Concentrations of organochlorine pesticides, polybrominated diphenyl ethers and perfluorinated compounds in the atmosphere of North Greenland

Suspect and non-target screening of chemicals of emerging Arctic concern in air, biota and human serum

Contaminants of emerging concern receive increasing attention in the Arctic environment. The aim of this study was to screen for chemicals of emerging Arctic concern (CEACs) in different types of Arctic samples including biota, air and human serum. We used a combination of gas chromatography (GC) and liquid chromatography (LC) with high resolution mass spectrometry (HRMS) for suspect and non-target screening (NTS). Suspect screening of 25 CEACs was based on published in-silico approaches for the identification of CEACs and revealed tetrabromophthalic anhydride (TBPA) in pilot whale and air, albeit with low detection frequencies (17 and 33%, respectively). An NTS workflow detected a total of 112 contaminants, i.e. 49, 42, 31 and 30 compounds in pilot whale, ringed seal, air, and human serum respectively at confidence level 2 and 3. Although legacy POPs still dominated the samples, 64 CEACs were tentatively identified and further tentatively assessed for persistence (P), bioaccumulation (B), mobility (M), toxicity (T), and long-range transport potential (LRTP). While four PBT compounds were identified, 37 PMT substances dominated among these 64 contaminants. Our study indicated that many chemicals of potential risk might be present in Arctic samples that would benefit from confirmation and further studies of their transport to and accumulation in the Arctic environment.

Residues of atrazine and diuron in rice straw, soils, and air post herbicide-contaminated straw biomass burning

This study investigates the environmental impact of burning herbicide-contaminated biomass, focusing on atrazine (ATZ) and diuron (DIU) sprayed on rice straw prior to burning. Samples of soil, biomass residues, total suspended particulate (TSP), particulate matter with an aerodynamic diameter ≤ 10 µm (PM10), and aerosols were collected and analyzed. Soil analysis before and after burning contaminated biomass showed significant changes, with 2,4-dichlorophenoxyacetic acid (2,4-D) initially constituting 79.2% and decreasing by 3.3 times post-burning. Atrazine-desethyl, sebuthylazine, and terbuthylazine were detected post-burning. In raw rice straw biomass, terbuthylazine dominated at 80.0%, but burning ATZ-contaminated biomass led to the detection of atrazine-desethyl and notable increases in sebuthylazine and terbuthylazine. Conversely, burning DIU-contaminated biomass resulted in a shift to 2,4-D dominance. Analysis of atmospheric components showed changes in TSP, PM10, and aerosol samples. Linuron in ambient TSP decreased by 1.6 times after burning ATZ-contaminated biomass, while atrazine increased by 2.9 times. Carcinogenic polycyclic aromatic hydrocarbons (PAHs), including benzo[a]anthracene (BaA), benzo[a]pyrene (BaP), and benzo[b]fluoranthene (BbF), increased by approximately 9.9 to 13.9 times after burning ATZ-contaminated biomass. In PM10, BaA and BaP concentrations increased by approximately 11.4 and 19.0 times, respectively, after burning ATZ-contaminated biomass. This study sheds light on the environmental risks posed by burning herbicide-contaminated biomass, emphasizing the need for sustainable agricultural practices and effective waste management. The findings underscore the importance of regulatory measures to mitigate environmental contamination and protect human health.

The Ins and Outs of Per- and Polyfluoroalkyl Substances in the Great Lakes: The Role of Atmospheric Deposition

As part of the Integrated Atmospheric Deposition Network, precipitation (n = 207) and air (n = 60) from five sites and water samples (n = 87) from all five Great Lakes were collected in 2021-2023 and analyzed for 41 per- and polyfluoroalkyl substances (PFAS). These measurements were combined with other available data to estimate the mass budget for four representative compounds, PFBA, PFBS, PFOS, and PFOA for the basin. The median Σ41PFAS concentrations in precipitation across the five sites ranged between 2.4 and 4.5 ng/L. The median Σ41PFAS concentration in lake water was highest in Lake Ontario (11 ng/L) and lowest in Lake Superior (1.3 ng/L). The median Σ41PFAS concentration in air samples was highest in Cleveland at 410 pg/m3 and lowest at Sleeping Bear Dunes at 146 pg/m3. The net mass transfer flows were generally negative for Lakes Superior, Michigan, and Huron and positive for Lakes Erie and Ontario, indicating that the three most northern lakes are accumulating PFAS and the other two are eliminating PFAS. Atmospheric deposition is an important source of PFAS, particularly for Lake Superior.

Nationwide assessment of atmospheric organochlorine pesticides over a decade during 2008-2017 in South Korea

Long-term nationwide atmospheric monitoring of organochlorine pesticides (OCPs) was performed in South Korea during 2008-2017. Their occurrences, seasonal and temporal variability, sources, and effect of ambient temperature were investigated. The OCPs are pronounced with a mean concentration of total OCPs ranging from 5.2 to 256 pg/Sm³. However, a decrease of 54 % was observed in the mean concentration of total OCPs from 2008 to 2017 associated with regulatory actions. OCP concentrations did not show any variations between the different site types, and OCPs were ubiquitously present at all site types. The mean concentration of total OCPs in summer was two-fold higher than in winter. The concentrations of DRINs, DDTs, ENDOs, and HCHs were significantly higher in summer, but the concentrations of chlordane and heptachlor were higher in winter. The diagnostic ratios identified major sources as ongoing sources, past use, and atmospheric transport. Clausius Clapeyron plots strongly suggested the re-emission of α-endosulfan, β-endosulfan, α-HCH, and β-HCH, and ΔH_sa (enthalpy of surface air exchange) values suggested the influence of the transport and/or new sources on aldrin, dieldrin, and chlordane. The occurrence of OCPs due to re-emissions, ongoing sources, and long-range atmospheric transport could be a challenge towards the complete phase-out of OCPs in South Korea.

Per- and polyfluoroalkyl substances and volatile methyl siloxanes in global air: Spatial and temporal trends

The study reports on the atmospheric concentrations of per- and polyfluoroalkyl substances (PFAS) and volatile methyl siloxanes (VMS) measured using sorbent-impregnated polyurethane foam disks (SIPs) passive air samplers. New results are reported for samples collected in 2017, which extends temporal trend information to the period 2009-2017, for 21 sites where SIPs have been deployed since 2009. Among neutral PFAS, fluorotelomer alcohols (FTOHs) had higher concentrations than perfluoroalkane sulfonamides (FOSAs) and perfluoroalkane sulfonamido ethanols (FOSEs) with levels of ND‒228, ND‒15.8, ND‒10.4 pg/m³, respectively. Among ionizable PFAS, the sum of perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs) in air were 0.128-781 and 6.85-124 pg/m³, respectively. Longer-chain i.e. C₉-C₁₄ PFAS, which are relevant to the recent proposal by Canada for a listing of long-chain (C₉-C₂₁) PFCAs to the Stockholm Convention, were also detected in the environment at all site categories including Arctic sites. Cyclic and linear VMS ranged between 1.34‒452 and 0.01-12.1 ng/m³, respectively, showing dominance in urban areas. Despite the wide range of levels observed across different site categories, geometric means of the PFAS and VMS groups were fairly similar when grouped according to the five United Nations regions. Variable temporal trends in air (2009-2017) were observed for both PFAS and VMS. PFOS, which has been listed in the Stockholm Convention since 2009, is still showing increasing tendencies at several sites, indicating constant input from direct and/or indirect sources. These new data inform international chemicals management for PFAS and VMS.

