PCB Concentrations Research Articles

Aroclor misidentification in environmental samples: how do we communicate more effectively between the laboratory and the data user?

Disposal of carbonless copy paper (CCP) paper sludge during the 1960s contaminated a site in the USA with PCBs. Despite historic records of CCP sludge disposal and absence of evidence of any other disposal, a dispute arose among the parties over the source of the PCBs. Aroclor 1242 is well documented as the PCB mixture used in CCP, yet Aroclors 1242, 1248, 1254, and 1260 were reported by the analytical laboratory. How could the PCBs at a single, small site be reported as four different Aroclors? Some claimed that there had to be at least four Aroclors source inputs to the site. Disposal of four different Aroclors at this site would simply defy logic and the historic record. Weathering of the mixtures is part of the story. A larger issue is the conflict between the intent of the USEPA 8082 method to determine the total PCB content in environmental samples to facilitate environmental cleanup and disposal decisions within a regulatory context versus the data users' intent to identify the PCB sources. This inappropriate extension of the data leads to erroneous conclusions. To mitigate problems like this, laboratory analysis requests need to be matched to the intended data usage; conversely, the data must not be over-interpreted beyond the limits of the method. The PCB analysis community needs to develop a better articulation of the limits of Aroclor identification for the broader community that may naïvely assume that if the laboratory reports "Aroclor 1248," then someone must have placed Aroclor 1248 at the site. After all, when a laboratory reports "lead" or "chloroform," those identifications are never in question.

Seasonal variations in the atmospheric concentrations of polychlorinated biphenyls in Kuwait

The spatial and temporal variations in the atmospheric concentrations of PCBs were concomitantly measured at several sites over a twelve-month period in Kuwait to examine seasonal variability and urban-rural concentration gradients using two sampling methods. The annual mean (and range) of ∑PCB concentrations measured using high volume samplers was 10.8 (1.2–32) pg m−3 at the remote site and 39.4 (1.1–128) pg m−3 at the urban site. The median concentrations of ΣPCBs at the urban location (30.3 pg m−3) was significantly higher (p < 0.001) than that measured at the remote location (8.6 pg m−3) consistent with the view that urban centers are an important net source of these compounds to the environment. Passive sampler derived concentrations across the country showed a uniform distribution except at a few locations in the vicinity of suspected sources where elevated concentrations were measured. As with active sampling data, the concentrations measured using passive samplers were higher in urban areas (range, 4–78 pg/m3) compared to remote sites (range, 2.2–17 pg/m3). The concentrations measured at some urban sites correlated extremely well with mean temperature during the deployment period whereas temperature correlations with measured concentrations were negative at remote and semi-rural sites suggesting that air-surface exchange maybe a key driving mechanism of the current levels of PCBs in Kuwait.

Organochlorine contaminants in wild mink from the lower Great Lakes basin, Canada, 1998-2006.

Organochlorine contaminants were measured in livers of wild mink (Neovison vison) trapped in the lower Great Lakes basin from 1998 to 2006. To assess exposure and potential risk in mink feeding on Great Lakes biota, concentrations of contaminants were compared in mink trapped within 7.8km of the shoreline as well as at inland sites (i.e., 8-40km). Overall, significant spatial variation in mean hepatic concentrations of sum PCBs and seven other organochlorines was found in mink from 13 Great Lakes sites, many of which are within the Great Lakes Areas of Concern. Mean sum PCB concentrations, on a lipid weight basis, ranged from 2μg/g in mink from inland Lake Ontario sites to 44μg/g in mink from western Lake Erie. Concentrations of other organochlorines in mink were generally low. Mink from western Lake Erie had the highest mean cumulative organochlorine burdens dominated largely by PCBs. A significant age effect was found with 1-year-old mink having significantly higher PCB burdens than mink less than 1year in age. With respect to published PCB threshold effect concentrations, some mink exceeded those associated with effects on reproduction and survival as well as the presence of jaw lesions. This was most consistently found in western Lake Erie where the health of populations of wild mink may be adversely affected and where no mink 2years of age or older were collected.

