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A passive air sampler comprising a polyurethane foam (PUF) disk impregnated with XAD-4 powder has been developed. This sorbent-impregnated PUF (SIP) disk builds on previous work using PUF disk passive air samplers that have been effective in spatial air mapping studies of nonpolar hydrophobic chemicals, without the need of electricity or expensive air sampling equipment. In this study, PUF disks and SIP disks are calibrated for sampling volatile polyfluorinated chemicals-specifically, the fluorotelomer alcohols (FTOHs) and perfluoroalkyl sulfonamides (PFASs). Results demonstrate the low sorprive capacity of the PUF disk samplers, particularly for the FTOHs, with PUF disks reaching equilibrium within 1 day, after collecting ~0.4 and 1.2 [m.sup.3] of air for 8:2 FTOH and 10:2 FTOH, respectively. This limits their use for these target compounds when time-weighted, linear-phase sampling is desired. The presence of just 0.4 g of XAD powder in the SIP disks greatly increases the sorptive capacity (by ~2 orders of magnitude for the FTOHs) and provides linear-phase sampling for a period of several weeks. PUF-air partition coefficients, [K.sub.PUF]-A, calculated for the FTOHs and PFASs are considerably lower than values predicted using previously established correlations against the octanol-air partition coefficient, [K.sub.OA], demonstrating the unique partitioning behavior of the polyfluorinated chemicals. Using results from these calibration tests, air concentrations of FTOHs were derived from PUF disk samples that were deployed in 52 homes in Ottawa, Canada, during 2002/2003. These represent the first comprehensive measurements of FIOHs in indoor air in North America. Range and (geometric mean) air concentrations (pg [m.sup.-3]) were 261-28 900 (2070) for 8:2 FTOH and 104-9210 (890) for 10:2 FTOH. These air concentrations are orders of magnitude higher than observed for outdoor air, establishing indoor environments as important for human exposure and also as potential sources to the larger environment.

Relative gas chromatographic retention times on a nonpolar stationary phase can be used to determine the octanol--air partition coefficient ([K.sub.OA]) and the energy of phase transfer between octanol and the gas phase ([[DELTA].sub.OA]U) for semivolatile, nonpolar organic compounds. The only prerequisites are knowledge of the temperature-dependent [K.sub.OA] of a standard reference compound and directly measured [K.sub.OA] values at one temperature for a sufficient number of calibration compounds. It is shown that the technique is capable of predicting the [K.sub.OA] of polychlorinated benzenes, biphenyls and naphthalenes as well as polybrominated diphenyl ethers within the environmentally relevant temperature range with an average deviation from directly measured values of

In this study, air samples in Alabama were gathered in January-October 1996 and May 1997 to review the seasonal variations of toxaphene and other OC pesticides. The study is broken down into an introduction, a discussion of the experiment and its results. Various tables and graphs accompany the article.

In the winter of 1998, air samples were taken for four sampling events at three different locations, including one urban center and two rural locations, and they were measured for PCDD/Fx, PCBs, and PAHs. The study is broken down into an introduction, a discussion of the materials and methods used in the experiment, and a discussion of the results. Various tables and graphs accompany the table.

Air masses measured over northwest England originating in Scandinavia contain less polychlorinated naphthalene than those that crossed over southern England, showing that the UK produces relatively high concentrations of the chemical.

A report researches air pollution and polychlorinated dibenzo-p-dioxin and furan concentrations.

Researchers measured the atmospheric concentrations of five organochlorine pesticides and polychlorinated naphthalenes at a U.K. site to determine the factors affect the air-surface exchange rate of semivolatile organic compounds.

The KOA absorption model proved useful in describing particle/gas partitioning. The model, which was compared to the adsorption model or Junge-Pankow model, was able to identify the differences between ortho-chlorine substituted groups of polychlorinated biphenyls. The KOA absorption model also proved capable of describing the partitioning of polychlorinated naphthalenes.

Analysis of the concentrations of polychlorinated biphenyls (PCB) in the air, soil and vegetation in the UK from 1942-1992 shows that levels of PBC emissions have decreased significantly since it reached its peak in the 1960s. During this time, PCB contamination were maintained at very low levels because of its active degradation or 'degassing,' reducing its half-life to 10-20 years. A simple model to represent the heteregeneous interaction between air and soil has been developed to provide insights on how the soil acts as a buffer to reduce the spread of harmful atmospheric pollutants.

