Organochlorine Pollutants Research Articles

The effect of organochlorine pesticide pollution on pregnancy and labour in the environment of Osh Province.

Objective: To study the effect of organochlorine pesticide pollution on pregnancy and labour in the environment of Osh Province. Materials and methods: A total of 10755 pregnant women and women in labor were subjected to analysis to study the effect of environmental pollution on pregnancy and labour in the environment of Osh Province. Group I consisted of 10 029 women residing in cotton-growing area (heavily polluted with OCPs), Group II (Control Group) comprised 726 women living in unpolluted areas. The rates of the diagnosed complications are expressed in percentage. Results: In Group I, abortions were observed in 275 (2.742%) of the 10029 pregnant women and women in labour. In Group II, abortions were reported in 8 (1.1%) of the 726 births. A missed abortion in Group I was diagnosed in 73 (0.728%), antenatal death in 43 (0.43%), stillbirth cases in 36 (0.36%), the number of newborns died during 6 days was 34 (0.34%), preeclampsia in 116 (1.15%), eclampsia in 1 (0.01%). In group II, such complications were not reported. In Group I, proteinuria was diagnosed in 201 (2.0%), in Group II in 2 (0.27%). Hypertension was diagnosed in 96 (0.96%) and 5 (0.69%), respectively; thyroid disease in 624 (6.2%) and 121 (16.7%), respectively. In Group I, cervical erosion was detected in 255 (2.54%) and in 5 (0.69%) in Group II. Extragenital diseases in Group I were revealed in 2541 (25.33%) versus 87 (1.2%) in Group II; urogenital diseases in 648 (6.46%) and 23 (3.17%), including kidney disease in 370 (3.69%) and 20 (2.75%), respectively; anemia was diagnosed in 7115 (70.94%) and 354 (48.76%), respectively. Thus, OCPs are considered the major cause of severe complications (miscarriages, missed abortion, antenatal deaths and stillbirths, preeclampsia) in pregnant women living in cotton-growing area of Osh Province. Complications during pregnancy and labour are found more frequently among the women residing in cotton-growing area than among the women from unpolluted areas.

Trace elements and organochlorine pollutants in selected fish species from Lake Phewa, Nepal

ABSTRACTLake water and fish livers and gills of sahar (Tor putitora), spiny eel (Mastacembelus armatus), African magur (Clarias gariepinus), and tilapia (Oreochromis niloticus) from Lake Phewa, Nepal, were assessed for the concentrations of trace metals/elements and persistent organic pollutants. The lake water was neutral with low ionic and metallic concentrations as compared to high-altitude lakes of Nepal. The four elements Cu, Zn, Se, and Cd had highest concentrations in livers, indicating uptake from diet, whereas four other metallic elements Cr, Mn, Ni, and Pb had highest concentrations in gills, indicating uptake from lake water. O. niloticus tended to have most of trace metals in the liver at higher concentrations than the other species but significant differences among the different species were found only for Mn, Ni, and Zn in the gills. A pilot study on the concentrations of persistent organic pollutants in muscle revealed that dichlorodiphenyltrichloroethane and related compounds were the dominant organochlorine pesticides, having highest concentrations in C. gariepinus and lowest in O. niloticus.

Investigation about the presence of organochlorine pollutants in mussels from the Black Sea, Bulgaria

Abstract The aim of this study was to investigate the presence of polychlorinated biphenyls (PCBs), organochlorine pesticides (HCB, DDT and its metabolites) and HCBD in mussels from Bulgarian Black Sea coast. Mussels (Mytilus galloprovincialis) are aquatic organisms which are immobile so that the concentration of pollutants should primarily be considered as an indication of local levels of organochlorine compounds. Samples were collected from three areas of Black Sea coast of Bulgaria in summer 2015. The fifteen congeners of PCBs, HCB, HCBD, DDT and its metabolites DDE and DDD were performed by gas chromatography system with mass spectrometry detection. The metabolites DDE and DDD were found in all analyzed mussel samples, but PCBs were not detected in any sample. DDE concentrations were found in mussels from 1.09 to 1.63 ng/g wet weight. In mussel total DDT concentrations (2.14 ng/g ww) were found comparable to those in mussels, sampled in 2013 and 2014 (1.87 ng/g ww). The levels of DDTs and polychlorinated biphenyls in mussels from the Black Sea were found comparable to levels measured in the same molluscs from neighbor seas - Mediterranean Sea and Adriatic Sea.

