Polychlorinated Biphenyls Concentrations In Air Research Articles

Impact of smoking and candle burning on air concentrations of PCB in a PCB contaminated indoor environment

Long-lasting elevated indoor air concentrations of semi-volatile organic compounds (SVOCs) can cause contamination of indoor surface materials because these compounds have physical-chemical properties causing them to be sorbed (and desorbed) from various surfaces in the indoor environment. Due to this material-gas partitioning and the extensive area of surface materials, the surfaces have the potential to counteract changes in gaseous air concentrations by re-emitting or absorbing SVOCs. In the air itself a partitioning between the gaseous and particulate bound SVOCs exists, relying on among other things the amount and characteristics of the particles. The aim of this study was to investigate the impact of increased particle matter in a contaminated environment, i.e. whether an increase in particles would increase the total air concentration of SVOC through a displacement from the gaseous to the particle phase and at the same time a re-establishment of the gaseous concentration caused by desorption from the surface materials. The study was conducted by measuring the gas and particle bound concentration of SVOCs among a range of congeners of polychlorinated biphenyls (PCBs) in indoor air and quantify the influence of an increased concentration of particulate matter. The experiments were conducted in a room within a dwelling that had elevated levels of PCBs for the last five decades. The increased amount of particulate matter was generated by burning candles and cigarettes, which was measured as particle number concentration and size fractions. Increased cigarette particle concentration increased the indoor air concentration of the sum of all congeners measured by almost 70% compared to background level. Particles from candle burning did not have a similarly significant effect, even though their number concentration was higher. This was likely due to the chemical composition of the particles; cigarette smoke consists primarily of organic particles, while the steady burning of candles produces smaller, mainly inorganic particles. The concentrations of 15 PCB congeners were determined and it was observed that their sorption to cigarette smoke increased with increasing chlorination. A partitioning model indicates absorptive behaviour of PCB to cigarette particles. The results show that smoking inside a residence with long-lasting, elevated PCB concentrations can further increase the concentration of PCB in the air due to its interaction with particulate matter.

Temporal Variations of PCBs and Their Estimated Air-Soil Exchange Fluxes Measured in Seven Sites in Bursa-Turkey

ABSTRACT Polychlorinated biphenyls (PCBs) can travel in ambient air for long distances and exchange between different environments. Soil and ambient air samples were simultaneously gathered during the winter and summer months in 7 regions in Bursa, Turkey, to study spatio-temporal fluctuations and soil-air exchange of PCBs. Σ25 PCB concentrations for the winter and summer seasons were 0.007–0.04 ng/m3 and 0.03–0.24 ng/m3 in air, also 4.09–10.00 ng/g DM and 1.65–10.01 ng/g DM in soil, respectively. PCB concentrations showed spatial variations in air and soil samples. The lowest total PCB levels were measured both in air and soil samples in the R (rural) site. The highest Σ25 PCB concentrations were measured in the SR3 site in soil samples, while the I1 site was the most polluted in air samples. Ambient air concentrations of PCBs in the summer months were greater than those in winter. In SR1, SR2, SR3, and I1 sites, soil PCB levels in the summer were higher than in the winter. The opposite was observed in the other sites (R, U, I2). Net flux values and fugacity fraction (ff) values for all regions indicated that PCBs represented a transfer from soil to air. The air-soil net gas phase flux values changed between 0.04 - 1.01 ng/m2-day and 0.02–0.83 ng/m2-day in the summer and winter, respectively. The PCB homologous distributions of mean flux values differed depending on the regions and seasons. PCBs with 4- and 5-CBs were dominant in both seasons.

