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Chlorinated paraffins (CPs) have been applied as additives in a wide range of consumer products, including polyvinyl chloride (PVC) products, mining conveyor belts, paints, sealants, adhesives and as flame retardants. Consequently, CPs have been found in many matrices. Of all the CP groups, short-chain chlorinated paraffins (SCCPs) have raised an alarming concern globally due to their toxicity, persistence and long-range transportation in the environment. As a result, SCCPs were listed in the Stockholm Convention on Persistent Organic Pollutants (POPs) in May 2017. Additionally, a limit for the presence of SCCPs in other CP mixtures was set at 1% by weight. CPs can be released into the environment throughout their life cycle; therefore, it becomes crucial to assess their effects in different matrices. Although about 199 studies on SCCP concentration in different matrices have been published in other continents; however, there are scarce/or limited studies on SCCP concentration in Africa, particularly on consumer products, landfill leachates and sediment samples. So far, published studies on SCCP concentration in the continent include SCCPs in egg samples, e-waste recycling area and indoor dust in Ghana and South Africa, despite absence of any production of SCCPs in Africa. However, there still remains a huge research gap in the continent of Africa on SCCPs. Consequently, there is a need to develop robust SCCP inventories in Africa since the Stockholm Convention has already developed guidance document in this respect. This review, therefore, examines the state of knowledge pertaining to the levels and trends of these contaminants in Africa and further provides research gaps that need to be considered in order to better understand the global scale of the contaminant.

Chlorinated paraffins (CPs) are environmental pollutants of emerging concern. Long-chain CPs (LCCPs) are considered of lesser concern than other CPs in food due to their lower accumulation in most organisms. However, LCCPs have been shown to accumulate preferentially in birds. We used ultrahigh-performance liquid chromatography combined with electrospray ionization Orbitrap mass spectrometry (UPLC-ESI-Orbitrap MS) to analyze CPs (C10-26Cl4-12) in tissues of free-range hens, their feed, and local soils. Feed was found to be the main source of CP intake. The CP carbon chain length had little impact on their absorption. C18-CPs were excreted in preference to C13-CPs by laying. The metabolic elimination rates of CPs (0.2 μg/mL) estimated using chicken liver microsomes were in the order C12Cl6 (91%) > C12Cl8 (57%) > C18Cl6 (12%) > C18Cl8 (6%). CPs with longer carbon chains accumulated preferentially in muscle and adipose tissues, and the accumulation of specific carbon chain lengths was related to the content and composition of different CPs in the intake source.

This study provides guidance on using polyurethane foam-based passive air samplers (PUF-PASs) for atmospheric nonane chlorinated paraffins (C9-CPs) and short-chain CPs (SCCPs) and reports SCCP concentrations in air in the Greater Toronto Area (GTA), Canada. We estimated the partition coefficients between PUF and air (KPUF-A) and between octanol and air (KOA) for C9-CP and SCCP congeners using the COSMO-RS method, so that PUF disk uptake profiles for each formula group could be calculated. We then measured SCCP concentrations in PUF disk samples collected from distinct source sectors in urban air across the GTA. Concentrations in samplers were used to calculate C9-CP and SCCP concentrations in air and the PUF disk uptake profiles revealed that time-weighted linear phase sampling was possible for congeners having log KOA values greater than 8.5. The highest SCCP concentrations, with an annual average concentration of 35.3 ng/m3, were measured at the industrial site, whereas lower but comparable SCCP concentrations were found in residential and background sites, with annual averages of 7.73 and 10.5 ng/m3, respectively. No consistent seasonal variation in SCCP concentrations was found in the six distinct source sectors. Direct measurements of KPUF-A and KOA values as a function of temperature could be used to increase accuracy in future studies.

Short-chain chlorinated paraffins (SCCPs) have been listed as a new class of persistent organic pollutants by the Stockholm Convention. SCCPs exhibit carcinogenic-, endocrine-, and metabolism-disrupting effects. However, the knowledge of the immunomodulatory effects of SCCPs and their underlying mechanisms, especially in specific immune cells, remains limited. In addition to SCCPs, C9-13-CPs have also been detected in humans. In this study, murine RAW264.7 macrophages were exposed to C9-13-CPs at environmentally relevant concentrations to investigate whether or how C9-13-CPs exhibit immunomodulatory effects. The results showed that the exposure of RAW264.7 cells to C9-13-CPs increased cell viability, as assayed by MTT analysis at 490 nm, and also promoted cell proliferation, as indicated by EdU uptake assay, which was measured at excitation and emission wavelengths of 488 and 512 nm, respectively. In addition, exposure to C9-13-CPs not only led to elevated ATP level and intracellular Ca2+ level but also caused AMPK signaling activation and NF-κB signaling inhibition. Moreover, molecular docking showed that the β2-AR receptor could bind to C9-13-CPs. Taken together, these results suggest that the immune dysfunction of RAW264.7 cells caused by C9-13-CPs is closely related to the β2-AR/AMPK/NF-κB signaling axis.

