Search

Passive air sampling (PAS) has been used to monitor semivolatile organic compounds (SVOCs) for the past 20 years, but limitations and uncertainties persist in the derivation of effective sampling volumes, sampling rates, and concentrations. As a result, the comparability of atmospheric levels measured by PAS and concentrations measured by active air sampling (AAS) remains unclear. Long-term PAS data, without conversion into concentrations, provide temporal trends that are similar to, and consistent with, trends from AAS data. However, for more comprehensive environmental and human health assessments of SVOCs, it is also essential to harmonize and pool air concentration data from the major AAS and PAS monitoring networks in Europe. To address this need, we calculated and compared concentration data for 28 SVOCs (including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and polycyclic aromatic hydrocarbons (PAHs)) at the six monitoring sites in Europe with 10 years of co-located AAS (EMEP) and PAS (MONET) data: Birkenes, Kosetice, Pallas, Rao, Storhofoi, and Zeppelin. Atmospheric SVOC concentrations were derived from PAS data using the two most common computation models. Long-term agreement between the AAS and PAS data was strong for most SVOCs and sites, with 79% of the median PAS-derived concentrations falling within a factor of 3 of their corresponding AAS concentrations. However, in both models it is necessary to set a sampler-dependent correction factor to prevent underestimation of concentrations for primarily particle-associated SVOCs. In contrast, the models overestimate concentrations at sites with wind speeds that consistently exceed 4 m s(-1). We present two recommendations that, if followed, allow MONET PAS to provide sufficiently accurate estimates of SVOC concentrations in air so that they can be deployed together with AAS in regional and global monitoring networks., Environmental Science: Processes & Impacts, 24 (6), ISSN:2050-7887, ISSN:2050-7895

International audience; For decades pesticides have been used in agriculture, however, the occurrence of legacy organochlorine pesticides (OCPs) and current-use pesticides (CUPs) is poorly understood in Africa. This study investigates air concentrations of OCPs and CUPs in three South African agricultural areas, their spatial/seasonal variations and mixture profiles.Between 2017 and 2018, 54 polyurethane foam-disks passive air-samplers (PUF-PAS) were positioned in three agricultural areas of the Western Cape, producing mainly apples, table grapes and wheat. Within areas, 25 CUPs were measured at two sites (farm and village), and 27 OCPs at one site (farm). Kruskal-Wallis tests investigated area differences in OCPs concentrations, and linear mixed-effect models studied differences in CUPs concentrations between areas, sites and sampling rounds.In total, 20 OCPs and 16 CUPs were detected. A median of 16 OCPs and 10 CUPs were detected per sample, making a total of 11 OCPs and 24 CUPs combinations. Eight OCPs (trans-chlordane, o,p’-/p,p’-dichlorodiphenyldichloroethylene (DDE)/dichlorodiphenyltrichloroethane (DDT), endosulfan sulfate, γ-hexachlorocyclohexane and mirex) and two CUPs (carbaryl and chlorpyrifos) were quantified in all samples. p,p’-DDE (median 0.14 ng/m3) and chlorpyrifos (median 0.70 ng/m3) showed the highest concentrations throughout the study. Several OCPs and CUPs showed different concentrations between areas and seasons, although CUPs concentrations did not differ between sites. OCPs ratios suggest ongoing chlordane use in the region, while DDT and endosulfan contamination result from past-use.Our study revealed spatial and seasonal variations of different OCPs and CUPs combinations detected in air. Further studies are needed to investigate the potential cumulative or synergistic risks of the detected pesticides.

Concerns about the possible negative impacts of current use pesticides (CUPs) for both the environment and human health have increased worldwide. However, the knowledge on the occurrence of CUPs in soil and air and the related human exposure in Africa is limited. This study investigated the presence of 30 CUPs in soil and air at two distinct agricultural sites in South Africa and estimated the human exposure and related risks to rural residents via soil ingestion and inhalation (using hazard quotients, hazard index and relative potency factors). We collected 12 soil and 14 air samples over seven days during the main pesticide application season in 2018. All samples were extracted, purified and analyzed by high-performance liquid chromatography coupled with tandem mass spectrometry. In soils, nine CUPs were found, with chlorpyrifos, carbaryl and tebuconazole having the highest concentrations (up to 63.6, 1.10 and 0.212 ng g(-1), respectively). In air, 16 CUPs were found, with carbaryl, tebuconazole and terbuthylazine having the highest levels (up to 25.0, 22.2 and 1.94 pg m(-3), respectively). Spatial differences were observed between the two sites for seven CUPs in air and two in soils. A large dominance towards the particulate phase was found for almost all CUPs, which could be related to mass transport kinetics limitations (non-equilibrium) following pesticide application. The estimated daily intake via soil ingestion and inhalation of individual pesticides ranged from 0.126 fg kg(-1) day(-1) (isoproturon) to 14.7 ng kg(-1) day(-1) (chlorpyrifos). Except for chlorpyrifos, soil ingestion generally represented a minor exposure pathway compared to inhalation (i.e.

Pollution of indoor environment, where people spend much of their time, comprises complex mixtures of compounds with vastly understudied hazard potential. This study examined several important specific toxic effects and pollutant levels (177 compounds) of indoor samples (air gas phase, PM10 and dust) from different microenvironments after two extractions with focus on their gas/particle/dust distribution and polarity. The endocrine disruptive (ED) potential was assessed by human cell-based in vitro bioassays addressing anti-/estrogenicity, anti-/androgenicity, aryl hydrocarbon, thyroid and peroxisome proliferator-activated receptor-mediated activities. Potential toxicity to respiratory tract tissue was assessed using human bronchial cell line. The toxicological analyses pointed out the relevance of both inhalation and ingestion exposure, with significant effects detected after exposure to extracts from all three studied matrices with distinct gas/particle distribution patterns. Chemical analyses document the high complexity of indoor pollutant mixtures with greatest levels of phthalates, their emerging alternatives, and PAHs in dust. Despite the detection of up to 108 chemicals, effects were explained only to low extent. This emphasizes data gaps regarding ED potencies of many detected abundant indoor contaminants, but also potential presence of other unidentified ED compounds. The omnipresent ED potentials in indoor environment rise concern regarding associated human health risk.