Inhalation and Dietary PCB Exposures in Urban and Rural Cohorts of U.S. School Children and their Mothers

PDS 62: Chemicals and metals: exposure and biomarkers, Johan Friso Foyer, Floor 1, August 28, 2019, 10:30 AM - 12:00 PM Background: Polychlorinated biphenyls (PCBs) are persistent man-made compounds that are carcinogenic, neurotoxic, immunotoxic, and act as endocrine disrupters. The AESOP Study is a rural and urban, community-based, prospective cohort study that assesses airborne and dietary exposures to all 209 PCBs and 72 OH-PCB metabolites in adolescent school children and their mothers. Methods: Exposures and risk factors were assessed through demographic, health, dietary (DHQ2), occupational and activity questionnaires and measurements of blood, urine, DNA, air, and food. We repeatedly evaluated indoor and outdoor air concentrations of PCBs from participants’ homes and from two rural and four urban schools over multiple seasons and years. The urban schools were located near a PCB-contaminated shipping canal off Lake Michigan. Air, blood and food samples were analyzed for PCBs using GC/MS-MS. Whole blood and surficial soil samples were analyzed for toxic metals using ICP-MS. Results: Concentrations of PCBs inside schools were 1−2 orders of magnitude higher than outdoors and were generally higher than in homes. Congener air profiles differed between schools and indicated the PCB sources as both legacy Aroclors and non-Aroclors from building materials. PCBs and OH-PCBs in the serum of the children showed enrichment of lower-chlorinated congeners compared to their mothers. Breast feeding was found to significantly decrease PCBs in mothers and increase PCBs in children who were breast fed. Modeling dietary intake and inhalation exposures (apportioning airborne exposures by time and location from activity logs) revealed that some children’s PCB inhalation exposure exceeded their exposure through diet, especially for the lower-chlorinated and more volatile PCBs. The AESOP study also showed that inhalation at school dominates children’s PCB inhalation exposures. Conclusions: To enhance children’s environmental health, air concentrations of PCBs in U.S. schools should be assessed in order to identify high-exposure locations and prioritize schools for replacement or repurposing.

PCBs and organochlorine pesticides in indoor environments - A comparison of indoor contamination in Canada and Czech Republic

Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) are restricted compounds that are ubiquitously detected in the environment, including indoor matrices such as air and residential dust. We report concentrations of PCBs and selected OCPs in indoor air and dust from homes in Canada (23 homes) and Czech Republic (20 homes). Indoor air concentrations of PCBs and OCPs were ∼10 times higher than that outdoors. PCB concentrations of ∼450 ng/m3 were similar in both countries, higher in homes built before the restrictions on PCBs, and had congener profiles consistent with PCB mixtures manufactured or used in each country. All OCP air concentrations were higher in the Czech Republic than in the Canadian samples, suggesting greater indoor use of, for example, DDT and HCH. These data emphasize the persistence of these organochlorine compounds indoors and their presence in homes even decades after new usage was prohibited. Indoor levels of these legacy POPs remain at similar concentrations to compounds of current concern, such as brominated flame retardants and perfluorinated alkyl substances, emphasizing that they deserve ongoing attention in view of knowledge of PCB and OCP toxicity.

Ambient Air Exposure to PCBs: Regulation and Monitoring at Five Contaminated Sites in EPA Regions 1, 2, 4, and 5.

Existing regulations seek to protect the public from exposure to polychlorinated biphenyls (PCBs) in food, water, and soil. Exposure to PCBs in ambient air has recently been given explicit consideration in the human health risk assessments that form the basis of risk management decisions at contaminated sites. The objective of this paper is to examine how ambient air exposure to PCBs is regulated and monitored at five contaminated sites in the United States. We reviewed online accessible materials (including Environmental Protection Agency-site specific websites, data repositories, and other agency websites). Results indicate that the five sites vary in regard to the measured PCB concentrations in air, the sampling and monitoring methodologies, and the established site-specific guidelines/standards and their basis. We conclude that current practices may not adequately protect those living or working near these sites from airborne PCB exposure and that regulations should include recognition of exposure to indoor sources.

Community reporting of ambient air polychlorinated biphenyl concentrations near a Superfund site

In this manuscript, we describe the process of establishing partnerships for community-based environmental exposure research, the tools and methods implemented for data report-back to community members, and the results of evaluations of these efforts. Data discovery and report-back materials developed by Statistics for Action (SFA) were employed as the framework to communicate the environmental data to community members and workshops. These data communication and research translation efforts are described in detail and evaluated for effectiveness based on feedback provided from community members who attended the workshops. Overall, the methods were mostly effective for the intended data communication.

