Range Of Persistent Organic Pollutants Research Articles

<i>Danio rerio</i> as a model for studying reproductive risks associated with human exposure to polychlorinated biphenils: a systematic review

This review presents the findings of a comprehensive investigation that involved a systematic search, critical analysis, and synthesis of scientific evidence regarding the impact of a broad range of persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs), on the reproductive functions, postembryonic survival, and morphofunctional development of offspring in the aquarium fish species Danio rerio, commonly known as Zebrafish. These fish are extensively utilized in experimental studies to simulate carcinogenic, mutagenic, and general toxic effects.
 The literature search was conducted using Web of Science, Scopus, PubMed, and eLIBRARY.RU databases following the PRISMA 2020 recommendations. A total of 613 articles were identified, out of which 14 were selected for detailed analysis. Among them, 11 focused on assessing the impact of PCB exposure on the reproductive system of Danio rerio. Additionally, 8 articles reported on the results of studying the effects of parental exposure to PCBs on the viability and postembryonic development of their offspring. The adverse effects of PCBs, either alone or in combination with other POPs, have been studied to a lesser extent in male Danio rerio compared to females. Furthermore, the transmission of morphological and functional disorders to subsequent generations resulting from separate parental exposure to PCBs in both sexes, as well as the dose-response relationship, have not been adequately assessed based on the published works. Moreover, developmental disorders in offspring have mostly been studied for the first generation following parental exposure to mixtures of POPs and PCBs. The lack of such information hinders a proper evaluation of the transgenerational risk inheritance phenomenon, specifically regarding the transmission of morphological and functional disorders associated with progenitor exposure to PCBs and other environmental endocrine-disrupting pollutants.
 The findings of this analysis can be used for planning experimental quantitative assessments, predicting, and preventing impairments to human reproductive health, and safeguarding the well-being of future generations.

South polar skua (Catharacta maccormicki) as biovectors for long-range transport of persistent organic pollutants to Antarctica

Migratory bird species may serve as vectors of contaminants to Antarctica through the local deposition of guano, egg abandonment, or mortality. To further investigate this chemical input pathway, we examined the contaminant burdens and profiles of the migratory South polar skua (Catharacta maccormicki) and compared them to the endemic Adélie penguin (Pygoscelis adeliae). A range of persistent organic pollutants were targeted in muscle and guano to facilitate differentiation of likely exposure pathways. A total of 56 of 65 targeted analytes were detected in both species, but there were clear profile and magnitude differences between the species. The South polar skua and Adélie penguin muscle tissue burdens were dominated by p,p′-dichlorodiphenyldichloroethylene (mean 5600 ng g−1 lw and 330 ng g−1 lw respectively) and hexachlorobenzene (mean 2500 ng g−1 lw and 570 ng g−1 lw respectively), a chemical profile characteristic of the Antarctic and Southern Ocean region. Species profile differences, indicative of exposure at different latitudes, were observed for polychlorinated biphenyls (PCBs), with lower chlorinated congeners and deca-chlorinated PCB-209 detected in South polar Skua, but not in Adélie penguins. Notably, the more recently used perfluoroalkyl substances and the brominated flame retardants, hexabromocyclododecane and tetrabromobisphenol A, were detected in both species. This finding suggests local exposure, given the predicted slow and limited long-range environmental transport capacity of these compounds to the eastern Antarctic sector.

Are Aquaporins (AQPs) the Gateway that Conduits Nutrients, Persistent Organic Pollutants and Perfluoroalkyl Substances (PFASs) into Plants?