The study presents a fast and high throughput method for determination of short-chain chlorinated paraffins (SCCPs) together with other halogenated persistent organic pollutants (POPs) in sediment. The analytes (SCCPs, 11 polychlorinated biphenyls, 6 polybrominated diphenyl ethers, 11 organochlorine compounds) were determined in a single gas chromatography‒triple quadrupole tandem mass spectrometry (GC‒QqQ-MS/MS) run after miniaturized sample preparation combining ultrasonic solvent extraction (USE) and stir bar sorptive extraction (SBSE). The method was validated in terms of selectivity, matrix effect, matrix-matched recovery, linearity and range, detection and quantification limits (LOD and LOQ) and accuracy (including analysis of certified reference materials). The QqQ-MS/MS detector allowed the determination of all target analytes without interferences. The LODs and LOQs for SCCPs were 6.5 and 22 ng g‒1 dw (dry weight), while for other analytes were in the ranges 0.029‒0.073 ng g‒1 and 0.097‒0.24 ng g‒1, respectively. The recoveries for all the analytes were in the range 84‒101% with relative standard deviations in the range 5.5‒19%. In terms of environmental impact, the method was classified as “an excellent green analysis method”. Finally, the method was compared with other published methods and its applicability was confirmed by the analysis of sediment samples collected in 23 Slovak water reservoirs during a survey conducted in 2019.

Short-chain chlorinated paraffins (SCCPs) have attracted attention because of their toxicological potential in humans and wildlife at environmentally relevant doses. However, limited information is available regarding mechanistic differences across species in terms of the biological pathways that are impacted by SCCP exposure. Here, a concentration-dependent reduced human transcriptome (RHT) approach was conducted to evaluate 15 SCCPs in HepG2 cells and compared with our previous results using a reduced zebrafish transcriptome (RZT) approach in zebrafish embryos (ZFEs). Generally, SCCPs induced a broader suite of biological pathways in ZFEs than HepG2 cells, and all of the 15 SCCPs were more potent in HepG2 cells compared to ZFEs. Despite these general differences, the transcriptional potency of SCCPs in both model systems showed a significant linear relationship (p = 0.0017, r2 = 0.57), and the average ratios of transcriptional potency for each SCCP in RZT to that in RHT were ∼100,000. C10H14Cl8 was the most potent SCCP, while C10H17Cl5 was the least potent in both ZFEs and HepG2 cells. An adverse outcome pathway network-based analysis demonstrated model-specific responses, such as xenobiotic metabolism that may be mediated by different nuclear receptor-mediated pathways between HepG2 cells (e.g., CAR and AhR activation) and ZFEs (e.g., PXR activation). Moreover, induced transcriptional changes in ZFEs associated with pathways and molecular initiating events (e.g., activation of nicotinic acetylcholine receptor) suggest that SCCPs may disrupt neural development processes. The cross-model comparison of concentration-dependent transcriptomics represents a promising approach to assess and prioritize SCCPs.

Chlorinated paraffins (CPs) are of growing public health concern because of their ubiquitous presence in food samples. To get more insight into levels of CPs in vegetable oils from the Dutch market and human exposure via these oils, two series of samples were analysed in this study for the presence of CPs by UHPLC coupled with Q-Exactive Orbitrap mass spectrometry: 1) 39 vegetable oils from local supermarkets; 2) 13 paired crude and refined vegetable oils obtained from a contract refining company. Short chain CPs (SCCPs) and medium chain CPs (MCCPs) were detected in vegetable oils from supermarkets with an overall range from