The use of gas chromatography - high resolution mass spectrometry for suspect screening and non-targeted analysis of per- and polyfluoroalkyl substances

This study is a workflow development for the analysis, identification, and categorization of per- and polyfluoroalkyl substances (PFAS) using gas chromatography-high resolution mass spectrometry (GC-HRMS) with non-targeted analysis (NTA) and suspect screening techniques. The behavior of various PFAS in a GC-HRMS was studied with regards to retention indices, ionization susceptibility, fragmentation patterns, etc. A custom PFAS database was constructed from 141 diverse PFAS. The database contains mass spectra from electron ionization (EI) mode, as well as MS and MS/MS spectra from positive and negative chemical ionization (PCI and NCI, respectively) modes. Common fragments of PFAS were identified across a diverse set of 141 PFAS analyzed. A workflow for suspect screening of PFAS and partially fluorinated products of incomplete combustion/destruction (PICs/PIDs) was developed which utilized both the custom PFAS database and external databases. PFAS and other fluorinated compounds were identified in both a challenge sample (designed to test the identification workflow) and incineration samples suspected to contain PFAS and fluorinated PICs/PIDs. The challenge sample resulted in a 100% true positive rate (TPR) for PFAS which were present in the custom PFAS database. Several fluorinated species were tentatively identified in the incineration samples using the developed workflow.

Concentrations and distributions of fluorotelomer alcohols and perfluoroalkane sulfonamido substances in the atmosphere in the Pearl River Delta, China

Per and polyfluoroalkyl substances (PFASs) have attracted major global concerns because some of them are environmentally persistent, bioaccumulative, and toxic. Perfluoroalkyl acids (PFAAs) have been well-characterized in water, soil, and sediment; however, fluorotelomer alcohols and perfluoroalkane sulfonamido substances have been overlooked. In this study, concentrations of three fluorotelomer alcohols and four perfluoroalkane sulfonamido substances were determined in the air at nine locations representing urban, rural-urban transect, and urban areas in the Pearl River Delta region, China to investigate their seasonal and spatial distributions and potential sources. At least two of the targeted PFASs were detected in all air samples in the Pearl River Delta region, with concentrations ranging from 371 pg/sampler to 18700 pg/sampler. Fluorotelomer alcohols were dominant compounds (contributing 46% to the ∑₇PFAS concentration on average) in the atmosphere in the Pearl River Delta region. The total concentrations of the seven targeted PFASs were significantly higher in summer than in other seasons in urban areas. PFAS concentrations were positively related to the population density in the Pearl River Delta region. Local diffusive emission and long range transport could be sources of the seven PFASs in the air in the Pearl River Delta region.

EI/IOT of PFCs: Environmental impacts/interactions, occurrences, and toxicities of perfluorochemicals

Various studies have been conducted on the perfluorochemicals (PFCs) family over the years. These compounds have been sought in various industrial aspects involving the synthesis of everyday utilities due to their broad range of applications. As a result, PFCs have built up in the environment, causing concern. The presence of PFCs in various environmental media, such as terrestrial and marine settings, as well as the mechanisms of transport, bioaccumulation, and physio-chemical interactions of PFCs within plants, aquatic organisms, microplastics, and, ultimately, the human body, are discussed in this review, which draws on a variety of research publications. The interaction of PFCs with proteins, translocation, and adsorption by hydrophobic interactions were observed, and this had an impact on the natural functioning of biological processes, resulting in events such as phylogenic clustering, competitive inhibition, and many others, posing potential hazards to human health and other relevant organisms in the ecosystem. However, further research is needed to have a better knowledge of PFCs and their interactions so that low-cost treatments can be developed to eliminate them. It is therefore, future research should focus on the role of soil matrix as a defensive mechanism for PFCs, as well as the impact of PFC chain length rejection.

Perfluoroalkyl substance pollution: detecting and visualizing emerging trends based on CiteSpace

In recent years, perfluoroalkyl substances (PFASs) have been detected in all kinds of environmental media and can harm animals and human beings. They have attracted the attention of environmental workers worldwide and have become another research hotspot in the field of environment. However, analyses of PFASs have seldom been studied systematically. Therefore, this study summarizes the available data in 6756 publications (2000-2022) using the CiteSpace software to provide insights into the specific characteristics of PFASs and consequently shows global development trends that scientists can use for establishing future research directions. As opposed to traditional review articles by experts, this study provides a new method for quantitatively visualizing information about the development of this field over the past 23 years. Results show that the countries with more research in this field are mainly the USA and China. The research on PFASs is mainly concentrated in environmental sciences and ecology. Zhanyun Wang and Robert C. Buck's research has the highest influence rate in this field, and their research group is worthy of attention. Through the analysis of hot keywords, we conclude that the research hotspots are mainly focused on PFASs' transmission media and pathways, human exposure and the mechanism of toxicity, and degradation and remediation measures. Collectively these results indicate the major themes of PFAS research are as follows: (1) transmission media and pathways, (2) human exposure and the mechanism of toxicity, (3) degradation and remediation measures. This study maps the major research domains of PFAS research; explanations and implications of the findings are discussed; and emerging trends highlighted.

Health-related toxicity of emerging per- and polyfluoroalkyl substances: Comparison to legacy PFOS and PFOA

Per- and polyfluoroalkyl substances (PFAS) are highly persistent, manufactured chemicals used in various manufacturing processes and found in numerous commercial products. With over 9000 compounds belonging to this chemical class, there is increasing concern regarding human exposure to these compounds due to their persistent, bioaccumulative, and toxic nature. Human exposure to PFAS may occur from a variety of exposure sources, including, air, food, indoor dust, soil, water, from the transfer of PFAS from non-stick wrappers to food, use of cosmetics, and other personal care products. This critical review presents recent research on the health-related impacts of PFAS exposure, highlighting compounds other than Perfluorooctanoic acid (PFOA) and Perfluoroctane sulfonate (PFOS) that cause adverse health effects, updates the current state of knowledge on PFAS toxicity, and, where possible, elucidates cause-and-effect relationships. Recent reviews identified that exposure to PFAS was associated with adverse health impacts on female and male fertility, metabolism in pregnancy, endocrine function including pancreatic dysfunction and risk of developing Type 2 diabetes, lipid metabolism and risk of childhood adiposity, hepatic and renal function, immune function, cardiovascular health (atherosclerosis), bone health including risk for dental cavities, osteoporosis, and vitamin D deficiency, neurological function, and risk of developing breast cancer. However, while cause-and-effect relationships for many of these outcomes were not able to be clearly elucidated, it was identified that 1) the evidence derived from both animal models and humans suggested that PFAS may exert harmful impacts on both animals and humans, however extrapolating data from animal to human studies was complicated due to differences in exposure/elimination kinetics, 2) PFAS precursor kinetics and toxicity mechanism data are still limited despite ongoing exposures, and 3) studies in humans, which provide contrasting results require further investigation of the long-term-exposed population to better evaluate the biological toxicity of chronic exposure to PFAS.

Legacy and emerging organic contaminants in the polar regions

The presence of numerous emerging organic contaminants (EOCs) and remobilization of legacy persistent organic pollutants (POPs) in polar regions have become significant concerns of the scientific communities, public groups and stakeholders. This work reviews the occurrences of EOCs and POPs and their long-range environmental transport (LRET) processes via atmosphere and ocean currents from continental sources to polar regions. Concentrations of classic POPs have been systematically monitored in air at several Arctic stations and showed seasonal variations and declining trends. These chemicals were also the major POPs reported in the Antarctica, while their concentrations were lower than those in the Arctic, illustrating the combination of remoteness and lack of potential local sources for the Antarctica. EOCs were investigated in air, water, snow, ice and organisms in the Arctic. Data in the Antarctica are rare. Reemission of legacy POPs and EOCs accumulated in glaciers, sea ice and snow may alter the concentrations and amplify their effects in polar regions. Thus, future research will need to understand the various biogeochemical and geophysical processes under climate change and anthropogenic pressures.