Polychlorinated Biphenyls and Polychlorinated Dioxins–Furans in Lake Trout and Whitefish Composite Samples from Commercial Fisheries in Lakes Erie, Huron, and Superior

Polychlorinated biphenyls (PCBs; sum of 36 congeners) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs; sum of 17 2,3,7,8-substituted congeners) were measured in 93 composite samples prepared from individual lake trout (Salvelinus namaycush) and whitefish (Coregonus clupeaformis) samples collected from Lake Erie, Lake Huron, and Lake Superior. All samples had detectable concentrations of PCBs and PCDD/Fs; maximum PCB concentrations in both trout (750 ng g-1 whole weight [ww]) and whitefish (210 ng g-1 ww) were found in composites from fish collected from Lake Huron. The maximum toxic equivalent concentration was found in a lake trout composite sample from Lake Huron (53 pg g-1 ww). PCB and PCDD/F congener profiles were comparable to patterns observed in fishes collected from other regions of Canada, although concentrations were above those found in other regions. A positive correlation was found between PCB concentrations determined using the historical Aroclor equivalency method and those determined using the sum of the congeners measured (r2 = 0.871; Spearman correlation r = 0.917) or using the six indicator PCB congeners (28, 52, 101, 138, 153, and 180; r2 = 0.850; Spearman correlation r = 0.935). PCBs were the dominant contributor to the overall toxic equivalent concentrations in the fish composite samples tested. These findings provide insight into PCB and PCDD/F concentrations in two commercially important fish species over a discrete time period.

Food contamination by PCBs and waste disposal crisis: Evidence from goat milk in Campania (Italy)

AimThe study aims at investigating whether, and if so, to what extent the strong presence of urban and industrial waste in a territory may cause PCB contamination in goat milk produced therein. MethodsWe compared PCB concentrations in goat milk from three different locations in the Campania region (Italy). One of the three locations, together with its surrounding area, has long suffered from illegal waste disposal and burning mainly by the so-called Ecomafia. The other locations, not involved in these illegal activities, allowed us to create a control group of goats with characteristics very similar to those of main interest. ResultsIn milk from the waste contaminated area we identified high PCB concentrations (six indicator PCBs amounted to 170 ng g−1 on lipid weight, on average), whereas there was an almost total absence of such pollutants in milk from the control group. Concentrations of the six indicator PCBs were above the current European maximum residue limit fixed by the EU. At the same time, we found a lower average value of lipid content and a negative relationship between lipid content and PCB concentrations. ConclusionEvidence indicates the potential health risk for consumers living in areas involved in illegal dumping of waste.

Survey on the presence of non-dioxine-like PCBs (NDL-PCBs) in loggerhead turtles (Caretta caretta) stranded in south Mediterranean coasts (Sicily, Southern Italy).

A total of 71 loggerhead turtles (Caretta caretta) stranded along the coasts of Sicily (Southern Italy) were examined for non-dioxine like polychlorinated biphenyl (NDL-PCB) levels in muscle and adipose tissue by a gas chromatography-mass spectrometry/mass spectrometry (GC-MS/MS) method. The results revealed 6 high-indicator congener (∑6 PCBIND ) levels in 45% of the loggerhead turtles examined, with mean values of 980.39 ± 2508.39 ng/g wet weight in adipose tissue and 102.53 ± 238.58 ng/g wet weight in muscle tissue. The hexachloro and heptachloro PCB congeners were the most abundant in both the sample types. The highest NDL-PCB levels were reached in an adipose tissue sample of a loggerhead turtle of 80 kg stranded along the coasts of Termini Imerese (14 183.85 ng/g wet wt). No significant correlation was found between modified Fulton's K values of the loggerhead turtles and PCB contents (S = 47 151, p > 0.05). Furthermore, no significant differences were found between sexes (W = 365, p > 0.05). The PCB levels found in the present study were much higher than those found in the literature. The present study is the first report on the existence of NDL-PCBs in loggerhead turtles stranded in Sicilian coasts confirming C. caretta as a valuable indicator of contaminant exposure in the marine environment because of their specific biological and ecological characteristics. Environ Toxicol Chem 2017;36:2997-3002. © 2017 SETAC.

The Effect of Microplastic on the Uptake of Chemicals by the Lugworm Arenicola marina (L.) under Environmentally Relevant Exposure Conditions.