Over the last decades, short-chain chlorinated paraffins (SCCPs), medium-chain chlorinated paraffins (MCCPs), and long-chain chlorinated paraffins (LCCPs) have become the most heavily produced monomeric organohalogen compound class of environmental concern. However, knowledge about their toxicology is still scarce, although SCCPs were shown to have effects on the thyroid hormone system. The lack of data in the case of MCCPs and LCCPs and the structural similarity with perfluoroalkyl substances (PFAS) prompted us to test CPs in the novel TTR-TR CALUX assay for their thyroid hormone transport disrupting potential. Four self-synthesized and additionally purified single chain length CP mixtures (C10-CPs, C11-CPs, C14-CPs and C16-CPs) and two each of industrial MCCP and LCCP products were tested in parallel with PFOA. All CP mixtures influenced the TTR binding of T4, giving activities of 1,300 to 17,000 µg/g PFOA equivalents and lowest observable effect concentrations (LOELs) of 0.95 to 0.029 mM/L incubate. Highest activities and lowest LOELs were observed for C16-CPs (48.3% Cl content, activity 17,000, LOEL 0.047 mM/L) and a LCCP mixture (71.7% Cl content; activity 10,000; LOEL 0.029 mM/L). A trend of higher activities and lower LOELs towards longer chains and higher chlorination degrees was implied, but could not be statistically confirmed. Irrespectively, the less well examined and current-use LCCPs showed the highest response in the TTR-TRβ CALUX assay.

Pristine alpine regions are ideal regions for investigating the long-range atmospheric transport and cold trapping effects of short chain chlorinated paraffins (SCCPs). The concentrations and alpine condensation of SCCPs were investigated in lichen samples collected from the southeastern Tibetan Plateau. The concentrations of SCCPs ranged from 3098 to 6999 ng/g lipid weight (lw) and appeared to have an increasing trend with altitude. For congeners, C10 dominated among all the congener groups. The different environmental behavior for different congener groups was closely related to their octanol-air partition coefficient (Koa). C10 congeners showed an increasing trend with altitude, whereas C13 congeners were negatively correlated with altitude. Volumetric bioconcentration factors (BCF) of SCCPs reached 8.71 in lichens, which were higher than other semivolatile organic compounds (SVOCs) such as organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), and hexabromocyclododecane (HBCD). These results suggested that SCCPs were prone to accumulate in the lichen from the air and provided evidence for the role of lichens as a suitable atmospheric indicator in the Tibetan Plateau.

COSMO-RS-trained fragment contribution models (FCMs) to predict the partition properties of chlorinated paraffin (CP) congeners were refined and extended. The improvement includes (i) the use of an improved conformer generation method for COSMO-RS, (ii) extension of training and validation sets for FCMs up to C20 congeners covering short-chain (SCCPs), medium-chain (MCCPs) and long-chain CPs (LCCPs), and (iii) more realistic simulation of industrial CP mixture compositions by using a stochastic algorithm. Extension of the training set markedly improved the accuracy of model predictions for MCCPs and LCCPs, as compared to the previous study. The predicted values of the log octanol/water partition coefficients (Kow) for CP mixtures agreed well with experimentally determined values from the literature. Using the established FCMs, this study provided a set of quantum chemically based predictions for 193 congener groups (C10–20 and Cl0–21) regarding Kow, air/water (Kaw), and octanol/air (Koa) partition coefficients, subcooled liquid vapor pressure (VP) and aqueous solubility (Sw) in a temperature range of 5–45 °C as well as the respective enthalpy and internal energy changes.

Short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) are among the most complex and commonly used chlorinated pollutants in the environment. Their temporal and s...

Studies on the biomagnification of short- and medium-chain chlorinated paraffins (SCCPs and MCCPs) in terrestrial ecosystems and their bioamplification during metamorphosis in insects and amphibians are scarce. Therefore, this study sought to characterize the occurrence and trophic dynamics of SCCPs and MCCPs in an insect-dominated terrestrial food web in an e-waste recycling site in South China. Median ∑SCCPs and ∑MCCPs concentrations in the organisms ranged from 2200 to 34 000 ng/g lipid weight and from 990 to 19 000 ng/g lipid weight, respectively. The homologue profiles of CPs in the predators were distinct from those in insects, presenting more short chain-high chlorinated congeners (C

Food consumption has been identified as a major pathway for human exposure to short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs), but evaluations of SCCP and MCCP intake from major dietary sources are limited. We used the sixth Chinese Total Diet Study to perform a comprehensive investigation of SCCPs and MCCPs in cereals, vegetables, potatoes, legumes, eggs, milk, meats, and aquatic foods from nine southern provinces. The geographical distribution of CP concentrations showed higher levels in Jiangsu, Hubei, and Zhejiang provinces. The CP concentrations in most animal-origin foods were higher than those in foods of plant origin. The total estimated daily intakes (EDIs) of SCCPs and MCCPs, with average values of 7.0 × 102 and 4.7 × 102 ng kg-1 day-1, respectively, were mostly contributed by cereals, vegetables, and meats. Risk assessment indicated the EDIs of CPs posed no significant risk to residents in South China.

