Kg Of Polychlorinated Biphenyls Research Articles

PCB related effects thresholds as derived through gene transcript profiles in locally contaminated ringed seals (Pusa hispida).

Causal evidence linking toxic injury to polychlorinated biphenyl (PCB) exposure is typically confounded by the complexity of real-world contaminant mixtures to which aquatic wildlife are exposed. A local PCB "hotspot" on the Labrador coast provided a rare opportunity to evaluate the effects of PCBs on the health of a marine mammal as this chemical dominated their persistent organic pollutant (POP) burdens. The release of approximately 260 kg of PCBs by a military radar facility over a 30 year period (1970-2000) contaminated some local marine biota, including the ringed seal (Pusa hispida). The abundance profiles of eight health-related gene transcripts were evaluated in liver samples collected from 43 ringed seals in the affected area. The mRNA transcript levels of five gene targets, including aryl hydrocarbon receptor (Ahr), interleukin-1 β (Il1b), estrogen receptor α (Esr1), insulin like growth factor receptor 1 (Igf1), and glucocorticoid receptor α (Nr3c1) correlated with increasing levels of blubber PCBs. PCB threshold values calculated using best-fit hockey-stick regression models for these five genes averaged 1,680±206 ng/g lw, with the lowest, most conservative, being 1,370 ng/g lw for Il1b. Approximately 14% of the seals in the region exceeded this threshold. The dominance of PCBs in the seals studied enabled an assessment of the effects of this chemical on gene transcripts involved in regulating the health of a highly mobile predator, something that is rarely possible in the world of complex mixtures.

Polychlorinated biphenyls in the exterior caulk of San Francisco Bay Area buildings, California, USA

Extensive evidence of the adverse impacts of polychlorinated biphenyls (PCBs) to wildlife, domestic animals, and humans has now been documented for over 40years. Despite the ban on production and new use of PCBs in the United States in 1979, a number of fish consumption advisories remain in effect, and there remains considerable uncertainty regarding ongoing environmental sources and management alternatives. Using a blind sampling approach, 25 caulk samples were collected from the exterior of ten buildings in the San Francisco Bay Area and analyzed for PCBs using congener-specific gas chromatography–mass spectrometry (GC–MS) and chlorine using portable X-ray fluorescence (XRF). PCBs were detected in 88% of the caulk samples collected from the study area buildings, with 40% exceeding 50ppm. Detectable PCB concentrations ranged from 1 to 220,000ppm. These data are consistent with previous studies in other cities that have identified relatively high concentrations of PCBs in concrete and masonry buildings built between 1950 and 1980. Portable XRF was not a good predictor of the PCB content in caulk and the results indicate that portable XRF analysis may only be useful for identifying caulk that contains low concentrations of Cl (≤10,000ppm) and by extension low or no PCBs. A geographic information system-based approach was used to estimate that 10,500kg of PCBs remain in interior and exterior caulk in buildings located in the study area, which equates to an average of 4.7kg PCBs per building. The presence of high concentrations in the exterior caulk of currently standing buildings suggests that building caulk may be an ongoing source of PCBs to the San Francisco Bay Area environment. Further studies to expand the currently small international dataset on PCBs in caulking materials in buildings of countries that produced or imported PCBs appear justified in the context of both human health and possible ongoing environmental release.

Partitioning and bioaccumulation of PCBs and PBDEs in marine plankton from the Strait of Georgia, British Columbia, Canada

The Strait of Georgia is a large, deep, fjord-like estuary on the southern coast of British Columbia which is subject to local and atmospheric inputs of persistent environmental contaminants. We measured 204 polychlorinated biphenyls (PCBs) and 61 polybrominated diphenyl ethers (PBDEs) seasonally in water (two depths; dissolved and particle-bound) and plankton (vertical tow) samples collected at two stations. Principal components analysis clearly distinguished the dissolved and particulate water fractions and plankton samples, with the latter two compartments associated more with heavier congeners. Bioaccumulation factors (logBAFs) for PCBs and PBDEs in plankton were best described by parabolic relationships against octanol–water partitioning coefficients (logKow), peaking at a logKow of 5–7, underscoring the important role of physico-chemical properties in driving the uptake of these persistent contaminants by plankton from water. The estimated total quantity of PCBs (annual average of 0.61±SEM 0.12kg) and PBDEs (annual average of 0.64±0.19kg) in Strait of Georgia plankton biomass were remarkably similar, highlighting the emergence of currently-used PBDEs as a priority concern. The estimated total of 52.1±8.41kg of PCBs in water (dissolved+particle-bound) was higher than the estimated 26.8±5.20kg of PBDEs (dissolved+particle-bound), reflecting the dichotomous use histories for these two contaminant classes. Results provide insight into the biological availability of PCBs and PBDEs to the Strait of Georgia food web, and describe an important initial partitioning process by which the region’s endangered killer whales have become highly contaminated.