Despite the success of passive sampler-based monitoring networks in capturing global atmospheric distributions of semivolatile organic compounds (SVOCs), their limited spatial resolution remains a challenge. Adequate spatial coverage is necessary to better characterize concentration gradients, identify point sources, estimate human exposure, and evaluate the effectiveness of chemical regulations such as the Stockholm Convention on Persistent Organic Pollutants. Land use regression (LUR) modelling can be used to integrate land use characteristics and other predictor variables (industrial emissions, traffic intensity, demographics, etc.) to describe or predict the distribution of air concentrations at unmeasured locations across a region or country. While LUR models are frequently applied to data-rich conventional air pollutants such as particulate matter, ozone, and nitrogen oxides, they are rarely applied to SVOCs. The MONET passive air sampling network (RECETOX, Masaryk University) continuously measures atmospheric SVOC levels across Czechia in monthly intervals. Using monitoring data from 29 MONET sites over a two-year period (2015-2017) and a variety of predictor variables, we developed LUR models to describe atmospheric levels and identify sources of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and DDT across the country. Strong and statistically significant (R2 > 0.6; p < 0.05) models were derived for PAH and PCB levels on a national scale. The PAH model retained three predictor variables - heating emissions represented by domestic fuel consumption, industrial PAH point sources, and the hill:valley index, a measure of site topography. The PCB model retained two predictor variables - site elevation, and secondary sources of PCBs represented by soil concentrations. These models were then applied to Czechia as a whole, highlighting the spatial variability of atmospheric SVOC levels, and providing a tool that can be used for further optimization of sampling network design, as well as evaluating potential human and environmental chemical exposures.

Long-term exposure to polycyclic aromatic hydrocarbons (PAHs) and their nitrated (NPAHs) and oxygenated (OPAHs) derivatives can cause adverse health effects due to their carcinogenicity, mutagenicity and oxidative potential. The distribution of PAH derivatives in the terrestrial environment has hardly been studied, although several PAH derivatives are ubiquitous in air and long-lived in soil and water. We report the multi-annual variations in the concentrations of NPAHs, OPAHs and PAHs in soils sampled at a semi-urban (Mokrá, Czech Republic) and a regional background site (Košetice, Czech Republic) in central Europe. The concentrations of the Σ18NPAHs and the Σ11+2OPAHs and O-heterocycles were 0.31 ± 0.23 ng g−1 and 4.03 ± 3.03 ng g−1, respectively, in Košetice, while slightly higher concentrations of 0.54 ± 0.45 ng g−1 and 5.91 ± 0.45 ng g−1, respectively, were found in soil from Mokrá. Among the 5 NPAHs found in the soils, 1-nitropyrene and less so 6-nitrobenzo(a)pyrene were most abundant. The OPAHs were more evenly distributed. The ratios of the PAH derivatives to their parent PAHs in Košetice indicate that they were long-range transported to the background site. Our results show that several NPAHs and OPAHs are abundant in soil and that gas-particle partitioning is a major factor influencing the concentration of several semi-volatile NPAHs and OPAHs in the soils. Complete understanding of the long-term variations of NPAH and OPAH concentrations in soil is limited by the lack of kinetic data describing their formation and degradation.

Derivatives of polycyclic aromatic hydrocarbons (PAHs) such as nitrated- and oxygenated-PAHs (NPAHs and OPAHs) could be even more toxic and harmful for the environment and humans than PAHs. We assessed the spatial and seasonal variations of NPAHs and OPAHs atmospheric levels, their cancer risks and their gas-to-particle partitioning. To this end, about 250 samples of fine particulate matter (PM2.5) and 50 gaseous samples were collected in 2017 in central Europe in the cities of Brno and Ljubljana (two traffic and two urban background sites) as well as one rural site. The average particulate concentrations were ranging from below limit of quantification to 593 pg m−3 for Σ9NPAHs and from 1.64 to 4330 pg m−3 for Σ11OPAHs, with significantly higher concentrations in winter compared to summer. In winter, the particulate levels of NPAHs and OPAHs were higher at the traffic site compared to the urban background site in Brno while the opposite was found in Ljubljana. NPAHs and OPAHs particulate levels were influenced by the meteorological parameters and co-varied with several air pollutants. The significance of secondary formation on the occurrence of some NPAHs and OPAHs is indicated. In winter, 27–47% of samples collected at all sites were above the acceptable lifetime carcinogenic risk. The gas-particle partitioning of NPAHs and OPAHs was influenced by their physico-chemical properties, the season and the site-specific aerosol composition. Three NPAHs and five OPAHs had higher particulate mass fractions at the traffic site, suggesting they could be primarily emitted as particles from vehicle traffic and subsequently partitioning to the gas phase along air transport. This study underlines the importance of inclusion of the gas phase in addition to the particulate phase when assessing the atmospheric fate of polycyclic aromatic compounds and also when assessing the related health risk., Graphical abstract Unlabelled Image, Highlights • NOPAH particulate levels were generally correlated with PM, OC, EC, CO, Cu and Zn. • In winter, NOPAH levels generally increased with NO2 but decreased with O3. • Significant cancer risks from the inhalation of PAHs, NPAHs and OPAHs were found. • Cancer risks might be significantly underestimated if the gas phase is not sampled.

Persistent halogenated compounds (PHC) are of concern for human and environmental health. Persistent Organic Pollutants (POPs) are regulated by international treaties, but alternative compounds such as novel brominated flame retardants (NBFRs) and Dechlorane Plus (DP) are not-yet they are increasingly used. There are no data on PHCs in coral reef biota from tropical islands in the western Indian Ocean (WIO). For this assessment, three hard coral genera, two soft coral genera, and ember parrotfish (Scarus rubroviolaceus) were collected from the remote Rodrigues, Agalega, and St. Brandon's Atoll (Republic of Mauritius) in the Mascarene Basin of the WIO. Five compounds - Pentabromotoluene (PBT), γ-HCH, p,p'-DDE, HCB, and BDE-47- were quantifiable in all samples. Hard coral consistently contained the lowest concentrations of PHCs, except for NBFRs. The presence of BDE-47 suggests long-range aerial transport. We quantified DP, currently a candidate POP, in coral reef biota. PBT was measured in all samples also suggests long-range transport. Because the hard coral, soft coral, and fish had differing concentrations and patterns of PHCs, future surveys should stratify sampling accordingly. Agalega and St. Brandon's Atoll can be considered as locations to monitor changes in background concentrations of pollutants due to their remoteness.

