Chemical and biological assessment of sediments and water of Khalid Khor, Sharjah, United Arab Emirates

Investigating heavy metal concentrations in sea snakes (Elapidae: Hydrophiinae) as an outcome of oil spill exposure

This study reports the concentration of heavy metals in the tissues of stranded sea snakes that died as a result of exposure to an oil spill on the eastern coast of Sharjah, UAE. Given the limited occurrence of stranded sea snakes observed along Sharjah's eastern coast outside this spill incident, we are using strandings collected from the nearby Arabian Gulf coast of Sharjah to compare the levels of heavy metals in sea snakes affected by the oil spill against their non-oiled counterparts. The sample comprised 14 Arabian Gulf Coral Reef Sea Snakes (Hydrophis lapemoides), 6 Yellow-bellied Sea Snakes (Hydrophis platurus), and 4 Yellow Sea Snakes (Hydrophis spiralis). Overall, our results show significantly higher concentrations of Al, Cd, Pb, Cr, Mn, Fe, Ni, Cu and Zn in sea snakes that were mired in oil.

Factors influencing the prevalence of polycystic ovary syndrome (PCOS) in the United Arab Emirates

Statistics indicate that at least 20-25% of women suffer from PCOS in the Gulf region. Despite its prevalence and negative implications on reproductive, metabolic, and physiological heath the exact cause of PCOS is unknown, in part due to the diversity of symptoms manifested by this disorder. In this review, we investigate causes of PCOS globally and draw on these studies, to determine the potential contributing factors for PCOS pathogenesis in the UAE population. The most frequently identified factors promoting PCOS pathogenesis that may be pertinent to this population include physiological factors such as insulin resistance, vitamin D deficiency, genetic factors, obesity, and anti-mullerian hormone (AMH) levels in the body as well as environmental factors such as air pollution, endocrine disrupting chemicals, and pesticide use. This evidence will help inform healthcare workers and government agencies to set up optimal guidelines for control and awareness of PCOS in the UAE.

Assessment of Metals Concentrations in Soils of Abu Dhabi Emirate Using Pollution Indices and Multivariate Statistics

The aim of this study was twofold. Firstly, we performed a land capability class determination of the agricultural soils from the Abu Dhabi Emirate, the United Arab Emirates, based on the concentrations of 17 chemical elements determined in the soil samples collected from 84 locations. Secondly, we assess the soil pollution with different metals, using several pollution indices. The results of Principal Component Analysis (PCA) shows that four principal components (PCs) are responsible for describing the total metals concentrations’ variance, the highest contribution on PC1 being that of Mn, and Cr, on PC2 that of Fe, on PC3 that of Cu, and on PC4 that of Al. After determining the optimal number of clusters, we classified the sites into three clusters, while the studied metals were grouped function on their concentrations. Then, we used five indices to assess the pollution level of the soil at the study sites and in the clusters. The geo—accumulation index (I_geo) indicates uncontamination/moderately contamination with Cu in cluster 1, uncontaminated/moderately contaminate soils with Cd, Cu, and Ni in cluster 2, and uncontaminated/moderately contaminated soil with Cu and moderately contaminated with Pb, Zn, and Ni in cluster 3. By comparison, the enrichment factors overestimate the pollution of the studied sites. The pollution load index (PLI) indicates a baseline level of pollution at 14 sites and the deterioration of the soil quality at four sites. The Nemerow pollution index provides similar results as PLI.

The Photocatalytic Degradation of 2,3,7,8-Tetrachlorodibenzo-p-Dioxin in the Presence of Silver–Titanium Based Catalysts