Organochlorines and polychlorinated biphenyl environmental pollution in south coast of Rio De Janeiro state

The objective of this study was to evaluate the burden of environmental pollution by Polychlorinated Biphenyls (PCBs) and Organochlorine Pesticides (OCs) in two localities of Rio de Janeiro coast, through the determination of these levels in specimens of mullets and croakers collected from May to August 2008, at Guanabara Bay (GB) and from Araújo Island (AI), at Paraty Bay. Twenty three organochlorine pollutants were detected in croakers at GB and twenty in mullets and all PCBs congeners investigated in the study were present in the two species. Ratio ∑DDT/∑PCB of 1.4 shows an important contribution of agricultural residues in GB and p,p′-DDE/∑DDT of 0.1 demonstrates a reintroduction of DDT. Consumption of mullet may represent a risk to the health of fishermen families from GB, with average and maximum estimated daily intake of ∑DDT of 9.012μg/kg p.c. and 26,174μg/kg p.c., representing 45% and 131% of ADI established by WHO.

Accelerated telomere shortening in peripheral blood lymphocytes after occupational polychlorinated biphenyls exposure

Polychlorinated biphenyls (PCBs) are organochlorine pollutants with a worldwide dissemination. We examined telomere length (TL) in peripheral blood cells of 207 individuals with a high body burden of PCBs due to occupational exposure in a transformer recycling company. Whereas TL in granulocytes was not affected, the age-adjusted TL in lymphocytes (∆TLLymph) of exposed individuals was significantly shorter than expected [−0.77 kb; 95 % confidence interval (CI) −0.9316; −0.6052; p = 0.0001]. PCB exposure did not affect lymphocyte numbers or T cell receptor excision circle (TREC) levels in T cells, suggesting that PCBs cause loss of telomeric DNA in T cells due to their metabolic activation and antigen-stimulated proliferation. In support of this hypothesis, blood plasma levels of PCB-exposed individuals inhibited expression of telomerase, the telomere elongating enzyme in vitro in antigen-specific T cell proliferation assays. 3-OH-CB28, a downstream metabolite of the lower chlorinated PCB-28 in PCB-exposed individuals (mean blood plasma concentration: 0.185 ± 0.68 ng/mL), inhibited telomerase gene expression within 48 h of incubation in lymphoproliferative assays starting at a concentration of 0.27–6.75 µg/mL and accelerated telomere shortening in long-term cell culture experiments. Accelerated telomere shortening due to PCB exposure may lead to limitations of cell renewal and clonal expansion of lymphocyte populations. As PCB-related immune dysfunctions have been linked to increased susceptibility to infectious diseases and increased risk of cancer, our data provide a possible explanation, for how PCBs could promote infections and cancer through limiting immune surveillance.

Synthesis of 2-(hydroxyethyl)mercapturic acid from p-acetylcysteine and 2-bromoethanol

In conditions of environmental pollution with organochlorine compounds the development of efficient methods for determining metabolites of ecotoxicants in the human body is a topical task. One of metabolites of electrophilic xenobiotics, in particular, of organochlorine pollutants, is 2-(acetylamino)-3-[(2-hydroxy-ethyl)sulfanyl]propionic [2-(hydroxyethyl)mercapturic] acid 1 that as known is formed in a human body as a result of metabolism of haloethanes or haloethylene [1, 2].