The air humidity in Antarctica is very low and this peculiar weather parameter make the use of flame retardants in research facilities highly needed for safety reasons, as fires are a major risk. Legacy and novel flame retardants (nFRs) including polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDs), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), Dechlorane Plus (DP), and other nFRs were measured in indoor dust samples collected at research Stations in Antarctica: Gabriel de Castilla, Spain (GCS), Julio Escudero, Chile (JES), and onboard the RRS James Clark Ross, United Kingdom (RRS JCR). The GC-HRMS and LC-MS-MS analyses of dust samples revealed ∑PBDEs of 41.5 ± 43.8 ng/g in rooms at GCS, 18.7 ± 11.6 ng/g at JES, and 27.2 ± 37.9 ng/g onboard the RRS JCR. PBDE pattern was different between the sites and most abundant congeners were BDE-183 (40%) at GCS, BDE-99 (50%) at JES, and BDE-153 (37%) onboard the RRS JCR. The ∑HBCDs were 257 ± 407 ng/g, 14.9 ± 14.5 ng/g, and 761 ± 1043 ng/g in indoor dust collected in rooms at GCS, JES, and RRS JCR, respectively. The ∑nFRs were 224 ± 178 ng/g at GCS, 14.1 ± 13.8 ng/g at JES, and 194 ± 392 ng/g on the RRS JCR. Syn- and anti-DP were detected in most of the samples and both isomers showed the highest concentrations at GCS: 163 ± 93.6 and 48.5 ± 61.1 ng/g, respectively. The laboratory and living room showed the highest concentration of HBCDs, DPs, BTBPE. The wide variations in FR levels in dust from the three research facilities and between differently used rooms reflect the different origin of furnishing, building materials and equipment. The potential health risk associated to a daily exposure via dust ingestion was assessed for selected FRs: BDEs 47, 99, and 153, α-, β-, and γ-HBCD, BTBPE, syn- and anti-DP. Although the estimated exposures are below the available reference doses, caution is needed given the expected increasing use of novel chemicals without a comprehensive toxicological profile., This work was supported by Project SENTINEL-CTM2015- 70535-P (JD and BJ), Projects ANID-FONDECYT 1130329 (KP) and 1161673 (KP), 11150548 (CGM), ANID-FONDAP 15110027 (RA-H), ANID-PIA-INACh-ACT192057 (CGM), INACH RT_12_17 (CGM), and INACH RT_08_13 (RA-H), PNRA 2013/C1.04 (SC). We thank the Project PLANET (PNRA 14_0009) in collaboration with the British Antarctic Survey- Ecosystems Team for the collection of samples on board the RRS James Clarke Ross (EB). This research was also supported by the RECETOX Research Infrastructure (Czech Ministry of Education, Youth and Sports: LM2018121), RECETOX RI (CZ.02.1.01/0.0/0.0/16_013/ 0001761), and CETOCOEN EXCELLENCE Teaming 2 project supported by Horizon2020 (857560) and the Czech Ministry of Education, Youth and Sports (02.1.01/0.0/0.0/18_046/0015975).

Nitrated and oxygenated polycyclic aromatic hydrocarbons (NPAHs, OPAHs) are abundant in the atmosphere and contribute significantly to the health risk associated with inhalation of polluted air. Despite the health hazard they pose, NPAHs and OPAHs were rarely included in monitoring. The aim of this study is to provide the first multi-year temporal trends of the concentrations, composition pattern and fate of NPAHs and OPAHs in air from a site representative of background air quality conditions in central Europe. Samples were collected every second week at a rural background site in the Czech Republic during 2015 -2017. Concentrations ranged from 1.3 to 160 pg m(-3) for Sigma(17)NPAHs, from 32 to 2600 pg m-3 for Sigma(10)OPAHs and from 5.1 to 4300 pg m(-3) for Sigma O-2-heterocycles. The average particulate mass fraction (q) ranged from 0.01 +/- 0.02 (2-nitronaphthalene) to 0.83 +/- 0.22 (1-nitropyrene) for individual NPAHs and from

Plastic waste of electrical and electronic equipment (WEEE) can contain polybrominated diphenyl ethers (PBDEs) that have been used as fire retardants for a long time. PBDEs were listed in the Stockholm Convention as persistent organic pollutants, so PBDE-containing plastic waste should be separated and disposed of in an ecologically sound manner. In the article, the results of bromine and PBDE content in plastic samples of WEEE collected in Belarus are presented. The screening method for bromine identification and HRGC/HRMS for PBDE identification were applied. It is shown that bromine is present in 43% of the 111 studied samples. Most often, Br-containing plastic was found in CRT monitor, CRT TVs and LCD monitor (about 50%), printers (35%), and LCD TVs (25%). PBDEs were revealed in 12 Br-containing samples, representing TVs, monitors, and printers. The sum of ∑10PBDEs varied from 6.6 to 21,000 μg/kg. BDE-209 dominated in 9 samples (75% of cases); BDE-183, in two; and BDE-47 and BDE-99, in one sample. Based on the low content of PBDEs in the plastic, year of equipment production, and year of restriction of PBDEs applied in the countries-manufacturers, it was concluded that the presence of PBDEs in plastic is a consequence of contaminated waste recycling. Despite the relatively low concentrations of PBDEs (below the limit values established by the Stockholm and Basel conventions for POP wastes), further research is necessary with an extension of the list of analyzed types of equipment and identification of other brominated flame retardants.

Among the nitrated and oxygenated polycyclic aromatic hydrocarbons (NPAHs and OPAHs) are some of the most hazardous substances to public health, mainly because of their carcinogenicity and oxidative potential. Despite these concerns, the concentrations and fate of NPAHs and OPAHs in the atmospheric environment are largely unknown. Ambient air concentrations of 18 NPAHs, 5 quinones, and 5 other OPAHs were determined at two urban and one regional background sites in central Europe. At one of the urban sites, the total (gas and particulate) concentrations of Sigma(10)OPAHs were 10.0 +/- 9.2 ng/m(3) in winter and 3.5 +/- 1.6 ng/m(3) in summer. The gradient to the regional background site exceeded 1 order of magnitude. Sigma(18)NPAH concentrations were typically 1 order of magnitude lower than OPAHs. Among OPAHs, 9-fluorenone and (9,10)-anthraquinone were the most abundant species, accompanied by benzanthrone in winter. (9,10)-Anthraquinone represented two-thirds of quinones. We found that a large fraction of the target substance particulate mass was carried by submicrometer particles. The derived inhalation bioaccessibility in the PM10 size fraction is found to be approximate to 5% of the total ambient concentration of OPAHs and up to approximate to 2% for NPAHs. For 9-fluorenone and (9,10)-anthraquinone, up to 86 and 18%, respectively, were found at the rural site. Our results indicate that water solubility could function as a limiting factor for bioaccessibility of inhaled particulate NPAHs and OPAHs, without considerable effect of surfactant lipids and proteins in the lung lining fluid.

