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A retrospective analysis of a comprehensive series of high-volume air samples (n = 70) collected during 2010-2011 in Toronto (Canada) was performed. Seven UV compounds were analyzed by gas chromatography-tandem mass spectrometry (GC-MS/MS) with sum of concentrations (gas + particle phase) ranging from 80 to 2030 pg/m3. Homosalate (HMS) was the most prevalent organic UV-filter in air (47% of the total concentration), followed by 2-ethylhexyl salicylate (EHS, ∼29%), E- and Z-2-ethylhexyl 4-methoxycinnamate (EHMC, ∼17%). Ambient air (gas + particle phase) concentrations of organic UV-filters showed a strong seasonality, with peak levels during the summer. An analysis of Clausius-Clapeyron slopes indicated that much of the ambient burden of organic UV-filters are explained by volatilization from terrestrial and aquatic surfaces and supplemented with human activities and use of lotions and sunscreens, containing organic UV-filters, in addition to its use in plastics, textiles, paints, and pesticides. The results showed that organic UV-filters exist mainly in the gas phase with some exceptions, for instance, octocrylene (OCR), which was associated with both gas and particle phases, and avobenzone (AVB), which was predominantly in the particle phase. Lastly, this study revealed the need for basic physical chemical property data for organic UV-filters, including information on transformation rates and products, for better evaluating their environmental fate and effects.

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A special initiative in the Global Atmospheric Passive Sampling (GAPS) Network was implemented to provide information on new and emerging persistent organic pollutants (POPs) in the Group of Latin America and Caribbean (GRULAC) region. Regional-scale atmospheric concentrations of the new and emerging POPs hexachlorobutadiene (HCBD), pentachloroanisole (PCA) and dicofol indicators (breakdown products) are reported for the first time. HCBD was detected in similar concentrations at all location types (<20-120 pg/m3). PCA had elevated concentrations at the urban site Concepción (Chile) of 49-222 pg/m3, with concentrations ranging <1-8.5 pg/m3 at the other sites in this study. Dicofol indicators were detected at the agricultural site of Sonora (Mexico) at concentrations ranging 30-117 pg/m3. Legacy POPs, including a range of organochlorine (OC) pesticides and polychlorinated biphenyls (PCBs), were also monitored to compare regional atmospheric concentrations over a decade of monitoring under the GAPS Network. γ-hexachlorocyclohexane (HCH) and the endosulfans significantly decreased (p < 0.05) from 2005 to 2015, suggesting regional levels are decreasing. However, there were no significant changes for the other legacy POPs monitored, likely a reflection of the persistency and slow decline of environmental levels of these POPs. For the more volatile OCs, atmospheric concentrations derived from polyurethane foam (PUF) (acting as an equilibrium sampler) and sorbent impregnated PUF (SIP) (acting as a linear phase sampler), were compared. The complimentary methods show a good agreement of within a factor of 2-3, and areas for future studies to improve this agreement are further discussed.

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A special initiative was run by the Global Atmospheric Passive Sampling (GAPS) Network to provide atmospheric data on a range of emerging chemicals of concern and candidate and new persistent organic pollutants in the Group of Latin America and Caribbean (GRULAC) region. Regional-scale data for a range of flame retardants (FRs) including polybrominated diphenyl ethers (PBDEs), organophosphate esters (OPEs), and a range of alternative FRs (novel FRs) are reported over 2 years of sampling with low detection frequencies of the novel FRs. Atmospheric concentrations of the OPEs were an order of magnitude higher than all other FRs, with similar profiles at all sites. Regional-scale background concentrations of the poly- and perfluoroalkyl substances (PFAS), including the neutral PFAS (n-PFAS) and perfluoroalkyl acids (PFAAs), and the volatile methyl siloxanes (VMS) are also reported. Ethyl perfluorooctane sulfonamide (EtFOSA) was detected at highly elevated concentrations in Brazil and Colombia, in line with the use of the pesticide sulfluramid in this region. Similar concentrations of the perfluoroalkyl sulfonates (PFAS) were detected throughout the GRULAC region regardless of location type, and the VMS concentrations in air increased with the population density of sampling locations. This is the first report of atmospheric concentrations of the PFAAs and VMS from this region.

