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Priority pollutants polycyclic aromatic hydrocarbons (PAHs) in muscle and livers of stranded green sea turtles, Chelonia mydas (Linnaeus, 1778) were extracted using a quick, easy, cheap, effective,...

A hypersaline protected wetland in the UAE was assessed from February to April of 2021 for parameters such as temperature, pH, COD, total dissolved solids, ORP, electrical conductivity, total and E. coli, salinity, turbidity, chloride, ammonia, nitrate, total nitrogen, phosphorus, and heavy metals to assess its current status. Wasit Nature Reserve’s salinity values ranged between 17.1 and 64.78 psu, while D.O values ranged between 6.3 and 8.41 ppm. The values for nitrate were between 50.70 and 57.6 ppm, while the values for chloride were between 12,642.0 and 37,244.0 ppm. Results for heavy metals showed that Iron and Aluminum were the highest concentrations in sediments, with an average of 5599.3 mg/kg and 3171.1 mg/kg, respectively. Mercury and arsenic reported the lowest concentrations, with an average of 0.0 mg/kg and 2.4 mg/kg, respectively. Hazard quotient values were 2239.72 mg/kg for iron, 0 mg/kg for mercury, and 0.05 mg/kg for arsenic, indicating that iron levels are considered hazardous and water-quality indicators concluded high pollution levels. The results indicate that the hypersaline nature of the wetland contributes to the deviation from the permissible limits, as demonstrated by the calculated “poor“water-quality index and “highly polluted” water-pollution index. Due to their ecological relevance, wetlands in the region could serve as indicators of ecological well-being, highlighting the need for regular monitoring and evaluation.

Oil spills in the marine environment inflict significant impacts on a wide diversity of marine fauna. Despite the abundance of literature describing these impacts on numerous species, no studies describe the impacts on sea snakes. In this study we report, for the first time, details of an oil spill which caused mass mortality of sea snakes. In this study, 39 sea snake mortalities from the Gulf of Oman, in particular, the coast of Kalba, Sharjah, UAE, were examined. The investigated sea snakes belong to four different species (Hydrophis platurus, H. lapemoides, H. spiralis and H. ornatus). The majority (84.6%) of sea snakes were observed to have oil covering 75-100% of their bodies. The majority (91.4%) of sea snakes were also observed with oil covering their snouts and eyes. A large proportion (25.8, 41.4 and 34.5%) of sea snakes were observed with oil in their mouth, esophagus and stomach.

This study presents a comprehensive data analysis using univariate and multivariate statistical techniques as a tool to establish a baseline for the assessment of water quality parameters in environmental compartments. The Al Wasit Nature Reserve is a hypersaline wetland in the UAE with a spatial fluctuation in water parameters as water flows above ground as well as ponds forming in deeper areas and over the year due to the arid climate and seasonality. Water samples were collected at fifteen sites along the hypersaline wetland over three periods during the months of February to March 2021 as temperatures started to rise with the oncoming summer. Water quality parameters, including the temperature, pH, turbidity, dissolved oxygen (DO), oxidation-reduction potential (ORP), electrical conductivity (EC), chemical oxygen demand (COD), chloride, ammonia, and nitrates, were measured. The results of the data analysis were used to group the sites, which were divided into three groups with similar water quality characteristics. Correlation assessments between all studied parameters revealed significant differences in the values of eight of the evaluated parameters between the three identified clusters, with only the nitrate concentrations and dissolved oxygen parameters not being significant. It was found that one of the three clusters (cluster 1) performed better than the other two for most of the studied parameters. The results of this study demonstrate the applicability and the potential time and cost savings of the usage of data analysis tools for long-term data monitoring in the wetland and other environmental systems worldwide.

For the first time, the qualitative and quantitative characteristics of marine debris ingested by six hawksbill (Eretmochelys imbricata) and seven olive ridley (Lepidochelys olivacea) sea turtles from the Gulf of Oman coast of the United Arab Emirates were investigated. The numeric and gravimetric proportions of ingested marine debris obtained from the esophagus, stomach and intestines were quantified following categories of presumed sources, Marine Strategy Framework Directive (MSFD), rigidity, color and plastic polymer types. Marine debris was observed in 28.6% of olive ridley (x: 2.00 items; 4.83 g) and 83.3% of hawksbill specimens (x: 6.00 ± 2.32 items; 0.32 ± 0.24 g). Overall, the results of this preliminary study suggest that hawksbill sea turtles were ingesting marine debris at higher frequencies and that plastics were observed to be the most predominant debris ingested. However, non-plastic rubbish, particularly metallic fishing gear (fish hooks and fish traps), were observed to present lethal hazards for both species.