Extracts of passive air samples collected from 15 passive sampling network sites across the Athabasca Oil Sands region were used to explore the application of in vitro assays for mutagenicity (Salmonella mutation assays) and cytotoxicity (lactate dehydrogenase assay) to assess the toxicity of the air mixture. The air monitoring of polycyclic aromatic compounds (PACs) and PAC transformation products, including nitrated polycyclic aromatic hydrocarbons (NPAHs) and oxygenated polycyclic aromatic hydrocarbons (OPAHs) was then linked to the potential toxicity of air. The PACs in air during April to May 2014 were elevated near mining activities and declined with distance from the source region, whereas NPAHs and OPAHs exhibited a more variable spatial distribution with the highest levels in Fort McMurray. Overall, the air samples exhibited a weak mutagenicity. The highest indirect-acting mutagenicity was observed for sites closest to mining activities; however, the indirect-acting mutagenicity did not decline sharply with distance from mining areas. Indirect-acting mutagenicity was strongly correlated with levels of total PACs, benzo(a)pyrene equivalent mass, and OPAHs. Most of the samples exhibited cytotoxic potential, but the magnitude of the response was variable across the sample region and did not correlate with levels of target analytes. This indicates that PACs and PAC derivatives were not a major contributor to the cytotoxicity observed in the air samples. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbon (PAH) measurements were conducted by Wood Buffalo Environmental Association (WBEA) at four community ambient Air quality Monitoring Stations (AMS) in the Athabasca Oil Sands Region (AOSR) in Northeastern Alberta, Canada. The 2012 and 2013 mean concentrations of a subset of the 22 PAH species were 9.5, 8.4, 8.8, and 32 ng m-3 at AMS 1 (Fort McKay), AMS 6 (residential Fort McMurray), AMS 7 (downtown Fort McMurray), and AMS 14 (Anzac), respectively. The average PAH concentrations in Fort McKay and Fort McMurray were in the range of rural and semirural areas, but peak values reflect an industrial emission influence. At these stations, PAHs were generally associated with NO, NO2 PM2.5, and SO2 indicating the emissions were from the combustion sources such as industrial stacks, vehicles, residential heating, and forest fires, whereas the PAH concentrations at AMS 14 (~35 km south of Fort McMurray) were more characteristic of urban areas with a unique pattern: eight of the lower molecular weight PAHs exhibited strong seasonality with higher levels during the warmer months. Enthalpies calculated from Clausius--Clapeyron plots for these eight PAHs suggest that atmospheric emissions were dominated by temperature-dependent processes such as volatilization at warm temperatures. These findings point to the potential importance of localized water--air and/or surface--air transfer on observed PAH concentrations in air. [ABSTRACT FROM AUTHOR]

A passive air sampling network has been established to investigate polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) at Global Atmospheric Passive Sampling (GAPS) sites and six additional sites in the Group of Latin American and Caribbean Countries (GRULAC) region. The air sampling network covers background, agricultural, rural, and urban sites. Samples have been collected over four consecutive periods of 6 months, which started in January 2011 [period 1 (January to June 2011), period 2 (July to December 2011), period 3 (January to June 2012), and period 4 (July 2012 to January 2013)]. Results show that (i) the GAPS passive samplers (PUF disk type) and analytical methodology are adequate for measuring PCDD/F burdens in air and (ii) PCDD/F concentrations in air across the GRULAC region are widely variable by almost 2 orders of magnitude. The highest concentrations in air of ∑4-8PCDD/Fs were found at the urban site São Luis (Brazil, UR) (i.e., 2560 fg/m3) followed by the sites in São Paulo (Brazil, UR), Mendoza (Argentina, RU), and Sonora (Mexico, AG) with values of 1690, 1660, and 1610 fg/m3, respectively. Very low concentrations of PCDD/Fs in air were observed at the background site Tapanti (Costa Rica, BA), 10.8 fg/m3. This variability is attributed to differences in site characteristics and potential local/regional sources as well as meteorological influences. The measurements of PCDD/Fs in air agree well with model-predicted concentrations performed using the Global EMEP Multimedia Modeling System (GLEMOS) and emission scenario constructed on the basis of the UNEP Stockholm Convention inventory of dioxin and furan emissions. [ABSTRACT FROM AUTHOR]