International audience; The risk assessment of chlorinated paraffins (CPs), chemicals of widespread industrial use, is struggling without standardized analytical methods to obtain reliable occurrence data. Indeed, scientists face analytical challenges that hinder the comparability of analytical methods, among them uncontrolled ionization efficiency and lack of quantification standards. In this study, our goal was to investigate potential issues faced when comparing data from different mass spectrometry platforms and quantification methods. First, the injection of the same set of single-chain length standards in three different instrumental mass spectrometry set-ups (liquid chromatography-electrospray-Orbitrap (LC/ESI-HRMS), liquid chromatography-electrospray-time-of-flight (LC/ESI-MS), and gas chromatography-electron capture negative ion-Orbitrap (GC/ECNI-HRMS)) revealed a shift of homologue response patterns even in-between LC/ESI-based set-ups, which was more pronounced for CPs of low chlorination degree. This finding emphasizes the need for a comprehensive description of instrument parameters when publishing occurrence data. Second, the quantification of a data set of samples with four quantification methods showed that quantification at the sum SCCP and MCCP levels presented good comparability, while quantification at the homologue level remained unsatisfactory. In light of those results, we suggest that (i) response pattern comparison should only be performed between similar instrumental set-ups, (ii) experimental chlorination degrees should be used when quantifying according to the %Cl (instead of those provided by the suppliers), and (iii) concentration results should be expressed as the sum of SCCPs and MCCPs primarily, with an indication on the match between samples and quantification standards (for example their chlorine content).

Risk assessment of chemical mixtures isRisk assessment of chemical mixtures is challenging because information about the chemical structure, concentration, properties, and toxicity, down to the individual compounds, is generally not readily accessible. To cope with this challenge, we think Mixture Touch― a web platform that offers a one-window solution, for free, for the risk assessment of complex mixtures that are analyzed with comprehensive two-dimensional gas chromatography (GC × GC). GC × GC is a powerful analytical technique for target and nontarget analysis of complex mixtures. Our web platform allows users to visualize the GC × GC data, conduct spectral identification, estimate properties, and analyze potential risks based on established methods. For illustration purpose, we show how to assess the aquatic bioaccumulation potential of short-chain chlorinated paraffin (SCCP), which is an industrially manufactured mixture. The platform readily demonstrated that most of the SCCP congeners did not have the tendency to accumulate in aquatic organisms but in humans. The platform can bridge the gap between the GC × GC experts, GC × GC users, analytical experts, and risk assessors. It could enhance the level of risk assessments of mixtures utilizing the high performance of the state-of-the-art analytical instruments.

Chlorinated paraffins (CPs) are produced in large amounts and used worldwide. Dietary intake is the primary pathway for the exposure of pets to CPs, but limited information is available concerning the potential contamination of pet food by CPs. In the present study, the concentrations and congener group profiles of short-chain CPs (SCCPs) and medium-chain CPs (MCCPs) were assessed in 35 imported commercial dry cat and dog foods collected in China, and the estimated daily intakes of SCCPs and MCCPs for cats and dogs through the consumption of such foods was calculated. The concentrations of SCCPs and MCCPs in the cat and dog foods were determined to be in the ranges of 108–45,300 ng/g (median: 1340 ng/g) and 3.8–52,700 ng/g (median: 11 ng/g), respectively. The predominant congener groups were C10Cl6 for SCCPs and C14Cl7-8 for MCCPs. The high levels of CPs found in certain pet foods suggest the potential for adverse health effects.

Chlorinated paraffins (CPs) have been produced for a wide range of applications, mostly in open uses, such as metalworking fluids, lubricants, coolants or additives in consumer goods. The production volume is more than one million tonnes requiring control of the lifecycle of these persistent and bioaccumulative chemicals. In May 2017, the Stockholm Convention amended its Annex A to list short chain chlorinated paraffins (SCCPs) as a Persistent Organic Pollutant (POP). Additionally, a limit for the presence of SCCPs in other CP mixtures was set at 1% by weight. CPs can be released to the environment throughout their lifecycle. Therefore, the major objective of this review was to assess and compile information on SCCPs and other CPs regarding their lifecycle in the technosphere to support the Stockholm Convention implementation. A few studies have assessed CP production plants and contamination in the surrounding environments. However, there was no systematic investigation of release routes from production and no assessment of associated landfills, even though these are known major pollution sources at other organochlorine production sites. Some studies have reported that industrial areas, where CPs have likely been used, have elevated levels of CPs in sediments and soil. However, although CPs are largely released when used as metalworking fluids or lubricants, no systematic assessment of releases has been conducted at the thousands of sites where CPs are used in high volumes. Many CPs, mainly medium chain chlorinated paraffins (MCCPs) and SCCPs, are used as additives in the production of consumer goods, resulting in exposure risks. Levels above the European Union regulation for SCCPs of 1500 mg kg−1 and up to approx. 20% are frequently found. The end-of-life management of CP-containing products is difficult since no labelling requirement exists even for products containing SCCPs. The Stockholm Convention prohibits the recycling of SCCP-containing products, which will result in challenges recycling the impacted waste categories. The activities under the Stockholm Convention related to SCCPs, such as the inventory, phase-out, and management of impacted products, provide opportunities to address existing data gaps and challenges. Special attention needs to be given to developing countries with lacking analytical capacity as well as waste management and destruction capacity.