Livability indicators and assessments are critical to promoting campus sustainability and livability. Despite the various indicator frameworks and local initiatives aimed at attaining sustainability, campus livability assessments in the Middle East are scarce. An extensive literature search was used in this paper to obtain the best livability indicators, and the Delphi method was used to reach consensus using a panel of experts in the fields of sustainability and livability. The determining indicators were identified and categorized according to Environmental Quality, Social and Cultural Elements, Accessibility, Amenities and Services, Safety, Housing, and Other Services. A questionnaire using both qualitative and quantitative questions was used, taking into consideration the perceptions of students, faculty, and staff residing at the American University of Sharjah (AUS) campus in the United Arab Emirates (UAE). A score of 87/100 was obtained in this study, indicating that the AUS can be considered a highly livable campus. Responses showed that social and cultural elements, such as social gatherings, availability of restaurants, and children’s activities, were of utmost importance to the respondents. Additionally, services on campus, accessibility, and quality of housing played a major role in respondents’ choices. The index obtained in this study serves as a reference/benchmark for similar and comparative studies of campus livability, and can be adapted to similar scenarios. Moreover, this study opens the doors for future studies to gain deeper insights into the required steps to evaluate the livability of a campus, in order to facilitate future transformation of a traditional campus into a livable campus.

There is scarce information on the current importance of oyster beds as fishing grounds in the United Arab Emirates (UAE). This study aims to understand the socio-economic value of oyster bed fisheries through questionnaire-based surveys with fishers. Of 106 Emirati fishers interviewed, 67 % use oyster beds due to the proximity to shore, better catch quality, and species abundance. Oyster bed fisheries are recreational and commercial, with handline and fish traps the most common used gears. They provide food for local consumption and cash income. All respondents noticed a fish abundance and size decrease throughout the last decade. Fishers suggest establishing marine protected areas and updating fishing regulations to improve fishing stock status. During the Covid-19 pandemic, oyster fisheries increased, highlighting the value of these fishing grounds for food availability. These fisheries support the local economy and heritage, and urgently need management to ensure the protection of these often-overlooked habitats.

Pollution of the marine environment by plastic marine debris has become one of the most pervasive threats impacting marine environments. In this study, for the first time, we evaluate the polymer types of the plastic marine debris ingested by 49 green and 14 loggerhead sea turtle strandings in the Gulf of Oman. Plastic marine debris was ingested by 73.5% of green and 42.9% of loggerhead sea turtles in this study. Overall, evidence suggested that green sea turtles from the Gulf of Oman coast of the United Arab Emirates ingested high levels of plastic marine debris, predominantly Polypropylene (PP)Polyethylene (PE), followed by Nylon, PP-PE mixture, Polystyrene (PS), Poly vinyl chloride (PVC) and Ethylene vinyl acetate (EVA), respectively. Loggerhead sea turtles also ingested high levels of plastic marine debris, which also predominantly consisted of PPPE, followed by PP-PE mixture, Nylon and PS. While recent studies were directed into polymer characterization of micro-plastics in aquatic life, our study focuses on macro-plastics which impose significantly greater risks.

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.

Midwakh, which originated in the Middle East, has started to spread globally with different brands commercialized online and in local stores across Europe and the USA. Dokha is the tobacco used in midwakh. To this day, risk of midwakh smoking is poorly understood. Three different types of dokha were evaluated in this study, classified as cold, medium, and hot using gas chromatography–mass spectrometry (GC–MS). The concentrations of nicotine and polycyclic aromatic hydrocarbons (PAHs) in raw and smoked dokha samples were measured, and the results were compared to data in the literature on different types of tobacco products. PAH concentrations were used to estimate the toxic equivalency quotient, daily exposures, incremental lifetime cancer risk, and hazard quotient. The level of nicotine in raw dokha exceeded by far the levels reported in cigarettes, cigar, waterpipe, and chewing tobacco. Although only a portion of the nicotine is released into the smoke, the amount of nicotine in dokha smoke exceeded those reported for cigarettes. Two PAHs were found in raw dokha at trace amounts and 12 PAHs were detected in dokha smoke in amounts that exceeded those reported for cigarette smoke. The PAHs distribution showed a specific pattern in the smoke and a higher risk factor than that obtained for cigarettes and other tobacco products. Dokha products present a potential higher risk and immediate action should be taken to avoid its global consumption.