Biomagnification of polychlorinated biphenyls in a harbor seal (Phoca vitulina) food web from the strait of Georgia, British Columbia, Canada

Polychlorinated biphenyl (PCB) biomagnification was characterized in a harbor seal food web in the Strait of Georgia, British Columbia, Canada. Trophic magnification factors (TMFs) for PCBs averaged 3.6, with a range of 0.7 to 9.4. The TMFs for individual congeners correlated with log K(OW) (r(2) = 0.56, p < 0.001), reflecting the role that physicochemical properties play in driving the biomagnification of PCBs in marine food webs. However, TMFs differed among PCB structure activity groups, clearly indicating an additional role for metabolic transformation of certain PCBs. The known feeding preferences of harbor seals enabled the calculation of trophic level-adjusted biomagnification factors (BMF(TL)) for PCBs in this species, which averaged 13.4 and ranged from 0.2 to 150.6. Metabolic transformation in seals explained some of the variation in congener-specific biomagnification, with lower BMF(TL) values for PCB congeners with meta- and parachlorine unsubstituted positions. Principal components analysis revealed the distinct roles played by trophic level, log K(OW), and metabolic transformation in explaining the notable differences in PCB patterns among harbor seals, their pups, and their prey. In the present study, the authors estimate there to be approximately 76 kg of PCBs in the biota of the Strait of Georgia, of which 1.6 kg is retained by harbor seals.

PCBs and OCPs on a East-to-West Transect: The Importance of Major Currents and Net Volatilization for PCBs in the Atlantic Ocean

Air-water exchange gradients of selected polychlorinated biphenyl (PCB) congeners across a large section of the tropical Atlantic suggested net volatilization of PCBs to the atmosphere. Only for the higher chlorinated PCB 153 and hexachlorobenzene (HCB) were gradients near equilibrium detected. The use of passive samplers also enabled the detection of dichlorodiphenyltrichloroethane (DDT) and its transformation products across the tropical Atlantic, indicating net deposition. There were clear differences between the southern and northern hemisphere apparent in terms of atmospheric concentrations: Once the ship moved from the southern into the northern hemisphere air, concentrations of HCB and other organochlorine pesticides increased several-fold. For large swaths of the tropical Atlantic Ocean, neither PCB nor organochlorine pesticide dissolved concentrations varied much longitudinally, probably due to efficient mixing by ocean currents. In selected samples, dissolved concentrations reflected the influence of river plumes and major ocean currents far away from the continents. Dissolved concentrations of PCBs 28, 52, 101, 118, and HCB increased in the Amazon plume and the Gulf Stream. While the Amazon plume flushed only a few kg of PCBs and HCB, the Gulf Stream is potentially delivering tons of PCBs into the North Atlantic annually.

Application of life cycle assessment (LCA) to remediation technologies selection for PCBs contaminated sites

There are numerous polychlorinated biphenyls (PCBs) contaminated sites throughout China, and the two existing fixed hightemperature incineration plants struggle to meet the remediation needs for these sites. For environmentally sound management of thecontaminated sites, mobile remediation technologies and equipment are required. In this research, life cycle assessment was carried outto study the environmental impacts of two mobile remediation technologies in application at a PCBs contaminated site. The chosentechnologies were base catalyzed decomposition (BCD) and infrared high temperature incineration (IHTI), which are mobilenon-incineration and incineration technologies, respectively. A combined midpoint/damage approach was adopted using SimaPro 7.2and IMPACTA2002+to assess the human toxicity, ecotoxicity, climate change impact, and resource consumption from five IHTI andBCD subsystems. Based on treatment of 1000 kg of PCBs contaminated soil, our preliminarily conclusion is that the environmentalimpact of BCD is less than that of IHTI. The total single score of BCD was 0.147 Pt while that of IHTI was 0.279 Pt. The majorenvironmental impacts through the whole lifecycle arose from the treatment process, off-gas treatment, and wastewater treatment inboth BCD and IHTI. These results could be used to optimize treatment technologies.