Prenatal exposure to persistent organochlorine pollutants and female reproductive function in young adulthood

BackgroundThe biopersistent organochlorine pollutants dichlorodiphenyldichloroethylene (p,p′-DDE), hexachlorobenzene (HCB) and polychlorinated biphenyls (PCBs) can be detected in humans worldwide. The chemicals can cross the placenta and may interfere with endogenous hormonal homeostasis. ObjectivesTo investigate effects on female reproduction following intrauterine exposure to selected biopersistent organochlorines. MethodsWe used data from a Danish pregnancy cohort with follow-up on 436 eligible daughters at approximately 20years of age. Information on age of menarche (n=335), menstrual cycle length (n=230) and serum concentrations of reproductive hormones (n=243) was obtained. Number of antral follicles was counted by vaginal ultrasound (n=147). Of 244 daughters who attended clinical examination, 170 used hormonal contraceptives and 74 were non-users. Concentrations of p,p′-DDE, HCB and six PCB congeners were analysed in maternal serum samples obtained in pregnancy week 30. ResultsAge of menarche and menstrual cycle length were found not to be statistically significant associated with prenatal organochlorine exposure. Among non-users of hormonal contraceptives with information on antral follicle number (n=43), daughters exposed to the highest tertile of p,p′-DDE had 28% (95% confidence interval (95% CI): 5; 46%) lower follicle number compared to the low-level exposed reference group. Those exposed to medium and higher levels of HCB had 30% (95% CI: 5; 48%) and 28% (95% CI: 7; 44%) lower follicle number compared to the reference group. Furthermore, maternal serum HCB concentrations were inversely associated with free androgen index among non-users of hormonal contraceptives (n=73). These associations were not found in users of hormonal contraceptives. ConclusionsAmong non-users of hormonal contraceptives, we found indications of adverse long-term effects on female reproduction following prenatal exposure to biopersistent organochlorines. These findings may have wide implications for public health as intrauterine exposure occurs worldwide.

The invasive lionfish, Pterois volitans, used as a sentinel species to assess the organochlorine pollution by chlordecone in Guadeloupe (Lesser Antilles)

In Guadeloupe, many marine organisms are affected by an organochlorine pollution used in the past by the banana industry to fight against the banana weevil. In the present study, we evaluated the level of contamination of the invasive Indo-Pacific lionfish, Pterois volitans, all around the island. Concentrations of chlordecone varied from 3 to 144μg.kg−1 wet weight. The highest concentrations were recorded when samples were captured in the marine zones located downstream of the previous banana plantations. This contamination seemed to decrease rapidly with the distance from the coast. Mean concentration of chlordecone in Pterois volitans was higher than that of five other fish species collected in similar sites. Due to its position at the top of the trophic web, lionfish was affected by bioaccumulation of chlordecone and can be used as a sentinel species to assess and control the level of contamination of the marine environment by chlordecone.

Influence of parasitism in dogs on their serum levels of persistent organochlorine compounds and polycyclic aromatic hydrocarbons

Persistent organochlorine pollutants (POPs) are toxic chemicals, which accumulate in humans and animals, as only few species have the capability of eliminating them. However, some authors have pointed to the possibility that certain species of invertebrates (i.e. nematodes) could metabolize this type of compounds. As certain species of nematodes act as parasites of vertebrates, this research was designed to explore the influence of some of the most common parasites of the dogs in their serum levels of 56 common POPs. The study included three groups of dogs (n=64), which were prospectively recruited in the island of Gran Canaria (Canary Islands, Spain): a) control animals, non-parasitized (serologically tested negative, n=24); b) dogs tested positive for intestinal parasites and negative for other parasites (n=24); and c) dogs tested positive for heartworm disease (Dirofilaria immitis) and negative for other parasites (n=16). The presence of Dirofilaria immitis was strongly associated with lower serum levels of a wide range of pollutant in their hosts (PCB congeners 28, 52, 118, 138, 153, and 180; hexachlorobenzene, lindane, aldrin, dieldrin, anthracene and pyrene). We also found an inverse association between the hosts' serum levels of PCBs and intestinal parasites. We did not find any association with DDT or its metabolites, but this might be explained by the recently suggested ability of dogs for the efficient metabolization of these compounds. According to the results of this study certain forms of parasitism would reduce the bioavailability of the major classes of POPs in dogs. However, further studies are needed to elucidate whether this phenomenon is due to a competence between parasites and hosts or could respond to a possible capability of parasitic nematodes for the metabolization of these POPs.