It has been hypothesized that ingestion of microplastic increases exposure of aquatic organisms to hydrophobic contaminants. To date, most laboratory studies investigated chemical transfer from ingested microplastic without taking other exposure pathways into account. Therefore, we studied the effect of polyethylene (PE) microplastic in sediment on PCB uptake by Arenicola marina as a model species, quantifying uptake fluxes from all natural exposure pathways. PCB concentrations in sediment, biota lipids (Clip) and porewater measured with passive samplers were used to derive lipid-normalized bioaccumulation metrics Clip, Biota sediment accumulation factor (BSAF), Bioaccumulation factor (BAF) and the Biota plastic accumulation factor (BPAF). Small effects of PE addition were detected suggesting slightly increased or decreased bioaccumulation. However, the differences decreased in magnitude dependent on the metric used to assess bioaccumulation, in the order: Clip > BSAF > BPAF > BAF, and were nonsignificant for BAF. The fact that BAF, that is, normalization of Clip on porewater concentration, largely removed all effects of PE, shows that PE did not act as a measurable vector of PCBs. Biodynamic model analysis confirmed that PE ingestion contributed marginally to bioaccumulation. This work confirmed model-based predictions on the limited relevance of microplastic for bioaccumulation under environmentally realistic conditions, and illustrated the importance of assessing exposure through all media in microplastic bioaccumulation studies.

Assessing the influence of confounding biological factors when estimating bioaccumulation of PCBs with passive samplers in aquatic ecosystems

Passive samplers are promising surrogates for organisms, mimicking bioaccumulation. However, several biological characteristics disturb the passive partitioning process in organisms by accelerating or restraining bioaccumulation, resulting in species-specific body residues of hydrophobic organic contaminants (HOCs). In addition to site-specific characteristics and HOC concentrations, age, sex, diet, biotransformation capability and habitat-specific characteristics may affect body residues.Two passive sampler types, polyethylene (PE) and polydimethylsiloxane (PDMS) were deployed in a PCB-contaminated freshwater lake water and sediment, respectively, to assess their bioaccumulation prediction capacity. In order to understand the importance of biological characteristics in the bioaccumulation process, we explored bioaccumulation in biota from plants and plankton to mussels and fish. The PCB concentrations in the PE sheet reflected the bioavailable concentration of PCBs slightly better than those in the PDMS samplers. Passive samplers were good predictors of PCB concentrations in fish, whereas concentrations in algae and invertebrates were overestimated. When comparing the measured concentrations in biota to the estimated concentrations using the PE samplers, the average regression slope was 0.87 for all biota and 1.22 for fish, and average modeling efficiency (EF) was 3.02 for all biota and 0.6 for fish. The best model performance was achieved for fish in trophic levels 3–4. Bioaccumulation was species-specific and dependent on the trophic level and diet. Closer examination revealed that metabolic capability changes during the life span, and source of nutrition determined the biomagnification of HOCs, which differed between the fish species. Thus, species composition and available prey selection compose a unique bioaccumulation scenario and the resulting body residues. Due to the existing variation in body residues derived from passive samplers, extrapolating the results from one to another ecosystem must be done with caution. Passive samplers, however, offer a very powerful tool for risk assessment on the ecosystem level.

Atmospheric concentrations, distributions and air-soil exchange tendencies of PAHs and PCBs in a heavily industrialized area in Kocaeli, Turkey

Dilovasi is one of the heavily industrialized areas in Turkey with serious environmental problems. In this study, the atmospheric concentration of PAHs and PCBs were measured for a whole year at 23 sites. The average ambient air Σ15PAH and Σ41PCB concentrations were found as 285 ± 431 ng m−3 and 4152 ± 6072 pg m−3, respectively. PAH concentrations increased with decreasing temperature especially in urban areas, indicating the impact of residential heating. However, PCB concentrations mostly increased with temperature probably due to enhanced volatilization from their sources. The gradient obtained for PCBs, rural < suburban < urban < industrial/urban, is more clear than those obtained for PAHs. The average Σ15PAH and Σ41PCB soil concentrations were found as 992 ± 1323 and 18.8 ± 32.0 μg kg−1, respectively. PCB soil concentrations did not show significant temporal variations while PAH concentrations were variable especially for urban areas. The volatilization tendencies of low and medium molecular weight PAHs from soil to air were higher in industrial-urban areas than rural sites, showing that soil was a secondary source for PAHs. Fugacity ratios of PCBs were mostly <1.0 for the whole sampling period. Although the source/sink tendency of soil for some PCBs depends on their volatility, considering the whole data, PCBs were generally deposited to soil.

