table 2. Before beginning, we should say that the sediments were sampled only once during the time period from 1997 to 2014. Indeed, we added, for Oualidia lagoon, the concentrations of 210Pb (1281 Bq Kg−1 dw) obtained in 1997(21) in order to highlight this high concentration, while the other reference considered(43) constitutes a complement to the work carried out by our laboratory. Figure 3 Open in new tabDownload slide Histogram of mean values of radionuclide activity concentrations in some Moroccan coastal areas. Figure 3 Open in new tabDownload slide Histogram of mean values of radionuclide activity concentrations in some Moroccan coastal areas. Table 2 Activity concentrations of radionuclides in sediment samples taken from some Moroccan coastal areas. Location . Activity concentrations in sediment (Bq kg−1 dw) . Sampling date . Reference . 40K . 210Pb . 226Ra . 137Cs . 234Th . 228Th . 228Ra . Sebou estuary 319 (209–385) 45 (39–55) 18 (16–19) 3 (1.7–3.5) 19 (16–20) 28 (26–30) 15 (16–21) April 2009 (22) Loukkos estuary — 21 10 3.2 — — — 2004 (29) M’diq Bay — 680 28 — — — — Dec. 1999 (35) Moulay Bousselham lagoon — 479 39 2.4 — — — 2009 (41) Sidi Moussa lagoon 428 (403–461) 2099 (1762–2588) 66 (55–78) 2.3 (1.9–2.7) 241 (126–348) — 23 (19–25) mai-2014 Our laboratory Oualidia lagoon 348 (291–380) 754 (227–1281) 34 (20–47) 2.28 55 (26–76) — 10 1997–2012 (21, 43) Our laboratory Location . Activity concentrations in sediment (Bq kg−1 dw) . Sampling date . Reference . 40K . 210Pb . 226Ra . 137Cs . 234Th . 228Th . 228Ra . Sebou estuary 319 (209–385) 45 (39–55) 18 (16–19) 3 (1.7–3.5) 19 (16–20) 28 (26–30) 15 (16–21) April 2009 (22) Loukkos estuary — 21 10 3.2 — — — 2004 (29) M’diq Bay — 680 28 — — — — Dec. 1999 (35) Moulay Bousselham lagoon — 479 39 2.4 — — — 2009 (41) Sidi Moussa lagoon 428 (403–461) 2099 (1762–2588) 66 (55–78) 2.3 (1.9–2.7) 241 (126–348) — 23 (19–25) mai-2014 Our laboratory Oualidia lagoon 348 (291–380) 754 (227–1281) 34 (20–47) 2.28 55 (26–76) — 10 1997–2012 (21, 43) Our laboratory Open in new tab Table 2 Activity concentrations of radionuclides in sediment samples taken from some Moroccan coastal areas. Location . Activity concentrations in sediment (Bq kg−1 dw) . Sampling date . Reference . 40K . 210Pb . 226Ra . 137Cs . 234Th . 228Th . 228Ra . Sebou estuary 319 (209–385) 45 (39–55) 18 (16–19) 3 (1.7–3.5) 19 (16–20) 28 (26–30) 15 (16–21) April 2009 (22) Loukkos estuary — 21 10 3.2 — — — 2004 (29) M’diq Bay — 680 28 — — — — Dec. 1999 (35) Moulay Bousselham lagoon — 479 39 2.4 — — — 2009 (41) Sidi Moussa lagoon 428 (403–461) 2099 (1762–2588) 66 (55–78) 2.3 (1.9–2.7) 241 (126–348) — 23 (19–25) mai-2014 Our laboratory Oualidia lagoon 348 (291–380) 754 (227–1281) 34 (20–47) 2.28 55 (26–76) — 10 1997–2012 (21, 43) Our laboratory Location . Activity concentrations in sediment (Bq kg−1 dw) . Sampling date . Reference . 40K . 210Pb . 226Ra . 137Cs . 234Th . 228Th . 228Ra . Sebou estuary 319 (209–385) 45 (39–55) 18 (16–19) 3 (1.7–3.5) 19 (16–20) 28 (26–30) 15 (16–21) April 2009 (22) Loukkos estuary — 21 10 3.2 — — — 2004 (29) M’diq Bay — 680 28 — — — — Dec. 1999 (35) Moulay Bousselham lagoon — 479 39 2.4 — — — 2009 (41) Sidi Moussa lagoon 428 (403–461) 2099 (1762–2588) 66 (55–78) 2.3 (1.9–2.7) 241 (126–348) — 23 (19–25) mai-2014 Our laboratory Oualidia lagoon 348 (291–380) 754 (227–1281) 34 (20–47) 2.28 55 (26–76) — 10 1997–2012 (21, 43) Our laboratory Open in new tab The activity concentrations of 40K, 210Pb, 226Ra, 137Cs, 234Th, 228Th and 228Ra were found to be in the range (209–461), (21–2588), (10–78), (1.7–3.5), (16–348), (26–30) and (10–25) Bq kg−1 dw, respectively. Except for anthropogenic radionuclide (137Cs) that presents the lowest value and nearly the same results at all sites, the other radionuclides present the highest values particularly in Sidi Moussa lagoon probably due to its proximity to the industrial phosphate plants and other anthropogenic activities(11). The different radionuclides can be divided as follows (Figure 4): 210Pb with an average concentration of 680 Bq kg−1 dw, or 55% of all radionuclides 40K with an average concentration of 365 Bq kg−1 dw, with a percentage of 30% 234Th with an average concentration of 105 Bq kg−1 dw, with a percentage of 9% 226Ra with an average content of 33 Bq kg−1 dw, i.e. 3% 228Th, with an average concentration of 28 Bq kg−1 dw, with a percentage of 2% 228Ra with an average content of 16 Bq kg−1 dw, i.e. a percentage of 1% 137Cs has an average concentration of 3 Bq kg−1 dw, with a percentage lower than 1% Figure 4 Open in new tabDownload slide Percentage contribution of radionuclides in different sediment samples. Figure 4 Open in new tabDownload slide Percentage contribution of radionuclides in different sediment samples. Overall, 210Pb has the highest concentrations; it is the predominant radionuclide observed. 210Pb and 226Ra activities in the Sebou and Loukkos estuaries sediments show the lowest activities similar to those measured in Moroccan soils(57), reflecting deposition of eroded local soil and mixing with sediment as a result of heavy rains and floods(22). As for 40K, it is possibly coming in Sebou estuary from erosion, transport and deposition of large quantities of soil following flood event(22), and the presence of the clay in Oualidia lagoon(58, 59) and Sidi Moussa lagoon(58, 60); in fact, the clays contain a relatively high concentration of potassium, while 137Cs has the lowest contents. In fact, as there is no nuclear activity at the sampling sites, the detection of this anthropogenic radionuclide, even at the low concentrations obtained, is mainly due to atmospheric fallout coupled with natural decay following its deposition or remobilization from sediment into seawater(8). By comparing our results with similar works reported in sediment samples from other coastal areas of the world in Mediterranean Sea and Atlantic Ocean (Table 3), we note that, with the exception of Sidi Moussa lagoon that experiences high concentrations of 210Pb and Algeria Bay Algeria characterized by high contents of 137Cs, our results are almost in agreement with the values obtained by these works. Table 3 Activity concentrations of radionuclides in sediment samples taken from other coastal zones of the world. Location . Activity concentrations in sediment (Bq kg−1 dw) . Sampling date . Reference . 