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Passive air samplers were used to evaluate long-term trends and spatial distribution of trace organic compounds in Antarctica. Duplicate PUF disk samplers were deployed at six automatic weather stations in the coastal area of the Ross sea (East Antarctica), between December 2010 and January 2011, during the XXVI Italian Scientific Research Expedition. Among the investigated persistent organic compounds, Hexachlorobenzene was the most abundant, with air concentrations ranging from 0.8 to 50 pg m-3. In general, the following decreasing concentration order was found for the air samples analyzed: HCB > PeCB > PCBs > DDTs > HCHs. While HCB concentrations were in the same range as those reported in the atmosphere of other Antarctic sampling areas and did not show a decline, HCHs and DDTs levels were lower or similar to those determined one or two decades ago. In general, the very low concentrations reflected the pristine state of the East Antarctica air. Backward trajectories indicated the prevalence of air masses coming from the Antarctic continent. Local contamination and volatilization from ice were suggested as potential sources for the presence of persistent organic pollutants in the atmosphere.

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Polyurethane foam - air partition coefficients (KPUF-air) for 9 polycyclic aromatic hydrocarbons (PAHs), 10 alkyl-substituted PAHs, 4 organochlorine pesticides (OCPs) and dibenzothiophene were measured as a function of temperature over the range 5 °C-35 °C, using a generator column approach. Enthalpies of PUF-to-air transfer (ΔHPUF-air, kJ/mol) were determined from the slopes of log KPUF-air versus 1000/T (K), and have an average value of 81.2 ± 7.03 kJ/mol. The log KPUF-air values at 22 °C ranged from 4.99 to 7.25. A relationship for log KPUF-air versus log KOA was shown to agree with a previous relationship based on only polychlorinated biphenyls (PCBs) and derived from long-term indoor uptake study experiments. The results also confirm that the existing KOA-based model for predicting log KPUF-air values is accurate. This new information is important in the derivation of uptake profiles and effective air sampling volumes for PUF disk samplers so that results can be reported in units of concentration in air.

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In this study passive air samplers containing polyurethane foam (PUF) disks were deployed in three cities across Chile; Santiago (STG) (n=5, sampling sites), Concepciόn (CON) (n=6) and Temuco (TEM) (n=6) from 2008 to 2009. Polychlorinated biphenyls (PCBs) (7 indicator congeners), chlorinated pesticides hexachlorocyclohexanes (HCHs), dichlorodiphenyl trichloroethanes (DDTs) and flame retardants such as polybrominated diphenyl ethers (PBDEs) were determined by gas chromatography coupled mass spectrometry (GC/MS). A sampling rate (R) typical of urban sites (4m3/day) was used to estimate the atmospheric concentrations of individual compounds. PCB concentrations in the air (pg/m3) ranged from ~1-10 (TEM), ~1-40 (STG) and 4-30 (CON). Higher molecular weight PCBs (PCB-153, -180) were detected at industrial sites (in Concepción). The HCHs showed a prevalence of γ-HCH across all sites, indicative of inputs from the use of lindane but a limited use of technical HCHs in Chile. DDTs were detected with a prevalence of p,p'-DDE accounting for ~50% of the total DDTs. PBDE concentrations in air (pg/m3) ranged from 1 to 55 (STG), 0.5 to 20 (CON) and from 0.4 to 10 (TEM), and were generally similar to those reported for many other urban areas globally. The pattern of PBDEs was different among the three cities; however, PBDE-209 was dominant at most of the sites. These results represent one of the few assessments of air concentrations of POPs across different urban areas within the same country. These data will support Chilean commitments as a signatory to the Stockholm Convention on POPs and for reporting as a member country of the Group of Latin America and Caribbean Countries (GRULAC) region.