The atmosphere as a source/sink of polychlorinated biphenyls to/from the Lower Duwamish Waterway Superfund site

Waterbodies polluted with polychlorinated biphenyls (PCBs) may cause the air in the surrounding area to become PCB-contaminated. Conversely, when a waterbody is located in or near an urban area, the deposition of atmospheric PCBs may act as a low-level, ongoing source of PCB contamination to that water. Distinguishing these situations is necessary to be protective of human populations and to guide efforts seeking to cleanup such aquatic ecosystems. To assess the situation at the Lower Duwamish Waterway (LDW) Superfund site, low-density polyethylene passive samplers were deployed in the summer of 2015 to quantify freely dissolved water and gaseous air concentrations of PCBs thereby enabling estimates of the direction and magnitude of air-water exchange of PCB congeners. For the sum of the 27 PCB congeners, average concentrations were 220 pg/m3 (95% C.I.: 80–610) in the air and 320 pg/L (95% C.I.: 110–960) in the water. The sum of air-water exchange fluxes of these PCB congeners was estimated to be 68 ng/m2/day (95% C.I.: 30–148) into the lower atmosphere, contrasting with the reported wet and dry depositional flux of only 5.5 ng/m2/day (95% C.I.: 1–38) from the air into the water. Therefore, the atmosphere was ultimately a sink of PCBs from the LDW Superfund site, at least under 2015 summertime conditions. However, we conclude that air-water exchange of PCBs is likely only a minor sink of PCBs from the LDW and only a minor source of contamination to the region's local atmosphere.

Spatial variation of PAHs and PCBs in coastal air, seawater, and sediments in a heavily industrialized region

Concurrent coastal seawater (n=22), sediment (n=22), and atmospheric samples (n=10) were collected in the Aliaga industrial region, Turkey, to explore the spatial variation, sources, and air-seawater exchange of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). Seawater Σ16PAH concentrations (particle+dissolved) ranged between 5107 and 294,624pgL-1, while Σ41PCB concentrations were in the range of 880-50,829pgL-1. Levels in sediments were highly variable ranging between 35.5-49,682 and 2.7-2450μgkg-1 in dry weight for Σ16PAHs and Σ41PCBs, respectively. Atmospheric concentrations varied between 1791-274,974 and 104-20,083pgm-3 for Σ16PAHs and Σ41PCBs, respectively. Sediment organic matter (OM) content and levels of Σ16PAHs and Σ41PCBs correlated weakly (r 2=0.19-0.23, p<0.05) suggesting that the spatial variations of PAHs and PCBs were mainly affected by local sources rather than their sorption to OM. The geographical distribution of PAH and PCB concentrations in air, seawater, and sediment and factor analysis on the sediment levels pointed out that the major sources in the region are steel plants, petroleum refinery, petrochemical complex, ship breaking, loading/unloading activities at the ports, vehicular emissions, and fossil fuel combustion emissions. The direction of the air-seawater exchange was also explored by estimating seawater fugacity fractions of PAHs and PCBs. For PAHs, the number of cases implying deposition (43.0%) and volatilization (39.5%) was similar, while for PCBs, the number of cases implying volatilization (60.4%) was much higher compared to deposition (21.6%). Fugacity fractions were generally <0.36 (deposition) at the sites close to industrial and ship breaking activities where the highest seawater and sediment levels were measured, implying that atmospheric deposition is an important mechanism affecting seawater and sediment PAH and PCB levels.