40K . 210Pb . 226Ra . 137Cs . 234Th . 228Th . 228Ra . Algerian Basin Algeria — 460–800 36–42 8.4–9.4 — — — 2001–2004 (60) Algeria Bay Algeria 374 (56–607) — 16 (4.5–25) 4.2 (0.9–9.5) — — 19.5 (6.5–32) — (61) Burullus Lake Egypt 312–325 — 13–17 3.5–8.9 — — — 2002 (62) Dakar Senegal 261 (63–626) — — — — — — 2015–2016 (63) Gran Canaria Spain 518 (130–1055) — 18 (8–27) — — — — — (64) Greater Accra Ghana 320 (250–570) 210 (20–310) 14 (10–20) 1.5 (0.5–2.3) — 31 (20–72) 29 (18–67) 2013 (8) Location . Activity concentrations in sediment (Bq kg−1 dw) . Sampling date . Reference . 40K . 210Pb . 226Ra . 137Cs . 234Th . 228Th . 228Ra . Algerian Basin Algeria — 460–800 36–42 8.4–9.4 — — — 2001–2004 (60) Algeria Bay Algeria 374 (56–607) — 16 (4.5–25) 4.2 (0.9–9.5) — — 19.5 (6.5–32) — (61) Burullus Lake Egypt 312–325 — 13–17 3.5–8.9 — — — 2002 (62) Dakar Senegal 261 (63–626) — — — — — — 2015–2016 (63) Gran Canaria Spain 518 (130–1055) — 18 (8–27) — — — — — (64) Greater Accra Ghana 320 (250–570) 210 (20–310) 14 (10–20) 1.5 (0.5–2.3) — 31 (20–72) 29 (18–67) 2013 (8) Open in new tab Table 3 Activity concentrations of radionuclides in sediment samples taken from other coastal zones of the world. Location . Activity concentrations in sediment (Bq kg−1 dw) . Sampling date . Reference . 40K . 210Pb . 226Ra . 137Cs . 234Th . 228Th . 228Ra . Algerian Basin Algeria — 460–800 36–42 8.4–9.4 — — — 2001–2004 (60) Algeria Bay Algeria 374 (56–607) — 16 (4.5–25) 4.2 (0.9–9.5) — — 19.5 (6.5–32) — (61) Burullus Lake Egypt 312–325 — 13–17 3.5–8.9 — — — 2002 (62) Dakar Senegal 261 (63–626) — — — — — — 2015–2016 (63) Gran Canaria Spain 518 (130–1055) — 18 (8–27) — — — — — (64) Greater Accra Ghana 320 (250–570) 210 (20–310) 14 (10–20) 1.5 (0.5–2.3) — 31 (20–72) 29 (18–67) 2013 (8) Location . Activity concentrations in sediment (Bq kg−1 dw) . Sampling date . Reference . 40K . 210Pb . 226Ra . 137Cs . 234Th . 228Th . 228Ra . Algerian Basin Algeria — 460–800 36–42 8.4–9.4 — — — 2001–2004 (60) Algeria Bay Algeria 374 (56–607) — 16 (4.5–25) 4.2 (0.9–9.5) — — 19.5 (6.5–32) — (61) Burullus Lake Egypt 312–325 — 13–17 3.5–8.9 — — — 2002 (62) Dakar Senegal 261 (63–626) — — — — — — 2015–2016 (63) Gran Canaria Spain 518 (130–1055) — 18 (8–27) — — — — — (64) Greater Accra Ghana 320 (250–570) 210 (20–310) 14 (10–20) 1.5 (0.5–2.3) — 31 (20–72) 29 (18–67) 2013 (8) Open in new tab According to the world reference value for soils(66) but also considered by several authors for sediments(22, 67–69), we observe that the values of 226Ra in Moulay Bousselham, Sidi Moussa and Oualidia lagoons were higher than the world range value fixed at 35 Bq kg−1(66), since these areas are highly urbanized that leads to overexploitation by many activities such as aquaculture, sand quarries, use of fertilizers etc.(9, 24) and industrialized (for example industrial phosphate plants at Sidi Moussa lagoon)(11). Recommended value of 40K (400 Bq kg−1)(66) is only exceeded at Sidi Moussa lagoon. These values are respected in Sebou and Loukkos estuaries and in M’diq Bay. Application of ERICA tool Before applying the ERICA tool, it should be noted that due to the lack of data on the organisms at the sampling sites for this study, we relied on the thirteen (13) reference organisms suggested by the ERICA database (Table 1). Also, the highest measured activity concentrations in the sediments (Bq kg−1 dw) were used as input data to represent ‘worst-case scenarios’. As well, since, by default, 40K was not included in the ERICA database, this isotope was also not considered here(8). Moreover, default values have been systematically used for all ecosystems (the distribution coefficients (Kd), concentration ratios (CF), occupancy factors etc.). To finish, we only considered the surface layer of the sediment cores, because we assumed, as said before, that the reference organisms spend their time on the sediment surface also Kd for sediment core consider only the activity in the upper sediment slice. And finally, it is necessary to begin by tier 1, in order to decide whether or not to use tier 2. As we have two ecosystems, we divided our study into two parts: Freshwater ecosystems As said before, we consider Sebou and Loukkos estuaries as freshwater. The sum of the risk quotients for those estuaries is greater than 1, so we cannot conclude that the radiological risk to the environment is negligible (Table 4). The ERICA tool then recommends conducting the second tier. Table 4 Risk quotients and limiting reference organisms at Sebou and Loukkos estuaries using Tier 1 of the ERICA tool. Isotopes . Risk quotient (unitless) . Limiting reference organism . Freshwater EMCLs for sediments (Bq kg−1 dw) by ERICA . Sebou estuary . Loukkos estuary . 210Pb 1.10E−02 4.20E−03 Mollusc-bivalve 5.00E03 226Ra 6.78 3.57 Insect larvae 2.80 137Cs 2E−04 1.85E−04 Reptile 1.75E04 234Th 1.73E−02 − Vascular plant 1.06E03 228Th 2.02E01 − Vascular plant 1.48 228Ra 1.77E-02 − Mollusc-bivalve 1.19E03 ∑ Risk quotients 2.70E01 > 1 3.57 > 1 Isotopes . Risk quotient (unitless) . Limiting reference organism . Freshwater EMCLs for sediments (Bq kg−1 dw) by ERICA . Sebou estuary . Loukkos estuary . 