Besides water and sunlight, plants and/or crops also require an assortment of dissimilar nutrients/elements to grow. Thus, some of these nutrients have been classified as essential or macronutrients, [e.g. calcium (Ca), magnesium (Mg) and sulphur (S)], for they facilitate plant growth; while others, such as copper (Cu), iron (Fe), zinc (Zn), etc., are considered as micronutrients. However, it is apparent now that plants are exposed to a variety of other chemical compounds, including a range of persistent organic pollutants (POPs) and perfluoroalkyl substances (PFASs), which have been found in several plants. Hence, it has been common knowledge that mechanisms, such as mass flow, diffusion, etc., facilitated by plant root systems, have allowed the translocation of these nutrients and pollutants into plants, although other researchers have argued that roots on their own cannot elucidate the dissemination of these chemical constituents into plants. This dissension remained until the discovery of aquaporins (AQPs), which ultimately led to numerous AQPs being identified in plants. Thus, the aim of this review is to present an overview on the progress made thus far in attempting to understand the possibility of these proteins (i.e. AQPs) being the gateway that conduits nutrients, POPs and PFASs into plants; however, the gathered evidence currently remains rudimentary and limited, suggesting that further research is required to elucidate plant AQPs involvement at this stage in POP transportation and storage in plants.

Historical record and fluxes of DDTs at the Palos Verdes Shelf Superfund site, California.

Marine sediments at many locations in the world are contaminated with a wide range of persistent organic pollutants. The Palos Verdes Shelf (PVS) is located in the ocean off the coast of Los Angeles, California and has been listed as a Superfund site by the US EPA since 1997, because of heavy contamination of DDTs and PCBs. However, little is known about the historical trend in the deposition of DDTs as a result of decades-long discharge of wastewater effluents. In this study, sediment cores were taken from the PVS site and determined for DDT and its metabolites including DDE and DDD (denoted as DDTs). Individual DDTs were found in the majority (95%) of the samples analyzed. The highest ∑DDT concentrations were found in three cores along the 60-meter isobath with geometric means of 31300, 7490, and 5010ng/gdw and medians of 82400, 17300, and 5200ng/g dw, respectively. Among DDT congeners, p,p'-DDE, o,p'-DDE and p,p'-DDD were predominant, contributing to approximately 54%, 27%, and 14% of the ΣDDTs in sediment. The vertical profiles of concentrations of contaminants in the sediment cores were examined. For most of the cores, a steady increase in the concentrations of DDTs during 1940s to 1980s was observed, while the concentrations declined gradually toward the surficial layers. On the basis of the mass flux of DDTs calculated and the area of the PVS Superfund site, we estimated the total deposition amount of DDTs in sediment and the deposition amount of ΣDDTs in this region during 1947-1971 was 132 tons, which was fairly close to what was reported in earlier studies for industrial wastewater discharge in the PVS site (870-1450tons). Our findings suggest that the elevated levels of DDTs in sediment from the PVS site are linked to the discharge of these contaminants between the 1940s-1980s.

UK Dietary Exposure to a range of persistent organic pollutants (PBDEs, PBBs, PCBs, PBDD/Fs and PCDD/Fs): Comparison of results from 24 hour duplicate diet with total diet study estimation and health risk assessment

Governments and international organisations measure chemicals in food to monitor the amount of contaminated food that reaches consumers and evaluate dietary exposure. Total Diet Studies (TDS) provi...

Country-specific chemical signatures of persistent organic pollutants (POPs) in breast milk of French, Danish and Finnish women