Organophosphate esters in Arctic air from 2011 to 2019: Concentrations, temporal trends, and potential sources

Concentrations of seven organophosphate ethers (OPEs) were quantified in passive air samples deployed for eight consecutive one-year periods from August 2011 to August 2019 at seven sampling sites in the area of Ny-Ålesund, Svalbard, Arctic. Non-chlorinated and chlorinated OPEs were approximately equally abundant and the mean atmospheric concentration for the sum of OPEs was around 300 pg/m³. Levels of OPEs were two orders of magnitude higher than those of polybrominated diphenyl ethers in the sampling regions, likely a result of efficient long-range transport and higher environmental release rates. For the two most abundant compounds, tris(2-chloroethyl) phosphate and tris-n-butyl phosphate, increasing temporal trends in atmospheric concentrations were observed, with estimated doubling times of 2.9 and 4.2 years, respectively. Slightly elevated OPE levels at two sampling sites in the vicinity of a research station and the local airport suggest the possible influence of local contamination sources. Re-volatilization from glaciers may also influence levels of OPE in the Arctic atmosphere.

Assessment of PCBs in Surface Waters at Ultratrace Levels: Traditional Approaches and Biomonitoring (Lake Baikal, Russia)

This article presents the results of the assessment of PCB concentrations in surface waters at ultratrace level of concentrations. The assessment of PCB concentrations is based on data from monitoring PCBs in Baikal water within the conventional approach as well as from biomonitoring of PCBs using Baikal omul, Coregonus migratorius, Georgi, 1775 (C. migratorius), as a bioindicator. The time cycle of the monitoring covered the period from 2014 to 2021. The concentrations of PCBs in the water were estimated from the concentrations of seven indicator congeners: 28, 52, 101, 118, 138, 153, and 180, and from congeners of dioxin-like (dl) PCBs in the tissues of C. migratorius. The average value and the statistically significant range of the detected total concentrations (Ʃ7PCBs) in Baikal water were 0.30 and 0.26–0.34 ng/L, respectively. In the tissues of C. migratorius, the average value and the range of Ʃ7PCB concentrations were 5.6 and 4.9–6.3 ng/g (ww), respectively, and for dl-PCBs, 1.5 and 1.3–1.7 ng/g (ww), respectively. The total toxicity equivalent of the detected dl-PCBs was in the WHO-TEQ (2005) range from 0.03 to 0.06 pg/g (ww). The concentrations of Ʃ7PCBs in Baikal water and dl-PCBs in the tissues of C. migratorius corresponded to the concentration levels in the European alpine lakes and the tissues of S. trutta fish inhabiting these lakes.

PFAS Molecules: A Major Concern for the Human Health and the Environment

Per- and polyfluoroalkyl substances (PFAS) are a group of over 4700 heterogeneous compounds with amphipathic properties and exceptional stability to chemical and thermal degradation. The unique properties of PFAS compounds has been exploited for almost 60 years and has largely contributed to their wide applicability over a vast range of industrial, professional and non-professional uses. However, increasing evidence indicate that these compounds represent also a serious concern for both wildlife and human health as a result of their ubiquitous distribution, their extreme persistence and their bioaccumulative potential. In light of the adverse effects that have been already documented in biota and human populations or that might occur in absence of prompt interventions, the competent authorities in matter of health and environment protection, the industries as well as scientists are cooperating to identify the most appropriate regulatory measures, substitution plans and remediation technologies to mitigate PFAS impacts. In this review, starting from PFAS chemistry, uses and environmental fate, we summarize the current knowledge on PFAS occurrence in different environmental media and their effects on living organisms, with a particular emphasis on humans. Also, we describe present and provisional legislative measures in the European Union framework strategy to regulate PFAS manufacture, import and use as well as some of the most promising treatment technologies designed to remediate PFAS contamination in different environmental compartments.

Prenatal exposure to persistent organic pollutants and metals and problematic child behavior at 3-5 years of age: a Greenlandic cohort study

High levels of persistent organic pollutants (POPs) and heavy metals are found in Arctic populations. POP and heavy metals are linked to impaired cognitive development. This study examined associations between prenatal POP and metals exposure and problematic child behavior using the Strength and Difficulties Questionnaire (SDQ). POPs and metals were measured in 102 pregnant Greenlandic women. During follow-up at 3–5 years, parents answered an assisted questionnaire including children’s SDQ scores. Associations were analyzed using linear and logistic regression analyses and adjusted for maternal plasma cotinine, educational level and age at delivery. In the adjusted analyses, the medium tertile of hexachlorobenzene (β = 3.06, p = 0.010), β-hexachlorocyclohexane (β = 3.58, p = 0.004) and trans-nonachlor (β = 2.06, p = 0.082) were positively associated with SDQ scores. The continuous cis-nonachlor (OR = 1.09, p = 0.079), dichloro-diphenyl-dichloroethylene (OR = 1.01, p = 0.077), trans-nonachlor (OR = 1.01, p = 0.091), and sum Organochlorine-Pesticides (OR = 1.00, p = 0.094) were positively associated with abnormal SDQ score and the continuous mirex (OR = 1.28, p = 0.096), oxychlordane (OR = 1.04, p = 0.066), and trans-nonachlor (OR = 1.02, p = 0.071) with abnormal hyperactivity score. We found no consistent evidence of associations between polychlorinated biphenyls, perfluoroalkylated substances and heavy metals and problematic behavior. Prenatal organochlorine pesticide exposure associated significantly with problematic behavior in 3–5 year old children.

Chemical hazard in glacial melt? The glacial system as a secondary source of POPs (in the Northern Hemisphere). A systematic review

Toxicity of compounds belonging to persistent organic pollutants (POPs) is widely known, and their re-emission from glaciers has been conclusively demonstrated. However, the harmful effects associated with such secondary emissions have yet to be thoroughly understood, especially in the spatial and temporal context, as the existing literature has a clear sampling bias with the best recognition of sites in the European Alps. In this review, we elaborated on the hazards associated with the rapid melting of glaciers releasing organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and polycyclic aromatic hydrocarbons (PAHs). To this end, we collated knowledge on: (1) the varying glacier melt rate across the Northern Hemisphere, (2) the content of POPs in the glacial system components, including the less represented areas, (3) the mechanisms of POPs transfer through the glacial system, including the importance of immediate emission from snow melt, (4) risk assessment associated with POPs re-emission. Based on the limited existing information, the health risk of drinking glacial water can be considered negligible, but consuming aquatic organisms from these waters may increase the risk of cancer. Remoteness from emission sources is a leading factor in the presence of such risk, yet the Arctic is likely to be more exposed to it in the future due to large-scale processes shifting atmospheric pollution and the continuous supply of snow. For future risk monitoring, we recommend to explore the synergistic toxic effects of multiple contaminants and fill the gaps in the spatial distribution of data.