Two passive air sampler (PAS) rnedia were characterized under field conditions for the measurement of per and polyfluoroalkyl substances (PFASs) in the atmosphere. The PASs, consisting of polyurethane foam (PUF) and sorbent-impregnated PUF (SIP) disks, were deployed for over one year in parallel with high volume active air samplers (HV-AAS) and low volume active air samplers (LV-AAS). Samples were analyzed for perfluoroalkyl carboxylic acids (PFCAs), perfluoroalkane sulfonic acids (PFSAs), fluorotelomer alcohols (FTOHs), fluorotelomer methacrylates (FTMACs), fluoro- telomer acrylates (FTACs), perfluorooctane sulfonamides (FOSAs), and perfluorooctane sulfonamidoethanols (FOSEs). Sampling rates and the passive sampler medium (PSM)-air partition coefficient (KPSM-A) were calculated for individual PFASs. Sampling rates were similar for PFASs present in the gas phase and particle phase, and the linear sampling rate of 4 m-3 d-1 is recommended for calculating effective air sample volumes in the SIP-PAS and PUF-PAS for PFASs except for the FOSAs and FOSEs in the PUF-PAS. SIP disks showed very good performance for all tested PFASs while PUF disks were suitable only for the PFSAs and their precursors. Experiments evaluating the suitability of different isotopically labeled fluorinated depuration compounds (DCs) revealed that 13C8-perfluorooctanoic acid (PFOA) was suitable for the calculation of site-specific sampling rates. Ambient temperature was the dominant factor influencing the seasonal trend of PFASs. [ABSTRACT FROM AUTHOR]

Modified polymer-coated glass samplers (POGs), termed EVA samplers, consist of micrometer-thin layers of ethylene vinyl acetate (EVA) coated onto a glass fiber filter or aluminum foil substrate. These samplers were designed to equilibrate rapidly with priority pollutants in air, making them ideal for short-term spatial studies in ambient or indoor air. The EVA sampler was calibrated by measuring the uptake of polychlorinated biphenyls (PCBs) over 8 weeks in an indoor environment, and four different film thicknesses were monitored that ranged from 0.1 to 30 μm. The results were used to calculate the average mass transfer coefficient (50.5 m/day) and generate contour maps that provide guidance in choosing an appropriate EVA sampler for a particular study based on film thickness, deployment time, and the log KOA of the anlayte. A range of air pollutant classes was also added to the EVA sampler prior to deployment to assess depuration rates. These included polychlorinated biphenyls (PCBs), current-use pesticides (CUPs), perfluorinated compounds (PFCs), and polybrominated diphenyl ethers (PBDEs). On the basis of the depuration profiles, the EVA sampler was a suitable equilibrium sampler for several CUPs and PCBs; however, for the high molecular weight PCBs and PBDEs, the EVA sampler operates as a linear uptake sampler. Samplers were also evaluated for their use as a rapid screening tool for assessing concentrations of siloxanes in indoor air. The EVA sampler was used to estimate air concentrations for D4 and D5 in laboratory air to be 118 and 89 ng/m³, respectively. Analyses were performed directly using thermal desorption gas chromatography/mass spectrometry (TDS-GC-MS). EVA samplers show promise due to their relatively low cost and ease of deployment and applicability to a wide range of priority chemicals. The ability to alter the film thickness, and hence the sorption capacity and performance of the EVA sampler, allows for a versatile sampler that can be used under varying sampling conditions and deployment times. [ABSTRACT FROM AUTHOR]

Gas-phase perfluoroalkyl carboxylic acids (PFCAs) sorb strongly on filter material (i.e., GFF, QFF) used in conventional high volume air samplers, which results in an overestimation of the particle-phase concentration. In this study, we investigated an improved technique for measuring the gas-particle partitioning of per- and polyfluoroalkyl substances (PFASs) using an annular diffusion denuder sampler. Samples were analyzed for 7 PFAS classes [i.e., PFCAs, perfluoroalkane sulfonic acids (PFSAs), fluorotelomer alcohols (FTOHs), fluorotelomer methacrylates (FTMACs), fluorotelomer acrylates (FTACs), perfluorooctane sulfonamides (FOSAs), and perfluorooctane sulfonamidoethanols (FOSEs)]. The measured particulate associated fraction (Φ′) using the diffusion denuder sampler generally followed the trend FTACs (0%) < FTOHs (8%) < FOSAs (21%) < PFSAs (29%) < FOSEs (66%), whereas the Φ′ of the C8-C18 PFCAs increased with carbon chain length, and ranged from 6% to 100%. The ionizability of some PFASs, when associated with particles, is an important consideration when calculating the gas-particle partitioning coefficient as both ionic and neutral forms can be present in the particles. Here we differentiate between a gas-particle partitioning coefficient for neutral species, Kp, and one that accounts for both ionic and neutral species of a compound, Kp′. The measured Kp′ for PFSAs and PFCAs was 4-5 log units higher compared to the interpolated Kp for the neutral form only. The measured Kp′ can be corrected (to apply to the neutral form only) with knowledge of the pKa of the chemical and the pH of the condensed medium ("wet" particle or aqueous aerosol). The denuder-based sampling of PFASs has yielded a robust data set that demonstrates the importance of atmospheric pH and chemical pKa values in determining gas-particle partitioning of PFASs. [ABSTRACT FROM AUTHOR]

Perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) are widely detected in human blood and serum and are of concern due to their potential toxicity. This study investigated the indoor sources of these compounds and their neutral precursors through a survey of 152 homes in Vancouver, Canada. Samples were collected of indoor air, outdoor air, indoor dust, and clothes dryer lint and analyzed for neutral [i.e., fluorotelomer alcohols (FTOHs), perfluorooctane sulfonamide (FOSA), and perfluorooctane sulfonamidoethanol (FOSE)] and ionic [i.e., PFOS and perfluoroalkyl carboxylates (PFCAs)] poly- and perfluorinated compounds (PFCs). Indoor air was dominated by 8:2 FTOH with a geometric mean concentration (pg/m³) of 2900. Among the FOSAs and FOSEs, MeFOSE exhibited the highest air concentration with a geometric mean of 380 pg/m³. PFOA was the major ionic PFC and was detected in all indoor air samples with a geometric mean of 28 pg/m³, whereas PFOS was below the detection limit. The results for the ionic PFCs in indoor air are the first for North America. The pattern of the neutral PFCs in house dust was also dominated by 8:2 FTOH, with a geometric mean of 88 ng/g. Dusts were enriched (relative to air) with sulfonamidoethanol (FOSE) which comprised 22% of the total neutral PFC content compared to only 3% in air. PFOS and PFOA were the most prominent compounds detected in dust samples. Levels of neutral PFCs in clothes dryer lint were an order of magnitude lower compared to house dust. Human exposure estimates to PFCs for adults and children showed that inhalation was the main exposure route for neutral and ionic PFCs in adults. For toddlers, ingestion of PFCs via dust was more relevant and was on the order of a few mg/day. Results from this study contribute to our understanding of exposure pathways of PFCs to humans. This will facilitate investigations of related health effects and human monitoring data. [ABSTRACT FROM AUTHOR]

The global distribution of linear and cyclic volatile methyl sibraanes (VMS) was investigated at 20 sites worldwide, including 5 locations in the Arctic, using sorbentimpregnated polyurethane foam (SIP) disk passive air samplers. Cyclic VMS are currently being considered for regulation because they are high production volume chemicals that are potentially persistent, bioaccumulative, and toxic. Linear and cyclic VMS (including L3, L4, L5, D3, D4, D5, and D6) were analyzed for in air at all urban, background, and Arctic sites. Concentrations of D3 and D4 are significantly correlated, as are DS and D6, which suggests different sources for these two pairs of compounds. Elevated concentrations of D3 and D4 on the West coast on North America and at high elevation sites suggest these sites are influenced by trans-Pacific transport, while D5 and D6 have elevated concentrations in urban areas, which is most likely due to personal care product use. Measured concentrations of D5 were compared to modeled concentrations generated using both the Danish Eulerian Hemispheric Model (DEHM) and the Berkeley-Trent Global Contaminant Fate Model (BETR Global). The correlation coefficients (r) between the measured and modeled results were 0.73 and 0.58 for the DEHM and BETR models, respectively. Agreement between measurements and models indicate that the sources, transport pathways, and sinks of D5 in the global atmosphere are fairly well understood. [ABSTRACT FROM AUTHOR]

Polychlorinated biphenyl (PCB) concentrations in air and soil, measured by various research groups from around the world, were compiled and analyzed. Data for air were available from most regions, particularly in Europe and Asia. The average air concentrations (pg/m³) for ΣPCB at background sites were 70 (5.1-170) for Europe, 79 (49-120) for North America, 66 (18-110) for South America, 270 (9-670) for Central America, 59 (17-150) for Asia, and 15 (13-17) for Australia. Data for soils exhibited better global coverage compared to air and were available from most regions. The average soil concentrations (pg/g dry weight) for ΣPCB at background sites were 7500 (47-97000) for Europe, 4300 (110-25000) for North America, 1400 (61-9 500) for South America, 580 (120-2 900) for Asia, 390 (94-620) for Africa, and 280 (140-540) for Australia. Based on available studies where coupled measurements of PCBs in air and soil were made, the equilibrium status of PCBs in the air-soil system was investigated for China, West Midlands of the UK, central and southern Europe, and along a latitudinal transect from the south of the UK to the north of Norway. Differences were observed in plots of the soil-air equilibrium status (expressed as the soil-air fugacity fraction, ff) for different PCB homologues. This was explained by varying contributions from primary and secondary emissions-spatially and temporally. The net effect after several decades of PCB emissions to air, preferential transport of lower molecular weight PCBs through primary and secondary emission, and reductions in emissions to air in recent decades is that the lower molecular weight PCBs have achieved (and in some cases exceeded) soil-air equilibrium in many parts of the world. The exception is remote and background sites that are still dominated by primary sources. [ABSTRACT FROM AUTHOR]