The present study compares concentrations and chemical profiles of an extended range of persistent organic pollutants (dioxins, polychlorobiphenyls, brominated flame retardants and organochlorine pesticides) in breast milk samples from French (n = 96), Danish (n = 438) and Finnish (n = 22) women. Median exposure levels observed in French women (WHO-TEQ2005 PCDD/F = 6.1 pg/g l.w., WHO-TEQ2005 dl-PCB = 4.3 pg/g l.w., sum of 6 ndl-PCB = 85.2 ng/g l.w., sum of 7 i-PBDE = 1.5 ng/g l.w.) appeared overall lower than in Danish and Finnish women for all examined POPs, except for α-HBCD (2-fold higher level at 0.6 ng/g l.w.). Furthermore, the observed exposure levels of dioxins and PCBs were higher in Danish women (WHO-TEQ2005 PCDD/F = 13.2 pg/g l.w., WHO-TEQ2005 dl-PCB = 6.6 pg/g l.w., sum of 6 ndl-PCB = 162.8 ng/g l.w.) compared to Finnish women (WHO-TEQ2005 PCDD/F = 9.0 pg/g l.w., WHO-TEQ2005 dl-PCB = 4.6 pg/g l.w., sum of 6 ndl-PCB = 104.0 ng/g l.w.), whereas the concentrations of PBDEs were similar for Danish and Finnish women (sum of 7 i-PBDE = 4.9 and 5.2 ng/g l.w. respectively). The organochlorine (OC) pesticide contamination profile, determined in a subset of French samples, was dominated by p,p’-DDE (56.6%), followed by β-HCH (14.2%), HCB (9.7%) and dieldrin (5.2%), while other compounds were only minor contributors (<5%). The three countries appeared to be discriminated by the observed contamination patterns of the PCDD/F versus PCB, and the 1,2,3,6,7,8-HxCDD versus 1,2,3,4,7,8-HxCDD ratios, in addition to the relative contributions of specific congeners to the contamination profile (PCBs #118 and #156, PBDEs #28, #47, #99 and #153). In conclusion, unique chemical signatures were observed for each country on the basis of some POP congeners. Future biomonitoring studies will need to consider the high variability of individual exposure profiles in relation to multiple exposure sources but also physiological and metabolic differences.

Monthly variation in faeces:blood concentration ratio of persistent organic pollutants over the first year of life: a case study of one infant

Previous studies have found that the concentrations of a range of persistent organic pollutants (POPs) in faeces is linearly proportional to the POP concentrations in blood of human adults irrespective of age and gender. In order to investigate the correlation between POP concentrations in faeces and blood in infants, the monthly variation of POP concentrations in faeces over the first year of life of one infant was investigated in this study and compared to modelled blood concentrations. Faecal samples were collected from one male infant daily. The samples were pooled by month and analysed for three selected POPs (2,2′,4,4′,5,5′-Hexachlorobiphenyl (PCB153), p,p′-dichlorodiphenyldichloroethylene (p,p′-DDE) and 2,2′,4,4′-tetrabromodiphenyl ether (BDE47)). The POP concentrations in faecal samples increased for the first four months by a factor of 2.9, 4.9 and 1.4 for PCB153, BDE47, and p,p′-DDE, respectively. The faecal concentrations of all POPs decreased rapidly following the introduction of formula and solid food to the diet and subsequent weaning of the infant. Further, a one-compartment model was developed to estimate the daily POP concentrations in the blood of the infant. The POP concentrations in blood were predicted to vary much less over the first year than those observed in faeces. The faeces:blood concentration ratio of selected POPs (Kfb) differed significantly (P<0.0001) between the period before and after weaning, and observed changes in Kfb are far greater than the uncertainty in the estimated Kfb. A more stable Kfb after weaning indicates the possibility of applying the stable Kfb values for non-invasive assessment of internal exposure in infants after weaning. The intra-individual variation in Kfb in infants is worthy of further investigation.

Simultaneous extraction and cleanup of high-lipid organs from white sturgeon (Acipenser transmontanus) for multiple legacy and emerging organic contaminants using QuEChERS sample preparation

The objective of this research was to utilize the QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method to extract a broad range of persistent organic pollutants from sturgeon organs (liver and gonad) as indicators of exposure. The analyte list was prioritized to include carcinogenic polyaromatic hydrocarbons (PAHs), the most commonly occurring polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs), persistent bioaccumulative and toxic chemicals (PBTs), and emergent contaminants of concern (ECCs) as indicators of human sewage exposure. White sturgeon (Acipenser transmontanus) were selected for this study to support a larger ecotoxicological study to monitor contaminants as an assessment of fish health. Organ tissues contained high lipid content with percentages of 15% and 34% for liver and gonad, respectively. Overall recoveries from fortified sturgeon tissues were high, 71–98% for PAHs, 60–107% for PBDEs and PCBs, 86–107% for PBT chemicals, and 88–107% for ECCs with the exception of octinoxate (28%) from liver tissues. Analyte recovery trends decreased as analyte lipophilicity and molecular weight increased. These recoveries demonstrate that extraction using QuEChERS can be used for screening of the most common bioaccumulating organic compounds in high lipid fish tissue using a single extraction and analysis.