210Pb 1.10E−02 4.20E−03 Mollusc-bivalve 5.00E03 226Ra 6.78 3.57 Insect larvae 2.80 137Cs 2E−04 1.85E−04 Reptile 1.75E04 234Th 1.73E−02 − Vascular plant 1.06E03 228Th 2.02E01 − Vascular plant 1.48 228Ra 1.77E-02 − Mollusc-bivalve 1.19E03 ∑ Risk quotients 2.70E01 > 1 3.57 > 1 Open in new tab Table 4 Risk quotients and limiting reference organisms at Sebou and Loukkos estuaries using Tier 1 of the ERICA tool. Isotopes . Risk quotient (unitless) . Limiting reference organism . Freshwater EMCLs for sediments (Bq kg−1 dw) by ERICA . Sebou estuary . Loukkos estuary . 210Pb 1.10E−02 4.20E−03 Mollusc-bivalve 5.00E03 226Ra 6.78 3.57 Insect larvae 2.80 137Cs 2E−04 1.85E−04 Reptile 1.75E04 234Th 1.73E−02 − Vascular plant 1.06E03 228Th 2.02E01 − Vascular plant 1.48 228Ra 1.77E-02 − Mollusc-bivalve 1.19E03 ∑ Risk quotients 2.70E01 > 1 3.57 > 1 Isotopes . Risk quotient (unitless) . Limiting reference organism . Freshwater EMCLs for sediments (Bq kg−1 dw) by ERICA . Sebou estuary . Loukkos estuary . 210Pb 1.10E−02 4.20E−03 Mollusc-bivalve 5.00E03 226Ra 6.78 3.57 Insect larvae 2.80 137Cs 2E−04 1.85E−04 Reptile 1.75E04 234Th 1.73E−02 − Vascular plant 1.06E03 228Th 2.02E01 − Vascular plant 1.48 228Ra 1.77E-02 − Mollusc-bivalve 1.19E03 ∑ Risk quotients 2.70E01 > 1 3.57 > 1 Open in new tab The application of tier 2 allows us to estimate radionuclide activity concentrations for water and the 13 reference organisms in freshwater ecosystem in Bq kg−1 fresh weight (fw) (Figure 5) using radio-ecological parameters such as Kd and CF. Activity concentrations for water are much less than the unity, so they were neglected in this work. Figure 5 Open in new tabDownload slide Activity concentrations, risk quotients and external and internal dose rates for all reference organisms in freshwater ecosystems. Figure 5 Open in new tabDownload slide Activity concentrations, risk quotients and external and internal dose rates for all reference organisms in freshwater ecosystems. For Sebou estuary, we remark that insect larvae, mollusc-bivalve, mollusc gastropod and zooplankton present relatively high concentrations, especially for 226Ra and 228Ra, followed by 210Pb compared to other radionuclides. Crustacean also knows a relative elevation of 210Pb. We remark also that the three radionuclides of this biota have the same order of magnitude as those of the sediments. And, the risk quotients calculated for all organisms are less than the unity, indicating that considered reference organisms are not at risk. In terms of dose rates, internal dose rate especially for 226Ra contributes most for all organisms, while the contribution for the external dose rate is negligible. The organisms (insect larvae, mollusc-bivalve, mollusc gastropod and zooplankton) receive the maximum total dose rate, about half of the screening dose rate of 10 μGy h−1, so in this case, ERICA recommends reviewing assessment and results; this does not necessarily mean an automatic progression to Tier 3; for instance, it may be possible to refine the input data or tool parameters (monitoring data, objective of the assessment, obtain CR vales applicable to the site etc.) and to then rerun the assessment at Tier 2(55). For Loukkos estuary, we find almost the same results with acceptable maximum total dose rate. Marine ecosystems Especially for M’diq Bay and the three lagoons (Moulay Bousselham, Sidi Moussa and Oualidia), we always have the sum of the risk quotients greater than 1 (Table 5), so we go to tier 2. Table 5 Risk quotients and limiting reference organisms at M’diq Bay and Moulay Bousselham, Sidi Moussa and Oualidia lagoons using Tier 1 of the ERICA tool. Isotopes . Risk quotient (unitless) . Limiting reference organism . Marine EMCLs for sediments (Bq kg−1 dw) by ERICA . M’diq Bay . My. Bousselham lagoon . Sidi Moussa lagoon . Oualidia lagoon . 210Pb 2.92E−01 2.05E−01 1.11 5.50E−01 Phytoplankton 2.33E03 226Ra 1.55 2.16 4.31 2.60 Phytoplankton 1.81E01 137Cs — 9.53E−05 1.07E−04 9.21E−05 Reptile 2.48E04 234Th — — 8.18E−03 1.79E−03 Phytoplankton 2.26E04 228Ra — — 1.90E−03 7.62E−04 Polychaete worm 1.31E04 ∑ Risk quotients 1.84 > 1 2.36 > 1 5.43 > 1 3.15 > 1 Isotopes . Risk quotient (unitless) . Limiting reference organism . Marine EMCLs for sediments (Bq kg−1 dw) by ERICA . M’diq Bay . My. Bousselham lagoon . Sidi Moussa lagoon . Oualidia lagoon . 210Pb 2.92E−01 2.05E−01 1.11 5.50E−01 Phytoplankton 2.33E03 226Ra 1.55 2.16 4.31 2.60 Phytoplankton 1.81E01 137Cs — 9.53E−05 1.07E−04 9.21E−05 Reptile 2.48E04 234Th — — 8.18E−03 1.79E−03 Phytoplankton 2.26E04 228Ra — — 1.90E−03 7.62E−04 Polychaete worm 1.31E04 ∑ Risk quotients 1.84 > 1 2.36 > 1 5.43 > 1 3.15 > 1 Open in new tab Table 5 Risk quotients and limiting reference organisms at M’diq Bay and Moulay Bousselham, Sidi Moussa and Oualidia lagoons using Tier 1 of the ERICA tool. Isotopes . Risk quotient (unitless) . Limiting reference organism . Marine EMCLs for sediments (Bq kg−1 dw) by ERICA . M’diq Bay . My. Bousselham lagoon . Sidi Moussa lagoon . Oualidia lagoon . 210Pb 2.92E−01 2.05E−01 1.11 5.50E−01 Phytoplankton 2.33E03 226Ra 1.55 2.16 4.31 2.60 Phytoplankton 1.81E01 137Cs — 9.53E−05 1.07E−04 9.21E−05 Reptile 2.48E04 234Th — — 8.18E−03 1.79E−03 Phytoplankton 2.26E04 228Ra — — 1.90E−03 7.62E−04 Polychaete worm 1.31E04 ∑ Risk quotients 1.84 > 1 2.36 > 1 5.43 > 1 3.15 > 1 Isotopes . Risk quotient (unitless) . Limiting reference organism . Marine EMCLs for sediments (Bq kg−1 dw) by ERICA . M’diq Bay . My. Bousselham lagoon . Sidi Moussa lagoon . Oualidia lagoon . 