Population status of freshwater turtles across a PCB contamination gradient

AB Aquatic Biology Contact the journal Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections AB 26:57-68 (2017) - DOI: https://doi.org/10.3354/ab00676 Population status of freshwater turtles across a PCB contamination gradient James P. Gibbs1,*, Shahrokh Rouhani2, Leyla Shams2 1Department of Environmental and Forest Biology, Illick Hall, State University of New York College of Environmental Science and Forestry, Syracuse, NY 13210, USA 2NewFields, Atlanta, GA 30309, USA *Corresponding author: jpgibbs@esf.edu ABSTRACT: Remarkably few studies on the effects of PCBs on wild turtles have been conducted. We contrasted population-level parameters of 2 species of freshwater turtles, the snapping turtle Chelydra serpentina and the painted turtle Chrysemys picta, across a strong PCB concentration gradient in the upper Hudson River, New York State, USA. Our study employed standardized capture methods that yielded 465 turtles during 1968 trap-nights over 2 yr (2006 and 2007) at 246 trapping sites. Individuals of both turtle species were relatively heavier in a contaminated river segment, but PCB concentration did not otherwise influence relative abundance of turtles, probabilities of habitat occupancy or detection, sex or age ratios, body size, incidence of deformities, external parasite occurrence, or several movement parameters in a manner consistent with adverse impacts to wild turtles. This lack of spatial trend in parameters of wild populations of aquatic turtles across a strong gradient of PCB contamination contrasts with predictions of adverse impacts derived from population modeling, dose-response studies, and tissue residue analyses. KEY WORDS: PCB · Hudson River · Populations · Snapping turtle · Painted turtle Full text in pdf format PreviousNextCite this article as: Gibbs JP, Rouhani S, Shams L (2017) Population status of freshwater turtles across a PCB contamination gradient. Aquat Biol 26:57-68. https://doi.org/10.3354/ab00676 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AB Vol. 26. Online publication date: May 15, 2017 Print ISSN: 1864-7782; Online ISSN: 1864-7790 Copyright © 2017 Inter-Research.

Health risk assessment for the consumption of fresh and preserved fish (Alosa agone) from Lago di Como (Northern Italy)

BackgroundAlthough banned in many countries for decades, DDTs and PCBs still represent a global threat to food safety. As these contaminants are still present in aquatic ecosystems, fish can be an important contributor to their total dietary intake. ObjectivesAlosa agone specimens were sampled over a period of 10 years (from 2006 to 2015) to provide a representative overview of the DDT and PCB levels of Lago di Como, a deep Italian lake where a DDT input due to secondary sources was observed in recent years. The potential health risk from the consumption of both fresh and preserved fish was evaluated. ResultsWhile DDT levels have generally decreased during the monitored period, reaching quite stable levels, PCB concentrations were variable, with values exceeding, in some cases, the European Union limit for human consumption and enabling potential carcinogenic effects. However, typical local processing of this fish species markedly appeared to decrease these contaminant levels, thus making the fish product (called missoltino) a safer food. ConclusionsThe results of this work highlighted the need of continuous biomonitoring of those contaminants considered a past issue along with the emergent ones.

Distribution and residue profile of organochlorine pesticides and polychlorinated biphenyls in sediment and fish of Lake Manzala, Egypt.

Distributions of OCPs and PCBs in sediment and tilapia from Lake Manzala were investigated. Chlorpyrifos, ∑DDT, and HCB sediment concentrations were spatially variable and relatively elevated. ∑96PCBs, ∑DDT, and 4,4'-DDE exceeded the Effects Range Low in 88, 75, and 42% of the sediments, respectively. The major input from Cairo, the Bahr Al-Baqar drain, exceeded the Probable Effects Level for DDT isomers in sediments. OCP and PCB concentrations in tilapia were below action and tolerance levels set by the US-EPA.