Seasonality of diffusive exchange of polychlorinated biphenyls and hexachlorobenzene across the air–sea interface of Kaohsiung Harbor, Taiwan

Gaseous and dissolved concentrations of polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB) were measured in the ambient air and water of Kaohsiung Harbor lagoon, Taiwan, from December 2003 to January 2005. During the rainy season (April to September), gaseous PCB and HCB concentrations were low due to both scavenging by precipitation and dilution by prevailing southwesterly winds blown from the atmosphere of the South China Sea. In contrast, trace precipitation and prevailing northeasterly winds during the dry season (October to March) resulted in higher gaseous PCB and HCB concentrations. Instantaneous air–water exchange fluxes of PCB homologues and HCB were calculated from 22 pairs of air and water samples from Kaohsiung Harbor lagoon. All net fluxes of PCB homologues and HCB in this study are from water to air (net volatilization). The highest net volatile flux observed was + 172 ng m − 2 day − 1 (dichlorobiphenyls) in December, 2003 due to the high wind speed and high dissolved concentration. The PCB homologues and HCB fluxes were significantly governed by dissolved concentrations in Kaohsiung Harbor lagoon. For low molecular weight PCBs (LMW PCBs), their fluxes were also significantly correlated with wind speed. The net PCB and HCB fluxes suggest that the annual sums of 69 PCBs and HCB measured in this study were mainly volatile (57.4 × 10 3 and 28.3 × 10 3 ng m − 2 yr − 1 , respectively) and estimated yearly, 1.5 kg and 0.76 kg of PCBs and HCB were emitted from the harbor lagoon surface waters to the ambient atmosphere. The average tPCB flux in this study was about one-tenth of tPCB fluxes seen in New York Harbor and in the Delaware River, which are reported to be greatly impacted by PCBs.

Chemical and bioassay monitoring of PCB-contaminated soil remediation using solvent extraction technology

Illegal dumping of polychlorinated biphenyl (PCB) capacitors was discovered in Kobe, Japan, in 2001, leaving about 68 m(3) (92 tons) of soil contaminated with approximately 6.6 kg of PCBs. Solvent extraction technology carried out in 2002-2003 using isopropyl alcohol remedied the affected soil at the site. Forty-seven batch treatments were conducted during full-scale treatment. On average, 8.4 extraction cycles per batch were needed to achieve the clean-up goal for PCBs (i.e., the Japanese environmental quality standard for soil). Analytical results showed that the average PCB concentration (88 microg g(-1)-dry soil) in untreated soil samples of all the batches was decreased to 1.2 microg g(-1)-dry soil in treated soil samples, yielding a removal efficiency of 98.6%. Dioxin responsive-chemical activated luciferase gene expression assay (DR-CALUX) and enzyme-linked immunosorbent assay (ELISA) adopting a monoclonal antibody against 2,3',4,4',5-pentachlorobiphenyl (PCB #118) were used to rapidly screen soil samples before and after solvent extraction. The DR-CALUX and ELISA results were in good agreement with World Health Organization toxicity equivalent values and analytically determined PCB concentrations, respectively. Regular monitoring during the treatment period confirmed that the applied technology met Japanese environmental and control regulations concerning treatment and disposal of contaminated soils and treatment residues. After full-scale treatment, the amount of PCBs recovered from the solvent purification system approximated the estimated amount of PCBs spilled.