Air and Soil Concentrations and Source Identification of Ambient Polychlorinated Biphenyls in the Northeastern Mediterranean Region

Ambient air and soil samples were taken in Istanbul between November 2012 and May 2013 in order to determine polychlorinated biphenyl (PCB) concentrations. A high volume air sampler was operated to collect air samples. Soil samples were taken from top of bare land. Air PCB concentrations ranged from 201 to 705 pg m−3 with an average of 360 pg m−3. The dry weight soil PCB concentrations varied from 3.4 to 13.6 ng g−1 with an average of 8.3 ng g−1. The fate of PCBs was investigated through gas/particle partitioning. Further investigation was made between soil and air phases by fugacity fractions. Effect of wind direction was revealed by conditional probability function (CPF). Potential source contribution function was employed to determine the likely distant PCB sources. Di‐chlorinated biphenyls (Di‐CBs) tended to accumulate in soil while 5‐, 7‐, and 8‐CBs volatilized from the soil. According to CPF, 3‐CBs were likely to be released from the Marmara Sea. Additionally, SW wind direction was dominant for Σ‐, 2‐, 5‐, 6‐, 7‐CBs, and concentration of 9‐CBs increased for the winds of NW, N, NE directions. Previously reported hot‐spot zones for iron‐steel manufacturing industry were identified to contribute to PCBs in air masses, arriving from SW direction. Additional contribution was detected when air masses arrived from the north. These sources were from the south of the Ukraine.

Release of Airborne Polychlorinated Biphenyls from New Bedford Harbor Results in Elevated Concentrations in the Surrounding Air.

Qualitatively and quantitatively, we have demonstrated that airborne polychlorinated biphenyl (PCB) concentrations in the air surrounding New Bedford Harbor (NBH) are caused by its water PCB emissions. We measured airborne PCBs at 18 homes and businesses near NBH in 2015, with values ranging from 0.4 to 38 ng m–3, with a very strong Aroclor 1242/1016 signal that is most pronounced closest to the harbor and reproducible over three sampling rounds. Using U.S. Environmental Protection Agency (U.S. EPA) water PCB data from 2015 and local meteorology, we predicted gas-phase fluxes of PCBs from 160 to 1200 μg m–2 day–1. Fluxes were used as emissions for AERMOD, a widely applied U.S. EPA atmospheric dispersion model, to predict airborne PCB concentrations. The AERMOD predictions were within a factor of 2 of the field measurements. PCB emission from NBH (110 kg year–1, average 2015) is the largest reported source of airborne PCBs from natural waters in North America, and the source of high ambient air PCB concentrations in locations close to NBH. It is likely that NBH has been an important source of airborne PCBs since it was contaminated with Aroclors more than 60 years ago.

Polyurethane foam (PUF) disk passive samplers derived polychlorinated biphenyls (PCBs) concentrations in the ambient air of Bursa-Turkey: Spatial and temporal variations and health risk assessment

Polyurethane foam (PUF) passive samplers were employed to assess air concentrations of polychlorinated biphenyls (PCBs) in background, agricultural, semi-urban, urban and industrial sites in Bursa, Turkey. Samplers were deployed for approximately 2-month periods from February to December 2014 in five sampling campaign. Results showed a clear rural-agricultural-semi-urban-urban-industrial PCBs concentration gradient. Considering all sampling periods, ambient air concentrations of Σ43PCBs ranged from 9.6 to 1240 pg/m3 at all sites with an average of 24.1 ± 8.2, 43.8 ± 24.4, 140 ± 190, 42.8 ± 24.6, 160 ± 280, 84.1 ± 105, 170 ± 150 and 280 ± 540 pg/m3 for Mount Uludag, Uludag University Campus, Camlica, Bursa Technical University Osmangazi Campus, Hamitler, Agakoy, Kestel Organised Industrial District and Demirtas Organised Industrial District sampling sites, respectively. The ambient air PCB concentrations increased along a gradient from background to industrial areas by a factor of 1.7–11.4. 4-Cl PCBs (31.50–81.60%) was the most dominant homologue group at all sampling sites followed by 3-Cl, 7-Cl, 6-Cl and 5-Cl homologue groups. Sampling locations and potential sources grouped in principal component analysis. Results of PCA plots highlighted a large variability of the PCB mixture in air, hence possible related sources, in Bursa area. Calculated inhalation risk levels in this study indicated no serious adverse health effects. This study is one of few efforts to characterize PCB composition in ambient air seasonally and spatially for urban and industrial areas of Turkey by using passive samplers as an alternative sampling method for concurrent monitoring at multiple sites.