Time trends of persistent organic pollutants (POPs) and Chemicals of Emerging Arctic Concern (CEAC) in Arctic air from 25 years of monitoring

The long-term time trends of atmospheric pollutants at eight Arctic monitoring stations are reported. The work was conducted under the Arctic Monitoring and Assessment Programme (AMAP) of the Arctic Council. The monitoring stations were: Alert, Canada; Zeppelin, Svalbard; Stórhöfði, Iceland; Pallas, Finland; Andøya, Norway; Villum Research Station, Greenland; Tiksi and Amderma, Russia. Persistent organic pollutants (POPs) such as α- and γ-hexachlorocyclohexane (HCH), polychlorinated biphenyls (PCBs), α-endosulfan, chlordane, dichlorodiphenyltrichloroethane (DDT) and polybrominated diphenyl ethers (PBDEs) showed declining trends in air at all stations. However, hexachlorobenzene (HCB), one of the initial twelve POPs listed in the Stockholm Convention in 2004, showed either increasing or non-changing trends at the stations. Many POPs demonstrated seasonality but the patterns were not consistent among the chemicals and stations. Some chemicals showed winter minimum and summer maximum concentrations at one station but not another, and vice versa. The ratios of chlordane isomers and DDT species showed that they were aged residues. Time trends of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) were showing decreasing concentrations at Alert, Zeppelin and Andøya. The Chemicals of Emerging Arctic Concern (CEAC) were either showing stable or increasing trends. These include methoxychlor, perfluorohexane sulfonic acid (PFHxS), 6:2 fluorotelomer alcohol, and C₉-C₁₁ perfluorocarboxylic acids (PFCAs). We have demonstrated the importance of monitoring CEAC before they are being regulated because model calculations to predict their transport mechanisms and fate cannot be made due to the lack of emission inventories. We should maintain long-term monitoring programmes with consistent data quality in order to evaluate the effectiveness of chemical control efforts taken by countries worldwide.

Occurrence and seasonal distribution of legacy and emerging per- and polyfluoroalkyl substances (PFASs) in different environmental compartments from areas around ski resorts in northern China

Skiing is an important direct input route of per- and polyfluoroalkyl substances (PFASs) to the environment. However, there has been no study on the occurrence of PFASs in Chinese ski area. In this study, 27 neutral PFASs (n-PFASs) and ionic PFASs (i-PFASs), including 4 emerging PFASs, were analyzed in the multimedia samples collected from areas around six ski resorts in Zhangjiakou and Shenyang to investigate the occurrence and seasonal distribution of PFASs. Both i-PFASs and n-PFASs were found in the air (13.2 ± 9.5 pg/m³ and 167 ± 173 pg/m³, respectively) and pine needles [1.44 ± 0.96 ng/g dry weight (dw) and 0.983 ± 0.590 ng/g dw], whereas only i-PFASs were found in the soil (0.755 ± 0.281 ng/g dw) and snow (3.30 ± 2.66 ng/kg). i-PFASs were significantly higher in samples collected around ski resorts than those from rural sites (n = 105, p < 0.05). Significantly higher perfluorooctanoate concentrations were found in the air around the ski resorts in winter (n = 33, p < 0.05). The i-PFASs were stable in the needle, and the short-chain PFASs in the needle could be ascribed to both air and root uptake. More attention should be paid to PFASs emissions in Zhangjiakou with the approaching 2022 Winter Olympic Games.

Atmospheric concentrations and temporal trends of polychlorinated biphenyls and organochlorine pesticides in the Arctic during 2011-2018

Passive air samples were deployed in Ny-Ålesund and London Island (Svalbard, High Arctic) annually for seven years (2011-2018) to investigate concentrations, temporal trends and potential sources of selected persistent organic pollutants (POPs). Nine polychlorinated biphenyls and twelve organochlorine pesticides were detected in all samples, with 3,3'-dichlorobiphenyl (PCB-11) being the prevalent congener. Concentrations of most compounds were declining. The ratio of the α- and γ-isomer of hexachlorocyclohexane (HCH) in Arctic air was comparable with that in technical HCH mixtures, but higher than that in the atmosphere of other countries, thereby indicating the impact of historical use as well as the possible photoisomerization of the γ- into the α-isomer. The parent dichlorodiphenyltrichloroethane (DDT) was always less abundant than its degradation products dichlorodiphenylethylene (DDE), indicative of the impact of aged DDT sources in the Arctic atmosphere. However, o,p'-/p,p'-DDT ratios suggest only a minor contribution of dicofol-type DDT. A slightly declining temporal trend of the trans-chlordane/cis-chlordane ratio indicated the impact of secondary sources. The atmospheric distribution of the investigated POPs in the Arctic was mainly attributed to long-range atmospheric transport, whereas the influence of human activities from the scientific research stations was minor.

Current Contributions of Organofluorine Compounds to the Agrochemical Industry

Currently, more than 1,200 agrochemicals are listed and many of these are regularly used by farmers to generate the food supply to support the expanding global population. However, resistance to pesticides is an ever more frequently occurring phenomenon, and thus, a continuous supply of novel agrochemicals with high efficiency, selectivity, and low toxicity is required. Moreover, the demand for a more sustainable society, by reducing the risk chemicals pose to human health and by minimizing their environmental footprint, renders the development of novel agrochemicals an ever more challenging undertaking. In the last two decades, fluoro-chemicals have been associated with significant advances in the agrochemical development process. We herein analyze the contribution that organofluorine compounds make to the agrochemical industry. Our database covers 424 fluoro-agrochemicals and is subdivided into several categories including chemotypes, mode of action, heterocycles, and chirality. This in-depth analysis reveals the unique relationship between fluorine and agrochemicals.

Mining the effect of the neonicotinoids imidacloprid and clothianidin on the chemical homeostasis and energy equilibrium of primary mouse neural stem/progenitor cells using metabolomics

The projection of plant protection products' (PPPs) toxicity to non-target organisms at early stages of their development is challenging and demanding. Recent developments in bioanalytics, however, have facilitated the study of fluctuations in the metabolism of biological systems in response to treatments with bioactives and the discovery of corresponding toxicity biomarkers. Neonicotinoids are improved insecticides that target nicotinic acetylocholine receptors (nAChR) in insects which are similar to mammals. Nonetheless, they have sparked controversy due to effects on non-target organisms. Within this context, mammalian cell cultures represent ideal systems for the development of robust models for the dissection of PPPs' toxicity. Thus, we have investigated the toxicity of imidacloprid, clothianidin, and their mixture on primary mouse (Mus musculus) neural stem/progenitor (NSPCs) and mouse neuroblastoma-derived Neuro-2a (N2a) cells, and the undergoing metabolic changes applying metabolomics. Results revealed that NSPCs, which in vitro resemble those that reside in the postnatal and adult central nervous system, are five to seven-fold more sensitive than N2a to the applied insecticides. The energy equilibrium of NSPCs was substantially altered, as it is indicated by fluctuations of metabolites involved in energy production (e.g. glucose, lactate), Krebs cycle intermediates, and fatty acids, which are important components of cell membranes. Such evidence plausibly suggests a switch of cells' energy-producing mechanism to the direct metabolism of glucose to lactate in response to insecticides. The developed pipeline could be further exploited in the discovery of unintended effects of PPPs at early steps of development and for regulatory purposes.