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&ndash, 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&ndash, 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.

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&ndash, 2.873 mg/L and 0.08&ndash, 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.

The level of contamination of selected priority pollutants consisting of polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) were investigated from the tissues of stranded green sea turtles, Chelonia mydas, from the Gulf of Oman coast of the United Arab Emirates. Tissue samples - muscle and liver - were collected from 22 stranded green sea turtles from the coasts of Kalba and Khorfakkan from 2016 to 2018. Overall, we detected persistent organic pollutants (POPs) in 77% of the turtles. PAH's were the most frequently detected followed by high concentrations of OCP's (71% and 25% of the turtles, respectively). PCB's were not detected in any samples. Factors such as specimen size, mass of debris ingested and toxin hydrophobicity were not important factors affecting the concentrations of these compounds.

Background: University campuses can be leaders of change by tracking carbon footprints and establishing strategies for reductions. The American University of Sharjah (AUS) has led this effort in the United Arab Emirates (UAE), establishing an Office of Sustainability to address energy consumption on its campus, resulting in a reduction of 30% by 2015. AUS campus uses the Greenhouse Gas Protocol to annually track carbon footprint. The purpose of this paper is to stablish a framework that institutions can use to calculate the carbon footprint (CF) on their university campuses. Methods: The GHG Protocol, which categorizes emissions into three scopes; 1: direct, 2: indirect, and 3: other indirect emissions, was used as a guideline. This paper covers the following: Scope 1: emissions from university fleet, Scope 2: emissions from electricity and water consumption, Scope 3: emissions from the university commute, limited business air travel and waste. The data for each category are analyzed and recommendations to reduce the carbon footprint are presented. Results: The total CO2 emissions for the AUS campus in 2018–2019 were 94,553.30 tCO2e. Additionally, the percentage contribution of total emissions for Scope 1, 2 and 3 were 0.37%, 61.12% and 38.51%. Conclusions: The two highest contributors of CO2 emissions at the AUS campus are electricity consumption (60.91%) and university commute (36.54%). AUS has hosted numerous educational campaigns and awareness programs to try to reduce carbon emissions, which helped in reducing electricity consumption throughout campus; however, these are still insufficient; hence, the importance of quantifying the CF of the AUS campus. Based on the results obtained, recommendations can be made to reduce overall CO2 emissions for AUS and other higher education institutions in the region and internationally.

Persistent organic pollutants (POPs) in the environment have generated great interest within the scientific community due to their toxic effect to animal, human health, and the environment. This review encompasses the historical presence of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in the world-wide environment. Information on exposure indicated that the main route of exposure of dioxins/furans to humans is through ingestion, which is discussed in this paper. In addition, we present a thorough assessment of sampling, methods for extraction, and analysis as well as the photodegradation of dioxins under various conditions. In general, extraction methods including USEPA 8290 are the most used with high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) preferred as a detection tool. Moreover, a detailed compilation of studies of the PCDD/F concentrations and environmental sources from major industrial regions in several countries are presented. In summary, the major sources of dioxins in the worldwide environment include combustion and industrial sources with major challenges related to the lack of data availability in the Middle East especially with the current Warfare conflicts in the region.

Organophosphate insecticides are persistent organic pollutants that have a variety of adverse impacts in several environmental compartments. The photo-degradation of organophosphate profenofos was researched in the presence and absence of silver-platinum-doped zeolite in (Ag-Pt-Zeolite) upon irradiation with ultraviolet light at wavelengths of 302 and 254 nm. Photo-degradation of profenofos at 302 nm and in the presence of Ag-Pt-Zeolite was 73 % complete in 60 min. GC/MS analysis indicated the formation of two major photo-degradation products upon irradiation with 302 nm in the presence of the catalyst. Moreover, four products were identified for the irradiation with 254 nm in the presence of the catalyst and for the uncatalyzed irradiated profenofos samples. The toxicity of the degradation products was assessed by exposure experiments using Drosophila melanogaster. These experiments showed that degradation resulted in overall less toxic products within the first 30 min of degradation, followed by an overall increase in toxicity after 30 min of UV exposure. The present work provides a treatment technique for the adequate removal of profenofos from water sources in order to mitigate its detrimental effects on the environment.