Bioaccumulation of organochlorine contaminants in fish species from Lake Qarun, a protected area of Egypt

ABSTRACTThe purpose of this study was to determine concentrations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in Nile tilapia (Oreochromis niloticus) and Bouri fish (Mugil cephalus) from Lake Qarun, a protected area of Egypt, and evaluate the relative ecological risk of these compounds. Different tissues of the fish species were analyzed for 26 chlorinated pesticides and 29 PCB congeners. Total concentrations (µg/kg wet weight, ww) of OCPs ranged between 1487 and 6217 (mean: 3260) and of PCBs between 9.0 and 61 (mean: 34). The trend of detected organochlorine pollutants was: endrin aldehyde > dieldrin > hexachlorobenzene > PCBs > endrin > 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethanes (DDTs). Heptachlor epoxide; oxy-, cis-, and trans-chlordane; trans-nonachlor; β-hexachlorocyclohexane; δ-hexachlorocyclohexane; and endosulfan I and endosulfan sulfate levels were below the detection limit. The ratios of (1,1-dichloro-2,2-bis(p-chlorophenyl)ethylenes [DDEs] + 1,1-dichloro-2,2-bis(p-chlorophenyl)ethanes [DDDs])/ΣDDTs in fish tissues indicated no recent DDT exposure. Concentrations of DDTs and PCBs were generally comparable or higher than those found in studies of similar species worldwide. The concentrations of hexachlorobenzene, dieldrin, and endrin aldehyde in fish muscles exceeded the maximum residue level recommended by various organizations.

Identification and level of organochlorine insecticide contamination in groundwater and iridology analysis for people in Upper Citarum cascade

Organochlorines are the main pollutants in the class of persistent organic pollutants which are types of pollutants that are being questioned worldwide due to chronic persistence, toxicity and bioaccumulation. Human around the Citarum River are still using groundwater as a drinking source. It is very risky for people health that consume groundwater because in 2009 the application of organochlorine still found in the Upper Citarum watershed rice field and had potential to contaminate groundwater. Groundwater was analyzed with nine species belonging to the organochlorine pollutants Organic Peristent types. 7 types of organochlorinesAldrin was detected with an average concentration of 0.09 ppb, dieldrin with an average concentration of 24 ppb, heptaklor with an average concentration of 0.51 ppb, with concentrations of endosulfan on average 0.73 ppb, DDT with average concentration of 0.13 ppb, Lindan with an average concentration of 1.2 ppb, endrin with an average concentration of 0.03 ppb. Types with the highest concentration of organochlorine a lindan and endosulfan. Residues of aldrin, dieldrin and heptaklor in groundwater already exceeds the quality standards for drinking water Permenkes 492/2010. Based on the iridology analysis obtained several systems are expected to nervous, immune and reproductive system disorders and toxin deposits under the skin.

Residues of plant protection products in grey partridge eggs in French cereal ecosystems.

The contamination of the eggs of farmland birds by currently used plant protection products (PPPs) is poorly documented despite a potential to adversely impact their breeding performance. In this context, 139 eggs of 52 grey partridge Perdix perdix clutches, collected on 12 intensively cultivated farmlands in France in 2010–2011, were analysed. Given the great diversity of PPPs applied on agricultural fields, we used exploratory GC/MS-MS and LC/MS-MS screenings measuring ca. 500 compounds. The limit of quantification was 0.01 mg/kg, a statutory reference. A total of 15 different compounds were detected in 24 clutches. Nine of them have been used by farmers to protect crops against fungi (difenoconazole, tebuconazole, cyproconazole, fenpropidin and prochloraz), insects (lambda-cyhalothrin and thiamethoxam/clothianidin) and weeds (bromoxynil and diflufenican). Some old PPPs were also detected (fipronil(+sulfone), HCH(α,β,δ isomers), diphenylamine, heptachlor(+epoxyde), DDT(Σisomers)), as well as PCBs(153, 180). Concentrations ranged between <0.01 and 0.05 mg/kg but reached 0.067 (thiamethoxam/clothianidin), 0.11 (heptachlor + epoxyde) and 0.34 (fenpropidin) mg/kg in some cases. These results testify an actual exposure of females and/or their eggs to PPPs in operational conditions, as well as to organochlorine pollutants or their residues, banned in France since several years if not several decades, that persistently contaminate the environment.Routes of exposure, probability to detect a contamination in the eggs, and effects on egg/embryo characteristics are discussed with regard to the scientific literature.Electronic supplementary materialThe online version of this article (doi:10.1007/s11356-016-6093-7) contains supplementary material, which is available to authorized users.