Short-chain chlorinated paraffins (SCCPs), a class of ubiquitous pollutants, are considered to be embryotoxic and teratogenic. However, little is known regarding the bioactivity and mechanisms at environmentally relevant concentrations at the embryonic period. Here, a concentration-dependent reduced transcriptomic approach was used to evaluate the environmental dose ( 60%) (p = 0.038), and the chlorine content of SCCP congeners affected the bioactivity associated with genotoxic pathways. The concentration-dependent reduced transcriptomic approach significantly improved the understanding of the ecological risk of environmental contaminants at early life stages.

This article covers the development of the thermoplastic extrusion films made of poly(vinyl acetate) (PVA) and poly(butyl methacrylate) (PBMA) for use as an inner layer in metal-polymer-metal multiple-layered vibro-damping materials that can work in contact with water. The effect of the amount of the introduced plasticizer on the dynamic properties of polymer films made of PVA and PBMA is studied on the example of plasticizers from the group of esters of dicarboxylic acids, organic phosphates and chloroparaffins. The processes of water sorption by polymer films and washing out plasticizers from them have been investigated. It has been demonstrated that PBMA-based films containing chlorinated paraffins as a plasticizer have the best water resistance.

Short-chain polychlorinated n-alkanes are ubiquitous industrial chemicals widely recognized as persistent organic pollutants. They represent only a small fraction of the 184,600 elemental compositions (C10-25) and the myriad isomers of all possible (mixed) halogenated n-alkanes (PXAs). This study prioritizes the PXAs on the basis of their potential to persist, bioaccumulate, and undergo long-range transport guided by quantitative structure-property relationships (QSPRs), density functional theory (DFT), chemical fate models, and partitioning space. The QSPR results narrow the list to 966 elemental compositions, of which 352 (23 Br, 83 Cl/F, 119 Br/Cl, and 127 Br/F) are likely constituents of substances used as lubricants, plasticizers, and flame retardants. Complementary DFT calculations suggest that an additional 1367 elemental compositions characterized by a greater number of carbon and fluorine atoms but fewer chlorine and bromine atoms may also pose a risk. The results of this study underline the urgent need to identify and monitor these suspected pollutants, most appropriately using mass spectrometry. We estimate that the resolving power required to distinguish ∼74% of the prioritized elemental compositions from the most likely interferents, i.e., chlorinated alkanes, is approximately 60,000 (full width at half-maximum). This indicates that accurate identification of the PXAs is achievable using most high-resolution mass spectrometers.

Short chain chlorinated paraffins (SCCPs) have attracted increasing attention due to their potential risks to the ecosystem and human health. However, there is still a lack of systematic research on their environmental fate in the coastal marine environment. In this study, we collected paired seawater (n = 40) and surface sediment samples (n = 40) from East China Sea, and investigated their spatial distribution, partitioning behaviors and ecological risks. The total SCCP concentrations (∑SCCPs) in seawater and sediment samples were in the range of 12.2–430 ng/L and 89.6–351 ng/g (dry weight), respectively. C10–11 SCCPs and Cl5–7 SCCPs were the predominant homologues in all of the samples. This study first calculated the field-based logKOC values for ∑SCCPs in the marine environment, which ranged from 5.0 to 6.5 (mean 5.5). The logKOC values of SCCP homologues (range 3.6–8.0, mean 5.6) showed a weak correlation with their logKOW (R = 0.214, p

Polyvinyl chloride (PVC), chlorinated polyvinyl chloride (CPVC) and chlorinated paraffin СP-66T, taken in an amount of 18% by weight of the composition, were chosen as fire retardants. It is shown that the main process of degradation of compositions of PDCPD with chlorinated paraffins is determined by the onset of degradation of the matrix polymer. It was found that the most effective of the considered flame retardants is chloroparaffin СP-66T, which reduces the thermal effect at the stage preceding combustion by 54,3%.