Silver clusters were introduced into the framework of zeolite Y. Low-temperature solid-state luminescence indicates the formation of silver–silver excimers and exciplexes that were found to be activated at 250 and 300 nm, respectively. The photodegradation of a persistent halogenated organic pollutant, namely 2,3,7,8-tetrachlorodibenzofuran (2,3,7,8-TCDF), was studied in the presence and absence of two catalysts, namely including AgY1 and AgY2, under mid- and high energy: 302 and 254 nm, respectively. The results showed that in the absence of a catalyst, degradation under 254-nm UV light resulted in changes to the peak intensity as well as energy, while the 302-nm profile showed only loss in peak intensity. In the presence of either catalyst, a higher rate of degradation of the 2,3,7,8-TCDF was observed. The amount of the adsorbed 2,3,7,8-TCDF on the AgY1 and AgY2 catalyst was estimated to reach 37.9 and 18.9% of its initial concentration, respectively. The toxicity of the intermediate and resultant products was further analyzed with the aid of an enzyme-linked immunosorbent assay. The optical density showed that in contrast to all the samples, the TCDF irradiated with 254 nm in the presence of AgY2 was high at 40 min inferring a decrease in toxicity of the resultant product. The present work shows an innovative and cost-efficient technique for the removal of dioxins and furans from water sources.

Aluminum (Al) is a widely produced metal in the United Arab Emirates (UAE) particularly for the use in development and construction industries. The waste products of the aluminum industry are categorized as hazardous and generally enter municipal waste landfills in the form of aluminum dross and salt cakes. Hence, aluminum industries in the UAE are currently searching for alternative uses and disposal methods for these waste derivatives. This paper investigates the plausible impacts of the aluminum waste products such as dross and salt cakes, through material characterization and leaching studies at different reaction conditions. The salt cake and dross from UAE were characterized by Fourier transformation infrared spectroscopy (FTIR), cation exchange capacity (CEC) and scanning electron microscopy coupled with energy dispersive X-ray Spectroscopy (SEM–EDS). The CEC values for salt cake and dross were 425.8 and 408.8 meqH+/100 g sample, respectively. The FTIR spectra for both wastes showed clear bands for Al (OH)3 and organic functional groups. A treatment with acidic, neutral and basic aqueous solutions was performed to both waste products and the results showed that the acid leachate is accompanied with gas evolution and heavy metals, including high concentrations of Al. The findings of this study prove that aluminum dross and salt cakes could have hazardous implications not only in the landfill but also in the surrounding environments. A feasible treatment method using acid is suggested in light of the experimental results to reduce the negative implications of the landfill process while keeping up with guidelines and goals regarding environmental waste management of aluminum waste products in the UAE.

Sewage sludge from Dubai was characterized using inductively coupled plasma and CHN elemental analysis. Selected sludge samples were washed with deionized water until constant conductivity was achieved. The sludge samples (washed and unwashed) were carbonized at 680°C in a semi-static steam environment that was self-generated inside a homemade reaction chamber and with the absence of any external flow. The carbonized materials were then activated by impregnation with sodium hydroxide at 3:1 mass ratio followed by thermal treatment at 680°C in the presence of water. The activated products were characterized using SEM/EDS, CHN elemental analysis, and sorption of nitrogen. The results showed that washing the sludge prior to the carbonization step significantly enhanced the surface area of the final activated product. Activation efficiencies were lower than the carbonization efficiencies. The surface area of the activated adsorbent developed from the washed sludge was 1,552 m2/g compared to 1,182 m2/g...

Scientific studies in higher education is becoming an increasing matter of discussion. The American University of Sharjah (AUS) encourages the scientific literacy of students who are not enrolled in science or engineering majors by including two required science courses in the curriculum. The courses of choice include biology, chemistry, environmental sciences, astronomy and physics. This study investigates the factors that contribute to students’ choice when selecting science courses at AUS. A survey comprised of open-ended questions as well as quantitative enquiries was administered to students enrolled in environmental science (ENV 100), aiming to investigate the main reason behind their choice. The results of this two year study showed significantly positive attitudes toward the course contents and the benefit of the course towards their future careers. Furthermore, it reveals that students are highly influenced by previous experiences with subjects, professors’ popularity, peer recommendation, their abilities in memorization, and skills in math. The study reveals that the main concern for students is related to the high amount of information and details that the course content covers. In addition, the possibility of obtaining a higher grade was also studied by observing the grade point average (GPA) for science courses over a period of four years. Nonetheless, the main factor for course choice was their genuine interest for the subject matter, which is this case study, was the environmental studies course.