The impact of multiple anthropogenic contaminants on the terrestrial environment of the Plitvice Lakes National Park, Croatia.

The anthropogenic impact on the terrestrial environment of the Plitvice Lakes National Park (PLNP) was investigated through the analysis of three groups of major contaminants (persistent organochlorine pollutants including 15 organochlorine pesticides (OCPs) and 17 polychlorinated biphenyls (PCBs), trace elements/heavy metals (6 major and 23 trace constituents), and anthropogenic radionuclides ((90)Sr, (134)Cs, and (137)Cs)) in three terrestrial compartments (soil, air, and bioindicators of air contamination) during 2011-2013. The correlation coefficients of element mass fractions with soil properties indicated that total Fe and Al minerals, soil organic matter (OM), and organic carbon (OC) content affected the mass fractions of most trace elements in the topsoils. The annual and spatial distributions of heavy metals in total deposited matter (TDM) indicated that the metals came from natural sources and long-range transfer of particulate matter. The PCB and OCP levels found in soil and conifer needles corresponded to global environmental pollution levels by persistent organic pollutants and represented the lower end of the mass fraction ranges reported in the relevant literature. Analyses of anthropogenic radionuclides in bioindicators (conifer needles, lichens, and mosses) showed low but measurable activity concentrations of (134)Cs (for the first time after the Chernobyl accident), which indicated origin from the March 2011 Fukushima Nuclear Power Plant accident. Our overall results indicated that human activity inside or near the PLNP had no significant impact either on contaminant spread by air or on their content in topsoils.

Persistent Organochlorine Pollutants in Obese Women after Diet Induced Weight Loss: Five Years Follow Up Study

Persistent organochlorine pollutants (POPs) from the environment are still bioaccumulating in human tissues. The aim of our study was to analyze the development of plasma POPs levels in obese women in relationship with their weight loss success in five year follow-up study. 20 obese women aged 25-73 years were studied just before and after having completed a 3 month controlled low calorie diet (LCD) intervention (5 MJ daily), and again after 6 and 60 months since the beginning of the study. Body weight and plasma levels of 7 POPs were measured: polychlorinated biphenyls (PCB) 153, 138, 180; 2,2-bis(4-chlorophenyl)-1,1,1-trichloroethylene (p,p'-DDE); 2,2-bis(4-chlorophenyl)-1,1,1-trichloroethane (p,p'-DDT), hexachlorocyclobenzene (HCB), hexachlorocyclohexane β (HCH β). Data shows that after 3 months of a completely controlled restrictive diet regimen, the weight loss was associated with an increase in POP plasma levels. However, after a five year follow-up, there were no differences in POPs plasma levels between those who kept losing weight or maintained the initial weight (WL/M) and the group of weight gainers (WG), except for HCB where the WG had a significantly higher level (p < 0.05). These results suggest that contrary to the long-term weight gain, the long-term weight loss or weight maintenance caused by diet restriction is associated with lower plasma levels of HCB.