Modeling PCB transfer into hen eggs: influence of physiological characteristics of the animal.

Laying hens are likely to be exposed to a wide range of persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs). To improve the safety of poultry farming systems in terms of POPs, the present research focused on assessing the impact of physiological characteristics of the hen on the transfer of ingested PCBs to eggs. Modeling was used as a research tool to explore the impact of some physiological characteristics on the transfer of PCBs in the laying hen. The mathematical model simulates the dynamics of the size of the lipid compartments in the animal and the frequency of laying, with the PCB concentrations in egg yolk and adipose tissue being model outputs. Simulations were run to assess effects of animal characteristics on the transfer of PCBs to eggs. Laying rate proportionally influenced the PCB level of eggs and adipose tissue at steady state. Body fat diluted absorbed PCBs in the absence of laying and significantly influenced the decontamination rate of tissues during depuration after an exposure period. Application of the present model to actual exposure cases highlights its value in improving the support of risk management in livestock farming.

Success of 2013-2020 World Health Organization action plan to control non-communicable diseases would require pollutants control.

To control diabetes epidemic and NCDs, WHO has been promoting its action plans since 2000, but diabetes epidemic is continuing. New action plan for 2013-2020 aim to reduce shared risk factors of NCDs, such as tobacco use, unhealthy (i.e., high fat) diet, physical inactivity and harmful use of alcohol and is strengthening the risk reduction measures, such as taxing on tobacco, alcohol and sugary beverages, banning advertisements of unhealthy foods. However it might fail because it did not consider the contribution of environmental pollution on the pathogenesis of diabetes and NCDs.

Indirect photochemistry in sunlit surface waters: photoinduced production of reactive transient species.

This paper gives an overview of the main reactive transient species that are produced in surface waters by sunlight illumination of photoactive molecules (photosensitizers), such as nitrate, nitrite, and chromophoric dissolved organic matter (CDOM). The main transients (˙OH, CO3(-˙) , (1)O2, and CDOM triplet states) are involved in the indirect phototransformation of a very wide range of persistent organic pollutants in surface waters.

Characterization of organochlorine pesticides, brominated flame retardants and dioxin-like compounds in shellfish and eel from Fiji

This article gives an overview of a range of persistent organic pollutant chemical levels in shellfish (Batissa violacea and Anadara antiquata) species and eel (Gymnothorax flavimarginatus) from Fiji. As there is limited data in published literature to date, this paper reports first data on a range of persistent organic pollutants and highlights the more prominent POP chemicals present in marine biota in Fiji. A significant number of POP chemicals were detected (e.g. 17 PCDD/PCDF, 12dl-PCBs, organochlorine pesticides and brominated flame retardants), the concentrations found were generally low (e.g. parts per billion level). The low levels of contamination are indicative of a low input from long range and short-range transport as well as few local point sources. Also concentrations of POPs in eel and shellfish from Fiji are low in comparison to wild species in other regions and are within acceptable limits for POP chemicals in fish and fishery products set by the European Union. It describes also results of early studies on basic POPs levels in shellfish in several Pacific Island Countries, which generally show relatively low levels.