210Pb 2.92E−01 2.05E−01 1.11 5.50E−01 Phytoplankton 2.33E03 226Ra 1.55 2.16 4.31 2.60 Phytoplankton 1.81E01 137Cs — 9.53E−05 1.07E−04 9.21E−05 Reptile 2.48E04 234Th — — 8.18E−03 1.79E−03 Phytoplankton 2.26E04 228Ra — — 1.90E−03 7.62E−04 Polychaete worm 1.31E04 ∑ Risk quotients 1.84 > 1 2.36 > 1 5.43 > 1 3.15 > 1 Open in new tab According to Figure 6a and b, the application of tier 2 allows us to estimate radionuclide activity concentrations in the 13 reference organisms in marine ecosystem. Figure 6 Open in new tabDownload slide Open in new tabDownload slide (a) Activity concentrations, risk quotients and external and internal dose rates for all reference organisms in marine ecosystems (Case of M’diq Bay and My. Bousselham lagoon). (b) Activity concentrations, risk quotients and external and internal dose rates for all reference organisms in marine ecosystems (Case of Sidi Moussa and Oualidia lagoons). Figure 6 Open in new tabDownload slide Open in new tabDownload slide (a) Activity concentrations, risk quotients and external and internal dose rates for all reference organisms in marine ecosystems (Case of M’diq Bay and My. Bousselham lagoon). (b) Activity concentrations, risk quotients and external and internal dose rates for all reference organisms in marine ecosystems (Case of Sidi Moussa and Oualidia lagoons). We note that biota, especially phytoplankton, present the highest concentrations for 210Pb compared to other radionuclides and exceed 210Pb levels in sediments. Sediments may therefore be an important source of 210Pb exposure to biota. This is an indication of a high potential for 210Pb bioaccumulation by phytoplankton(8), suggesting that it could be a good bioindicator for monitoring of radionuclide contamination. Also, the RQ calculated for all organisms are less than the unity, indicating that phytoplankton is not at risk. In terms of dose rates, 226Ra is the main contributor to the internal dose particularly for phytoplankton, while the contribution for the external dose rate is negligible. The maximum total dose rate is far less than the screening dose rate of 10 μGy h−1, so we may justifiably exit the assessment at this stage. Finally, we get nearly the same results for M’diq Bay and the three lagoons (Moulay Bousselham, Sidi Moussa and Oualidia). Recapitulation I present here a recapitulation of the results obtained from the application of ERICA tool (Table 6), distinguishing the two ecosystems considered, namely freshwater and marine with the sediments, reference organisms that received the higher radioactivity levels that could be considered as a good bioindicator for monitoring radionuclide contamination in the studied sites, as well as their highest RQ and internal dose rates that remain lower respectively to the unity and the screening dose rate. Table 6 Recapitulation of the results obtained from the application of ERICA tool for all ecosystems. Location . Freshwater ecosystem . Marine ecosystem . . Sebou estuary . Loukkos estuary . M’diq . Moulay Bousselham lagoon . Sidi Moussa lagoon . Oualidia lagoon . Radionuclides 210Pb 226Ra 228Ra 210Pb 226Ra 210Pb 210Pb 210Pb 210Pb Higher concentration in sediments (Bq kg−1 dw) 45 18 15 21 18 680 479 2099 754 Higher concentration in organism (Bq kg−1 fw) 22 33 36 8.5 17 1225 863 4663 2308 Risk quotient (unitless) 0.45 0.24 0.09 0.12 0.27 0.16 External dose rate (μGy h−1) Negligible Max. internal dose rate for 226Ra (μGy h−1) 4.5 2.4 0.83 1.2 2.3 1.4 Organisms Insect larvae, Mollusc-bivalve, Mollusc-gastropod, zooplankton Phytoplankton Location . Freshwater ecosystem . Marine ecosystem . . Sebou estuary . Loukkos estuary . M’diq . Moulay Bousselham lagoon . Sidi Moussa lagoon . Oualidia lagoon . Radionuclides 210Pb 226Ra 228Ra 210Pb 226Ra 210Pb 210Pb 210Pb 210Pb Higher concentration in sediments (Bq kg−1 dw) 45 18 15 21 18 680 479 2099 754 Higher concentration in organism (Bq kg−1 fw) 22 33 36 8.5 17 1225 863 4663 2308 Risk quotient (unitless) 0.45 0.24 0.09 0.12 0.27 0.16 External dose rate (μGy h−1) Negligible Max. internal dose rate for 226Ra (μGy h−1) 4.5 2.4 0.83 1.2 2.3 1.4 Organisms Insect larvae, Mollusc-bivalve, Mollusc-gastropod, zooplankton Phytoplankton Open in new tab Table 6 Recapitulation of the results obtained from the application of ERICA tool for all ecosystems. Location . Freshwater ecosystem . Marine ecosystem . . Sebou estuary . Loukkos estuary . M’diq . Moulay Bousselham lagoon . Sidi Moussa lagoon . Oualidia lagoon . Radionuclides 210Pb 226Ra 228Ra 210Pb 226Ra 210Pb 210Pb 210Pb 210Pb Higher concentration in sediments (Bq kg−1 dw) 45 18 15 21 18 680 479 2099 754 Higher concentration in organism (Bq kg−1 fw) 22 33 36 8.5 17 1225 863 4663 2308 Risk quotient (unitless) 0.45 0.24 0.09 0.12 0.27 0.16 External dose rate (μGy h−1) Negligible Max. internal dose rate for 226Ra (μGy h−1) 4.5 2.4 0.83 1.2 2.3 1.4 Organisms Insect larvae, Mollusc-bivalve, Mollusc-gastropod, zooplankton Phytoplankton Location . Freshwater ecosystem . Marine ecosystem . . Sebou estuary . Loukkos estuary . M’diq . Moulay Bousselham lagoon . Sidi Moussa lagoon . Oualidia lagoon . Radionuclides 210Pb 226Ra 228Ra 210Pb 226Ra 210Pb 210Pb 210Pb 210Pb Higher concentration in sediments (Bq kg−1 dw) 45 18 15 21 18 680 479 2099 754 Higher concentration in organism (Bq kg−1 fw) 22 33 36 8.5 17 1225 863 4663 2308 Risk quotient (unitless) 0.45 0.24 0.09 0.12 0.27 0.16 External dose rate (μGy h−1) Negligible Max. internal dose rate for 226Ra (μGy h−1) 4.5 2.4 0.83 1.2 2.3 1.4 Organisms Insect larvae, Mollusc-bivalve, Mollusc-gastropod, zooplankton