Atmospheric residence times and excess of unsupported 210Po in aerosol samples from the Kuwait bay-northern gulf

The concentration of cosmogenic radionuclide ⁷Be and the naturally occurring radionuclide ²²²Rn and its progenies ²¹⁰Pb, ²¹⁰Po, and ²¹⁴Pb were measured in the ground surface air in the urban area of the northern Arabian Gulf close to Kuwait Bay. A high-volume air sampler connected with a five-stage cascade impactor was used to collect approximately 1800 cubic meter weekly for a period of one year. The concentrations of ²¹⁰Pb and ²¹⁰Po varied from 0.35 to 1.65 mBq m^-3 and from 0.23 to 3.2 mBq m^-3, respectively; the ²¹⁰Po/²¹⁰Pb activity ratio was close to one. The average concentration of ⁷Be was 6.24 mBq m^-3, ranging from 3 to 10 mBq m^-3. The temporal variations of ²¹⁰Pb, ²¹⁰Po and ⁷Be showed maximum concentrations of ²¹⁰Po and ⁷Be in occurred summer months. The observed excess of ²¹⁰Po concentrations can be attributed to the local and long-range transport of suspended dust with ²¹⁰Pb and ²¹⁰Po in radioactive equilibrium state, oil industry emissions, local resuspended dust and the sea-salt-aerosols from the Arabian Gulf. The range of the residence time estimation using the ²²²Rn/²¹⁰Pb and ²¹⁴Pb/²¹⁰Pb activity ratio methods ranged from three to five days. Moreover, the estimated residence time by the application of ⁷Be from the activity median aerodynamic diameter method was 4.2 days. The method of using the ²¹⁰Po/²¹⁰Pb activity ratio was invalid because of the excess ²¹⁰Po sources of anthropogenic origin. Therefore, extensive accurate diurnal measurements of ²¹⁴Pb and ²²²Rn can be applied in hot arid regions for better aerosols residence time estimation.

Plutonium and cesium baseline concentrations in seawater from northern Arabian Gulf

The Arabian Gulf is a semi-enclosed water body that has witnessed accelerated anthropogenic activity, in terms of commissioning of nuclear power plants, desalination facilities, oil refineries and extensive coastal development. Furthermore, three wars during the past three decades is a potential worry. This study presents the first plutonium baseline in seawater from the Northern Arabian Gulf. The ^239+240Pu concentrations in seawater vary, between 2.9 and 4.9mBqm^-3, a range that is comparable to other water masses at this latitude. The ²³⁸Pu ranged between 0.04 and 0.05mBqm^-3 and the ¹³⁷Cs concentration between 1.04 and 1.18Bqm^-3. The ratio of ²³⁸Pu/^239+240Pu at all eight sampling stations was 0.01, while the ratio of ^239+240Pu/¹³⁷Cs varied between 0.01 and 0.02. The presence of ¹³⁷Cs and ^239+240Pu in seawater from this region can mainly be attributed to the global atmospheric deposition and fluvial transport. The seawater concentration of ^239+240Pu is five order of magnitude lower than bottom sediments in the area.

Radioactivity in the Kuwait marine environment--Baseline measurements and review

The Arabian Gulf region is moving towards a nuclear energy option with the first nuclear power plant now operational in Bushehr, Iran, and others soon to be constructed in Abu Dhabi and Saudi Arabia. Radiological safety is becoming a prime concern in the region. This study compiles available data and presents recent radionuclide data for the northern Gulf waters, considered as pre-nuclear which will be a valuable dataset for future monitoring work in this region. Radionuclide monitoring in the marine environment is a matter of prime concern for Kuwait, and an assessment of the potential impact of radionuclides requires the establishment and regular updating of baseline levels of artificial and natural radionuclides in various environmental compartments. Here we present baseline measurements for (210)Po, (210)Pb, (137)Cs, (90)Sr, and (3)H in Kuwait waters. The seawater concentration of (3)H, (210)Po, (210)Pb, (137)Cs, and (90)Sr vary between 130-146, 0.48-0.68, 0.75-0.89, 1.25-1.38 and 0.57-0.78 mBq L(-1), respectively. The (40)K concentration in seawater varies between 8.9-9.3 Bq L(-1). The concentration of (40)K, total (210)Pb, (137)Cs, (90)Sr, (226)Ra, (228)Ra, (238)U, (235)U, (234)U, (239+240)Pu and (238)Pu were determined in sediments and range, respectively, between 353-445, 23.6-44.3, 1.0-3.1, 4.8-5.29, 17.3-20.5, 15-16.4, 28.7-31.4, 1.26-1.30, 29.7-30.0, 0.045-0.21 and 0.028-0.03 Bq kg(-1) dry weight. Since, radionuclides are concentrated in marine biota, a large number of marine biota samples covering several trophic levels, from microalgae to sharks, were analyzed. The whole fish concentration of (40)K, (226)Ra, (224)Ra, (228)Ra, (137)Cs, (210)Po and (90)Sr range between 230-447, 0.7-7.3, <0.5-6.6, <0.5-15.80, <0.17, 0.88-4.26 and 1.86-5.34 Bq kg(-1) dry weight, respectively. (210)Po was found to be highly concentrated in several marine organisms with the highest (210)Po concentration found in Marica marmorata (193.5-215.6 Bq kg(-1) dry weight). (210)Po in most dissected fish samples shows increasing concentrations in the following order: edible tissue, gills, digestive system, liver and fecal matter. Fish fecal pellets had (210)Po concentrations several orders of magnitude higher than the seawater, fish muscle, and the fishes' ingested food. The high (210)Po concentration in fish fecal matter, suggest that the bulk of (210)Po content in fish was eventually excreted back into the environment as fecal pellets. In most fish high concentrations were noted in liver, with the highest (210)Po concentration recorded in shark liver (126.2-141.5 Bq kg(-1) wet). Moreover, (210)Po concentration in the soft tissue of molluscs (10.36-215.60 Bq kg(-1) dry weight) was far higher than that in fish muscle (0.05-7.49 Bq kg(-1) wet weight). A seasonal drop in (210)Po concentration in seawater was observed to vary with the abundance of phytoplankton and macroalgae due possibly to biological dilution. (137)Cs concentration in all the fish sampled was below the detection limit, and the concentration in seawater was also low; hence such low levels provide an opportunity to use this radionuclide as an indicator for any future radiocesium releases in this region.