A simple method for the determination of organochlorine pollutants and the enantiomers in oil seeds based on matrix solid-phase dispersion

A simple, rapid and effective method was developed based on matrix solid-phase dispersion (MSPD) for the determination of organochlorine pollutants including sixteen organochlorine pesticides (OCPs) and seven polychlorinated biphenyls (PCBs) in oil seeds (peanuts and soybeans). Among the organochlorine pollutants selected, α-HCH, heptachlor, o,p′-DDT, o,p′-DDD, trans-chlordane and cis-chlordane were chiral and their enantiomers were determined by GC–ECD with a chiral column. The MSPD procedure was optimized focusing on the type and amount of dispersion sorbent, co-column sorbent and eluting solvent. Under the optimized condition, good recoveries were obtained in the range of 68.9–103.3% with relative standard deviations (RSD) values below 16.1% in all cases. LODs and LOQs were in range of 0.1–2.0ngg−1 and 0.4–6.7ngg−1 respectively. In summary, the method set up was qualified to be used for the determination of the pollutants and the enantiomers in oil seeds.

Prenatal exposure to persistent organochlorine pollutants is associated with high insulin levels in 5-year-old girls

BackgroundSeveral persistent organochlorine pollutants (POPs) possess endocrine disrupting abilities, thereby potentially leading to an increased risk of obesity and metabolic diseases, especially if the exposure occurs during prenatal life. We have previously found associations between prenatal POP exposures and increased BMI, waist circumference and change in BMI from 5 to 7 years of age, though only among girls with overweight mothers. ObjectivesIn the same birth cohort, we investigated whether prenatal POP exposure was associated with serum concentrations of insulin and leptin among 5-year-old children, thus possibly mediating the association with overweight and obesity at 7 years of age. MethodsThe analyses were based on a prospective Faroese Birth Cohort (n=656), recruited between 1997 and 2000. Major POPs, polychlorinated biphenyls (PCBs), p,p′-dichlorodiphenyldichloroethylene (DDE) and hexachlorobenzene (HCB), were measured in maternal pregnancy serum and breast milk. Children were followed-up at the age of 5 years where a non-fasting blood sample was drawn; 520 children (273 boys and 247 girls) had adequate serum amounts available for biomarker analyses by Luminex® technology. Insulin and leptin concentrations were transformed from continuous to binary variables, using the 75th percentile as a cut-off point. Multiple logistic regression was used to investigate associations between prenatal POP exposures and non-fasting serum concentrations of insulin and leptin at age 5 while taking into account confounders. ResultsGirls with highest prenatal POP exposure were more likely to have high non-fasting insulin levels (PCBs 4th quartile: OR=3.71; 95% CI: 1.36, 10.01. DDE 4th quartile: OR=2.75; 95% CI: 1.09, 6.90. HCB 4th quartile: OR=1.98; 95% CI: 1.06, 3.69) compared to girls in the lowest quartile. No significant associations were observed with leptin, or among boys. A mediating effect of insulin or leptin on later obesity was not observed. ConclusionThese findings suggest, that for girls, prenatal exposure to POPs may play a role for later development of metabolic diseases by affecting the level of insulin.

Effect of prolonged exposure to sublethal concentrations of DDT and DDE on protein expression in human pancreatic beta cells

Pollution of the environment represents one of less explored potential reasons for the worldwide epidemic of type 2 diabetes. One of the most prevalent organochlorine pollutants remains the pesticide DDT and its degradation product DDE. Despite some epidemiologic correlations between levels of DDT and DDE in human organism and the prevalence of diabetes, there is almost no information about the exact targets of these compounds inside pancreatic beta cells. To detect functional areas of pancreatic beta cells that could be affected by exposure to DDT and DDE, we analyzed changes in protein expression in the NES2Y human pancreatic beta cell line exposed to three sublethal concentrations (0.1μM, 1μM, 10μM) of DDT and DDE for 1 month. Protein separation and identification was achieved using high-resolution 2D-electrophoresis, computer analysis and mass spectrometry. With these techniques, four proteins were found downregulated after exposure to 10μM DDT: three cytoskeletal proteins (cytokeratin 8, cytokeratin 18 and actin) and one protein involved in glycolysis (alpha-enolase). Two proteins were downregulated after exposure to 10μM DDE: cytokeratin 18 and heterogenous nuclear ribonucleoprotein H1 (HNRH1). These changes correlate with previously described effects of other stress conditions (e.g. exposure to palmitate, hyperglycemia, imidazoline derivative, and cytokines) on protein expression in pancreatic beta cells. We conclude that cytoskeletal proteins and their processing, glucose metabolism, and mRNA processing may represent targets affected by exposure to conditions hostile to pancreatic beta cells, including exposure to DDT and DDE.

