Migration behavior of radiostrontium and radiocesium in arid-region soil.

The time-dependent of the average migration, depths and migration rates of radiostrontium and radiocesium were experimentally determined in sandy soil in Kuwait. The study aimed to describe the behavior of these radionuclides in typical soil types in Kuwait. Custom-made large-diameter lysimeters (30 cm) were constructed to hold about 70 kg of undisturbed soil. The top surface soil was contaminated with known activity concentrations of 85Sr and 134Cs radionuclides. The topsoil was wetted with 1 L of water weekly using a rain simulator tool. Gamma scanning of the lysimeters in a step of 5 cm from three sides was performed at three measurement times by a high-resolution portable gamma spectrometry system. The vertical distribution pattern of 85Sr and 134Cs concentration exhibited an exponential trend. The average migration depth and migration rates were calculated, and 90% of the 85Sr and 134Cs were situated at 10.38 and 5.73 cm in the topsoil layer, respectively. The average vertical migration rate of 85Sr varied from 2.2 to 4.4 cm y-1, and 134Cs was from 0.3 to 0.9 cm y-1. It was demonstrated that the mobility of the 85 Sr and 134 Cs in the sandy soil could be attributed to the physicochemical properties of the radionuclide, in particular the distribution coefficient (Kd). The obtained results could be adopted by the regions of similar climatological conditions, especially, the gulf countries region when the radiological risk assessment of contaminated sites and dose estimation is required.

Depositional time trends of phosphorous accumulation in a dated sediment core from the northwestern Arabian Gulf: Can phosphorous be used to support 210Pb chronologies in coastal aquatic sediments?

The use of 210Pb dating for the reconstruction of contaminant profiles in undisturbed sediments is the most widely acceptable technique historically. Due to the uncertainties associated with the technique, dating of sediments have often been supported by ancillary evidence such as an alternative historical marker in the catchment that is preserved in the sedimentary records. The most widely used verification marker is 137Cs, which is attributed to global fallout from past nuclear weapons testing, and the Chernobyl accident. In the southern hemisphere, and the mid-latitudes, the 137Cs signal from Chernobyl fallout is often absent from the sedimentary records making it very difficult to verify the 210Pb chronologies in these natural archives. This study reports the spatial and temporal variability of total phosphorus (TP) and its forms in sediments from Kuwait Bay and provides evidence of the possibility of using Phosphorous as a potential marker to support dates derived from 210Pb dating. In the current study we report the spatial and temporal variations in the concentrations of Phosphorus from near-shore sediments from Kuwait. The mean (and range) of TP concentration in surficial sediments is 19.4 (12.2 to 24) µmol-P g-1 dry weight. The highest concentrations were measured in the deepest portions of the Bay which is characterized by fine grained sediments. The vertical profile of TP in the sediments was characterized by a gradual increase in concentration from lower layers to a subsurface maximum (at approximately 4-5 cm) followed by an exponential decrease to the sediment-water interface. The sedimentary TP profile correlated remarkably well with changes in the population of Kuwait over the last three decades, suggesting that wastewater inputs into the Bay from treatment plants are an important source of phosphorus in the coastal waters. The decrease in concentration in sediment deposited over the last five years of the core is explained by the commissioning of an improved wastewater treatment plant with higher phosphorus removal efficiency. These fluctuations preserved in the sedimentary records linked to identifiable historical events provides powerful evidence that this nutrient associated with wastewater inputs in coastal aquatic environments can be used as ancillary information to support 210Pb dating.

Activity size distributions of radioactive airborne particles in an arid environment: a case study of Kuwait.

Atmospheric radioactive airborne released from several natural and artificial sources can travel for long distances and disperse in different directions. Both the physical and chemical characteristics of the atmospheric aerosols control this movement. The concentrations of 210Pb, 210Po, 7Be, 40K and 137Cs radionuclides in the ground surface air were determined in three particle sizes (2.4-10.2, 0.73-2.4 and less than 0.73 µm). High-volume air samples were collected from five different locations representing the five governorates of Kuwait using high-volume air samplers connected to a five-stage cascade impactor. The radioactivity concentrations of almost all fallout radionuclides were concentrated on the fine particle size fractions. The cosmogenic 7Be radioactivity level in all locations was relatively comparable and varied between 1.16 and 18.38 mBq/m3, with a geometric mean value of 6.80 mBq/m3. 137Cs was infrequently recorded with concentration varied between 4 and 14.3 µBq/m3. The geometric mean levels of the 210Po and 210Pb were 0.899 mBq/m3 and 1.03 mBq/m3, respectively, indicating that anthropogenic sources likely enrich 210Po. 40K was concentrated on large particle size fractions with a geometric mean value of 2.34 mBq/m3, reflecting the effects of the local dust sources. It was concluded that the radiological hazards due to airborne radioactive inhalation are low and can be negligible, where the annual estimated effective dose is about 64.0 µSv. The radioactive airborne measurements compose the base of estimating the aerosols residence time, resuspension rate of dust, soil redistribution and source apportionment, particularly the 210Pb and 210Po radionuclides.