Phytoplankton Open in new tab CONCLUSION As conclusion of this work, we found that sediment samples in Sidi Moussa lagoon are characterized by the highest activity concentrations due to human activities. And, the lowest levels of sediment samples were in Sebou estuary due to the effect of the flood period. For the other sampling areas, concentrations were nearly of the same order of magnitude. Among the studied radionuclides, 210Pb and 40K were those of significant contributions (717 ± 33 Bq kg−1 dw and 356 ± 24 Bq kg−1 dw, respectively), followed by 234Th and 226Ra (71.4 ± 10.2 Bq kg−1 dw and 35.4 ± 10.3 Bq kg−1 dw, respectively) and in the last position 137Cs (4.44 ± 0.45 Bq kg−1 dw) with in general an agreement with similar works.. Furthermore, the international standards for the natural radionuclides have been exceeded several times (for 226Ra in the three lagoons and for 40K in Sidi Moussa lagoon). Finally, the application of ERICA tool revealed the highest contribution to the internal dose rate due to 226Ra. The obtained results indicate no significant radiation impact. Despite the insufficient data in this work, we managed to get a good idea for all the ecosystems treated. ACKNOWLEDGEMENT This work is a part of the Coordinated Research Project (CRP) with IAEA on Behavior and Effects of Natural and Anthropogenic Radionuclides in the Marine Environment and their use as Tracers for Oceanography Studies. CONFLICT OF INTEREST The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. References 1. Abdullah , A. , Hamzah , Z., Saat , A. and Wood , A. K. Vertical and horizontal distribution of radionuclides (232Th, 238U and 40K) in sediment from Manjung Coastal Water Area Perak, Malaysia. Advancing Nuclear Science and Engineering for Sustainable Nuclear Energy Infrastructure AIP Conf. Proc. 1704, 050011; doi: 10.1063/1.4940107 . 10p ( 2016 ). 2. Rudjord , A. L. , Oughton , D., Bergan , T. D. and Christensen , G. Radionuclides in Marine Sediments—Distribution and Processes . (IFE, Ås, Noway: Norwegian Radiation Protection Authority, Agricultural University ) pp. 81 – 106 ( 2001 ). Google Scholar Google Preview OpenURL Placeholder Text WorldCat COPAC 3. Hassan , N. N. and Khoo , K. S. Measurement of natural radioactivity and assessment of radiation hazard indices in soil samples at Pengerang, Kota Tinggi, Johor. In: Advancing Nuclear Research and energy Development AIP Conference Proceedings . Vol. 1584 . pp. 190 – 195 ( 2014 ). doi: 10.1063/1.4866130 . 4. Zakaly , H. M. , Uosif , M. A. M., Hashim , M., Issa , S. and Tamam , M. Radiological hazards resulting from natural radioactivity in sediments at Ras Gharib Coast, Red Sea, Egypt . Int. J. New Horiz Phys 3 , 5 – 10 ( 2016 ). Google Scholar OpenURL Placeholder Text WorldCat 5. Uosif , M. A. M. , Issa , S. A. M., Ebrahim , A. A., Zahran , E. M. and Moussa , M. Determination of natural radioactivity in building raw materials from the quarries of Assiut cement company, Assiut, Egypt . Int. J. New Horiz. Phys. 1 , 25 – 32 ( 2014 ). Google Scholar OpenURL Placeholder Text WorldCat 6. Uosif , M. A. M. , Hashim , M., Issa , S., Tamam , M. and Zakaly , H. M. Natural radionuclides and heavy metals concentration of marine sediments in Quseir City and surrounding areas, Red Sea Coast-Egypt . Int. J. Adv. Sci. Technol. 86 , 9 – 30 ( 2016 ). Google Scholar Crossref Search ADS WorldCat 7. El Gamal , A. A. Assessment of natural radioactivity distribution in surface sediments at erosion and accretion sites of Nile Delta Coastal Profiles, Egypt . Int. J. Marine Sci. 4 , 1 – 12 ( 2014 ). Google Scholar OpenURL Placeholder Text WorldCat 8. Botwe , B. O. , Schirone , A., Delbono , I., Barsanti , M., Delfanti , R., Kelderman , P., Nyarko , E. and Lens , P. N. L. Radioactivity concentrations and their radiological significance in sediments of the Tema Harbour (Greater Accra, Ghana) . J. Radiat. Res. Appl. Sci. 10 , 63 – 71 ( 2017 ). Google Scholar Crossref Search ADS WorldCat 9. Maanan , M. Etude sédimentologique du remplissage de la Lagune Sidi Moussi (Côte Atlantique Marocaine): Caractérisation granulométrique, Minéralogique, géochimique . ( El Jadida : Chouaib Doukkali University, Science Faculty ) p. 132 ( 2003 ). Google Scholar Google Preview OpenURL Placeholder Text WorldCat COPAC 10. Idardare , Z. , Moukrim , A., Chiffoleau , J. F., Ait Alla , A., Auger , D. and Rozuel , E. Evaluation de la contamination métallique dans deux lagunes marocaines: Khnifiss et Oualidia . Rev. maroc. des sci. agron. et vétérinaires. 2 , 58 – 67 ( 2013 ). Google Scholar OpenURL Placeholder Text WorldCat 11. Benmhammed , A. , Laissaoui , A., Mejjad , N., Ziad , N., Chakir , E., Benkdad , A., Bouh , H. A. and el Yahyaoui , A. Recent pollution records in Sidi Moussa coastal lagoon (western Morocco) inferred from sediment radiometric dating . J. Environ. Radioact. 227 , 106464 ( 2021 ). Google Scholar Crossref Search ADS PubMed WorldCat 12. Kalloul , S. , Hamid , W., Maanan , M., Robin , M., Sayouty , E. and Zourarah , B. Source Contributions to Heavy Metal Fluxes into the Loukous Estuary (Moroccan Atlantic Coast) . J. Coast. Res. 28 , 174 – 183 ( 2012 ). Google Scholar OpenURL Placeholder Text WorldCat 13. Laissaoui , A. , Mejjad , N., Ziad , N., Ait Bouh , H., El Hammoumi , O., Benkdad , A. and Fekri , A. Evidence for a recent increase in delivery of atmospheric 210 Pb to Oualidia lagoon, coastal Morocco . Environ. Monit. Assess. 