Saif Uddin

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.

Phthalates in indoor dust in Kuwait: implications for non‐dietary human exposure

Phthalates are semivolatile organic compounds with a ubiquitous environmental distribution. Their presence in indoor environments is linked to their use in a variety of consumer products such as childrens toys, cosmetics, food packaging, flexible PVC flooring among others. The goal of this study was to investigate the occurrence and concentration of phthalates in dust from homes in Kuwait and to assess non-dietary human exposure to these phthalates. Dust samples were randomly collected from 21 homes and analyzed for eight phthalates. The concentrations of total phthalates were log normally distributed and ranged from 470 to 7800 μg/g. Five phthalates [Di(2-ethylhexyl) phthalate (DEHP), Di-n-octyl phthalate (DnOP), Di-n-butyl phthalate (DBP), Benzyl butyl phthalate (BzBP), and Dicyclohexyl phthalate (DcHP)] were routinely detected. The major phthalate compound was DEHP at a geometric mean concentration of 1704 μg/g (median, 2256 μg/g) accounting for 92% of the total phthalates measured. Using the measured concentrations and estimates of dust ingestion rates for children and adults, estimated human non-dietary exposure based on median phthalate concentrations ranged from 938 ng/kg-bd/day for adults to 13362 ng/kg-bd/day for toddlers. The 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.

Baseline concentration of 210Po and 210Pb in Sargassum from the northern Gulf

This baseline study highlights the (210)Po and (210)Pb concentration in two species of the benthic macroalgae Sargassum from northern Gulf, also known as the ROPME Sea Area (RSA). Within the marine environment, (210)Po is initially absorbed from water and concentrated by phytoplankton and macroalgae, and this concentrated (210)Po can then readily be passed along to the higher trophic level of the marine food web. The (210)Po concentration measured in Sargassum boveanum (22.5-25.6 Bq kg(-1)) was higher than that in Sargassum oligocystum (20.2-22.5 Bq kg(-1)), but is not statistically significant (p>0.064), where as the difference between (210)Pb concentrations in Sargassum boveanum (15.3-16.8 Bq kg(-1)) and Sargassum oligocystum (18.4-22.0 Bq kg(-1)) was statistically significant (p>0.019). The measured concentration factor for (210)Po in Sargassum in the northern Gulf varied between 0.55 and 1.2×10(4), values higher to the IAEA recommended value of 1×10(3). The (210)Po enrichment is observed in both the species of Sargassum,(210)Po/(210)Pb ratio was >1 at all the stations for all the samples.

Baseline concentration of 210Po in Kuwait's commercial fish species.

This baseline study highlights the (210)Po variation in whole fishes with different feeding habits. Whole-body (210)Po concentrations were determined in ten important commercial fish species found in the northern Arabian Gulf to serve as baseline data. Primarily, (210)Po is absorbed from water, concentrated by phytoplankton and microzooplankton, and then transferred to the next trophic level along the marine food chain. The lowest concentration of (210)Po was measured in larger carnivorous fishes like hamoor (0.089 Bq kg(-1)), while the highest was found in the fishes that feed on algae, zooplanktons and detritus, like battan (3.30 Bq kg(-1)). The baseline data can be used to understand both the trophic transfer of (210)Po in the marine food chain and the (210)Po concentration factors in fish from the Arabian Gulf.

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 radionuclides show low concentration of tritium, polonium, strontium and cesium; their concentration is comparable to most oceanic waters.

Estimation of suspended particulate matter in Gulf using MODIS data

Mapping of suspended particulate matter can be achieved through satellite-based optical sensors and has growing applications for understanding sediment transport. A suspended particulate matter algorithm developed by Nechad (2010) for turbid conditions in the North Sea was applied in Gulf water using MODIS band 13 data centered at 667 nm. Satellite estimates of suspended particulate matter are extremely well correlated with the in-situ measurements (p = 0.97 and 1.00 for north (turbid) and south (clear) transects. Therefore, this technique can be effective for such estimation in Gulf waters as a surrogate for in-situ measurements.

Development of a Coupled Spatiotemporal Algal Bloom Model for Coastal Areas: A Remote Sensing and Data Mining-Based Approach

We developed and successfully applied data-driven models that heavily rely on readily available remote sensing datasets to investigate probabilities of algal bloom occurrences in Kuwait Bay. An artificial neural network (ANN) model, a multivariate regression (MR) model, and a spatiotemporal hybrid model were constructed, optimized, and validated. Temporal and spatial submodels were coupled in a hybrid modeling framework to improve on the predictive powers of conventional ANN and MR generic models. Sixteen variables (sea surface temperature [SST], chlorophyll a OC3M, chlorophyll a Generalized Inherent Optical Property (GIOP), chlorophyll a Garver-Siegel-Maritorena (GSM), precipitation, CDOM, turbidity index, PAR, euphotic depth, Secchi depth, wind direction, wind speed, bathymetry, distance to nearest river outlet, distance to shore, and distance to aquaculture) were used as inputs for the spatial submodel; all of these, with the exception of bathymetry, distance to nearest river outlet, distance to shore, and distance to aquaculture were used for the temporal sub-model as well. Findings include: 1) the ANN model performance exceeded that of the MR model and 2) the hybrid models improved the model performance significantly; 3) the temporal variables most indicative of the timing of bloom propagation are sea surface temperature, Secchi disk depth, wind direction, chlorophyll a (OC3M), and wind speed; and 4) the spatial variables most indicative of algal bloom distribution are the ocean chlorophyll from OC3M, GSM, and the GIOP products; distance to shore; and SST. The adopted methodologies are reliable, cost-effective and could be used to forecast algal bloom occurrences in data-scarce regions.

Baseline concentrations of strontium and 90Sr in seawater from the northern Gulf.

Baseline concentration of strontium and Sr-90 in Gulf is presented. The strontium concentration is much higher than reported for other oceanic waters, while the Sr-90 concentration is low at 0.7-1.0 mBq l(-1), that represents the background level following nuclear tests and can be used as an effective tracer in case of any radioactive release in the region. The strontium concentration is primarily related to the increasing salinity off the Gulf coast.

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.

Baseline radionuclide specific activity in commercial fishes of Kuwait

Radionuclide concentration in commercial fish species of Kuwait has been determined primarily with the intention of creating the baseline for 210Po, 137Cs, 40K, 226Ra, 224Ra, 228Ra, and 90Sr. This baseline information can be useful for issuing food advisories and determining annual intakes and radiation doses due to fish consumption. The highest fresh weight concentration of 210Po and 90Sr was in Battan and the lowest in Sobaity. Highest fresh weight 40K concentration was observed in Meid and the lowest in Battan. The 224Ra, 226Ra and 228Ra concentrations were highest in Meid, whereas the lowest was in Nuwaibi. In all the collected fish samples, 137Cs was below the detection limit.