Passive air sampling of semivolatile organic compounds (SVOCs) is a relatively inexpensive method that facilitates extensive campaigns with numerous sampling sites. An important question in the design of passive-sampling networks concerns the number and location of samplers. We investigate this question with the example of 17 SVOCs sampled at 14 background sites across the Czech Republic. More than 200 time series (length 5-11 years) were used to characterize SVOC levels and trends in air between 2003 and 2015. Six polychlorinated biphenyls (PCBs), 6 polyaromatic hydrocarbons (PAHs), and 5 organochlorine pesticides (OCPs) at 14 sites were assessed using data from the MONET passive sampling network. Significant decreases were found for most PCBs and OCPs whereas hexachlorobenzene (HCB) and most PAHs showed (mostly insignificant) increases. Spatial variability was rather low for PCBs and OCPs except for dichlorodiphenyltrichloroethane (DDT) and rather high for PAHs. The variability of the SVOC levels and trends depends on characteristics of the sites including their remoteness, landscape, population, and pollution sources. The sites can be grouped in distinct clusters, which helps to identify similar and, thereby, potentially redundant sites. This information is useful when monitoring networks need to be optimized regarding the location and number of sites.

Persistent organic pollutants that have accumulated in soils can be remobilised by volatilisation in response to chemical equilibrium with the atmosphere. Clean air masses from the Indian Ocean, advected with the onset of the summer monsoon, are found to reduce concentrations of hexachlorocyclohexane (HCH), dichlorodiphenyltrichloroethane (DDT) and its derivatives, endosulfan and polychlorinated biphenyls (PCBs) in air at a mountain site (all in the range 5–20 pg m−3) by 77 %, 70 %, 82 % and 45 %, respectively. The analysis of fugacities in soil and air suggest that the arrival of summer monsoon triggers net volatilisation or enhances ongoing revolatilisation of the now-banned chemicals HCH and PCBs from background soils in southern India. The response of the air–soil exchange was modelled using a regional air pollution model, WRF-Chem PAH/POP. The results suggest that the air is increasingly polluted during transport by the south-westerly monsoon winds across the subcontinent. Using a multidecadal multimedia mass balance model, it is found that air–surface exchange of HCH and DDT have declined since the ban of these substances from agriculture, but remobilisation of higher chlorinated PCBs may have reached a historical high, 40 years after peak emission.

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous semi-volatile organic pollutants. Their environmental occurrence is of global concern as some of them are carcinogens, mutagens, and teratogens. In this study, concentrations and distributions of 16 priority PAHs (∑PAHs) were measured in air, atmospheric deposition, and surface water at various locations in Himalayan, Middle, and Lower Reaches of the Ganges River, covering a spatial transect of 2500km, during two seasons (pre-monsoon and monsoon). The concentration of ∑PAHs ranged between 2.2 and 182.2ngm-3 in air, between 186 and 8810ngm-2day-1 in atmospheric deposition, and between 0.05 and 65.9ngL-1 in surface water. Air concentrations were strongly correlated with human population density. In the Middle and Lower Reaches of the Ganges River, atmospheric PAHs were mainly attributed to fossil fuel combustion sources. In the Himalayan Reach the influence of forest fire or biomass combustion was evident during the dry pre-monsoon season. Seasonality in concentrations of PAHs in river water was evident in the Himalayan Reach of the river, as a probable consequence of climate-modulated secondary source intensity (i.e. releases from glacier melting). Seasonality faded in the Middle and Lower Reaches of the Ganges where water contamination is expected to mainly reflect anthropogenic primary sources. Ambient air concentrations were used to calculate the probabilistic incremental lifetime cancer risk (ILCR). It was expectedly found to be higher in the Middle and Lower Reaches compared to the Himalayan Reach. The strong correlation between population density and air concentrations suggests population density may be used as a surrogate variable to assess human health risk in data-sparse regions such as the Ganges River basin.

Perfluorinated alkyl substances (PFASs) were determined in marine plastic litter (MPL) on six beaches of central Chile. MPL was characterized physically and chemically, showing an abundance of macroplastic (size >2.5 cm). The polypropylene (PP) (47%) was the predominant polymer found. The Desembocadura beach, located at the mouth of the Biobio River, recorded the highest abundance of MPL (3.7 items m−2). PFAS detected (n = 15/21) ranged from 279 to 1211 pg g−1 and accounted for MeFOSE (46%) > PFHxS (14%) > PFPA (11%) > PFBS (6%) > PFOA (4%) and > PFOS (4%). Long-chain PFAS were prevalent, which can be metabolically degraded into PFOS (new POPs). This study i) highlights the need to further investigate the occurrence of chemicals in the MPL to reduce their impact on the environment; and ii) points out the need to improve future coastal management strategies for the elimination of solid waste along the coast of the country.

Degradation of semivolatile organic compounds (SVOCs) occurs naturally in ambient air due to reactions with reactive trace gases (e.g., ozone, NOx). During air sampling there is also the possibility for degradation of SVOCs within the air sampler, leading to underestimates of ambient air concentrations. We investigated the possibility of this sampling artifact in commonly used active and passive air samplers for seven classes of SVOCs, including persistent organic pollutants (POPs) typically covered by air monitoring programs, as well as SVOCs of emerging concern. Two active air samplers were used, one equipped with an ozone denuder and one without, to compare relative differences in mass of collected compounds. Two sets of passive samplers were also deployed to determine the influence of degradation during longer deployment times in passive sampling. In active air samplers, comparison of the two sampling configurations suggested degradation of particle-bound polycyclic aromatic hydrocarbons (PAHs), with concentrations up to 2× higher in the denuder-equipped sampler, while halogenated POPs did not have clear evidence of degradation. In contrast, more polar, reactive compounds (e.g., organophosphate esters and current use pesticides) had evidence of losses in the sampler with denuder. This may be caused by the denuder itself, suggesting sampling bias for these compounds can be created when typical air sampling apparatuses are adapted to limit degradation. Passive air samplers recorded up to 4× higher concentrations when deployed for shorter consecutive sampling periods, suggesting that within-sampler degradation may also be relevant in passive air monitoring programs.