190 , 1 – 9 ( 2018 ). Google Scholar Crossref Search ADS WorldCat 14. Maanan , M. , Landesman , C., Maanan , M., Zourarah , B., Fattal , P. and Sahabi , M. Evaluation of the anthropogenic influx of metal and metalloid contaminants into the Moulay Bousselham lagoon, Morocco, using chemometric methods coupled to geographical information systems . Environ. Sci. Pollut. Res. 20 , 4729 – 4741 ( 2013 ). Google Scholar Crossref Search ADS WorldCat 15. Maanan , M. , Saddik , M., Maanan , M., Chaibi , M., Assobhei , O. and Zourarah , B. Environmental and ecological risk assessment of heavy metals in sediments of Nador lagoon, Morocco . Ecol. Indic. 48 , 616 – 626 ( 2014 ). Google Scholar Crossref Search ADS WorldCat 16. Maanan , M. , Ruiz-Fernandez , A. C., Maanan , M., Fattal , P., Zourarah , B. and Sahabi , M. A long-term record of land use change impacts on sediments in Oualidia lagoon, Morocco . Int. J. Sediment Res. 29 , 1 – 10 ( 2014 ). Google Scholar Crossref Search ADS WorldCat 17. Maanan , M. , El Barjy , M., Hassou , N., Zidane , H., Zourarah , B. and Maanan , M. Origin and potential ecological risk assessment of trace elements in the watershed topsoil and coastal sediment of the Oualidia Lagoon, Morocco . Hum. Ecol. Risk. Assess. 24 , 602 – 614 ( 2018 ). Google Scholar Crossref Search ADS WorldCat 18. Mejjad , N. , Laissaoui , A., El-Hammoumi , O., Benmansour , M., Benbrahim , S., Bounouira , H., Benkdad , A., Bouthir , F. Z., Fekri , A. and Bounakhla , M. Sediment geochronology and geochemical behavior of major and rare earth elements in the Oualidia Lagoon in the western Morocco . J. Radioanal. Nucl. Chem. 309 , 1133 – 1143 ( 2016 ). Google Scholar Crossref Search ADS WorldCat 19. Saddik , M. , Fadili , A. and Makan , A. Assessment of heavy metal contamination in surface sediments along the Mediterranean coast of Morocco . Environ. Monit. Assess. 191 , 1 – 19 ( 2019 ). Google Scholar Crossref Search ADS PubMed WorldCat 20. Zidane , H. , Maanan , M., Mouradi , A., Maanan , M., El Barjy , M., Zourarah , B. and Blais , J. F. Environmental and ecological risk of heavy metals in the marine sediment from Dakhla Bay, Morocco . Environ. Sci. Pollut. Res. 24 , 7970 – 7981 ( 2017 ). Google Scholar OpenURL Placeholder Text WorldCat 21. Zourarah , B. , Maanan , M., Carruesco , C., Aajjane , A., Mehdi , K. and Conceição Freitas , M. Fifty-year sedimentary record of heavy metal pollution in the lagoon of Oualidia (Moroccan Atlantic Coast) . Estuar. Coast. Shelf Sci. 72 , 359 – 369 ( 2007 ). Google Scholar Crossref Search ADS WorldCat 22. Laissaoui , A. , Mas , J. L., Hurtado , S., Ziad , N., Villa , M. and Benmansour , M. Radionuclide activities and metal concentrations in sediments of the Sebou Estuary, NW Morocco, following a flooding event . Environ. Monit. Assess. 185 , 5019 – 5029 ( 2013 ). Google Scholar Crossref Search ADS PubMed WorldCat 23. Wariaghli , F. and Yahyaoui , A. Anguillicoloides crassus (Nematoda: Dracunculoidea) infection in eels in Moroccan Estuaries . Aquac. Aquar. Conserv. Legis. 11 , 194 – 202 ( 2018 ). Google Scholar OpenURL Placeholder Text WorldCat 24. Snoussi , M. , Haïda , S. and Imassi , S. Effects of the construction of dams on the water and sediment fluxes of the Moulouya and the Sebou Rivers, Morocco . Reg. Environ. Change J. 3 , 5 – 12 ( 2002 ). Google Scholar Crossref Search ADS WorldCat 25. Ait Bouh, H., Laissaoui, A., Benmansour, M., Ziad, N., Mas, J.L., Hurtado, S. and Villa, M. The effect of flood onmetal concentrations in sediments, case of the Sebou Estuary, Morocco. Arab. J.Chem. Environ.Res. 08, 181– 192 (2021). 26. El Adnani , A. , Zourarah B. and Maanan , M. Sedimentary records of anthropogenic contribution to heavy metal content in Sebou Estuary (Morocco). In: First International ASRO Geological Congress (Asro-GC-2017) El Jadida (Morocco) , March 15–17 ( 2017 ). 27. Mansouri , D. , Fegrouche , R., Latifa , E. L., Allami , H. and Fadli , M. Contamination of the flesh of Scrobularia plana and Solen marginatus (Lamellibranch molluscs), hosting the estuary of Sebou (Morocco), by iron, zinc, copper and lead . Int. J. Fish. Aquat. Stud. 6 , 223 – 227 ( 2018 ). Google Scholar OpenURL Placeholder Text WorldCat 28. Haddout , S. , Igouzal , M. and Maslouhi , A. Seawater intrusion in semi-closed convergent estuaries (case study of Moroccan Atlantic Estuaries): application of salinity analytical models . Mar. Geod. 40 , 275 – 296 ( 2017 ). Google Scholar Crossref Search ADS WorldCat 29. Hamid , W. , Benmansour , M., Sayouty , H., Maanan , M. and Zourarah , B. 210Pb and 137Cs in a sediment core from Loukkos estuary (North of Morocco): implication for geochronological studies . Afr. Geosci. Rev. 17 , 189 – 204 ( 2010 ). Google Scholar OpenURL Placeholder Text WorldCat 30. Hamid , W. Techniques nucléaires d’analyse implication dans la datation des sédiments et la quantification de la sédimentation dans les environnements littoraux estuaires et lagunes . (Morocco: Hassan II University, Faculty of Sciences of Aïn Chock-Casablanca ) p. 120 ( 2011 ). Google Scholar Google Preview OpenURL Placeholder Text WorldCat COPAC 31. Evaluation Intégrée de l'Environnement de la Région Tanger – Tétouan. Rapport sur l'Etat de l'Environnement de la Région 2013. Ministère de l'Energie, des Mines, de l'Eau et de l'Environnement Département de l'Environnement, Ministère de l'Intérieur Région de Tanger – Tétouan, Observatoire Régional de l'Environnement et du Développement Durable de la Région Tanger – Tétouan, Royaume du Maroc . p. 242 ( 2013 ). 32. EL MORHIT, M. Hydrochimie, éléments traces métalliques et incidences écotoxicologiques sur les différentes composantes d'un écosystème estuarien (Bas Loukkos). Mohammed V University – Agdal, Faculty of Sciences, Rabat, Morocco, 260 p ( 2009 ). 