Assessing persistent organic pollutants (POPs) in the Sicily Island atmosphere, Mediterranean, using PUF disk passive air samplers.

In this study, PUF disk passive air samplers were deployed at eight sites, during two sampling periods, on the Island of Sicily in the Mediterranean basin. Samples were screened for a number of persistent organic pollutants (POPs) including polychlorinated biphenyls (PCBs) (n=28 congeners), organochlorine pesticides (OCPs) (n=16 compounds), and polybrominated biphenyl ethers (PBDEs n=28) using GC-MS. PCB concentrations in air ranged ~10-300pgm-3. The PCB pattern was dominated by lower to middle molecular weight PCBs (Cl3-5) and PCB-28 and PCB-52 were the most abundant congeners. α- and γ-Hexachlorocyclohexanes (HCHs) concentrations in air were relatively high ~420±320 (50-1000) and 460±340 (30-1000) pgm-3, respectively, with an average α/γ ratio of 1±0.5, indicating a tendency of higher use of lindane than of technical HCH. Among DDTs, only p,p'-DDT 90±15 (~10-800) and p,p'-DDE 60±60 (20-400) were frequently detected. DDT/DDE=0.4-3.0 (1.0±0.7 for both periods) suggesting past and fresh inputs of DDT at the sampling sites. α-Endosulfan, recently included in Annex A of the Stockholm Convention, fluctuated between 120±50 (50-1000) pgm-3. In contrast, PBDE levels were very low (0.2-2pgm-3). Back trajectories of advection suggest that POP levels are mainly related to local sources (primary or secondary) from Sicily (50-70% contribution of air masses), Southern Italy, and Sardinia (20%). This study provides new information for POP levels in the atmosphere of the Mediterranean region.

Determination of Atmospheric PCB Level Variations in Continuously Collected Samples.

Polychlorinated biphenyls (PCBs) were measured in ambient air samples (n=48) that were collected for a 2- to 3-day period in each season (winter, spring, summer, fall) of 2013. The samples were collected on the Campus of Uludag University, which is in a semirural region. The samples were collected using a high-volume air sampler. The gas and particle phase concentrations of 87 PCB congeners (Σ87PCB) were measured in these samples. The average gas and particle phase concentrations of the Σ87PCB were calculated to be 293±257 and 52±56ng/m(3), respectively. However, the results of short-term measurements showed that the variation among the measurements in the gas phase was up to 39-fold and up to 84-fold in the particle phase. These results demonstrated that the ambient air PCB concentrations were not stable and changed dramatically on a daily basis. Therefore, it was clear that a small number of samples could not be representative of the entire region. Furthermore, the obtained concentrations showed differences that depended on the meteorological conditions and long distance transportation. The sampling indicated that PCB homologues with 3 or 4 chlorines were dominant.

Modelling the impact of room temperature on concentrations of polychlorinated biphenyls (PCBs) in indoor air.

Buildings contaminated with polychlorinated biphenyls (PCBs) are a health concern for the building occupants. Inhalation exposure is linked to indoor air concentrations of PCBs, which are known to be affected by indoor temperatures. In this study, a highly PCB contaminated room was heated to six temperature levels between 20 and 30 C, i.e. within the normal fluctuation of indoor temperatures, while the air exchange rate was constant. The steady-state air concentrations of seven PCBs were determined at each temperature level. A model based on Clausius-Clapeyron equation, ln(P) = -ΔH/RT + a(0), where changes in steady-state air concentrations in relation to temperature, was tested. The model was valid for PCB-28, PCB-52 and PCB-101; the four other congeners were sporadic or non-detected. For each congener, the model described a large proportion (R(2)>94%) of the variation in indoor air PCB levels. The results showed that one measured concentration of PCB at a known steady-state temperature can be used to predict the steady-state concentrations at other temperatures under circumstances where e.g. direct sunlight does not influence temperatures and the air exchange rate is constant. The model was also tested on field data from a PCB remediation case in an apartment in another contaminated building complex where PCB concentrations and temperature were measured simultaneously and regularly throughout one year. The model fitted relatively well with the regression of measured PCB air concentrations, ln(P) vs. 1/T, at varying temperature between 16.3 and 28.2 °C, even though the measurements were carried out under uncontrolled environmental condition.