Many attempts have been made to quantify the relationship between the amount of persistent organic pollutants sequestered by passive air sampling devices and their actual concentrations in ambient air. However, this information may not be necessary for some applications. In this study, two sets of 30 ten-year-long time series of simultaneous passive and high-volume active air sampling carried out at the Košetice observatory in the Czech Republic were used for a comparison of temporal trends. Fifteen polyaromatic hydrocarbons, seven polychlorinated biphenyls and eight organochlorine pesticides were investigated. In most cases, a good agreement was observed between the trends derived from passive and active monitoring with the exception of several compounds obviously affected by sampling artifacts. Two sampling artifacts were observed: breakthrough of high-volume sampler filters for penta- and hexachlorobenzene and semiquantitative values for PAHs with a high molecular weight. It has been suggested before that annually aggregated results of passive air monitoring may be used directly for the assessment of the long-term behavior of these compounds. The extensive set of long-term data used in this study allowed us to confirm this finding and to demonstrate that it is also possible to derive temporal trends and the compounds' half-lives in air from the passive-sampling time series.

Concentrations of persistent organic pollutants (POPs) were measured for an entire year in the region of Tuscany, Italy. Passive air samplers consisting of polyurethane foam (PUF) disks were deployed over four sampling periods of 3-5 months from April 2008 to July 2009 in urban (n = 6) and rural (n = 4) sites. The aim of the study was to characterize the spatial and seasonal variations in selected POPs. The POP concentrations (pg m-3) in the air were dominated by dichlorodiphenyltrichloroethane and metabolites (DDTs) and polychlorinated biphenyls (∑7PCBs). DDTs, and ∑7PCBs showed a clear decreasing urban > rural gradient. The concentrations of DDTs and PCBs were up to 10 and 6 times higher, respectively, in urban sites than in rural sites. ∑7PCBs showed a significant correlation with the urbanized areas located

Plastic resin pellets were collected from coastal areas (n = 7) of central Chile. Pellets were analyzed using Fourier-transform infrared spectroscopy for polymer identification and gas chromatography-mass spectrometry for Persistent Organic Pollutants (POPs) determination. Screened compounds were PBDEs (n = 10), PCBs (n = 7), and OCPs (n = 13). Pellets were only found at Lenga Beach (San Vicente Bay), which is likely influenced by the presence of industrial activities in the surrounding coastal area. The diameter of the pellets was 4.0 ± 0.6 cm (n = 370), the color varied from white (32%) to yellowing (68%), and the most prevalent polymer identified was high-density polyethylene (99%). POPs concentrations (ng/g-pellet) ranged from 10 to 133 for Ʃ10PBDEs, from 3 to 60 for Ʃ7PCBs and between 0.1 and 7 for DDTs. Levels of POPs are consistent with other investigations around the world and highlight the sorbtion capacity of plastics resin pellets, and consequently transport of POPs into coastal environments.

The comparability of data from active (ACT) and passive sampling (PAS) of persistent organic pollutants (POPs) in air is hindered by uncertainties related to the derivation of sampling rates and concentrations, as well as differences in the duration, volume and frequency of sampling. Although data from ACT have been used extensively in short-term PAS calibration studies, no attempts have been made to evaluate the comparability of long-term trends calculated from PAS to established ACT trends. This is crucial, as continuous long-term ACT is unfeasible in most regions of the world. To address these challenges, we calculated and compared trends for organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) at the six sites in Europe with at least 5 years of co-located ACT and PAS data (2012–2016): Birkenes, Košetice, Pallas, Råö, Stórhöfði and Zeppelin. Strong agreement of ACT and PAS trends was observed for most OCPs and PCBs. Apart from two PCBs at Stórhöfði, all pairs of ACT and PAS trends followed the same direction. However, differences in the magnitude, significance and confidence intervals of their slopes were observed for some compounds and were primarily attributed to the short duration of the PAS time series. Despite some limitations, our results suggest that the comparability of ACT and PAS POP trends will continue to improve with additional years of data. This study confirms the suitability of PAS for the calculation of long-term POP trends in air, and highlights the importance of continuous sampling at established monitoring sites with consistent analytical methods. ISSN:2050-7887 ISSN:2050-7895

Polycyclic aromatic hydrocarbons (PAHs) and some of their nitrated derivatives, NPAHs, are seemingly ubiquitous in the atmospheric environment. Atmospheric lifetimes may nevertheless vary within a wide range, and be as short as a few hours. The sources and sinks of NPAH in the atmosphere are not well understood. With a Lagrangian field experiment and modeling, we studied the conversion of the semivolatile PAHs fluoranthene and pyrene into the 2-nitro derivatives 2-nitrofluoranthene and 2-nitropyrene in a cloud-free marine atmosphere on the time scale of hours to 1 day between a coastal and an island site. Chemistry and transport during several episodes was simulated by a Lagrangian box model i.e., a box model coupled to a Lagrangian particle dispersion model, FLEXPART-WRF. It is found that the chemical kinetic data do capture photochemical degradation of the 4-ring PAHs under ambient conditions on the time scale of hours to 1 day, while the production of the corresponding NPAH, which sustained 2-nitrofluoranthene/fluoranthene and 2-nitropyrene/pyrene yields of (3.7 ± 0.2) and (1.5 ± 0.1)%, respectively, is by far underestimated. Predicted levels of NPAH come close to observed ones, when kinetic data describing the reactivity of the OH-adduct were explored by means of theoretically based estimates. Predictions are also underestimated by 1-2 orders of magnitude, when NPAH/PAH yields reported from laboratory experiments conducted under high NOx conditions are adopted for the simulations. It is concluded that NPAH sources effective under low NOx conditions, are largely underestimated., Grant Agency of the Czech Republic (P503 16-115375); Izmir Institute of Technology Research Fund (2013IYTE-14); Max Planck Society; European Union (262254); Ministry of Education, Youth & Sports - Czech Republic (LM2015051/CZ.02.1.01/0.0/0.0/16_013/0001761)

Polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) are ubiquitous and toxic contaminants. Their atmospheric deposition fluxes on the regional scale were quantified based on simultaneous sampling during 1 to 5 years at 1 to 6 background/rural sites in the Czech Republic and Austria. The samples were extracted and analysed by means of gas chromatography coupled to mass spectrometry. For all seasons and sites, total deposition fluxes for Σ15PAHs ranged 23–1100 ng m−2 d−1, while those for Σ6PCBs and Σ12OCPs ranged 64–4400 and 410–7800 pg m−2 d−1, respectively. Fluoranthene and pyrene were the main contributors to the PAH deposition fluxes, accounting on average for 19% each, while deposition fluxes of PCBs and OCPs were dominated by PCB153 (26%) and γ-hexachlorobenzene (30%), respectively. The highest deposition flux of Σ15PAHs was generally found in spring, while no seasonality was found for PCB deposition. For deposition fluxes for Σ12OCPs, no clear spatial trend was found, confirming the perception of long-lived regional pollutants. Although most OCPs and PCBs hardly partition to the particulate phase in ambient air, on average, 42% of their deposition fluxes were found on filters, confirming the perception that particle deposition is more efficient than dry gaseous deposition. Due to methodological constraints, fluxes derived from bulk deposition samplers should be understood as lower estimates, in particular with regard to those substances which in ambient aerosols mostly partition to the particulate phase. Electronic supplementary material The online version of this article (10.1007/s11356-019-05464-9) contains supplementary material, which is available to authorized users.