33. Association Nationale des Améliorations Foncières, de l'Irrigation, de Drainage et de l'Environnement (ANAFIDE). Projet d'économie d'eau dans le perimètre du Loukkos ORMVA du Loukkos (L'Office régional de mise en valeur agricole du Loukkos), Ministère de l'Agriculture et du Développement rurale, Maroc. 126–6, Revue H.T.E. ( 2003 ). 34. Snoussi , M. Comportement du Pb, Zn, Ni et Cu dans les sédiments de l’estuaire du Loukkos et du proche plateau continental (Côte Atlantiquemarocaine) . Bull. Inst. Géol. Bassin Aquitaine. 35 , 23 – 30 ( 1984 ). Google Scholar OpenURL Placeholder Text WorldCat 35. Laissaoui , A. , Benmansour , M., Ziad , N., Ibn Majah , M., Abril , J. M. and Mulsow , S. Anthropogenic radionuclides in the water column and a sediment core from the Alboran Sea: application to radiometric dating and reconstruction of historical water column radionuclide concentrations . J. Paleo. 40 , 823 – 833 ( 2008 ). Google Scholar Crossref Search ADS WorldCat 36. Lakhdar Idrissi , J. , Orrbi , A., Zidane , F., Hilma , K. and Sarf , F. Caractérisation physico-chimique de la baie de M’diq en relation avec l’activité aquacole . Bull. Inst. Sci. Rabat Section Sci. 23 , 65 – 70 ( 2001 ). Google Scholar OpenURL Placeholder Text WorldCat 37. Alshawafi , A. , Analla , M., Alwashali , E., Ahechti , M. and Aksissou , M. Impacts of Marine Waste, Ingestion of Microplastic in the Fish, Impact on Fishing Yield, M’diq, Morocco . Int. J. Mar. Biol. Res. 3 , 1 – 14 ( 2018 ). https://doi.org/10.15226/24754706/3/2/00125. Google Scholar Crossref Search ADS WorldCat 38. Ezzahri , J. , El Fatni , H. and Ennabili , A. Aspect parasitologique du traitement des eaux usées urbaines par voie naturelle (M’diq, Nord-Ouest du Maroc) . Rev. AFN Maroc 1 , 55 – 56 ( 2005 ). Google Scholar OpenURL Placeholder Text WorldCat 39. Taouri , O. , El Ghammat , A., Hilal , I., Stitou , J., Hassani Zerrouk , M. and Drraz , C. Flood management: case of the city of M’diq and Fnideq . J. Water Sci. Environ. Technol 02 , 259 – 264 ( 2017 ). Google Scholar OpenURL Placeholder Text WorldCat 40. Rijal Leblad , B. , Nhhala , H., Daoudi , M., Marhraoui , M., Ouelad Abdellah , M. K., Veron , B. and Er-Raioui , H. Contamination and depuration of paralytic shellfish poisoning by Acanthocardia tuberculata cockles and Callista chione clams in Moroccan waters . J. Mater. Environ. Sci. 8 , 4634 – 4641 ( 2017 ). Google Scholar OpenURL Placeholder Text WorldCat 41. Ait Bouh , H. , Rokne , F., Ziad , N., Benkdad , A., Laissaoui , A. and Bounakhla , M. Comparison and application of three 210Pb dating models on a lagoon sediment core in Moulay Bousselham in Morocco . SMETox J. 1 , 93 – 99 ( 2018 ). Google Scholar OpenURL Placeholder Text WorldCat 42. Damsiri , Z. , Natij , L., Elkalay , K., Khalil , K. and Loudik , M. Comparative study on Moroccan lagoons (Mediterranean, Atlantic) . ScienceLib Editions Mersenne 6 N ° 140701 , 22 ( 2014 ) ISSN 2111-4706 . Google Scholar OpenURL Placeholder Text WorldCat 43. Mejjad , N. , Laissaoui , A., El Hammoumi , O., Benmansour M., Benkdad , A. and Fikri , A. Radioactive contamination in sediment from Oualidia lagoon: implications for dose assessment in edible marine species. In: Conference: the 4th African Regional IRPA congress (AFRIRPA04), Faculty of Medicine and Pharmacy of Rabat, Morocco . ( 2014 ). https://doi.org/10.13140/RG.2.1.3028.6323. 44. Karim , M. , Maanan , M., Maanan , M., Rhinane , H., Rueff , H. and Baidder , L. Assessment of water body change and sedimentation rate in Moulay Bousselham wetland, Morocco, using geospatial technologies . Int. J. Sediment Res. 34 , 65 – 72 ( 2019 ). Google Scholar Crossref Search ADS WorldCat 45. Fouad , M. , Bessi , H., Benhra , A. and Bouhallaoui , M. The benthic community used as bioindicator for assessment of the quality of a Moroccan Coastal ecosystem: Moulay Bousselham Lagoon . Int. J. Eng. Res. Technol. 8 , 127 – 133 ( 2019 ). Google Scholar OpenURL Placeholder Text WorldCat 46. Laissaoui , A. and Abril , J. M. A theoretical technique to predict the distribution of radionuclides bound to particles in surface sediments . J. Environ. Radioact. 44 , 71 – 84 ( 1999 ). Google Scholar Crossref Search ADS WorldCat 47. Trabelsi , Y. et al. Recent sedimentation rates in Garaet El Ichkeul Lake, NW Tunisia, as affected by the construction of dams and a regulatory sluice . J. Soil. Sediment. 12 , 784 – 796 ( 2012 ). Google Scholar Crossref Search ADS WorldCat 48. Hosseini , A. , Thorring , H., Brown , J. E., Saxén , R. and Ius , E. Transfer of radionuclides in aquatic ecosystems—default concentration ratios for aquatic biota in the Erica Tool . J. Environ. Radioact. 99 , 1408 – 1429 ( 2008 ). Google Scholar Crossref Search ADS PubMed WorldCat 49. Ulanovsky , A. , Pröhl , G. and Gomez-ros , J. M. Methods for calculating dose conversion coefficients for terrestrial and aquatic biota . J. Environ. Radioact. 99 , 1440 – 1448 ( 2008 ). Google Scholar Crossref Search ADS PubMed WorldCat 50. Brown , J. E. , Alfonso , B., Avila , R., Beresford , N. A., Copplestone , D., Pröhl , G. and Ulanovsky , A. The ERICA Tool . J. Environ. Radioact. 99 , 1371 – 1383 ( 2008 ). Google Scholar Crossref Search ADS PubMed WorldCat 51. Brown , J. E. , Alfonso , B., Avila , R., Beresford , N. A., Copplestone , D. and Hosseini , A. A new version of the ERICA tool to facilitate impact assessments of radioactivity on wild plants and animals . J. Environ. Radioact. 153 , 141 – 148 ( 2016 ). Google Scholar Crossref Search ADS PubMed WorldCat 52. Larsson , C. M. An overview of the ERICA integrated approach to the assessment and management of environmental risks from ionising contaminants . J. Environ. Radioact. 