Emissions of polychlorinated biphenyls in Switzerland: a combination of long-term measurements and modeling.

Ambient air concentrations of polychlorinated biphenyls (PCBs) in Zurich, Switzerland, are reported for the years 2011-2013. These measurements reveal a distinct seasonal trend with PCB concentrations in air during the summer that were three to five times higher than in the winter. We used a long-term dynamic multimedia model to analyze the seasonal trend and to back-calculate urban emissions of PCBs. In contrast to previous short-term studies that considered time periods of several days to months to extrapolate annual emissions, the use of long-term field data and the corresponding model reduces the uncertainty in these extrapolations. Comparison with measured PCB concentrations in air shows that our model is able to reproduce seasonal trends of the six indicator PCBs (iPCBs). The good agreement of the model results with measurements over a time period of three years provides confidence in model outputs and allows us to estimate the total annual PCB emissions of Zurich (86 μg capita(-1) d(-1)). The resulting summer emissions are nine times higher than emissions during winter. Interestingly, this factor corresponds to the expected increase in PCB volatilization due to the effect of temperature on vapor pressure. This finding implies that PCBs in Zurich are probably released mainly by volatilization from sources that are directly exposed to ambient air temperature (i.e., outdoor sources). The derived emissions are in accordance with previous studies performed at the same location and are also in agreement with an existing emission inventory.

Investigation of the importance of tertiary contamination, temperature and human behaviour on PCB concentrations in indoor air

High concentrations of polychlorinated biphenyls (PCBs) can still be measured in indoor air in many buildings built or renovated within the period from approximately 1950 until the late seventies. The increasing evidence of the importance of indoor exposure to PCBs has led to the initiation of remediation actions in many countries. Understandably, primary sources with original PCB content have been the main focus of the actions. However, removal of primary sources alone has shown to be insufficient in decreasing the high indoor PCB concentrations in contaminated buildings. The aim of this study was to investigate the importance of tertiary PCB sources to indoor air concentrations and identify predictors of PCB air concentrations in contaminated buildings. In this study, 24 PCB congeners were measured in the indoor air of 83 contaminated apartments as well as in sealants sampled in a random subset of 20 apartments. The sealants were identified to be the primary source containing the original PCBs. For total PCBs, the median air concentration was 859 ng/m3 and the median concentration in contaminated sealants was 16.5% by weight. Analyses performed in the present study indicate that the influence of tertiary sources on indoor air concentrations may be substantial and that removal of tertiary sources may be needed when performing PCB remediation in buildings.

From the City to the Lake: Loadings of PCBs, PBDEs, PAHs and PCMs from Toronto to Lake Ontario

Loadings from Toronto, Canada to Lake Ontario were quantified and major sources and pathways were identified, with the goal of informing opportunities for loading reductions. The contaminants were polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs) and polycyclic musks (PCMs). Loadings were calculated from measured concentrations for three major pathways: atmospheric processes, tributary runoff, and wastewater treatment plant (WWTP) effluents. Although atmospheric deposition to the Great Lakes has received the greatest attention, this was the dominant loading pathway for PCBs only (17 ± 5.3 kg/y or 66% of total loadings). PCB loadings reflected elevated urban PCB air concentrations due to, predominantly, primary emissions. These loadings contribute to consumption advisories for nearshore fish. PBDE loadings to the lake, again from mainly primary emissions, were 48% (9.1 ± 1.3 kg/y) and 42% (8.0 ± 5.7 kg/y) via tributaries and WWTPs, respectively, consistent with emissions deposited and subsequently washed-off of urban surfaces and emissions to the sewage system. PAHs loadings of 1600 ± 280 kg/y (71%) from tributaries were strongly associated with vehicle transportation and impervious surfaces. PCM loadings were 83% (±140 kg/y) from WWTP final effluent, reflecting their use in personal care products. Opportunities for source reduction lie in reducing the current inventories of in-use PCBs and PBDE-containing products, reducing vehicle emissions of PAHs and use of PAHs in the transportation network (e.g., pavement sealants), and improving wastewater treatment technology.