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The occurrence of persistent organic pollutants (POPs) in the atmosphere of the near-coast South Atlantic Ocean was studied. Air samples were collected using a high-volume air sampler (filter and polyurethane foam) on board the Argentinean research cruise R/V Puerto Deseado (CONICET). Samples were analyzed for 50 polychlorinated biphenyl (PCBs), 22 organochlorine pesticides (OCPs) and 14 polybrominated diphenyl ethers (PBDEs). These POPs classes showed a trend of decreasing levels from near-shore to open ocean sites. OCPs and PCBs were in the same order of magnitude (2.71-87.1pg/m(3) and 9.56-130pg/m(3), respectively) while PBDEs levels were significantly lower (0.69-2.58pg/m(3)). Dichlorodiphenyltrichloroethanes (DDTs), endosulfans, chlordanes, hexachlorocyclohexanes (HCHs) and heptachlors were between 0.20 and 17.8pg/m(3), while drines and hexachlorobenzene (HCB) were at lower levels (0.28-3.71pg/m(3)). The most frequently detected PCBs were congeners 32, 28, 44, 52, 95, representing >50% of the total. The PBDEs congener pattern was dominated by congener 209 (70%), followed by 47 and 99 (16% and 7%, respectively). Air parcel back trajectories for the study period provided few insights as trajectories mainly stemmed from the open ocean with limited inputs from continental sources. These results indicate that the concentration of POPs (namely PCBs, OCPs, and PBDEs) in air remain elevated in the near-shore environment and then drop-off substantially beyond a distance of about 400km. This has implications for the loading of POPs and delivery to the marine environment in the near coastal zone.

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This study addresses human health concerns in the city of Temuco that are attributed to wood smoke and related pollutants associated with wood burning activities that are prevalent in Temuco. Polycyclic Aromatic Hydrocarbons (PAHs) were measured in air across urban and rural sites over three seasons in Temuco using polyurethane foam (PUF) disk passive air samplers (PUF-PAS). Concentrations of ΣPAHs (15 congeners) in air ranged from BDL to ∼70 ng m(-3) and were highest during the winter season, which is attributed to emissions from residential heating by wood combustion. The results for all three seasons showed that the PAH plume was widespread across all sites including rural sites on the outskirts of Temuco. Some interesting variations were observed between seasons in the composition of PAHs, which were attributed to differences in seasonal point sources. A comparison of the PAH composition in the passive samples with active samples (gas+particle phase) from the same site revealed similar congener profiles. Overall, the study demonstrated that the PUF disk passive air sampler provides a simple approach for measuring PAHs in air and for tracking effectiveness of pollution control measures in urban areas in order to improve public health.

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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 Σ4-8PCDD/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.

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Polyurethane foam disk passive air samplers were deployed over four periods of approximately 3 months along an altitudinal gradient (1820, 2600, 4650, and 5200 masl) on the east side of the Andean mountain range in Bolivia. The purpose of the study was to assess the gas-phase concentration and the altitudinal and seasonal trends of organochlorine pesticides and polychlorinated biphenyls (PCBs). Target compounds that were regularly detected included alpha- and gamma-hexachlorocyclohexane (HCH), endosulfans, and select PCB congeners. Endosulfans and HCH concentrations increased with altitude. Enrichment factors (concentration at the highest altitude divided by concentration at the lowest altitude) ranged from 10 to 20 for HCHs and 3 to 10 for endosulfans. Air parcel back trajectory analysis indicated that, in general, the high-altitude sites were exposed to a larger airshed and hence susceptible to long-range atmospheric transport from more distant regions. Seasonal differences were also observed with SigmaHCH concentrations peaking during periods 2 and 3 (March-September 2005). Airsheds (derived from the analysis of back trajectories) for periods 2 and 3 were less oriented along the Andes range (mountain air) with greater input from coastal regions. Endosulfans peaked during periods 1 and 2 (February-June 2005) and also exhibited the highest air concentrations of the target compounds, reaching approximately 1500 pg/m3 at the two highest elevation sites. PCB air concentrations at all sites were generally typical of global background values (<12 pg/m3) and showed no increase with altitude. This is the first study to measure air concentrations of persistent organic pollutants (POPs) in Bolivia and one of only a few studies to investigate altitudinal gradients of POPs.

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