Atmospheric Deposition of Organochlorine Pesticides and Industrial Compounds to Seasonal Surface Snow at Four Glacier Sites on Svalbard, 2013-2014

Winter snow from four glacial sites on Svalbard was analyzed for atmospheric deposition of 36 organochlorine pesticides (OCPs) and 7 industrial compounds (OCICs) by GC-high-resolution MS. Thirteen of the OCPs and all OCICs were detected at all sites. Sampling sites are 230 km apart from west to east, but are at varying elevations, ranging from 700 to 1202 m a.s.l. Total OCP flux was greater than total OCIC at all sites and was 5 times greater at Lomonosovfonna, and 3 times greater at Austfonna, the most easterly site. Chlorpyrifos dominated OCP flux at Lomonosovfonna (81.7 pg cm^-2 yr^-1) and Kongsvegen (60.6 pg cm^-2 yr^-1), and at Austfonna, but not at Holtedahlfonna where dieldrin dominated. trans-chlordane was a major contributor to OCPs. These three pesticides comprised at least 50% of total OCP at each site. OCIC flux was dominated by pentachloroanisole (PCA) at Lomonosovfonna (23.5 pg cm^-2 yr^-1) and Kongsvegen (14.1 pg cm^-2 yr^-1). PCA and hexachlorobenzene comprised at least 63% of all OCICs at each site. Air mass frequency from likely source areas showed that Austfonna had the most frequent long-distance air flow, but showed lower amounts of chlorpyrifos and PCA, suggesting local sources of these compounds to other sites.

Concentrations and distributions of polybrominated diphenyl ethers (PBDEs) in surface soils and tree bark in Inner Mongolia, northern China, and the risks posed to humans

Three functional zones, namely the industrial (IND), the agricultural (AGR), and the grassland (GRA) areas from Inner Mongolia (a remote province in northern China), were selected to evaluate the levels and distributions of PBDEs and the risks posed to local humans. PBDEs concentrations in surface soils and tree bark were detected and the air levels were estimated based on bark measurements. The total concentrations (∑₈PBDEs) of BDE-28, -47, -100, -99, -154, -153, -183, and -209 in soils were 1.71-64.9 ng/g dry weight (d.w.), 0.720-4.08 ng/g d.w., and 0.604-3.76 ng/g d.w. in the IND, AGR and GRA areas respectively. The average total concentrations in bark and air were 0.792 ng/g d.w. and 0.125 ng/m³ in the AGR areas respectively, which were lower than those (1.69 ng/g d.w. in the bark and 0.476 ng/m³ in the air) in the IND areas. BDE-209 was the dominant congener, consistent with DeBDE being the dominant commercial products used in China. However, except for BDE-209, BDE-28 and BDE-47 in the AGR and GRA areas averagely contributed about half of the total PBDEs concentrations in soils. BDE-28 concentrations in the bark samples of the AGR areas were significantly higher (p < 0.05) than in the IND areas, and the average total hazard quotients (∑₈PBDEs) were higher for humans in the AGR areas (0.12) than in the IND areas (0.08). Degradation of higher-brominated congeners (e.g., BDE-209) and migration of lower-brominated congeners (mainly BDE-28 and BDE-47) may increase the risks to humans in pristine areas.

Immobilization of fluoride in the sediment of mine drainage stream using loess, Northwest China

Fluoride (F) is a necessary trace element in the human body, which would lead to some diseases if human body lacks or accumulates it excessively (1-1.5 mg d^-1). Fluoride contamination in sediments has become more and more serious, which has potential hazards to human body. In this paper, a novel sorbent (loess) was proposed to immobilize trace element F in sediment. The effectiveness of loess on F stabilization was evaluated by decreasing F bioavailability in contaminated sediment. The loess and the sediment were mixed at different proportions for stabilization. About 70 days after the application of loess, the soil column was subject to simulate acid rain leaching test to observe the leaching-migration of F, which can be used to predict the leaching migration of F in the study area. The results showed that when the loess dose was 5 kg, the loess converted highly effective fractions of F (i.e., water-soluble and exchangeable fractions) into a more stable state (i.e., residual state). After 30 days of leaching with HNO₃ solution with pH at 3.0, the lowest concentration of F was found in the leachate of soil column with 2 kg loess application. Correlation analysis showed that the F concentration in soil column profile was affected by CaCO₃, EC, pH, and OM, of which, pH and CaCO₃ have greater influence than other factors.

White-Tailed Eagle (Haliaeetus albicilla) Body Feathers Document Spatiotemporal Trends of Perfluoroalkyl Substances in the Northern Environment

We reconstructed the first long-term (1968-2015) spatiotemporal trends of perfluoroalkyl substances (PFAS) using archived body feathers of white-tailed eagles (Haliaeetus albicilla) from the West Greenland (n = 31), Norwegian (n = 66), and Central Swedish Baltic coasts (n = 50). We observed significant temporal trends of perfluorooctane sulfonamide (FOSA), perfluorooctane sulfonate (PFOS), and perfluoroalkyl carboxylates (∑PFCAs) in all three subpopulations. Concentrations of FOSA and PFOS had started decreasing significantly since the mid-1990s to 2000 in the Greenland and Norwegian subpopulations, consistent with the 3M phase-out, though in sharp contrast to overall increasing trends observed in the Swedish subpopulation. Moreover, ∑PFCA concentrations significantly increased in all three subpopulations throughout the study periods. These temporal trends suggest on-going input of PFOS in the Baltic and of ∑PFCAs in all three regions. Considerable spatial variation in PFAS concentrations and profiles was observed: PFOS concentrations were significantly higher in Sweden, whereas FOSA and ∑PFCA concentrations were similar among the subpopulations. PFOS dominated the PFAS profiles in the Swedish and Norwegian subpopulations, in contrast to the domination of FOSA and ∑PFCAs in the Greenland one. Our spatiotemporal observations underline the usefulness of archived bird of prey feathers in monitoring spatiotemporal PFAS trends and urge for continued monitoring efforts in each of the studied subpopulations.

Characteristic and human exposure risk assessment of per- and polyfluoroalkyl substances: A study based on indoor dust and drinking water in China

Per- and polyfluoroalkyl Substances (PFAS) are ubiquitous in the environmental matrix, and their eco-toxicity on wide life and health risks on humans arising concerns. Due to the information gap, current risk assessments of PFAS ignore the indoor exposure pathway such as indoor dust and the different sources of drinking water. We collected and analyzed 168 indoor dust and 27 drinking water samples (including tap water, filtered water and bottled water). The mean concentrations of six typical PFAS measured in indoor dust and drinking water are in the range of 15.13-491.07 ng g^-1 and 0.31-4.14 ng L^-1, respectively. For drinking water, PFOA and PFOS were the dominant compounds, while PFHxS was the most abundant in indoor dust. Short-chain PFAS concentrations were higher than long-chain PFAS in both drinking water and indoor dust. Higher concentration of PFAS was observed in tap water and filtered water than bottled water. The total daily intake (TDI) of six PFAS are 20.67-52.97 ng kg^-1 d^-1 for infants, children, teenagers, and adults. As to children, teenagers, and adults, perfluorooctanoate (PFOA) is the major compound, accounting for 72.9-74.7% of the total daily intake. And PFOA (38.7%) and perfluorooctane sulfonate (PFOS, 42.2%) are the dominant PFAS for infants. The quantitative proportions of exposure sources are firstly revealed in this study, which in the order of foodstuff > indoor dust > drinking water > indoor air. Although the contribution to the PFAS intake of drinking water and indoor dust was not predominant (<9%), the health risks caused by long-term exposure need our attention. The hazard quotient (HQ) values of total PFAS were in the range of 0.154-0.498, which suggesting the relatively lower exposure risk in Chinese population. This study provides important reference to understand PFAS exposure status other than foodstuff.