Influence of Selected Coagulants of Indicator and Dioxin-Like PCB Removal from Drinking Water

Abstract The aim of the research was to compare selected coagulants efficiency in indicator and chosen dioxin-like PCB removal from surface water. As coagulants, there were used aluminium sulfate and 5 hydrolyzed polyaluminium chlorides, with trade names: PAX-XL1, PAX-XL10, PAX-XL19, PAX-XL60, PAX-XL69. For the research, surface water was used, collected from dam reservoir. The water composition was modified with standard mixtures PCB MIX24 and MIX13, in order to obtain concentration of each congener equal to 300 ng/dm3. The PCB MIX24 mixture was composed of indicator congeners solution: 28, 52, 101, 118, 138, 153, and 180, whereas the MIX13 mixture - solution of three dioxin-like PCB 77, PCB 126, and PCB 169. It was demonstrated that the application of aluminium sulfate allowed for reaching better effects for purifying water of PCB, than with the usage of pre-hydrolyzed salts, polyaluminium chlorides. Out of the studied coagulants, the best effects for indicator PCB removal were obtained with the application of aluminium sulfate, total PCB concentration was decreased by 65%. The highest efficiency for indicator congeners removal (90%) was obtained for PCB 138 and 153. After the application of hydrolyzed polyaluminium chlorides PAX-XL1, PAX-XL10 decrease in higher chlorinated PCB concentration was obtained, in the range of 23 to 74%. Selectivity of chosen PCB congener removal, depending on applied coagulant, was demonstrated; with the usage of aluminium sulfate, removal of heptachlorobiphenyl PCB 180 at the level of 34% was obtained, whereas with the application of PAX-XL1 and PAX-XL10 higher reduction efficiency for this congener was obtained, i.e. 83 and 74% respectively. For dioxin-like PCB, after application of aluminium sulfate, total concentration reduction by 74% was obtained, efficiency of this congeners removal amounted to from 54 (PCB 77) up to 72% (PCB 126), similar results were obtained after the usage of PAX-XL1. The lowest PCB removal from water rate was stated for coagulants PAX-XL60 and PAX-XL69.

Historical data review and source analysis of PCBs/Arochlors in the Lower Leon Creek Watershed

PCBs have been banned since the late 1970s, but concentrations still exist in sediments and riverine fish and continue to exceed regulatory limits which can result in negative health effects. This study looks at historical records of PCB and Arochlor concentrations in surface water, sediments, and fish tissue for the Lower Leon Creek, Bexar County in Texas. Temporal analysis on the concentrations of PCBs and Arochlors was conducted for detection and exceedance of selected screening criteria. In addition, the half-lives of select PCB congeners were calculated for 2007-2012 data to ascertain differences in PCB concentrations with their hydrophobicity. Source analysis was conducted to determine the potential contributing sources of PCB contamination using source data (landfills, outfalls, etc.) and the PCB exceedance data. For sediment and fish tissue sampling results, historic data shows high concentrations of PCB/Arochlors over the course of several decades. The historical data is characterized as being widely variable for detections in Arochlors and concentrations between years, with a dramatic drop in concentrations detected starting in 2009. Overall, the sampling locations adjacent to and downstream from the former Kelly Air Force Base have the highest concentrations of PCB/Arochlors over the longest period of time. The results of this work will aid regulatory agencies in addressing impairment.

PCDD/Fs and dl-PCBs concentrations in water samples of Taiwan

Polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and coplanar polychlorinated biphenyls (dioxin-like PCBs) have received much public concern worldwide due to their persistence and toxicity. The presence of these compounds in environmental matrices, especially in water bodies, enhances the risk of human exposure to these toxic pollutants. In this study, seventeen 2,3,7,8 chlorinated PCDD/Fs and twelve dl-PCBs were measured in 11 groundwater samples collected throughout Taiwan and 2 surface water samples collected in northern Taiwan. PCDD/F and PCB concentrations in two surface water samples are relatively low, with the average concentrations of 0.038 and 0.001 pg WHO-TEQ/L (7.474 and 1.862 pg L−1), respectively. As for groundwater samples, PCDD/F concentrations measured range from 0.005 to 3.963 pg WHO-TEQ/L, while dl-PCB concentrations range from 2.5 × 10−5 to 0.189 pg WHO-TEQ/L. Total WHO-TEQ concentrations range from 0.005 to 3.963 pg WHO-TEQ/L, reflecting serious contamination of PCDD/Fs and PCBs in groundwater at some sampling sites. In term of total PCDD/Fs, PCDDs constitute a significant fraction (77.3%), and OCDD is most abundant, followed by HpCDD/Fs and HxCDD/Fs. PCB 118 is dominant among 12 dl-PCBs measured, followed by PCB 105 and PCB 77. Solid-phase PCDD/Fs generally predominate in water samples and PCDFs are of slightly lower distribution in solid phase in comparison with PCDDs, while PCBs are mainly distributed in dissolved phase. Results of principal component analysis (PCA) indicate that use of PCP and Na-PCP, thermal processes and PCBs-containing products might be the major sources of PCDD/Fs and PCBs in water samples measured.