Mass budget and dynamics of polychlorinated biphenyls in the eastern Mediterranean Sea

Polychlorinated biphenyls (PCBs) were measured in dry deposition and sediment trap samples from the eastern Mediterranean and the results of the present and previous studies were synthesized in order to construct a mass balance budget describing the status and dynamics of PCBs in this region. According to our calculations, the burden of total PCBs in the euphotic zone of the eastern Mediterranean should approach 84,000 kg, while the corresponding pool in the overlying atmosphere should be about 162 kg. The atmospheric input of PCBs in the respective water basin through dry and wet deposition should be 300 and 1300 kg yr−1, respectively. On the contrary, air‐sea exchange should cause a net volatilization of PCBs from seawater to the atmosphere by 3150 kg yr−1. Moreover, PCBs are removed from the water column with a settling flux of 350 kg yr−1 and under steady state conditions, an additional input of these pollutants should be required to counterbalance the outflows from the water basin. The discharge of urban and industrial sewage, riverine input and transport of more polluted surface waters from western to eastern Mediterranean may account for most of this inflow. In the atmospheric compartment, the removal flux of PCBs due to their destruction by hydroxyl radicals (6650 kg yr−1) was approximately 4 times higher than their deposition flux (wet plus dry). On the basis of these data, 5100 kg of PCBs should enter into the atmosphere of eastern Mediterranean annually in order to achieve steady state conditions. This influx may result from long or short range transport of atmospheric PCBs emitted from contaminated terrestrial surfaces.

Magnitude and origin of polychlorinated biphenyl (PCB) and dichlorodiphenyltrichloroethane (DDT) compounds resuspended in southern Lake Michigan

Polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDT) compounds are introduced into the water as a result of large‐scale storms and sediment resuspension in the southern basin of Lake Michigan. Settling and suspended sediments, as well as air and water samples, were collected in southern Lake Michigan over a 12 month period. Analysis of contaminant fluxes on settling particles shows that approximately 370 kg of PCBs and 110 kg of DDT compounds are resuspended in southern Lake Michigan during a single basin‐wide event (January 1999). Examination of contaminant signals indicates strong regional and temporal source‐receptor relationships between settling, suspended, and surficial sediments. The settling, suspended, and bottom surficial sediments in the shallow waters of the southern coastal region are enriched in lower molecular weight PCBs. The sediments in the water column and on the lake bottom in the deeper regions are enriched in higher molecular weight PCBs. Furthermore, falling sediments collected in the deeper regions of the lake are enriched in 4,4′‐DDT. The unique contaminant signal in deep water regions is surprising and suggests a source/receptor relationship among the bottom sediments and the sediments suspended and settling above them.

Fish, fishing, and pollutant reduction in the Baltic Sea.

The Baltic Sea is heavily polluted yet supports major commercial fisheries for cod (Gadus morhua), herring (Clupea harengus), and sprat (Sprattus sprattus). Emissions of persistent organic pollutants, such as polychlorinated biphenyls (PCBs) and DDT, were high during the 1960s and 1970s, and concentrations in fish and other fauna are still significant. Several models of the fluxes of these pollutants among the water, sediment, and atmosphere have been developed, but these generally omit the roles of fish and fisheries. We show that the standing stock of the most abundant fish species in the Baltic Sea was a sink for 260 kg of PCBs in the late 1980s to early 1990s and that the fishery removed as much or more PCB (31 kg yr(-1))than other budget components (e.g., degradation in the water column). Accounting for fish and fisheries could increase our understanding of the fluxes of pollutants, and banning the discard of highly contaminated organs such as cod liver could be part of the pollution management.

PCBs in Lake Superior, 1978-1992: Decreases in Water Concentrations Reflect Loss by Volatilization

Polychlorinated biphenyl (PCB) water concentrations in Lake Superior from 1978 to 1992 have been compiled in order to determine long-term trends. Based on the concentrations of the same 25 PCB congeners from surface water samples collected between 1980 and 1992, ΣPCBs have decreased with a first-order rate constant of 0.20 yr -1 . The concentration of ΣPCBs in 1980 based on 82 congeners was ∼2.4 ng/L, by 1992 the concentration had decreased to 0.18 ng/L, indicating a loss of ∼26 500 μg of PCBs from Lake Superior during this 12-yr period. PCB concentrations in dated sediment cores collected in 1986 and 1990 indicate that the sediments have accumulated ∼4900 kg of PCBs since 1930 when PCB production began in the United States

Investigation of Contaminant Transport from the Saginaw Confined Disposal Facility