Germany is one of several major European producers of chlorinated paraffins (CPs). This study showed that not only the legacy short-chain products (SCCPs, C10-13), but also the current-use medium- and long-chain products (MCCPs, C14-17; LCCPs, C>17) as well as the very-short-chain impurities (vSCCPs, C

Background: The current production and use of chlorinated paraffins (CPs) at >1 million tons/y likely exceeds the lifetime production of polychlorinated biphenyls (PCBs). These persistent organic pollutants (POPs) are a concern to human health. Objectives: The United Nations Environment Programme conducts global surveys of human milk samples from individual countries as a noninvasive method of investigating levels and trends in human exposures to POPs such as CPs. We measured CP concentrations and assessed their relation to other POPs in pooled samples collected during 2012–2019. Methods: We analyzed 57 official nationwide pooled milk samples from 53 countries on five continents (Africa, Central/South America, Asia, Europe, and Australia/Oceania). CP concentrations were further characterized by subgroups and compared with concentrations of 19 other POPs, including PCBs and a variety of pesticides. Results: CPs were detected in pooled samples from all 53 countries, with concentrations of 23–700 ng/g lipid. CPs accounted for 18–46% of the total summed POPs in human milk, second only to dichlorodiphenyltrichloroethane (DDT). CP concentrations exceeded PCB concentrations in pooled samples from most countries. Discussion: The presence of CPs in all samples, including samples from isolated locations (e.g., Pacific Island countries), emphasizes the ubiquitous presence of these compounds, whereas differences in subgroup ratios indicate a delay in the shift toward nonregulated medium-chain CPs (MCCPs) for these regions. The predominance of MCCPs in samples from many countries suggests a need for regulation and research on health effects. https://doi.org/10.1289/EHP7696

Hydroxyl radicals (•OH) are important reactive species that are photochemically generated through solar irradiation of chromophoric dissolved organic matter (CDOM) in surface waters. However, the spatial distribution within the complex three-dimensional structure of CDOM has not been examined. In this study, we used a series of hydrophobic chlorinated paraffins as chemical probes to elucidate the microheterogeneous distribution of •OH in illuminated CDOM solutions. The steady-state concentration of •OH inside the CDOM microphase is 210 ± 31-fold higher than the concentration in the aqueous phase. Our results suggest that the most photochemically generated •OH are confined into the CDOM microphase. Thus, illuminated CDOM behaves as a natural microreactor for •OH-based oxidations. By including intra-CDOM •OH, the quantum yield of •OH for CDOM solutions was estimated to be 2.2 ± 0.5 × 10-3, which is 2 orders of magnitude greater than previously thought. The elevated concentrations of photogenerated •OH within the CDOM microphase may improve the understanding of hydrophobic pollutant degradation in aqueous environments. Moreover, our results also suggest that •OH oxidation may play more important roles in the phototransformation of CDOM than previously expected.

As new persistent organic pollutants, short chain chlorinated paraffins (SCCPs) have recently received particular attention. However, knowledge on their bioaccumulation and trophic magnification in marine organisms from East China Sea (ECS) is still scare. In this study, we investigated the concentrations of SCCPs in seawater (n = 15) and marine organisms (n = 88) collected from ECS. The total concentrations of SCCPs (∑SCCPs) ranged from 12.5 to 242 ng/L in seawater and from 12.8 to 1819 ng/g wet weight (ww) in organisms. C10–11 SCCPs and Cl5–7 SCCPs were the predominant homologues in all samples, with the mean proportions of 70 ± 6.5% and 80 ± 7.8% in seawater, as well as 52–77% and 61–84% in marine organisms, respectively. The logarithm bioaccumulation factor (log BAF) values of ∑SCCPs were in the range of 2.04–3.79 in zooplankton, fish, shrimp, crab, shellfish, snail, and cephalopod. The log BAF values of SCCP homologues (1.33–4.75) increased significantly with the increase of their logarithm octanol–water partition coefficients (log KOW) values, indicating that hydrophobicity is the major factor controlling the bioaccumulation of SCCPs. The trophic magnification factor (TMF) value of ∑SCCPs was calculated to be 3.98, indicating the potential trophic magnification of SCCPs in this marine food web from ECS. A slightly increasing trend was observed between the TMF values of SCCP homologues and their log KOW values. Overall, for the first time, this study systematically examined the bioaccumulation and trophic magnification of SCCPs in the marine food web from East China Sea.