Recent exposure to particle radioactivity and biomarkers of oxidative stress and inflammation: The Framingham Heart Study.

BACKGROUND: Decay products of radioactive materials may attach to ambient fine particles and form radioactive aerosol. Internal ionizing radiation source from inhaled radioactive aerosol may contribute to the fine particulate matter (PM2.5)-inflammation pathway. However, few studies in humans have examined the associations. OBJECTIVES: To examine the associations between particle radioactivity and biomarkers of oxidative stress and inflammation among participants from the Framingham Offspring and Third Generation cohorts. METHODS: We included 3996 participants who were not current smokers and lived within 50 km from our central air pollution monitoring station. We estimated regional mean gross beta radioactivity from monitors in the northeastern U.S. as a surrogate for ambient radioactive particles, and calculated the 1- to 28-day moving averages. We used linear regression models for fibrinogen, tumor necrosis factor α, interleukin-6, and myeloperoxidase which were measured once, and linear mixed effect models for 8-epi-prostaglandin F2α, C-reactive protein, intercellular adhesion molecule-1 (ICAM-1), monocyte chemoattractant protein-1 (MCP-1), P-selectin, and tumor necrosis factor receptor-2 that were measured up to twice, adjusting for demographics, individual- and area-level socioeconomic positions, time, meteorology, and PM2.5. We also examined whether the associations differed by median age, sex, diabetes status, PM2.5 levels, and black carbon levels. RESULTS: The mean age was 54 years and 54% were women. An interquartile range (3 × 10-3 pCi/m3) higher beta radioactivity level at the 7-day moving average was associated with 5.09% (95% CI: 0.92, 9.43), 2.65% (1.10, 4.22), and 4.71% (95% CI: 3.01, 6.44) higher levels of interleukin-6, MCP-1, and P-selectin, but with 7.01% (95% CI: -11.64, -2.15) and 2.70% (95% CI: -3.97, -1.42) lower levels of 8-epi-prostaglandin F2α and ICAM-1, respectively. CONCLUSIONS: Regional mean particle radioactivity was positively associated with interleukin-6, MCP-1, and P-selectin, but negatively with ICAM-1 and 8-epi-prostaglandin F2α among our study participants.

Associations Between Ambient Particle Radioactivity and Blood Pressure: The NAS (Normative Aging Study).

BACKGROUND: The cardiovascular effects of low-level environmental radiation exposures are poorly understood. Although particulate matter (PM) has been linked to cardiovascular morbidity and mortality, and elevated blood pressure (BP), the properties promoting its toxicity remain uncertain. Addressing a knowledge gap, we evaluated whether BP increased with higher exposures to radioactive components of ambient PM, herein referred to as particle radioactivity (PR). METHODS AND RESULTS: We performed a repeated-measures analysis of 852 men to examine associations between PR exposure and BP using mixed-effects regression models. As a surrogate for PR, we used gross ß activity, measured by the US Environmental Protection Agency's radiation monitoring network. Higher PR exposure was associated with increases in both diastolic BP and systolic BP, for exposures from 1 to 28 days. An interquartile range increase in 28-day PR exposure was associated with a 2.95-mm Hg increase in diastolic BP (95% confidence interval, 2.25-3.66; P<0.001) and a 3.94-mm Hg increase in systolic BP (95% confidence interval, 2.62-5.27; P<0.001). For models including both PR and PM ≤2.5 µm, the PR-BP associations remained stable and significant. For models including PR and black carbon or PR and particle number, the PR-BP associations were attenuated; however, they remained significant for many exposure durations. CONCLUSIONS: This is the first study to demonstrate the potential adverse effects of PR on both systolic and diastolic BPs. These were independent and similar in magnitude to those of PM ≤2.5 µm, black carbon, and particle number. Understanding the effects of particle-bound radionuclide exposures on BP may have important implications for environmental and public health policy.

Concentration of selected radionuclides in seawater from Kuwait.

No baseline existed for the radionuclides in Kuwait territorial water. With changing trend in the region to embrace nuclear energy, the baseline study is imperative to create a reference and to record the influence-functioning of upcoming power plants. The first one in Bushehr, Iran is ready to start and several more are likely to come-up in UAE, Saudi Arabia and Kuwait. The present baseline concentration of the four considered radionuclide's show low concentration of tritium, polonium, strontium and cesium; their concentration is comparable to most oceanic waters.