Neutral polyfluoroalkyl and perfluoroalkyl substances in surface water and sediment from the Haihe River and Dagu Drainage Canal deserve more attention

Neutral polyfluoroalkyl and perfluoroalkyl substances (nPFASs) were detected in the surface water and sediment from the Haihe River (HR) and Dagu Drainage Canal (DDC), Tianjin, China. N-methyl perfluorooctane sulfonamide ethanol (MeFOSE) and N-ethyl perfluorooctane sulfonamide ethanol (EtFOSE) were the predominant nPFASs in surface water and sediment, which was different from the composition in air. The concentrations of ΣnPFASs in water from the HR (1.88-8.21 ng/L) were lower than those from the DDC (3.72-11.32 ng/L). Concentrations of ΣnPFASs were higher in the middle of the HR in the Dongli District due to industrial activity, whereas at lower reaches of the DDC, high ΣnPFAS concentrations might be due to effluent from wastewater treatment plants (WWTPs). The detection frequency in sediment (13.5%) was less than that in water (83%). The concentrations in sediment from the DDC (below limit of qualification (LOQ) to 5.58 ng/g) were higher than those from the HR (below LOQ to 2.46 ng/g). The distribution coefficient (log K_D) between water and sediment was calculated, and they were highly related to the compound structures. The contribution of nPFASs to nPFASs+PFAAs was up to 52% in sediment in the DDC, suggesting the importance of nPFASs in aquatic systems.

The occurrence of polybrominated diphenyl ether (PBDE) contamination in soil, water/sediment, and air

As a kind of brominated flame retardants (BFRs), polybrominated diphenyl ethers (PBDEs) are extensively used in different types of electronic equipment, furniture, plastics, and textiles. PBDEs are ubiquitous environmental contaminants that may impact human health and ecosystems. Here we highlight recent findings on the occurrence, contamination status, and transport of PBDEs in soil, water/sediment, and air. Four aspects are discussed in detail: (1) sources of PBDEs to the environment; (2) occurrence and transport of PBDEs in soil; (3) PBDEs in aquatic ecosystems (water/sediment) and their water-sediment partitioning; and (4) the occurrence of PBDEs in the atmosphere and their gas-particle partitioning. Future prospects for the investigation on PBDEs occurrence are also discussed based on current scientific and practical needs.

Characterization of Tibetan Soil As a Source or Sink of Atmospheric Persistent Organic Pollutants: Seasonal Shift and Impact of Global Warming

Background soils are reservoirs of persistent organic pollutants (POPs). After decades of reduced primary emissions, it is now possible that the POPs contained in these reservoirs are being remobilized because of climate warming. However, a comprehensive investigation into the remobilization of POPs from background soil on the largest and highest plateau on Earth, the Tibetan Plateau (TP), is lacking. In this study, a sampling campaign was carried out on the TP at three background sites with different land cover types (forest, meadow and desert). Field measurements of the air-soil exchange of POPs showed that previous prediction using empirical models overestimated the values of the soil-air partitioning coefficient ( K_SA), especially for chemicals with K_OA > 9. The direction of exchange for γ-HCH, HCB, and PCB-28 overlapped with the air-soil equilibrium range, but with a tendency for volatilization. Their emission fluxes were 720, 2935, and 538 pg m^-2 day^-1, respectively, and were similar in extent to those observed for background Arctic soil in Norway. Nam Co and Ngari are also permafrost regions, and most chemicals at these two sites exhibited volatilization. This is the first result showing that permafrost can also emit POPs. Seasonally, we found that chemicals tended to be re-emitted from soils to the atmosphere in winter and deposited from the air to the soil in summer. This finding is opposite to most previous results, possibly because of the higher air-soil concentration gradient caused by the prevailing transport of POPs in summer. Climate warming exerts a strong influence on air-soil exchange, with an increase of 1 °C in ambient temperature likely leading to an increase of Tibetan atmospheric inventories of POPs by 60-400%.

Pregnant Inuit Women's Exposure to Metals and Association with Fetal Growth Outcomes: ACCEPT 2010⁻2015

Environmental contaminants such as heavy metals are transported to the Arctic regions via atmospheric and ocean currents and enter the Arctic food web. Exposure is an important risk factor for health and can lead to increased risk of a variety of diseases. This study investigated the association between pregnant women's levels of heavy and essential metals and the birth outcomes of the newborn child. This cross-sectional study is part of the ACCEPT birth cohort (Adaption to Climate Change, Environmental Pollution, and dietary Transition) and included 509 pregnant Inuit women ≥18 years of age. Data were collected in five Greenlandic regions during 2010⁻2015. Population characteristics and birth outcomes were obtained from medical records and midwives, respectively, and blood samples were analyzed for 13 metals. Statistical analysis included one-way ANOVA, Spearman's rho, and multiple linear and logistic regression analyses. The proportion of current smokers was 35.8%. The levels of cadmium, chromium, and nickel were higher compared to reported normal ranges. Significant regional differences were observed for several metals, smoking, and parity. Cadmium and copper were significantly inversely related to birth outcomes. Heavy metals in maternal blood can adversely influence fetal development and growth in a dose⁻response relationship. Diet and lifestyle factors are important sources of toxic heavy metals and deviant levels of essential metals. The high frequency of smokers in early pregnancy is of concern, and prenatal exposure to heavy metals and other environmental contaminants in the Greenlandic Inuit needs further research.

Concentrations and variability of organophosphate esters, halogenated flame retardants, and polybrominated diphenyl ethers in indoor and outdoor air in Stockholm, Sweden

We investigated the concentrations and temporal variability of organophospate esters (OPEs), halogenated flame retardants (HFRs) and polybrominated diphenyl ethers (PBDEs) in indoor and outdoor urban air in Stockholm, Sweden over one year (2014-2015) period. The median concentrations of the three target chemical groups (OPEs, HFRs, PBDEs) were 1-2 orders of magnitude higher in indoor air than outdoor urban air. OPEs were the most abundant target FRs with median concentrations in indoor (Σ₁₀OPE = 340 000 pg/m³) and outdoor urban (Σ₁₀OPEs = 3100 pg/m³) air, being 3 orders of magnitude greater than for HFRs in indoor (Σ₁₅HFRs = 120 pg/m³) and outdoor urban (Σ₁₅HFRs = 1.6 pg/m³) air. In indoor air, PBDE concentrations (Σ₁₇PBDEs = 33 pg/m³) were lower than for the HFRs, but in outdoor urban air, concentrations (Σ₁₇PBDEs = 1.1 pg/m³) were similar to HFRs. The most abundant OPEs in both the indoor and outdoor urban air were tris(2-butoxyethyl)phosphate (TBOEP), tris(chloroisopropyl)phosphate (TCIPP), tris(2-chloroethyl)phosphate (TCEP), tri-n-butyl-phosphate (TnBP), triphenyl phosphate (TPhP) and tris(1,3-dichloroisopropyl)phosphate (TDCIPP). TCIPP in indoor air was found in the highest concentrations and showed the greatest temporal variability, which ranged from 85 000 to 1 900 000 pg/m³ during the one-year sampling period. We speculate that activities in the building, e.g. floor cleaning, polishing, construction, introduction of new electronics and changes in ventilation rate could explain its variation. Some OPEs (TnBP, TCEP, TCIPP, TDCIPP and TPhP), HFRs/PBDEs (pentabromotoluene, 2, 3-dibromopropyl 2, 4, 6-tribromophenyl ether, hexabromobenzene, BDE-28, -47, and -99) in outdoor urban air showed seasonality, with increased concentrations during the warm period (p < 0.05, Pearson's r ranged from -0.45 to -0.91). The observed seasonality for OPEs was probably due to changes in primary emission, and those for the HFRs and PBDEs was likely due to re-volatilization from contaminated surfaces.