Mountain Cold-Trapping Increases Transfer of Persistent Organic Pollutants from Atmosphere to Cows’ Milk

Concentrations of long-lived organic contaminants in snow, soil, lake water, and vegetation have been observed to increase with altitude along mountain slopes. Such enrichment, called "mountain cold-trapping", is attributed to a transition from the atmospheric gas phase to particles, rain droplets, snowflakes, and Earth's surface at the lower temperatures prevailing at higher elevations. Milk sampled repeatedly from cows that had grazed at three different altitudes in Switzerland during one summer was analyzed for a range of persistent organic pollutants. Mountain cold-trapping significantly increased air-to-milk transfer factors of most analytes. As a result, the milk of cows grazing at higher altitudes was more contaminated with substances that have regionally uniform air concentrations (hexachlorobenzene, α-hexachlorocyclohexane, endosulfan sulfate). For substances that have sources, and therefore higher air concentrations, at lower altitudes (polychlorinated biphenyls, γ-hexachlorocyclohexane), alpine milk has lower concentrations, but not as low as would be expected without mountain cold-trapping. Differences in the elevational gradients in soil concentrations and air-to-milk transfer factors highlight that cold-trapping of POPs in pastures is mostly due to increased gas-phase deposition as a result of lower temperatures causing higher uptake capacity of plant foliage, whereas cold-trapping in soils more strongly depends on wet and dry particle deposition. Climatic influences on air-to-milk transfer of POPs needs to be accounted for when using contamination of milk lipids to infer contamination of the atmosphere.

Optimization of Laccase-mediated Benzo[a]pyrene Oxidation and the Bioremedial Application in Aged Polycyclic Aromatic Hydrocarbons-contaminated Soil

Laccase is a polyphenol oxidase with the ability to oxidize a broad range of persistent organic pollutants, including benzo[a]pyrene, the most carcinogenic, mutagenic an dt eratogenic polycyclic aromatic hydrocarbons (PAHs). In this study, the reaction conditions for benzo[a]pyrene oxidation by laccase from Trametes versicolor were optimized in a liquid medium by a series of single factor experiments. The maximal benzo[a]pyrene oxidation rate was observed at 40 ◦ C, pH 4, 10% of acetonitrile and an incubation time of more than 24 hr, and the benzo[a]pyrene oxidation was enhanced significantly by the addition of a mediator, 2,2-azino-bis-(3ethylbenzothiazoline-6-sulfonicacid) (ABTS). Laccase was also applied to aged PAHs polluted soil to examine the efficiency of enzymatic bioremediation. The results showed that the enzyme was still effective in the degradation of anthracene, benzo[a]pyrene and benzo[a]anthracene in soil. Moreover, the degradation rate of most PAHs increased by the addition of ABTS. Our results indicated that the bioremediation of PAHs contaminated soil using laccase is feasible but a suboptimal pH might be a limiting factor in the enzymatic treatment of soil.

Blast from the Past: Melting Glaciers as a Relevant Source for Persistent Organic Pollutants

In this study, the hypothesis that melting Alpine glaciers may represent a secondary source of persistent organic chemicals is investigated. To this end, a dated sediment core from a glacier-fed lake (Lake Oberaar, Switzerland) was analyzed for a wide range of persistent organic pollutants, organochlorine pesticides, and synthetic musk fragrances. Input fluxes of all organochlorines increased in the 1950s, peaked in the 1960s-1970s, and decreased again to low levels in the 1980s-1990s. This observation reflects the emission history of these compounds and technical improvements and regulations leading to reduced emissions some decades ago. The input of synthetic musks remained at a high level in the 1950s-1990s, which is consistent with their relatively constant production throughout the second half of the 20th century. Since the late 1990s, input of all compound classes into the high-Alpine Lake Oberaar has increased sharply. Currently, input fluxes of organochlorines are similar to or even higher than in the 1960s-1970s. This second peak supports the hypothesis that there is a relevant release of persistent organic chemicals from melting Alpine glaciers. Considering ongoing global warming and accelerated massive glacier melting predicted for the future, our study indicates the potential for dire environmental impacts due to pollutants delivered into pristine mountainous areas.