Vicissitudes of oxidative stress biomarkers in the estuarine crab Scylla serrata with reference to dry and wet weather conditions in Ennore estuary, Tamil Nadu, India

The primary objective of this study was to understand the impact of monsoon and summer seasons on the Polychlorinated Biphenyls (PCB's) and petroleum hydrocarbon compounds (PHC's) load in Ennore estuary and how the physiological response of estuarine Scylla serrata inhabiting in this estuary changed with reference to antioxidant defense. Seasonal levels of PCB's and PHC's were assessed in the water along with their bioaccumulation in gills, hemolymph, hepatopancreas and ovary of S. serrata. Concentration of PCB's and PHC's in water and their bioaccumulation was found to be higher in summer season when compared to monsoon season. Enzymic antioxidant assays [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR), glutathione-S-transferase (GST)]; non-enzymic antioxidant assays [glutathione (GSH), vitamin C, vitamin E] and macromolecular alterations [membrane lipid peroxidation (LPO), and DNA Damage (strand breaks)] were assessed in the gills, hemolymph and hepatopancreas of S. serrata. There was a significant (p<0.05) upregulation in lipid peroxidation activity and DNA damage activity collected during the summer season when compared to the pre- and post-monsoon seasons. On the contrary, the enzymic and non-enzymic antioxidants exhibited significant (p<0.05) down regulation in the gills, hemolymph, hepatopancreas and ovary of S. serrata. Oxidative stress biomarkers represented a significant (p<0.05) maximum in gills when compared to hemolymph and hepatopancreas of S. serrata. Present study provided scientific evidences of how the antioxidant defense status of S. serrata responded to PCB's and PAH's stress with reference to seasonal vicissitudes, which indirectly represented the environmental health conditions of the estuary.

Concentrations and sources of pesticides and PCBs in surficial sediments of the Red Sea coast, Egypt

Sixteen surface sediments from the Egyptian coast of the Red Sea were collected and studied for organochlorine contamination. This research was endeavored to study sources, concentrations and risk factors of pesticides and PCBs in the surficial sediments collected from the studied locations. The sediments in the studied areas are predominantly sand. The most abundant PCB congeners detected in the investigated sediment samples of the Red Sea proper were a total of PCB 52 and a total of PCB 138 (225 and 465ngkg−1drywt., respectively). Meanwhile, in the Aqaba Gulf the most abundant PCB congener was a total of PCB 138 (226ngkg−1drywt.). At the Suez Gulf, the most abundant PCB congeners were a total of PCB 180 and 153 (127 and 103ngkg−1drywt., respectively). The input of direct industrial and domestic discharge in most of the contaminated zones of the studied area resulted in a larger concentration of total PCB 52, 138, 153 and 180. The results obtained showed fairly low levels of pesticide residues. The most dominant pollutants were the HCHs and DDTs, high proportions of α-HCH over γ-HCH isomer indicated less recent input of lindane. The α-HCH/γ-HCH ratios in most of the studied locations are slightly less than those in technical-grade HCH mixture (66.5% α isomer, 11.4% β isomer, 15.2% γ isomer (lindane), 6.4% δ isomer, and 0.5% other isomers) indicating that there was less input of lindane in the past several years. This study clearly indicates that PCB concentrations, DDTs, cyclodienes, HCHs were much lower than those recorded by the international organization.