Pinus mugo Turra is a typical pine tree from mountain habitats. It is ideal as a bioindicator for air quality monitoring, but, to the best of our knowledge, has never been implemented to determine organic compound concentrations. This study presents the initial methodology for the use of pine needles to measure contamination levels and evaluate genotoxicity potentials caused by long-range transport of pollutants at sites in the Slovak mountains in comparison to an industrial urban area. Pinus mugo needles have many positive attributes, particularly the five-year lifetime of needles compared with other species of pine. The presence of epicuticular wax on the surface of needles allows accumulation of lipophilic organic compounds. Pine needles were analyzed for POP compounds (PCBs, OCPs, PBDEs), PAHs, PFCs and lead. A pollen grain abortion assay with Pinus mugo species was also tested as a method to identify contamination of high mountain habitats. The concentration of organic compounds increased proportionally with needle age. Concentrations along the mountain transect were heavily influenced by atmospheric transport and proximity to potential sources of contamination from industry and residential areas from north and south of the mountain. The slope exposure direction had a large impact on concentrations of PBDEs (mainly for BDE 209). High concentrations of PFCs were discovered near a ski resort, where the use of these substances is high due to fluorinated ski waxes and personal outdoor clothing. A positive correlation between pollen grain abortivity and elevation was observed, with the strongest effect on pollutants at the top of the mountains. The results showed the highest genotoxicity at the site near a pulp mill (Zilina), where the frequency of abortive pollen grains was 3.1 times higher than at the control site. Lead content increased gradually with needle age, and a correlation was found between Pb levels in needles and pollen abortivity. It can be concluded that Pinus mugo is a suitable bioindicator species for assessment of long-term trends of atmospheric contamination in high mountain habitats.

Seven types of indoor samples, covering five indoor matrices, were collected in a residential room, and analyzed for five classes of semivolatile organic compounds (SVOCs). The goal was to improve the understanding of the relationship between indoor air, surface films and dust, based on differences in sources, physicochemical properties, and indoor environmental characteristics. Comparisons of the five matrices (gas- and particle-phase air, floor dust, surface dust/films and window films) demonstrated that within our test room a semi-quantitative measurement of the SVOC distributions and concentrations could be obtained by air, and composite dust or furniture surface wipes. Dust concentrations varied within the room, and spot samples were not necessarily representative of the average room conditions. Polyurethane foam passive air samplers (PUF-PAS) successfully quantified the total air concentrations of the studied SVOC compound groups, as indoor air concentrations were dominated by gas-phase compounds, however air concentrations of individual particle-bound compounds had higher uncertainty. Measured concentrations of dust/surfaces could be used to estimate air concentrations of legacy SVOCs, demonstrating equilibrium in the room. However, air concentrations of current-use compounds (flame retardants, polycyclic aromatic hydrocarbons (PAHs)) could not be estimated from dust/surface concentrations, demonstrating the influence of ongoing primary emissions and non-equilibrium status in the room.

As a consequence of long-range transported pollution, air–sea exchange can become a major source of persistent organic pollutants in remote marine environments. The vertical gradients in the air were quantified for 14 species, i.e. four parent polycyclic aromatic hydrocarbons (PAHs), three polychlorinated biphenyls (PCBs), three organochlorine pesticides (OCPs) and two polybrominated diphenylethers (PBDEs) in the gas-phase at a remote coastal site in the southern Aegean Sea in summer. Most vertical gradients were positive (Δc∕Δz > 0), indicating downward (net depositional) flux. Significant upward (net volatilisational) fluxes were found for three PAHs, mostly during daytime, and for two OCPs, mostly during night-time, as well as for one PCB and one PBDE during part of the measurements. While phenanthrene was deposited, fluoranthene (FLT) and pyrene (PYR) seem to undergo flux oscillation, hereby not following a day–night cycle. Box modelling confirms that volatilisation from the sea surface has significantly contributed to the night-time maxima of OCPs. Fluxes were quantified based on eddy covariance. Deposition fluxes ranged from −28.5 to +1.8 µg m−2 day−1 for PAHs and −3.4 to +0.9 µg m−2 day−1 for halogenated compounds. Dry particle deposition of FLT and PYR did not contribute significantly to the vertical flux.

In this study, we characterized plastic debris (PD) found on beaches from Concepcion Bay in central Chile during spring 2017 and summer 2018. The identification of polymers was carried out using FT-IR. Persistent organic pollutants (POPs) were extracted with hexane using an ultrasonic bath and further quantified through GC–MS. The highest abundance of PD was obtained during the summer (4.1 ± 3.7 items/m2), with the most common size range between 2.5 and 10 cm (42%) and the most frequent shape were plastic fragments (44%). FT-IR analysis showed that polypropylene was the most recurrent plastic polymer found. The ∑10PBDEs ranged from 2.1 to 1300 ng/g in spring 2017 and 392 to 3177 ng/g in summer 2018. ∑7PCBs ranged from 0.9 to 93 ng/g during the spring 2017 and 0.3 to 4.5 ng/g for summer 2018. This study is the first with information on POPs occurrence in the plastic debris of central Chile.