Pd-loaded magnetic mesoporous nanocomposites: A magnetically recoverable catalyst with effective enrichment and high activity for DDT and DDE removal under mild conditions

1,1,1-Trichloro-2,2-bis(4-chlorophenyl) ethane (DDT), an organochlorine pollutant, is highly persistent in environment and responsible for many ecological and health damages. Although remediation and degradation of DDT and its metabolites in soil and water by microorganisms and abiotic techniques can be accomplished, success is often accompanied by rigorous reaction conditions, such as anaerobic system, explosive gases, high pressure or temperature, and illumination. Here a triple-functional nanocomposite was prepared by integrating superparamagnetic Fe3O4 and palladium (Pd) nanoparticles onto mesoporous Fe3O4@nSiO2@mSiO2 nanospheres. These magnetic mesoporous materials display excellent capabilities of capturing and catalytically degrading DDT in water. Over these nanocomposites, DDT and its metabolite, 1,1-dichloro-2,2-bis(4-chlorophenyl) ethylene (DDE) could be quickly enriched and completely degraded at as low as 150°C. The nanocomposites can be magnetically separated from the dispersion after adsorption, and then be easily regenerated which is accompanied by catalytic reaction. The whole treatment process is convenient, energy-saving, and just requires ambient pressure and mild reaction conditions.

Research Article: DDT, Dioxins, and PCBs in Sediments in a Historically Polluted Estuary along the Gulf of Mexico

This study assessed current profiles of organochlorine pollutants in sediment of Escambia Bay and River in northwest Florida, United States (US), which experienced catastrophic environmental collapse in the 1970s as a result of unregulated industrial and domestic sewage releases. Fifty-seven composite sediment samples were collected with a ponar grab sampler. Organochlorines were extracted with United States Environmental Protection Agency (USEPA) Method 3550 and concentrations were determined with USEPA Method 1668A for polychlorinated biphenyls (PCBs), USEPA Method1613B for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and USEPA Method 8081A for 4,4′-dichlorodiphenyltrichloroethane (DDT), 4,4′-Dichlorodiphenyldichloroethane (DDD), and 4,4′-Dichlorodiphenyldichloroethylene (DDE). For PCBs, 12 (21%) out of the 57 samples exceed the Florida threshold effects level (TEL) of 21.6 μg/kg and no sample exceeds the Florida probable effects level (PEL) of 189 μg/kg. The 17 PCDD/F congeners that a...

Transatlantic movements of juvenile Atlantic bluefin tuna inferred from analyses of organochlorine tracers

Ratios of certain organochlorine pollutants in fish tissues are significantly different between the eastern and western North Atlantic and have been used to identify recent (&lt;1 year) transatlantic migrants of Atlantic bluefin tuna (Thunnus thynnus). In this study we observed limited variation of organochlorine pollutant ratios across collections of young-of-the-year (YOY) bluefin tuna from the western North Atlantic (WNA) and eastern North Atlantic (ENA) in different years and highly significant differences between WNA and ENA YOY samples each year and for all years combined. A significant increase in organochlorine ratios was noted between YOY and age-1 ENA bluefin tuna, consistent with the movement of YOY out of the Mediterranean Sea and into the ENA. Using baseline organochlorine ratios from WNA YOY to identify recent eastern migrants, 29% of age-2, 33% of age-3, and 24% of age-4 juvenile bluefin tuna in the WNA were identified as recent migrants from the east during 2011 and 2012. Applying baseline ratios from age-1 ENA bluefin tuna to identify recent migrants from the WNA, 14.3% of age-2, 9.5% of age-3, and 0% of age-4 juvenile bluefin tuna caught in the Bay of Biscay fishery were identified as recent western migrants during 2010 and 2011. These data reveal substantial connectivity of juvenile bluefin tuna across the North Atlantic and demonstrate that WNA juveniles are heavily subsidized by eastern fish.