Chronic Maternal Exposure to the Aryl Hydrocarbon Receptor Ligand (AHR), 2, 3, 7, 8-Tetrachloro-Dibenzo-P-Dioxin (TCDD) Causes Nuclear and Cytoskeletal Defects in the Early Rat Embryo.

The aryl hydrocarbon receptor (AHR) is an orphan nuclear receptor bound by a wide range of persistent organic pollutants. Activation of the aryl hydrocarbon receptor (AHR) pathway by acute exposure to the potent AHR ligand 2,3,7,8-tetrachloro-di benzo-p-dioxin (TCDD) has been shown to adversely affect fetal development. Less is known about the effects of long-term exposures to TCDD on the female reproductive axis and early embryogenesis. The aim of the present study was to determine the consequence of chronic AHR activation and antagonism on early embryonic development in the rat. Day 3.5 (morulae stage) embryos were collected from naturally mated female Sprague Dawley dams (n=39) following transgenerational exposure to two environmentally relevant doses of TCDD, (0, 20, or 200ng/kg/wk by gavage). Exposure began in-utero for the dams and continued through 3 months of age when breeding and morulae collection were performed. Rats also similarly received vehicle or resveratrol (10mg/kg/d in drinking water), a natural antagonist of the aryl hydrocarbon receptor pathway. Immediately upon collection, embryos were pooled in each treatment group, fixed in 4% paraformaldehyde, and stained with rhodamine phalloidin and Hoechst dyes to accentuate cytoskeleton and nuclear architecture. Ten embryos per group were evaluated for cell number, degree of compaction, cytoskeletal appearance, nuclear shape/size and presence of mitotic figures with a Zeiss Confocal Imaging system. Female rats treated with TCDD displayed a 7% and 10% increase in the mitotic index when compared to non-treated rats for low and high doses, respectively. Abnormal nuclear morphology, as defined by enlarged, irregularly shaped nuclei, increased by 30% in the low dose group, while rats with a high dose of TCDD exhibited an increase of 65% abnormal nuclei when compared to controls. Disruption of cytoskeletal organization was evident in all cells with abnormal nuclear morphology. Treatment with TCDD or resveratrol did not affect the number of embryos or cells per embryo or degree of compaction compared to vehicle controls. Additionally, resveratrol did not inhibit the impact of TCDD on early embryogenesis. Results indicate that chronic exposure to environmentally-relevant doses of TCDD has deleterious effects on nuclear structure, mitotic index and the cytoskeleton in the early embryo. (poster)

Observations on persistent organic pollutants in indoor and outdoor air using passive polyurethane foam samplers

Air quality data of persistent organic pollutants (POPs) indoors and outdoors are sparse or lacking in several parts of the world, often hampered by the cost and inconvenience of active sampling techniques. Cheap and easy passive air sampling techniques are therefore helpful for reconnaissance surveys. As a part of the Megacity Initiative: Local and Global Research Observations (MILAGRO) project in Mexico City Metropolitan Area in 2006, a range of POPs (polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs)) were analyzed in polyurethane foam (PUF) disks used as passive samplers in indoor and outdoor air. Results were compared to those from samplers deployed simultaneously in Gothenburg (Sweden) and Lancaster (United Kingdom). Using sampling rates suggested in the literature, the sums of 13 PAHs in the different sites were estimated to be 6.1–180 ng m −3, with phenanthrene as the predominant compound. Indoor PAH levels tended to be higher in Gothenburg and outdoor levels higher in Mexico City. The sum of PCBs ranged 59–2100 ng m −3, and seemed to be highest indoors in Gothenburg and Lancaster. PBDE levels (sum of seven) ranged 0.68–620 ng m −3, with the highest levels found in some indoor locations. OCPs (i.e. DDTs, HCHs, and chlordanes) were widely dispersed both outdoors and indoors at all three studied areas. In Gothenburg all POPs tended to be higher indoors than outdoors, while indoor and outdoor levels in Mexico City were similar. This could be due to the influence of indoor and outdoor sources, air exchange rates, and lifestyle factors. The study demonstrates how passive samplers can provide quick and cheap reconnaissance data simultaneously at many locations which can shed light on sources and other factors influencing POP levels in air, especially for the gaseous fractions.