This study presents four years ambient monitoring data of seventeen 2,3,7,8-chlorine substituted polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs), twelve dioxin-like polychlorinated biphenyls (dl-PCBs) and sixteen polycyclic aromatic hydrocarbons (PAHs) designed by the US EPA at a background site in central Europe during 2011–2014. The concentrations expressed as toxic equivalents (TEQs) using the WHO2005-scheme for PCDD/Fs (0.2 fg m−3-61.1 fg m−3) were higher than for dl-PCBs (0.01 fg m−3-2.9 fg m−3), while the opposite was found in terms of mass concentrations. ΣPAHs ranged from 0.20 ng m−3 to 134 ng m−3. The mass concentration profile of PCDD/Fs, dl-PCBs and PAHs was similar throughout the four years. PCDD/Fs and PAHs concentrations were dominated by primary sources peaking in winter, while those of dl-PCBs were controlled by secondary sources characterized by a spring-summer peak. During 2011–2014, no significant decrease in the atmospheric levels of ΣPCDD/Fs was observed. On the other hand, the concentrations of Σdl-PCBs and ΣPAHs were decreasing, with halving times of 5.7 and 2.7 years, respectively. We estimated that 422 pg m−2 year−1-567 pg m−2 year−1 TEQ PCDD/Fs and 3.48 pg m−2 year−1-15.8 pg m−2 year−1 TEQ dl-PCBs were transferred from the air to the ground surfaces via dry particulate deposition during 2011–2014.

The central and eastern Mediterranean is a receptor area for persistent organic pollutants (POPs) emitted in western, central and eastern Europe, particularly during summer. Atmospheric concentrations of PCBs, DDXs, PBDEs, penta- and hexachlorobenzene were measured during a ship-borne survey in the summer of 2010. The concentration of PCBs (sum of 7 congeners) was 3.61 (2.08-7.72) pg m(-3), of which 6.7% was associated with the particulate phase. The mean concentration of DDT isoi-ners and their metabolites, DDE and DDD, was 2.60 (0.46-7.60) pg m(-3) (particulate mass fraction theta = 0.097), of penta- and hexachlorobenzene 0.22 (

Indoor air pollution has been recognized as an important risk factor for human health, especially in areas where people tend to spend most of their time indoors. Many semi-volatile organic compounds (SVOCs) have primarily indoor sources and are present in orders of magnitude higher concentrations indoors than outdoors. Despite this, awareness of SVOCs in indoor air and assessment of the link between indoor concentrations and human health have tagged behind those of outdoor air. This is partially related to challenges associated with indoor sampling of SVOCs. Passive air samplers (PASs), which are widely accepted in established outdoor air monitoring networks, have been used to fill the knowledge gaps on indoor SVOCs distribution. However, their applicability for indoor environments and the assessment of human health risks lack sufficient experimental data. To address this issue, we performed an indoor calibration study of polyurethane foam (PUF) PAS deployed in a double-dome chamber, covering both legacy and new SVOC classes. PUF-PAS and a continuous low-volume active air sampler (AAS) were co-deployed for a calibration period of twelve weeks. Based on the results from this evaluation, PUF-PAS in a double-bowl chamber is recommended for indoor sampling and health risk assessment of gas phase SVOCs, including novel brominated flame retardants (nBFR) providing sufficient exposure time is applied. Data for particle associated SVOCs suffered from significant uncertainties caused by low level of detection and low precision in this study. A more open chamber design for indoor studies may allow for higher sampling rates (R-s) and better performance for the particle associated SVOCs.

Polyurethane foam (PUF) disk passive air samplers were deployed concurrently at five sites across Kolkata megacity and the rural mangrove wetland of Sundarban (UNESCO World Heritage Site) between January-March in 2014. Samples were analyzed for hexachlorocyclohexanes (HCHs), dichlorodiphenyltricholoroethanes (DDTs), polychlorinated biphenyls (PCBs) and, polybrominated diphenyl ethers (PBDEs) using gas chromatography and mass spectrometry (GC-MS). Derived air concentrations (pg/m(3)) for Kolkata ranged: for Sigma alpha- and gamma-HCH between 70 and 207 (114 +/- 62), Sigma 6DDTs: 127-216 (161 +/- 36), Sigma(7)PCBs: 53-213 (141 +/- 64), and Sigma 10PBDEs: 0.30-23 (11 +/- 9). Low values for all the studied POPs were recorded in the remote area of the Sundarban site (with the exception of DDTs: o,p'-DDT and p,p'-DDT), where Sigma 4DDTs was 161 +/- 36. In particular, the site of Ballygunge, located in the southern part of Kolkata, showed the highest level of all the metabolites/congeners of POPs, suggesting a potential hot spot of usage and emissions. From HCHs, alpha-/gamma-HCH isomers ratio was low (0.67-1.96) indicating a possible sporadic source of lindane. y-HCH dominated the HCH signal (at 3 sites) reflecting wide spread use of lindane both in Kolkata and the Sundarban region; however, isomeric composition in Kolkata also suggests potential technical HCHs use. Among DDT metabolites, both o,p'-DDT and p,p'-DDT shared the dominant percentages accounting for 26-46% of total DDTs followed by p,p'-DDE (similar to 12-19%). The PCB congener profile was dominated by tri- and tetra-CI at the southern and eastern part of Kolkata. These results are one of the few contributions that reports air concentrations of POPs, concurrently, at urban and remote villages in India. These data are useful to assess atmospheric pollution levels and to motivate local and regional authorities to better understand the potential human exposure risk associated to urban areas in India.

PCBs and PBDEs (7 and 10 congeners, respectively) were analyzed in four coastal surface sediments collected from the northern shore of Bahia Blanca estuary and in nine soils from different locations of Bahia Blanca city and the surrounding region (Southwest of Buenos Aires Province, Argentina). Sediment samples showed PCBs((Sigma 7)) concentrations ranged from 0.61 to 17.6 ng g(-1) (dry weight = dw) and PBDEs(Sigma 10) from 0.16 to 2.02 ng g(-1) dw, whereas in soil samples ranged from 0.04 to 1.67 ng g(-1) dw for PCBs((Sigma 7)) and 0.04 to 10.7 ng g(-1) dw for PBDEs(Sigma 10). The highest concentrations of both chemicals were detected in the urban and industrial/port areas showing a dominance of the higher chlorinated PCB congeners: in sediments for PCB-180 (56 +/- 33%) and PCB-153 (11 +/- 6%); and in soils for PCB-138 (23 +/- 3%), PCB-153 (22 +/- 2%) and PCB-180 (18 +/- 7%). In contrast, lower chlorinated PCB congeners were predominant at more distant sites; in sediments for congeners PCB-28 (33 +/- 4%) and PCB-52 (14.5 +/- 0.2%); and in soils PCB-28 (56 +/- 14%) and PCB-52 (33 +/- 19%). PBDE-209 (high brominated PBDE) showed the highest relative abundance in both sample types i.e., sediment (94 +/- 7%) and soil (80 +/- 12%). These findings can be considered lower or similar when compared with other sites of the world, and are likely associated with anthropogenic activities in their surrounding area, which has experienced a fast industrial growth in the last decade. This is the first investigation of PBDEs levels in the whole study area and of PCBs in soils from the Bahia Blanca city and surrounding region. This article provides new and useful information on POP levels in the South eastern part of the GRULAC region.

