Naturally Occurring Radioactive Material (NORM) in seawater of the northern Arabian Gulf - Baseline measurements.

This study focuses on creating baseline for 238U, 235U, 234U, 210Pb, 210Po and 40K concentrations in the northern Arabian Gulf. The respective concentration ranges were 0.047-0.050, 0.00186-0.00198, 0.054-0.057, 0.00085-0.00092, 0.00051-0.00062 and 18.6-19.1Bql-1. These results suggest that the levels are generally comparable to other marine waters in the northern hemisphere. There were no hot spots observed from oil and gas industry. These data will serve as a baseline to gauge possible future inputs of TENORMs in the northern Gulf. A positive and linear correlation was observed between 238,234U, 40K isotopes and seawater salinity. The results also suggest significant fractionation between 210Po and 210Pb, attributed to rapid removal of 210Po by biota compared to 210Pb. The mean residence time for 210Po in the study area was 371days. The 234U/238U and 238U/235U activity ratios in seawater samples vary between 1.14-1.15, and 0.038-0.040. The 234U/238U and 235U/238U ratio is similar to the expected composition of seawater (1.148±0.002) and 0.0462.

Spatial and temporal distributions of polycyclic aromatic hydrocarbons in the Northern Arabian Gulf sediments.

Surficial sediment samples were collected from 25 locations within Kuwait Bay and outside the Bay, in the Northwestern Arabian Gulf, to access recent polycyclic aromatic hydrocarbon pollution in Kuwait. Time trends in the depositional history of PAHs to this portion of the Arabian Gulf was reconstructed from the analysis of a dated sediment core. Intersite differences in concentration exist although these differences were not statistically significant (p=0.08). However, organic carbon normalized concentrations within Kuwait Bay were 4 times higher than the average concentrations outside the Bay and were shown to be statistically significant (p<0.001). The sedimentary record showed that ΣPAHs concentration fluctuated between 12 and 25ngg-1 before 1970. Concentrations then increased sharply to a maximum of 45ngg-1 around the late 1970s and early 1980s followed by an exponential decrease in concentration to pre-1970 "background" concentrations of between 12 and 25ngg-1.

Polybrominated diphenyl ether concentrations in sediments from the Northern Arabian Gulf: spatial and temporal trends.

Surficial sediment samples were obtained from 25 locations within Kuwait Bay and outside the Bay, in the Northwestern Arabian Gulf, to access recent pollution in Kuwait. The historical deposition of PBDEs to this portion of the Arabian Gulf was reconstructed by collecting a sediment core at the entrance of Kuwait Bay. The mean (and range) in concentrations of ∑11PBDEs in surficial sediments was 0.164±0.09 (0.06-0.44) pg/g dw. The concentrations measured in Kuwait Bay were generally higher than those measured in the open Gulf. When the concentrations were normalized to organic carbon, the average ∑11PBDEs concentrations measured in Kuwait Bay were seven times higher than average concentrations outside the Bay. The historical record, reconstructed from a sediment core collected at the entrance of Kuwait Bay, showed that Σ11PBDE concentrations were generally low in deeper sediment sections. The concentrations started to increase above background in the mid-1950s and increased sharply to a maximum Σ11PBDE concentration of ca 1,100 pg/g in the late 1980s. Concentrations decreased thereafter until another pulse in concentrations was observed around the early 2000 followed by a decrease in subsequent years. It is likely that the initial pulse in concentration recorded in sediments is related to inputs from the Gulf war of 1991. The penta congeners were observed throughout the length of the core although the concentrations were low. The congeners present in the Deca-PBDE technical mixture, particularly BDE 209 which is the main congener in the Deca-BDE mixture, occurred in sediment cores around the 1980s, and the concentrations increased rapidly thereafter being the most dominant congener since their first detection in sediments. The presence of nona-BDE congeners in proportions exceeding those in commercial mixtures may be suggestive of debromination of BDE 209 in sediments.

Seasonal variations in the atmospheric concentrations of polybrominated diphenyl ethers in Kuwait.

The study reports fortnightly atmospheric concentrations of PBDEs concomitantly measured at an urban and a remote location over a twelve-month period in Kuwait to examine seasonal variability and urban-rural concentration gradients. The annual mean (and range) of ∑PBDE concentrations was 32 (3-208) pgm(-3) at the remote site and 57 (0.3-445) pgm(-3) at the urban site. Although not statistically significant, the median (29 pg m(-3)) and mean (57 pg m(-3)) concentrations at the urban location were higher than those measured at the remote location (18 and 29 pg m(-3) respectively), consistent with the view that urban centers are an important net source of these compounds to the environment. Although Clausius-Clapeyron plots showed statistically significant correlations (p<0.05) with temperature for low molecular weight congeners (BDEs 28, 47, 100), correlations with the ΣPBDE concentrations were not significant at both urban and remote sites. The seasonal variations in ΣPBDE concentrations were not markedly different at the urban location, but the median summer ΣPBDE concentration at the remote location was significantly higher than winter median ΣPBDE concentrations. The absence in seasonality at the urban location may be due to ongoing primary emissions in urban areas.