Depuration compounds (DCs) are added to passive air samplers (PAS) prior to deployment to account for the wind-dependency of the sampling rate for gas-phase compounds. This correction is particularly useful for providing comparable data for samplers that are deployed in different environments and subject to different meteorological conditions such as wind speeds. Two types of PAS-the polyurethane foam (PUF) disk sampler and semipermeable membrane devices (SPMDs)-were deployed at eight heights on a 100 m tower to test whether the DC approach could yield air concentrations profiles for PCBs and organochlorine pesticides and account for the wind speed gradient with height. Average wind speeds ranged from 0.3 to 4.5 m s-1 over the 40 day deployment increasing with height. Two low volume active air samples (AAS), one collected at 25 m and one at 73 m over the 40 day deployment showed no significant concentration differences for target compounds. As expected, the target compounds taken up by PAS reflected the wind profile with height. This wind-dependency of the PAS was also reflected in the results of the DCs. A correction based on the DC approach successfully accounted for the effect of wind on PAS sampling rates, yielding a profile consistent with the AAS. Interestingly, in terms of absolute air concentrations, there were differences between the MS and PAS-derived values for some target compounds. These were attributed to different sampling characteristics of the two approaches that may have resulted in slightly different air masses being sampled. Based on the results of this study, guidelines are presented for the use of DCs and for the calibration of PAS using AAS. [ABSTRACT FROM AUTHOR]

Concentrations of persistent organic pollutants (POPs) in air are reported from the first full year of the Global Atmospheric Passive Sampling (GAPS) Network. Passive air samplers composed of polyurethane foam disks (PUF-disk samplers) were deployed over four consecutive three-month periods in 2005 to measure seasonal concentrations of POPs at a variety of site types on a global scale, with an emphasis on background! remote locations. Samples for the last three quarters are reported here for the first time. Annual geometric mean (GM) concentrations in air (pg·m-3) were highest for endosulfan, a currently used pesticide (GM = 82), and polychiorinated biphenyls (PCBs) (GM = 26). Other chemicals regularly detected included α- and γ-hexachlorocyclohexane (HCH), chlordanes, heptachlor, heptachlor epoxide, dieldrin, p,p'-DDE and polybrominated diphenyl ethers (PBDEs). With the exception of lower concentrations during the first quarter, no seasonal patterns were observed on a global basis. In contrast, some distinct seasonal patterns were observed on a site-specific basis. For instance, endosulfans exhibited strong seasonality with highest concentrations during the summer periods, especially at or near agricultural sites. The latitudinal distribution of target chemicals reflected the estimated spatial variability of global emissions, with highest concentrations observed in the midlatitudes of the northern hemisphere. In the case of PCBs, the GAPS data reflected and were well correlated with global emission estimates, with highest concentrations in developed and industrialized regions. Data provided through the GAPS Network establish global baseline values, and continuation of the time series will contribute to the effectiveness evaluation of global treaties on POPs (e.g., Stockholm Convention). Globally resolved data will also foster the development and validation of global transport models for POPs, and the investigation of seasonal and interannual trends in concentrations of POPs in the global atmosphere. [ABSTRACT FROM AUTHOR]

The Canadian Atmospheric Network for Currently Used Pesticides (CANCUP) was the first comprehensive, nationwide air surveillance study of pesticides in Canada. This paper presents the atmospheric occurrence and distribution of pesticides including organochiorine pesticides (OCPs), organophosphate pesticides (OPPs), acid herbicides (AHs), and neutral herbicides (NHs) during the spring to summer of 2004 and 2005 across agricultural regions in Canada. Atmospheric concentrations of pesticides varied within years and time periods, and regional characteristics were observed including the following: (i) highest air concentrations of several herbicides (e.g., mecoprop, triallate, and ethalfluralin) were found at Bratt's Lake, SK, a site in the Canadian Prairies; (ii) the west-coast site at Abbotsford, BC, had the maximum concentrations of diazinon; (iii) the fruit and vegetable growing region in Vineland, ON, showed highest levels for several insecticides including chlorpyrifos, [ABSTRACT FROM AUTHOR]