Chlorinated paraffins (CPs) are complex mixtures, which consist of thousands of individual compounds with no dominant representative. Consequently, knowledge on structure and environmental relevance of individual CP congeners is poor. Similarly to the synthesis of individual CPs, the generation of less complex CP mixtures that can be thoroughly analyzed may be used to overcome some drawbacks of the highly complex technical CP mixtures. Here, we present a new synthesis approach to generate such simple CP mixtures by decarboxylation of polyunsaturated fatty acids followed by saturation of the double bonds by chlorination. Specifically, α-linolenic acid (18:3Δ9,12,15) was decarboxylated to heptadecatriene. The resulting raw product was chlorinated with SO2Cl2. Purification by column chromatography led to a main fraction consisting of four major peaks originating from hexachloroheptadecane (C17H30Cl6) isomers (∼80% of the total peak area) along with ∼20 low abundant by-products, according to gas chromatography with electron capture negative ion mass spectrometry. In the same way, decarboxylation and subsequent chlorination of other polyunsaturated fatty acids may lead to further simple CP mixtures with other chain lengths. Although these simple CP mixtures cannot fully reflect the various structural features present in technical mixtures they could be beneficial for transformation studies because changes in the CP pattern can easily be noted which is in contrast to technical CP mixtures. Such simple CP mixtures could also be used in toxicity tests which are difficult to perform with technical CP mixtures because of their high complexity.

Chlorinated paraffins (CPs) are chemicals with multipurpose applications. Their global production has increased despite their adverse impacts on the environment and human health. In 2017, short-chain chlorinated paraffins (SCCPs) were listed as persistent organic pollutants (POPs) in the Stockholm Convention. Yet, specific exemptions were granted for their applications despite the recycling prohibition for products containing SCCPs. Therefore, we aimed to produce the first Brazilian inventory of SCCPs following its respective guidance to evaluate the applicability of the SCCP inventory guidance and to provide technical insights regarding SCCPs in the update of the Brazilian National Implementation Plan (NIP). Moreover, we performed a review of SCCP occurrence in Brazil to fulfil data gaps in the inventory development. We identified and consulted nationwide stakeholders and assessed foreign trade data of CPs and products that might contain CPs in relevant amounts. The Brazilian production of CPs was discontinued in 1994. However, CPs are still imported and used in the country. CPs have been mostly applied as plasticizers, flame retardants and lubricants in Brazil. The import of products containing CPs also pose a significant route of CP entrance into Brazil. Thus, the current end-of-life management of CP-containing products is a bottleneck towards the Convention implementation. The guidance application was feasible and useful despite the low engagement of stakeholders. To assess foreign trade of CPs and CP-containing products, we recommend the use of more specific tracking codes. Besides, the review of SCCP occurrence is not a demanded part for an inventory but was a useful complementation.

This study reports on concentrations of short- and medium-chain chlorinated paraffins (SCCPs and MCCPs, respectively) in a wide range of food samples (n = 211) purchased in Belgium during 2020. Samples were analysed by gas chromatography-mass spectrometry (GC-MS) and quantified using chlorine content calibration. ESCCPs were present above LOQ in 25% of samples with an overall range of

This study presents a comprehensive two-dimensional gas chromatography with negative chemical ionization quadrupole time-of-flight mass spectrometry (GC × GC-NCI-QTOF/MS) method, which allows for a precise chromatographic separation of short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs). A new reversed-phase column setup was used, which allows for more accurate separation of MCCPs compared to known GC × GC methods. In a pilot study, 25 freshwater fish samples were analyzed with this method to characterize chlorinated paraffin (CP) compositions. The CP composition was similar in the samples, an observation that is important for the development of a suitable routine method. MCCP contamination was considerably higher than SCCP contamination, with concentrations of 1.3-410 ng/g of wet weight and 0.67-6.5 ng/g of wet weight, respectively. These results were compared to those obtained using a second method, direct injection-atmospheric pressure chemical ionization (APCI)-Orbitrap/mass spectrometry (MS). GC × GC separation was considered to be advantageous for accurate quantification of CP contamination.