There is considerable concern on the rise in the incidence of asthma worldwide with statistics in the United Arab Emirates (UAE) indicating that at least 13% of schoolchildren, particularly of Emirati descent, suffer from asthma. With its high rates of hospital admissions, negative socioeconomic impact and significant morbidity, this is a disease that requires optimal guidelines for control and awareness. In this article, we review the current knowledge of asthma in the UAE and draw on studies, especially from the surrounding region, to identify its contributing factors within this population. The most frequently identified agents pertinent to the UAE include outdoor and indoor environmental causes exacerbated by the country’s rapid urbanization, genetic factors aided in transmission by consanguineous marriage, the patient’s socioeconomic status and a rise in vitamin D deficiencies. This evidence aims to inform healthcare professionals and governmental agencies in order to best create guidelines for controlling the burden of this debilitating disease.

Ag (I) nanoclusters doped in mordenite zeolite were prepared and spectroscopically analyzed. Strong luminescence emission that is dependent on the excitation wavelength was observed. These variations in the emission modes are due to the site selective luminescence where various luminophores might be excited upon selecting the proper excitation wavelength. The selected material was found to have strong affinity to remove the quinalphos pesticide, which is widely used for the protection of several vegetable and fruit crops, from water bodies. HPLC and GC–MS techniques were used to follow the kinetic data and to identify the photodecomposition products, respectively. The photodecomposition of quinalphos in the presence of the silver doped mordenite catalyst gives different products compared to the irradiation of quinalphos without catalyst. The presence of the Ag-mordenite catalyst not only adsorbs the quinalphos from the solution but it also reduces its toxic effect as tested on the fruit fly (Drosophila melanogaster).

Limited information is available on the applicability of polychlorinated dibenzo-p-dioxin/furan (PCDD/F) toxicity assays to their brominated counterparts: polybrominated dibenzo-p-dioxins/furans (PBDDs/Fs). We estimated the toxicity of mixtures of chlorinated, brominated, and mixed bromochloro-dioxins and -furan (PBCDDs/Fs) laboratory standards using a chemically-activated luciferase gene expression cell bioassay (CALUX). The relative effects potency (REP) values obtained were comparable to the World Health Organization (WHO) toxic equivalency factors (TEFs) and in agreement with the concept of additive congener toxicity of mixtures of dioxins and furans. Enzyme immunoassay (EIA)-based toxic equivalents (TEQs), however, showed overestimation for PCDDs/Fs (0–4 orders of magnitudes higher) and underestimation for PBDDs/Fs (0–1 orders of magnitude lower) when compared to high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS)-based TEQ calculation (using WHO TEFs) in samples from an industrial source line. No correlation was found between the EIA and the HRGC/HRMS data, which could be attributed to differences in homologue-specific cross-reactivity responses, sample matrix type, and presence of other compounds competing for antibody binding in the immunoassay. Keywords: PBDDs/Fs, PCDDs/Fs, PBCDDs/Fs, CALUX, EIA, HRGC/HRMS

Water and sediments were collected on March 2013 and April 2014 from Khalid Khor creek area in United Arab Emirates to assess their quality parameters. The pH and alkalinity of the water samples were measured and their values were similar to those of shallow saltwater ecosystems. In addition, elemental analyses and organic compounds were done using Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) and Gas Chromatography—Mass Spectroscopy (GC–MS), respectively. The concentration of heavy and trace metals in the water samples were within the acceptable limits except for lead which showed high values, while the concentrations of metals in the sediment samples were relatively high and ranged from 6517 to 13,768 mg/kg. GC–MS analysis showed the presence of polyaromatic heterocyclic (PAHs) compounds in sediments near the shipping area and in amounts classified as highly carcinogenic; however, no polychlorinated biphenyls (PCB) were identified. Moreover, fecal bacterial contamination in water was detected in concentrations that range between 300 and 10,140 organisms/100 mL.