Atmospheric concentrations and trends of poly- and perfluoroalkyl substances (PFAS) and volatile methyl siloxanes (VMS) over 7 years of sampling in the Global Atmospheric Passive Sampling (GAPS) network

Poly- and per-fluoroalkyl substances (PFAS) and volatile methyl siloxanes (VMS) were monitored at 21 sites in the Global Atmospheric Passive Sampling (GAPS) Network. Atmospheric concentrations previously reported from 2009 were compared to concentrations measured at these sites in 2013 and 2015, to assess trends over 7 years of monitoring. Concentrations of the fluorotelomer alcohols (FTOHs) and fluorinated sulfonamides and sulfonamidoethanols (FOSAs and FOSEs) were stable at these sites from 2009 to 2015 with no significant difference (p > 0.05) in concentrations. Elevated concentrations of all the neutral PFAS were detected at the urban sites as compared to the polar/background sites. The perfluorosulfonic acids (PFSAs), meanwhile, saw a significant increase (p < 0.001) in concentrations from 2009 to 2015. The perfluorocarboxylic acids (PFCAs) had elevated concentrations in 2015, however, the difference was not statistically significant (p > 0.05). Concentrations of the PFSAs and the PFCAs were similar at all location types, showing the global reach of these persistent compounds. Concentrations of the cyclic VMS (cVMS) were at least an order of magnitude higher than the linear VMS (lVMS) and the PFAS. Octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6) saw a weak significant increase in concentrations from 2009 to 2013 (p < 0.05), however, hexamethylcyclotrisiloxane (D3) had a strong significant decrease in concentrations from 2009 to 2015 (p < 0.01).

Emerging contaminants related to the occurrence of forest fires in the Spanish Mediterranean

Forest fires can be a source of contamination because, among others, of the use of chemicals to their extinction (flame retardants, FRs), or by the production of Polycyclic Aromatic Hydrocarbons (PAHs) derived from high temperature alteration of organic matter. Up to our knowledge, this study is the first to assess the direct (PAHs 16 on the USA EPA's priority list), and indirect [tri- to hepta- brominated diphenyl ethers (PBDEs), organophosphorus flame retardants (PFRs) and perfluoroalkyl substances (PFASs)] contamination related to forest fires. The abundance and distribution of these contaminants were monitored on two Mediterranean hillslopes, one burned and one unburned, near Azuébar (SE Spain). Samples were taken in the foot, middle, and top of the slope, at two depths, and in two environments (under canopy and bare soil). Sediments were collected from sediment fences after erosive rainfall events. Most of the screened compounds were found in both, burned and control hillslopes, though significant differences were found between both. In burned soil, low concentrations of PBDEs (maximum ΣPBDEs: 7.3ngg^-1), PFRs (664.4ngg^-1) and PFASs (56.4ngg^-1) were detected in relation to PAHs (Σ16 PAHs=1255.3ngg^-1). No significant influence of the hillslope position was observed for any of the contaminants but differences based on depth and vegetation presence tended to be significant, particularly for the PAHs. After the first erosive event, concentrations of PBDEs and PAHs were higher in sediment than in soil (ΣPBDEs: 17.8ngg^-1 and Σ16 PAHs=3154.2ngg^-1) pointing out the importance of connectivity processes, especially shortly after fire.

Airborne persistent toxic substances (PTSs) in China: occurrence and its implication associated with air pollution

In recent years, China suffered from extensive air pollution due to the rapidly expanding economic and industrial developments. Its severe impact on human health has raised great concern currently. Persistent toxic substances (PTSs), a large group of environmental pollutants, have also received much attention due to their adverse effects on both the ecosystem and public health. However, limited studies have been conducted to reveal the airborne PTSs associated with air pollution at the national scale in China. In this review, we summarized the occurrence and variation of airborne PTSs in China, especially in megacities. These PTSs included polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), halogenated flame retardants (HFRs), perfluorinated compounds (PFCs), organochlorine pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs) and heavy metals. The implication of their occurrence associated with air pollution was discussed, and the emission source of these chemicals was concluded. Most reviewed studies have been conducted in east and south China with more developed economy and industry. Severe contamination of airborne PTSs generally occurred in megacities with large populations, such as Guangzhou, Shanghai and Beijing. However, the summarized results suggested that industrial production and product consumption are the major sources of most PTSs in the urban environment, while unintentional emission during anthropogenic activities is an important contributor to airborne PTSs. It is important that fine particles serve as a major carrier of most airborne PTSs, which facilitates the long-range atmospheric transport (LRAT) of PTSs, and therefore, increases the exposure risk of the human body to these pollutants. This implied that not only the concentration and chemical composition of fine particles but also the absorbed PTSs are of particular concern when air pollution occurs.

Spring Melt and the Redistribution of Organochlorine Pesticides in the Sea-Ice Environment: A Comparative Study between Arctic and Antarctic Regions

Complementary sampling of air, snow, sea-ice, and seawater for a range of organochlorine pesticides (OCPs) was undertaken through the early stages of respective spring sea-ice melting at coastal sites in northeast Greenland and eastern Antarctica to investigate OCP concentrations and redistribution during this time. Mean concentrations in seawater, sea-ice and snow were generally greater at the Arctic site. For example, α-HCH was found to have the largest concentrations of all analytes in Arctic seawater and sea-ice meltwater samples (224-253 and 34.7-48.2 pg·L^-1 respectively compared to 1.0-1.3 and <0.63 pg·L^-1 respectively for Antarctic samples). Differences in atmospheric samples were generally not as pronounced however. Findings suggest that sea-ice OCP burdens originate from both snow and seawater. The distribution profile between seawater and sea-ice showed a compound-dependency for Arctic samples not evident with those from the Antarctic, possibly due to full submersion of sea-ice at the former. Seasonal sea-ice melt processes may alter the exchange rates of selected OCPs between air and seawater, but are not expected to reverse their direction, which fugacity modeling indicates is volatilisation in the Arctic and net deposition in the Antarctic. These predictions are consistent with the limited current observations.

Chlorinated pesticides and natural brominated anisoles in air at three northern Baltic stations

Polyurethane foam (PUF) disk passive samplers were deployed at one inland and two island locations in the Bothnian Bay region of the northern Baltic Sea. Uptake was linear over 81-147 d and a temperature range of -2.6 to 14.2 °C for organochlorine pesticides (OCPs) and current-use pesticides (CUPs) having log K_OA ≥9 at ambient temperatures. Partial saturation of the PUF disks occurred for the more volatile OCPs hexachlorocyclohexanes (HCHs) and hexachlorobenzene (HCB), and for bromoanisoles (BAs), which are products of bromophenols released by natural and anthropogenic sources. Correction for nonlinear uptake of these was made using experimentally measured PUF-air partition coefficients. Passive-derived air concentrations of pesticides were uniform over the bay and agreed within a factor of 2 or better with levels determined by active (pumped) sampling at one of the island stations. Levels of OCPs were similar to those reported at background sites in the European and Canadian Arctic and at monitoring stations in the central Baltic and southern Scandinavia, indicating long-range transport. The insecticide chlorpyrifos was 10 times lower at bay stations than in the Canadian Arctic. Insight to sources and processes was gained by examining compound profiles. Fractions F_alpha = α-HCH/(α-HCH + γ-HCH) and F_TC = trans-chlordane/(trans-chlordane + cis-chlordane) at bay stations were higher than in the Norwegian and Finnish Arctic and similar to those at the southern monitoring stations. Volatilization of chlordanes from Baltic seawater may also modify F_TC. Higher F_TriBA = 2,4,6-TriBA/(2,4,6-TriBA + 2,4-DiBA) distinguished local volatilization from the Baltic Sea versus lower F_TriBA found at the inland site and reported in air on the Norwegian coast, suggesting westerly transport from the Atlantic across Norway and Sweden.