Polychlorinated dibenzo-p-dioxins (PCDD) are persistent toxic compounds that are ubiquitous in the environment. The photodegradation of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in the presence of silver titanium oxide (AgTi) and silver titanium doped into the Y-zeolite (AgTiY) was tested using high (254 nm) and mid (302 nm) energy UV irradiation sources. AgTi and AgTiY, both showed success in the photodegradation of 2,3,7,8-TCDD dissolved in methanol/tetrahydrofuran solution. Both catalysts were found to effectively decompose TCDD at 302 nm (lower energy) reaching in between 98–99% degradation after five hours, but AgTiY showed better performance than AgTi at 60 min reaching 91% removal. Byproducts of degradation were evaluated using Gas chromatography/mass spectrometry (GC–MS), resulting in 2,3,7-trichlorodibenzo-p-dioxin, a lower chlorinated congener and less toxic, as the main degradation product. Enzyme Linked Immunosorbent Assay (ELISA) was used to evaluate the relative toxicity of the degradation byproducts were a decrease in optical density indicated that some products of degradation could be potentially more toxic than the parent TCDD. On the other hand, a decrease in toxicity was observed for the samples with the highest 2,3,7,8-TCDD degradation, confirming that AgTiY irradiated at 302 nm is an excellent choice for degrading TCDD. This is the first study to report on the efficiency of silver titanium doped zeolites for the removal of toxic organic contaminants such as dioxins and furans from aquatic ecosystems.

Assessment of the Environmental Status of the Mangrove Ecosystem in the United Arab Emirates

In the Arabian Gulf, mangroves play a particularly important role in maintaining biodiversity. Water and intertidal sediments were collected from eight sampling locations in April 2017 to assess the environmental status of the mangrove forest in the Khor al Beida, Umm Al Quwain, which is one of the largest natural mangrove forests in the United Arab Emirates (UAE). Khor al Beida is also a breeding ground for the largest Gulf colony of a regionally endemic Socotra cormorant. Total metal concentrations of water and sediments were measured using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) and ranged between 0.001–2.873 mg/L and 0.08–12683.02 mg/kg, respectively. Most metals were within permissible levels, except for copper, iron, aluminum, zinc, and nickel. Hazard Quotient calculations showed low risk to the ecosystem in relation to the presence of heavy metals, with the exception of zinc. Fifty-three diatom species of pennate benthic forms were identified in the intertidal sediments. For the first time in the UAE, diatom composition and diatom diversity values were quantitatively estimated in the surface sediments and a short sediment core. Overall, the assessment suggests that the mangrove forest is currently undisturbed and shows very little anthropogenic impact; yet, protection and conservation efforts are necessary in order to maintain its current status.

Bioaccumulation of heavy metals in tissues of Indian anchovy (Stolephorus indicus) from the UAE coast, Arabian Gulf

Pollution in the Arabian Gulf has risen in recent decades due to rapid development in the region. We studied 21 elements in the liver, gastrointestinal (GI) tract and muscles of the Indian anchovy (Stolephorus indicus) to characterize bioaccumulation in this abundant forage fish. Mean concentrations (μg/g wet weight) of elements ranged as follows: Cd: 0.1-8.0; Cr: 0.1-24.0; Cu: 1.2-24.0; Ni: 0.3-76.5; Ca: 1237.0-15,270.0; S: 2966.0-7467.0; Zn: 7.1-247.0; V: 0.1-27.0; Hg: 0.04-0.18 and Sr: 8.1-191.0. Zn, Cu, Cr, and Cd in the tissues exceeded the maximum permissible limit recommended by FAO, WHO and EC. We suggest that bioaccumulation in fish could be a hazard for human consumption. Therefore, further monitoring is needed to better characterize pollutant levels in fish of higher trophic levels in the Arabian Gulf.

Comparative cradle-to-grave life cycle assessment of biogas production from marine algae and cattle manure biorefineries

The environmental impacts resulting from the cradle-to-grave life cycles of Enteromorpha prolifera macroalgae and cattle manure biorefineries are assessed and compared. Sensitivity analysis is carried out to evaluate the response of the impacts to changes in biogas application by using Simapro 7.3.3. Three scenarios are considered in the biorefineries. In the first and second scenarios, the biogas produced is considered to be used for electricity production and transportation, respectively. In the third scenario, the biogas is considered to be recycled back to the systems. Process energy requirements and transportation of inputs contribute the largest share of the overall impacts. The cattle manure biorefinery is slightly more eco-friendly than the macroalgae biorefinery in Scenarios 1 and 2 because it requires more eco-friendly inputs. However, the macroalgae biorefinery becomes more eco-friendly than the cattle manure biorefinery in Scenario 3 because macroalgae require less energy and water for biogas production.