Detection of microcystin producing cyanobacteria in Spirulina dietary supplements using multiplex HRM quantitative PCR

Arthrospira species, under the name ‘Spirulina’, are used as food supplement for its protein, vitamins, and minerals which have several health benefits. Cyanobacterial toxins including microcystins can possibly contaminate these dietary supplements causing hepatotoxicity, tumour formation, and other disorders. The safe use of dietary supplements necessitates the need to assess such toxins in the algal food supplement. The methods which evaluate these dietary supplements should be highly sensitive, cost-effective, and rapid. In this study, multiplex HRM qPCR analysis was used to detect microcystin (MC)-producing cyanobacteria in Spirulina dietary supplements. The multiplex HRM qPCR detection limit was found to be 25 ag of mcyB spiked in a standard concentration of pcb (25 pg). Two distinct melt curves characteristic of pcb (Tm 82.8 ± 0.07 °C) and mcyB (Tm 77.9 ± 0.05 °C) were observed. Microcystin contamination was detected only in the fish food supplements and not in human dietary supplements of Spirulina. Liquid chromatography–high-resolution mass spectrometry analysis further confirmed the presence of the congeners of microcystin in the identified positive samples.

PAHs and PCBs in an Eastern Mediterranean megacity, Istanbul: Their spatial and temporal distributions, air-soil exchange and toxicological effects

Istanbul, one of the mega cities in the world located between Asia and Europe, has suffered from severe air pollution problems due to rapid population growth, traffic and industry. Atmospheric levels of PAHs and PCBs were investigated in Istanbul at 22 sampling sites during four different sampling periods using PUF disk passive air samplers and spatial and temporal variations of these chemicals were determined. Soil samples were also taken at the air sampling sites. At all sites, the average ambient air Σ15PAH and Σ41PCB concentrations were found as 85.6 ± 68.3 ng m−3 and 246 ± 122 pg m−3, respectively. Phenanthrene and anthracene were the predominant PAHs and low molecular weight congeners dominated the PCBs. The PAH concentrations were higher especially at urban sites close to highways. However, the PCBs showed moderately uniform spatial variations. Except four sites, the PAH concentrations were increased with decreasing temperatures during the sampling period, indicating the contributions of combustion sources for residential heating, while PCB concentrations were mostly increased with the temperature, probably due to enhanced volatilization at higher temperatures from their sources. The results of the Factor Analysis represented the impact of traffic, petroleum, coal/biomass and natural gas combustion and medical waste incineration plants on ambient air concentrations. A similar spatial distribution trend was observed in the soil samples. Fugacity ratio results indicated that the source/sink tendency of soil for PAHs and PCBs depends on their volatility and temperature; soil generally acts as a source for lighter PAHs and PCBs particularly in higher temperatures while atmospheric deposition is a main source for higher molecular weight compounds in local soils. Toxicological effect studies also revealed the severity of air and soil pollution especially in terms of PAHs in Istanbul.

Temporal variation in circulating concentrations of organochlorine pollutants in a pelagic seabird breeding in the high Arctic.

The present study explored short-term temporal variations in circulating concentrations of 3 legacy organochlorines with different physicochemical properties (polychlorinated biphenyl 153 [PCB-153], p,p'-dichlorodiphenyldichloroethylene [DDE], and hexachlorobenzene [HCB]) in breeding kittiwakes (Rissa tridactyla) in a colony in Svalbard (78°N), Norwegian Arctic. Concentrations were measured in blood of a large number (n = 412-521 blood samples, depending on the data analyses) of prebreeding, incubating, and chick-rearing birds over a period of 5 yr (2007-2011). The PCB-153 concentrations were equal in male and female blood in the prebreeding period, whereas females had significantly lower concentrations during incubation and chick rearing, probably because of their ability to eliminate organochlorines through egg laying. A similar temporal pattern was observed with DDE, although the lower concentrations in incubating females were not significant. Males and females had similar concentrations of HCB over all reproductive stages. The concentrations of all 3 compounds varied greatly between years. The concentrations of PCB-153 tended to decline over the study period, whereas concentrations of HCB showed an increasing trend, especially among chick-rearing males late in the season. Concentrations of PCB-153 increased approximately 2.5 times from the prebreeding to the chick-rearing period, concurrent with mobilization of body lipids (reduced body mass). A similar, but less pronounced trend was found for HCB. For DDE, however, kittiwakes had the highest concentrations in the prebreeding period, suggesting relatively high exposure in their winter areas. The present study documented large variations in circulating concentrations of legacy organochlorines among and within breeding seasons in kittiwakes, but the alterations within seasons were relatively consistent from year to year. Environ Toxicol Chem 2017;36:442-448. © 2016 SETAC.