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.

Depositional history of polychlorinated biphenyls in a dated sediment core from the northwestern Arabian Gulf.

The vertical distribution of polychlorinated biphenyls (PCBs) was measured in a dated sediment core from the northwestern Arabian Gulf to reconstruct their depositional history. The downcore profile showed an increase in concentrations from depth to a subsurface maximum of approximately 1,500 pg g(-1) in approximately 1991, followed by an exponential decrease to the sediment-water interface. Current concentrations of ΣPCBs are similar to levels predating the episodic input of PCBs in sediments dated coincident with the 1991 Arabian Gulf war. The spike in ΣPCB concentrations during the war may be related to the destruction of PCB-laden transformers during the conflict. The 15-fold decrease in ΣPCB concentrations from the period of maximum flux to prewar levels suggests that the factors delivering PCBs to sediments at present are similar to those that that existed before the war-related inputs.

Polybrominated diphenyl ethers (PBDEs) in soils along a rural-urban-rural transect: sources, concentration gradients, and profiles.

This study reports concentrations of PBDEs in surface soil samples collected along a 140 km transect across Kuwait to assess the role of urban centers as sources of persistent organic pollutants to the surrounding environment. The ΣPBDE concentrations varied by a factor of ~250 and ranged from 289 to 80,078 pgg (-1)d.w. The concentrations of PBDEs in Kuwait City were significantly higher (p<0.01) than those collected from sites outside the city supporting the hypothesis that urban centers are sources of PBDEs. The congener profiles were dominated by BDE-209, accounting for 93% of the PBDEs in the soil samples. The concentrations of all congeners (except BDE-209) were highly correlated with percent organic carbon (%OC) (p>0.05) when the data from Kuwait City was omitted from the analysis. These findings suggest that soil concentrations outside the urban centers were close to equilibrium with the atmosphere.

Localized hyper saline waters in Arabian Gulf from desalination activity--an example from South Kuwait.

Desalination is the only means of reliable water supply in most of the Arabian Gulf States including Kuwait, Saudi Arabia, Bahrain, Qatar, and United Arab Emirates. Huge desalination capacities are installed on the western margin of the Arabian Gulf contributing to increased salinity off the coast. This paper presents long term salinity observation made near outfall of Az Zour Power and Desalination Plant in South Kuwait. The salinity values peak at around 50 ppt at observation station located in open gulf around 5 km from the outfall of the power and desalination plant. The observation highlights the stress on the local marine environment continued incremental salinity can impair the marine biodiversity in the area. The study suggests that a stringent post construction and operational offshore water quality assessment can help in early detection of potentially complex environmental issues.

House dust as a source of human exposure to polybrominated diphenyl ethers in Kuwait.

This study reports concentrations of polybrominated diphenyl ethers (PBDEs) in dust samples collected from 17 homes in Kuwait. PBDEs were measured in all homes investigated with mean summation operatorPBDEs concentration ranging from 1 to 393 ng g(-1), with a geometric mean of 76 ng g(-1). The dominant congener in all samples was BDE 209 constituting ca. 85% of the summationPBDEs followed by BDE 99 (5%), BDE 47 (4.5%), and BDE 183 (2%). The congener mixture in dust is dominated by those in deca and penta formulations. Using the measured concentrations and estimates of dust ingestion rates for children and adults, estimated human non-dietary exposure based on mean PBDE levels were 14.8 and 1.5 ng day(-1) for children and adults, respectively. The 10-fold difference in exposure estimates between children and adults in this study supports previous reports that children are at greater risk from pollutants that accumulate indoors. The ubiquitous distribution of these chemicals as noted in this study highlights the fact that we are continuously exposed to low doses of chemicals in the indoor environment.

Spatial distribution of polybrominated diphenyl ethers in coastal marine sediments receiving industrial and municipal effluents in Kuwait.

Polybrominated diphenyl ether (PBDE) concentrations were measured in surficial sediments from coastal sediments receiving industrial and municipal effluents in Kuwait. The summation PBDE concentrations varied by two orders of magnitude ranging from 80 to 3800 pg g(-1)dw. The congener distribution was dominated by BDE 183, with minor contributions from BDEs 154 and 153. The similarity between the congener profile to that of the technical octa formulation (Bromkal 79-8DE) suggests a source of this product in Kuwait. The observed gradient in concentration distribution, with high summation PBDE concentrations near the shore and an exponential decrease seaward, indicates that wastewater discharge from industrial activities in the study area is the primary source of these compounds in the sediments.