Pilot biomonitoring and modeling studies were conducted at the Saginaw Confined Disposal Facility (CDF), Saginaw Bay, Lake Huron, during 1987 to develop methods to assess the potential for or magnitude of 1) contaminant transport from the dike interior to the outside environment, 2) impacts of CDF disposal on the water column and sediments, and 3) impacts of CDF disposal on aquatic biota living in the outdike zone. Polychlorinated biphenyls (PCBs) were selected for study due to their presence in the sediments of the Saginaw River/Bay ecosystem. A mathematical model of near-field contaminant transport through the dike walls was constructed. Model predictions indicate that the rate of contaminant transport through the dike is expected to be small, amounting to less than 0.25 kg of PCBs after 5,000 days of simulation. A mathematical model of the far-field impacts of CDF transport was also constructed. Model predictions indicate that the incremental increase in steady-state, water column PCB concentrations in Saginaw Bay is expected to be approximately 0.05 ng/Lper kg of PCB transported from the CDF. A biomonitoring program was developed to assess contaminant transport through dike walls and its impact on contaminant concentrations in biological tissues. Distinct transport of contaminants through the dike walls was not demonstrated using the biomonitoring approach.

In Situ Surfactant Washing of Polychlorinated Biphenyls and Oils from a Contaminated Site

AbstractOver the past four years, we have been developing an in situ surfactant‐washing method to decontaminate soil systems. This study addresses another major step in that development: a field test of the surfactant‐washing method at a site contaminated with polychlorinated biphenyls (PCBs) and oils. A test plot, 10‐ft diameter by 5‐ft deep, was selected in an area of high levels of contaminataion. The study involved applying a surfactant solution on the plot to wash the site material and carry the leachate down to the depressed water table, where it was collected by pumping a recovery well installed through the center of the plot. The leachate pumped to the surface was biotreated to degrade the oils and surfactant, and the PCBs were removed from the leachate by an activated carbon system. Soil cores from the test plot indicated concentrations of up to 6,223 mg/kg PCBs and 67,000 mg/kg oils. The test plot initially contained about 15 kg of PCBs and 157 kg of oils. The hydraulic response of the test plot to washing was monitored by measuring the water levels in wells around the test plot and the fluid pressure and saturation through the plot. These real‐time data were used to adjust the surfactant‐application rate to minimize lateral spread of the surfactant and leachate and the pumping rate to capture all the leachate by the recovery well. The response of contaminant concentrations in the test plot to washing and the performance of the leachate‐treatment system were also monitored during the test by collecting and analyzing samples from the recovery well and from the treatment system. An on‐site laboratory was used for these analyses. During the 70 days of the washing test, 5,375 gallons of a 0.75% aqueous surfactant solution was applied on the test plot at an average rate of 77 gal/day. During the same period, 10,981 gallons of leachate were recovered at an average rate of 157 gal/day. A total of 1.6 kg of PCBs and 16.9 kg of oils (about 10% of the initial mass) was washed from the test plot during the test. Maximum concentrations of 65 mg/1 PCBs and 709 mg/1 oils were measured in leachate samples. The leachate was adequately treated before it was discharged. These test results indicate that in situ surfactant washing is a promising candidate for the remediation of contaminated soil systems.

Radiolytic dechlorination of polychlorinated biphenyls

In the late 1960s, Sherman (J. Phys. Chem., 1968, 72 , 2287) found that in alkaline isopropanol solutions some chloro-organic compounds were radiolytically dechlorinated, via a chain reaction. In the 1970s, this work was extended to the polychlorinated biphenyls (PCBs) by Shinozaki and co-workers (Bull. Chem. Soc. Jpn., 1974 47 , 1889). We have successfully repeated and extended the work reported by Shinozaki and co-workers. We found a higher efficiency (G value) for dechlorination. The effects of various inorganic and organic additives on the dechlorination process were also determined. The radiolytic dechlorination process has been used successfully with drained capacitors containing adsorbed PCBs, as well as with soil contaminated with PCBs. Successful runs were done with 20-L solutions. A mobile industrial plant, with a capacity to dechlorinate about 25 000 kg of PCBs per year, is being designed. The results of the experiments and some aspects of the design of the mobile plant are presented.