Emission Factors and Importance of PCDD/Fs, PCBs, PCNs, PAHs and PM10 from the Domestic Burning of Coal and Wood in the U.K.

This paper presents emission factors (EFs) derived for a range of persistent organic pollutants (POPs) when coal and wood were subject to controlled burning experiments, designed to simulate domestic burning for space heating. A wide range of POPs were emitted, with emissions from coal being higher than those from wood. Highest EFs were obtained for particulate matter, PM10, (approximately 10 g/kg fuel) and polycyclic aromatic hydrocarbons (approximately 100 mg/ kg fuel for sigmaPAHs). For chlorinated compounds, EFs were highest for polychlorinated biphenyls (PCBs), with polychlorinated naphthalenes (PCNs), dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) being less abundant. EFs were on the order of 1000 ng/kg fuel for sigmaPCBs, 100s ng/ kg fuel for sigmaPCNs and 100 ng/kg fuel for sigmaPCDD/Fs. The study confirmed that mono- to trichlorinated dibenzofurans, Cl1,2,3DFs, were strong indicators of low temperature combustion processes, such as the domestic burning of coal and wood. It is concluded that numerous PCB and PCN congeners are routinely formed during the combustion of solid fuels. However, their combined emissions from the domestic burning of coal and wood would contribute only a few percent to annual U.K. emission estimates. Emissions of PAHs and PM10 were major contributors to U.K. national emission inventories. Major emissions were found from the domestic burning for Cl1,2,3DFs, while the contribution of PCDD/F-sigmaTEQ to total U.K. emissions was minor.

Characterisation and analysis of persistent organic pollutants and major, minor and trace elements in Calabash chalk

Analysis of Calabash chalk has been done using energy dispersive X-ray fluorescence spectroscopy (EDXRF), X-ray diffraction (XRD) and pressurised fluid extraction (PFE) followed by gas chromatography (GC) with mass selective detection (MSD). It was found by XRD that the composition of Calabash chalk was an aluminium silicate hydroxide from the kaolin clay group with the possible formula Al 2Si 2O 5(OH) 4. Multi-elemental analysis by EDXRF was able to quantify 22 elements in Calabash chalk including lead at a mean concentration of approximately 40 mg/kg. A range of persistent organic pollutants were identified and quantified in Calabash chalk including alpha lindane, endrin, endosulphan II and p, p ′-DDD using PFE-GC-MSD.

Passive air sampling of PCBs, PBDEs, and organochlorine pesticides across Europe.

This study presents concurrently sampled ambient air data for a range of persistent organic pollutants at the continental scale. This was achieved using a passive air sampling system, deploying polyurethane foam disks, which was prepared in one laboratory, sealed to prevent contamination, sent out by courier to volunteers participating in different countries, exposed for 6 weeks, collected, resealed, and returned to the laboratory for analysis. Europe was the study area--a region with a history of extensive POPs usage and emission and with marked national differences in population density, the degree of urbanization and industrial/agricultural development. Samplers were deployed at remote/rural/urban locations in 22 countries and analyzed for PCBs, a range of organochlorine pesticides (HCB, alpha-HCH, gamma-HCH, ppDDT, ppDDE), and PBDEs. Calculated air concentrations were in line with those obtained by conventional active air sampling techniques. The geographical pattern of all compounds reflected suspected regional emission patterns and highlighted localized hotspots. PCB and PBDE levels varied by over 2 orders of magnitude; the highest values were detected in areas of high usage and were linked to urbanized areas. HCB was relatively uniformly distributed, reflecting its persistence and high degree of mixing in air. Higher gamma-HCH, ppDDT, and ppDDE levels generally occurred in South and East Europe.