Pesticides in fine airborne particles: from a green analysis method to atmospheric characterization and risk assessment

The intensive use of pesticides such as herbicides, insecticides, fungicides and acaricides has been lead to ubiquitous contamination, being present not only in soils, water bodies and/or crops, but also in the atmosphere. Considering the massive amount of pesticides employed globally, together to their persistence, this may be an important concern regarding air quality and human health worldwide. In the present study we developed a green sensitive sample preparation method for determination of nine organophosphates, two pyrethroids, one carbamate, and one strobirulin in PM2.5 collected in a tropical coastal area in the Southern Hemisphere for the first time. Extraction of PM2.5 sample masses, as low as 206 µg, were performed in a miniaturized device using 500 μL of a mixture containing 18% acetonitrile in dichloromethane followed by sonication for 23 minutes and injection into GC-MS. A total of 12 pesticides were identified and quantified successfully, among them, eight banned pesticides. A risk assessment exposure and cancer risk for possible carcinogenic pesticides (bifenthrin, malathion, parathion and permethrin) were performed for exposure of adults, children and infants. Hazard Quotient and cumulative exposure for organophosphate and pyrethroid pesticides were less than 1, showing that cumulative risk is within acceptable range.

High levels of PFOS in eggs of three bird species in the neighbourhood of a fluoro-chemical plant

We studied perfluorooctane sulfonate (PFOS) levels in the eggs of three primarily invertivorous bird species sampled in 2006 near a fluoro-chemical plant: the great tit (Parus major), the northern lapwing (Vanellus vanellus) and the Mediterranean gull (Larus melanocephalus). Our study reported some of the highest PFOS levels ever measured in wildlife to date (i.e. up to 46182ng/g ww in lapwing eggs). A pronounced decrease in PFOS concentration in the Northern lapwing eggs with distance from the fluoro-chemical plant was found. A similar relationship was found for the great tit, with eggs being collected close to the fluoro-chemical plant having significantly higher PFOS levels than eggs collected 1700m further away. When comparing the PFOS levels in eggs for the three species, collected between 1700 and 5500m no significant differences were observed. In addition, when comparing PFOS levels in eggs between Northern lapwing and great tits closer to the plant (900-1700m) no significant differences were found neither. Despite the high levels found in great tit eggs, plasmatic biochemical biomarker responses did not appear to be affected.

Toward a Comprehensive Global Emission Inventory of C4-C10 Perfluoroalkanesulfonic Acids (PFSAs) and Related Precursors: Focus on the Life Cycle of C8-Based Products and Ongoing Industrial Transition

Here a new global emission inventory of C₄-C₁₀ perfluoroalkanesulfonic acids (PFSAs) from the life cycle of perfluorooctanesulfonyl fluoride (POSF)-based products in 1958-2030 is presented. In particular, we substantially improve and expand the previous frameworks by incorporating missing pieces (e.g., emissions to soil through land treatment, overlooked precursors) and updating parameters (e.g., emission factors, degradation half-lives). In 1958-2015, total direct and indirect emissions of perfluorooctanesulfonic acid (PFOS) are estimated as 1228-4930 tonnes, and emissions of PFOS precursors are estimated as 1230-8738 tonnes and approximately 670 tonnes for x-perfluorooctanesulfonamides/sulfonamido ethanols (xFOSA/Es) and POSF, respectively. Most of these emissions occurred between 1958 and 2002, followed by a substantial decrease. This confirms the positive effect of the ongoing transition to phase out POSF-based products, although this transition may still require substantial time and cause substantial additional releases of PFOS (8-153 tonnes) and xFOSA/Es (4-698 tonnes) in 2016 to 2030. The modeled environmental concentrations obtained by coupling the emission inventory and a global multimedia mass-balance model generally agree well with reported field measurements, suggesting that the inventory captures the actual emissions of PFOS and xFOSA/Es for the time being despite remaining uncertainties. Our analysis of the key uncertainties and open questions of and beyond the inventory shows that, among others, degradation of side-chain fluorinated polymers in the environment and landfills can be a long-term, (potentially) substantial source of PFOS.

Temporal trends of Persistent Organic Pollutants (POPs) in arctic air: 20 years of monitoring under the Arctic Monitoring and Assessment Programme (AMAP)

Temporal trends of Persistent Organic Pollutants (POPs) measured in Arctic air are essential in understanding long-range transport to remote regions and to evaluate the effectiveness of national and international chemical control initiatives, such as the Stockholm Convention (SC) on POPs. Long-term air monitoring of POPs is conducted under the Arctic Monitoring and Assessment Programme (AMAP) at four Arctic stations: Alert, Canada; Stórhöfði, Iceland; Zeppelin, Svalbard; and Pallas, Finland, since the 1990s using high volume air samplers. Temporal trends observed for POPs in Arctic air are summarized in this study. Most POPs listed for control under the SC, e.g. polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethanes (DDTs) and chlordanes, are declining slowly in Arctic air, reflecting the reduction of primary emissions during the last two decades and increasing importance of secondary emissions. Slow declining trends also signifies their persistence and slow degradation under the Arctic environment, such that they are still detectable after being banned for decades in many countries. Some POPs, e.g. hexachlorobenzene (HCB) and lighter PCBs, showed increasing trends at specific locations, which may be attributable to warming in the region and continued primary emissions at source. Polybrominated diphenyl ethers (PBDEs) do not decline in air at Canada's Alert station but are declining in European Arctic air, which may be due to influence of local sources at Alert and the much higher historical usage of PBDEs in North America. Arctic air samples are screened for chemicals of emerging concern to provide information regarding their environmental persistence (P) and long-range transport potential (LRTP), which are important criteria for classification as a POP under SC. The AMAP network provides consistent and comparable air monitoring data of POPs for trend development and acts as a bridge between national monitoring programs and SC's Global Monitoring Plan (GMP).

Air-Seawater Exchange of Organochlorine Pesticides in the Southern Ocean between Australia and Antarctica

This study contributes new data on the spatial variability of persistent organic pollutants in the Indian-Pacific sector of the Southern Ocean and represents the first empirical data obtained from this region in 25 years. Paired high-volume atmospheric and seawater samples were collected along a transect between Australia and Antarctica to investigate the latitudinal dependence of the occurrence and distribution of legacy organochlorine pesticides (OCPs) and the current use pesticide chlorpyrifos in the Southern Ocean. Dissolved ΣHCH and dieldrin concentrations decreased linearly with increasing latitude from 7.7 to 3.0 and from 1.0 to 0.6 pg·L(-1), respectively. There was no consistent trend observed in the latitudinal profile of atmospheric samples; however, some compounds (such as dieldrin) showed reduced concentrations from 7.5-3.4 to 2.7-0.65 pg·m(-3) at the highest latitudes south of the Polar Front. Chlorpyrifos was found in samples from this area for the first time. Estimated air-seawater fugacity ratios and fluxes indicate a current net deposition between -3600 and -900, -6400 and -400, and -1400 and -200 (pg·m(-2)·d(-1)) for γ-HCH, dieldrin, and chlorpyrifos, respectively. These findings suggest that, under current climatic conditions, the Southern Ocean reservoir in the Indian-Pacific sector serves as an environmental sink rather than a source of OCPs to the atmosphere.