99 , 1364 – 1370 ( 2008 ). Google Scholar Crossref Search ADS PubMed WorldCat 53. Prlić , I. , Mostečak , A., Mihić , M. S., Veinović , Ž. and Pavelić , L. Radiological risk assessment: an overview of the ERICA integrated approach and the ERICA tool use . Arh. Hig. Rada Toksikol. 68 , 298 – 307 ( 2017 ). Google Scholar Crossref Search ADS PubMed WorldCat 54. Garnier-Laplace , J. and Gilbin , R., Eds. Derivation of Predicted No Effect Dose Rate Values for Ecosystems (and their Sub-Organisational Levels) Exposed to Radioactive Substances. ERICA Deliverable D5 . (Sweden: European Commission 6th Framework, Contract No. FI6R-CT-2003–508847 ) ( 2006 ). Google Scholar Google Preview OpenURL Placeholder Text WorldCat COPAC 55. D-ERICA . An INTEGRATED APPROACH to the assessment and management of environmental risks from ionising radiation: description of purpose, methodology and application. FI6R-CT-2004-508847, Project co-funded by the European Commission and Training Program on Nuclear Energy (2002–2006). Copplestone D, Swedish Radiation Protection Authority . p. 151 ( 2007 ). 56. Brown, J.E., Beresford, N.A. and Hosseini, A. Approaches to providing missing transfer parameter values in the ERICA Tool—How well do they work? Journal J. Environ. Radioact. 126 , 399 – 411 ( 2013 ). Crossref Search ADS WorldCat 57. Mabit , L. , Benmansour , M. and Walling , D. E. Comparative advantages and limitations of the fallout radionuclides 137Cs, 210Pbex and 7Be for assessing soil erosion and sedimentation . J. Environ. Radioact. 99 , 1799 – 1807 ( 2008 ). Google Scholar Crossref Search ADS PubMed WorldCat 58. Khoukhouchi , M. , Errami , E., Hassou , N. and Irzan , E. The geomorphological heritage of the Oualidia and Sidi Moussa lagoons: assessment and promotion for a sustainable human and socio-economic development . J. Sci. Res. Stud. 5 , 73 – 87 ( 2018 ). Google Scholar OpenURL Placeholder Text WorldCat 59. Maanan , M. , Robin , M., Maanan , M. and Zourarah , B. A GIS analysis for heavy metal assessment of sediment in coastal Lagoon. Chapter 13. In: Geomatic Solutions for Coastal Environments . (United States: Nova Science Publishers ). ISBN 978-1-61668-140-1 ) pp. 311 – 326 ( 2010 ). Google Scholar Google Preview OpenURL Placeholder Text WorldCat COPAC 60. Maanan , M. , Zourarah , B., Carruesco , C., Aajjane , A. and Naud , J. The distribution of heavy metals in the Sidi Moussa lagoon sediments (Atlantic Moroccan Coast) . J. African Earth Sci. 39 , 473 – 483 ( 2004 ). Google Scholar Crossref Search ADS WorldCat 61. Noureddine , A. , Benkrid , M., Maoui , R., Menacer , M., Boudjenoun , R., Kadi-hanifi , M., Lee , S. H. and Povine , P. P. Radionuclide tracing of water masses and processes in the water column and sediment in the Algerian Basin . J. Environ. Radioact. 99 , 1224 – 1232 ( 2008 ). Google Scholar Crossref Search ADS PubMed WorldCat 62. Benamar , M. A. , Zerrouki , A., Idiri , Z. and Tobbeche , S. Natural and Artificial Radioactivity Levels in Sediments in Algiers Bay . Appl. Radiat. Isot. 48 , 1161 – 1164 ( 1997 ). Google Scholar Crossref Search ADS WorldCat 63. El-Reefy , H. I. , Sharshar , T., Elnimr , T. and Badran , H. M. Distribution of gamma-ray emitting radionuclides in the marine environment of the Burullus Lake: II. Bottom sediments . Environ. Monit. Assess. 169 , 273 – 284 ( 2010 ). Google Scholar Crossref Search ADS PubMed WorldCat 64. Dione , D. , Mbaye , M., Sane , M. L., Ahmadou , C., Dath , B. and dao , A. S. N. Survey of Activity Concentration and Dose Estimation of Naturally Occurring Radionuclides (232Th, 238U and 40K) in the Coastal area of Dakar, Senegal . Indian J. Sci. Technol. 11 , 1 – 7 ( 2018 ). Google Scholar OpenURL Placeholder Text WorldCat 65. Arnedo , M. A. , Tejera , A., Rubiano , J. G., Alonso , H., Gil , J. M., Rodriguez , R. and Martel , P. Natural radioactrivity measurements of beach sands in Gran Canaria, Canary Islands (Spain) . Radiat. Prot. Dosimetry 156 , 75 – 86 ( 2013 ). Google Scholar Crossref Search ADS PubMed WorldCat 66. Sources and Effects of Ionizing Radiation, United Nations Scientific Committee on the Effects of Atomic Radiation UNSCEAR 2000 Report to the General Assembly, with Scientific Annexes, VOLUME I: SOURCES. United Nations (New York), Sales No. E.00.IX.3, ISBN 92-1-142238-8, p. 659 ( 2000 ). 67. SureshGandhi , M. , Ravisankar , R., Rajalakshmi , A., Sivakumar , S., Chandrasekaran , A. and Anand , D. P. Measurements of natural gamma radiation in beach sediments of north east coast of Tamilnadu, India by gamma ray spectrometry with multivariate statistical approach . J. Radiat. Res. Appl. Sci. 7 , 7 – 17 ( 2014 ). Google Scholar Crossref Search ADS WorldCat 68. Abbasi , A. and Mirekhtiary , F. Heavy metals and natural radioactivity concentration in sediments of the Mediterranean Sea coast . Mar. Pollut. Bull. 154 , 111041 ( 2020 ). Google Scholar Crossref Search ADS PubMed WorldCat 69. Baba-Ahmed , L. , Benamar , M. E. A., Belamri , M., Azbouche , A., Benarous , S. and Benkhalifa , A. Natural radioactivity levels in sediments in Algiers Bay using instrumental neutron activation analysis . Radiochim. Acta. 106 , 939 – 948 ( 2018 ). https://doi.org/10.1515/ract-2018-2926. Google Scholar Crossref Search ADS WorldCat © The Author(s) 2021. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)
TI - LEVELS OF NATURAL AND ANTHROPOGENIC RADIONUCLIDES IN SEDIMENTS OF SOME MOROCCAN COASTAL AREAS AND DOSE ASSESSMENT BASED ON ERICA TOOL
JF - Radiation Protection Dosimetry
DO - 10.1093/rpd/ncab116
DA - 2021-09-08
UR - https://www.deepdyve.com/lp/oxford-university-press/levels-of-natural-and-anthropogenic-radionuclides-in-sediments-of-some-5HB8MM2FMd
SP - 99
EP - 113
VL - 195
IS - 2
DP - DeepDyve
ER -