Male common carp (Cyprinus carpio) from eastern Lake Erie, which is greatly effected by urbanization, agriculture, and industry, were analyzed for PCB and PBDE concentrations in plasma, muscle, and liver to evaluate exposure to these chemicals through habitat interactions. Additional male carp from two nearby relatively clean lakes (Bear Lake and Hemlock Lake, NY) were also sampled as controls. While PCBs were detected in muscle, liver, and plasma of Lake Erie carp, the largest concentrations were found in muscle, which also had the most number of congeners. The dominant congeners were PCB 138 and PCB 153. Concentrations of PCB 153 in the muscle were correlated with fish length, total weight, and age. Therefore, larger (and generally older) carp had the highest concentrations of PCB 153. In contrast, PBDEs were found only in muscle with the predominant congener being PBDE 47. The total PCB concentrations in muscle of male carp from eastern Lake Erie (ranging from nd to 15,000 ng g(-1) lipid) were 100-fold higher than the total PBDE observed (1.5-100 ng g(-1) lipid), indicating a higher level of contamination of PCBs in Lake Erie. The high PCB levels in carp points to PCB resistance to metabolic degradation.

This study provides baseline information on the extent of contamination in sediments of the Jobos Bay estuary and surrounding areas in Puerto Rico. Sediments from Jobos Bay area (n = 14) had higher overall average concentrations than those from La Parguera area (n = 5, used as reference site), in μg/g dw, for As (17 vs 9), Cu (29 vs 14), Pb (11 vs 4), and Zn (64 vs 28); and in %, for Fe (2.6 vs 0.6). Sediments (n = 8) screened for PAHs and PCBs exhibited total concentrations (ng/g dw) that ranged from 40.4 to 1912, and from not detected to 11.21, respectively. The quality of sediments of Jobos Bay could be classified as low to moderate pollution. The proximity to anthropogenic sources of contamination warrants a monitoring program for inorganic and organic pollutants in Jobos Bay area for an effective coastal management program of this tropical ecosystem.

Determination of toxic activity requires knowledge of both the concentration and toxicity to evaluate the risk for adverse human health and environmental effects. A chemically-activated luciferase gene expression cell bioassay system (CALUX) and an antibody-based method enzyme immunoassay (EIA) were used to detect the dioxin-like response of several polybrominated, polychlorinated, and polybrominated/chlorinated dibenzo-p-dioxins/furans (PBDDs/Fs, PCDDs/Fs, and PBCDDs/Fs, respectively). It has been suggested that the biological activity of the brominated and mixed bromo/chloro compounds is similar to their chlorinated analogues (measured by binding to the Ah receptor). PBDD/F, PCDD/F, and PBCDD/F laboratory standards exhibited biological activity ranging over three orders of magnitude. The highest relative potency (REP) values from CALUX analysis, when compared to 2,3,7,8-TCDD, were 2,3,7,8-TBDD at 0.99 (±0.07), 1,2,3,7,8-PeCDD at 0.69, and 2-Br-3,7,8-TriCDD at 0.72 (±0.02). Cross-reactivities were calculated using EIA for several PBDDs/Fs and PBCDDs. The highest percent cross-reactivity was found for 2,3,7,8-TBDD at 138 (±34%), and 2,3,7-TriBDD at 84 (±36%). Keywords: PBDD/F, PCDD/F, PBCDD/F, CALUX, ELISA, Dioxin-like activity

Sediments from Niagara River, an important waterway connecting two of the Great Lakes (Lake Erie to Lake Ontario), were analyzed for 14 congeners of polychlorinated biphenyls (PCBs) and 9 congeners of polybrominated diphenyl ethers (PBDEs) using accelerated solvent extraction and gas chromatography/mass spectrometry. Total concentrations of PCBs ranged from 1.7 to 124.6 ng/g were PCBs 138 and 153 were found in all samples. All sites but one showed PBDE in sediments with total concentrations as high as 148 ng/g, suggesting that PBDE is becoming an important class of POP. A land-use and coverage map was used to trace potential localized sources of PCB and PBDE contamination. Results indicate that the highest levels of PCBs and PBDEs were found in sediments collected from areas closest to the discharge locations of municipal wastewater treatment plants (WWTP) and local industries. This is the first study that suggests the importance of WWTP discharges as a potential source of PBDE contamination in the Great Lakes.