Concentrations of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs) in air and soil, their fugacities, and the experimental soil-air partitioning coefficient (KSA) were determined at two background sites in the Gt. Hungarian Plain in August 2013. The concentrations of the semivolatile organic compounds (SOCs) in the soil were not correlated with the organic carbon content but with two indirect parameters of mineralization and aromaticity, suggesting that soil organic matter quality is an important parameter affecting the sorption of SOCs onto soils. Predictions based on the assumption that absorption is the dominant process were in good agreement with the measurements for PAHs, OCPs, and the low chlorinated PCBs. In general, soils were found to be a source of PAHs, high chlorinated PCBs, the majority of OCPs and PBDEs, and a sink for the low chlorinated PCBs and γ-hexachlorocyclohexane. Diurnal variations in the direction of the soil-air exchange were found for two compounds (i.e., pentachlorobenzene and p,p'-dichlorodiphenyldichloroethane), with volatilization during the day and deposition in the night. The concentrations of most SOCs in the near-ground atmosphere were dominated by revolatilization from the soil.

Near-ground air (26 substances) and surface seawater (55 substances) concentrations of persistent toxic substances (PTS) were determined in July 2012 in a coordinated and coherent way around the Aegean Sea based on passive air (10 sites in 5 areas) and water (4 sites in 2 areas) sampling. The direction of air–sea exchange was determined for 18 PTS. Identical samplers were deployed at all sites and were analysed at one laboratory. hexachlorobenzene (HCB), hexachlorocyclohexanes (HCHs) as well as dichlorodiphenyltrichloroethane (DDT) and its degradation products are evenly distributed in the air of the whole region. Air concentrations of p,p′-dichlorodiphenyldichloroethylene (p,p′-DDE) and o,p′-DDT and seawater concentrations of p,p′-DDE and p,p′-DDD were elevated in Thermaikos Gulf, northwestern Aegean Sea. The polychlorinated biphenyl (PCB) congener pattern in air is identical throughout the region, while polybrominated diphenylether (PBDE)patterns are obviously dissimilar between Greece and Turkey. Various pollutants, polycyclic aromatic hydrocarbons (PAHs), PCBs, DDE, and penta- and hexachlorobenzene are found close to phase equilibrium or net-volatilisational (upward flux), similarly at a remote site (on Crete) and in the more polluted Thermaikos Gulf. The results suggest that effective passive air sampling volumes may not be representative across sites when PAHs significantly partitioning to the particulate phase are included., Granting Agency of the Czech Republic (312334); Czech Ministry of Education (LO1214--LM2011028); European Social Fund (CZ.1.07/2.3.00/30.0037); European Commission FP7 (262254 ACTRIS)

Wide distribution of chlorinated paraffins in the environment has already been demonstrated in several studies; however, information about their levels in the Central Europe is still very limited. First study focused on the SCCP contamination of the Czech aquatic environment have been performed recently, and its results motivated the authors to analyze sediments from a wide set of the Czech rivers in order to obtain more detailed information. Thirty-six sediment samples from eleven rivers and five drainage vents neighboring the chemical factories were analyzed; special attention was paid to the industrial areas. For the first time in the Czech Republic, medium-chain in addition to short-chain chlorinated paraffins were analyzed using GC-ECNI-MS. Chlorinated paraffins were detected in sediment samples on the concentration levels up to 347 ngg(-1) for short-chain chlorinated paraffins, and 5575 ngg(-1) for medium-chain chlorinated paraffins. Average chlorination degree of SCCPs was 65%.

The most commonly used passive air sampler (PAS) (i.e. polyurethane foam (PUF) disk) is cheap, versatile, and capable of accumulating compounds present both in gas and particle phases. Its performance for particle associated compounds is however disputable. In this study, twelve sets of triplicate PUF-PAS were deployed outdoors for exposure periods of 1–12 weeks together with continuously operated active samplers, to characterize sampling efficiency and derive sampling rates (RS) for compounds belonging to 7 SVOC classes (including particle associated compounds). PUF-PAS efficiently and consistently sampled polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs), and eight novel brominated flame retardant (nBFR) compounds. Low accuracy and lack of sensitivity was observed for most polychlorinated dibenzo-p-dioxins/furans PCDD/Fs and polybrominated diphenyl ethers (PBDEs) (under the conditions of this study), with the exception of some congeners which may be used as qualitative markers for their respective classes. Application of compound specific RS was found crucial for all compounds except PCBs. Sampling efficiency of the particle associated compounds was often low.

A 6-month air sampling survey was conducted at 26 sites across the African continent with the aim to establish baseline information on contamination of ambient air with persistent organic pollutants (POPs) as a reference for future monitoring programs in the region. Sampling sites included continental, rural and urban backgrounds, agricultural and industrial sites as well as waste and obsolete pesticide dumps. Concentrations of polycyclic aromatic hydrocarbons, polychlorinated dibenzo-p-dioxins and furans, polychlorinated biphenyls and organochlorine pesticides were low at most of the rural background sites, but they raise some concern in big cities. The large temporal variability in the pesticide concentrations suggested seasonal application of gamma-HCHs and endosulfans; levels of p,p'-DDT were often much higher than those of p,p'-DDE and indicated recent application of DDT.

Central and Eastern Europe is a region that is expected to need more data on the concentrations of persistent organic pollutants (POPs) in the ambient air in the future. Passive air sampling is a cheap screening method for comparison of contamination on various sites or for verification of information obtained by active samplers. Passive air samplers are sensitive enough to mirror even small-scale differences, which makes them capable of monitoring spatial, seasonal, and temporal variations. Different passive air samplers were employed between 1990 and 2013 from time to time in six Estonian air monitoring stations. The concentrations of PCB and its congeners, HCB, PeCB, HCH, and DDT (the same for PBDE, PCN, PCDD/F) in Estonian ambient air were very low, but they allow tracking transboundary air pollution. The main aim of this article is analysis of changes in the ambient air pollution in Estonia during a long period of time (1990-2013). Also, selection of Lahemaa background station for monitoring POPs in the European area is addressed.