Levels, distribution and air–soil exchange fluxes of polychlorinated biphenyls (PCBs) in the environment of Punjab Province, Pakistan

An initial survey of the concentrations of polychlorinated biphenyl (PCB) compounds in air and soils across industrial and agricultural areas of Punjab Province, Pakistan, was conducted from January to March 2011. The total concentration of all PCBs (<Sigma>31 PCBs) ranged from 34 to 389pgm−3 in air and from 7 to 45ngg−1 dry weight in soils, where both ranges were similar to the average ranges in other areas of the world. PCBs were elevated across industrial regions near urban and industrial sources. Consistently low air concentrations of PCBs at the agricultural sites suggest that they are less widespread or uniformly distributed in the Pakistani atmosphere. The calculated air and soil fugacity fraction values indicated that soils are a potential secondary source of PCBs in agricultural areas, whereas they are in equilibrium or atmospheric deposition in industrial and urban areas. TEQ concentrations of dioxin-like PCBs for soil samples met the Canadian standard. However, local authorities should address the human health threats from urban and industrial soils in Punjab Province, Pakistan.

Deciduous vegetation (Betula glandulosa) as a biomonitor of airborne PCB contamination from a local source in the Arctic

Concentrations of polychlorinated biphenyls (PCBs) were measured in the new-year growth of dwarf birch (Betula glandulosa) before (2001–2002), during (2003–2004), and for six years after (2005–2010) the screening and containerization of PCB-contaminated soils (>50μg/g PCBs) at a remote Arctic radar site. During the remediation activities, ambient air PCB concentrations were measured using active air samplers for comparison to the passive samplers (dwarf birch). PCB concentrations measured by the active samplers reached a maximum of 0.037μg/m3 which was below the project criteria of 0.15μg/m3 indicating minimal source emissions. During the same time period, PCB concentrations in the dwarf birch (passive samplers) showed significant increases of 2–14 fold compared to the baseline data from previous years. The birch data also showed significant changes between monitoring events within the 2003 and 2004 sampling seasons (June to September) and decreases when ambient air concentrations were low, indicating the sensitivity of new-year growth to reflect net accumulation and ambient conditions at a temporal scale of approximately two weeks. The dwarf birch PCB concentrations remained elevated compared to baseline levels for two years after the remediation was completed. In the third year following remediation, concentrations decreased to below baseline levels reflecting the overall remediation and source removal at the site. Spatial variations observed in dwarf birch PCB concentrations are likely due to the influence of wind direction on contaminant dispersal and deposition.

Using passive air samplers to assess local sources versus long range atmospheric transport of POPs

Passive air samplers (PAS) are cost-efficient tools suitable for spatial mapping of atmospheric concentrations of persistent organic pollutants (POPs). The objective of this study was to use PAS to (i) determine atmospheric concentrations of selected POPs in Norwegian coastal zones with consumption advisories on seafood (N = 22), and (ii) evaluate a simple nested monitoring approach to assess the relative influence of local vs. long-range atmospheric transport (LRAT) at coastal sites. The latter was facilitated by comparison with data from a coordinated European-wide campaign in which an identical sampling and analytical approach was followed. Air concentrations were calculated based on the loss of performance reference compounds (PRCs), and results are presented for selected polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB), dichlorodiphenyltrichloroethanes (DDTs) and chlordanes. Air concentrations of PCBs were generally highest at sites within larger cities and up to about an order of magnitude higher than anticipated on the basis of LRAT alone. The distribution of PAHs and HCB occasionally showed elevated concentrations at coastal sites with ongoing or former industrial activity, while an urban site was significantly influenced by banned insecticides (technical DDT and lindane). Coastal sites were also elevated in α-HCH beyond the anticipated LRAT contribution, which we attribute to volatilization from the sea. We conclude that a simple nested PAS monitoring approach provides useful information for screening efforts aiming to assess both atmospheric burdens as well as the relative significance of local sources in controlling these burdens at sites in contaminated areas.