Chlorinated paraffins (CPs) are chemicals with high production volumes that can accumulate at high levels in general populations. The pharmacokinetics of CPs as pollutants is unknown, and there is no evidence that the medium chain chlorinated paraffins (MCCPs) and long chain chlorinated paraffins (LCCPs) are safe replacements for short chain chlorinated paraffins (SCCPs). In this study, SCCPs, MCCPs, and LCCPs were first in vivo and in vitro exposed to rat and liver microsomes, respectively. Toxicokinetics of these compounds were assessed and used to establish the corresponding physiologically based pharmacokinetic (PBPK) models in rats. More than 90% of ingested CPs were deposited in the liver and fat, and the compounds were extremely resistant to metabolism and mostly eliminated via biliary excretion. Then, humans' external and internal exposures to CPs were investigated for one year in Shenzhen, South China. The results were used to calibrate the key parameters for the establishment of a PBPK model in humans. In the PBPK models of rats and humans, the rate of biliary excretion had the greatest influence on the accumulated levels and half-lives of CPs. The body half-lives of human were estimated to be 5.1, 1.2, and 0.6 years for SCCPs, MCCPs, and LCCPs, respectively, suggesting the high accumulation of SCCPs in humans compared to other CPs.

With the phasing out of short-chain chlorinated paraffins (SCCPs), the production and emissions of medium- and long-chain chlorinated paraffins (MCCPs and LCCPs) are expected to increase. In this study, cell viability assay and pseudotargeted metabolomics approach were adopted to define and compare the toxic effects induced by SCCPs, MCCPs and LCCPs. The dose response curves indicated that three CP mixtures with comparable chlorine contents produced similar inhibitory effects on cell viability. At exposure concentration of 100 μg/L, three CP mixtures all induced significant increases in levels of reactive oxygen species (ROS) and malondialdehyde (MDA) and a significant reduction in level of adenosine triphosphate production (ATP), and produced similar impact intensities on overall metabolism. A stronger perturbation in phospholipid and fatty acid metabolism was observed in all CP exposure groups. In comparison with SCCPs and MCCPs, LCCPs produced a stronger suppressive effect on amino acid transport across cell membrane and induced an opposite effect on purine metabolism. Furthermore, the toxicity mechanism and possible health risks of the three types of CPs were discussed. MCCPs shared the most similar cytotoxicity and metabolic perturbation with SCCPs, suggesting that there should be concern about using MCCPs as alternatives to SCCPs.

Incineration experiments with solid wastes containing approximately 3% (w/w) short-chain chlorinated paraffins (SCCPs) that have recently been listed as persistent organic pollutants (POPs) and medium-chain chlorinated paraffins (MCCPs) were conducted using a pilot-scale incinerator to investigate the efficiency of their destruction as well as the unintentional formation of POPs and their destruction behaviors during controlled incineration. A series of experiments demonstrated that SCCPs and MCCPs in solid wastes were progressively destroyed and removed during rotary kiln combustion and downstream flue gas treatments. Destruction efficiencies of SCCPs and MCCPs exceeding 99.9999% were confirmed. SCCPs in bottom and fly ash samples were present at levels below their quantification limits (0.021 and 0.31 mg/kg), and MCCPs in the bottom and fly ash samples were likewise present at concentrations below their quantification limits (0.034 and 0.50 mg/kg). Total concentrations of toxicity equivalency quantities (TEQs) for polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (dl-PCBs) in emission gas samples collected at the bag filter exit and final exit were 0.083–0.30 and 8.7 × 10−7 to 1.3 × 10−4 ng-TEQ/m3N, respectively, and those in bottom and fly ash samples were 0.12–0.47 and 9.0 × 10−3 to 0.14 ng-TEQ/g, respectively. The results obtained in this study suggest that controlled incineration of solid wastes under the current regulations for incinerators in Japan and the countries with regulations and monitoring to minimize emissions of PCDDs/DFs and dl-PCBs is one of the best available technologies for the environmentally sound management of wastes containing SCCPs and MCCPs.

Short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) are high-production-volume persistent and toxic industrial chemicals found ubiquitously in various environme...

Bromo-chloro alkenes (Br-Cl PXAs) have been used for over 30 years as flame retardants and are listed on several national chemical inventories. Very little publicly available information is available on Br-Cl PXAs, and thus preliminary ecological risk screening is challenging due to the lack of basic information such as molecular structure and associated physicochemical properties. Due to their likely similarity with chlorinated paraffins (CPs), Br-Cl PXAs may pose a similar environmental hazard. Several structural databases list such substances as "alkenes", although the industrial synthesis involves halogenation of linear alpha-olefins and would be expected to produce linear alkanes. In this study, a combination of high-resolution separation and mass spectrometric techniques were used to characterize a Br-Cl PXA industrial technical product, C12-30 bromo-chloro alpha-alkenes (CAS RN 68527-01-5). The results show this product is dominated by C18 carbon chain lengths, substituted with 3-7 chlorine atoms and 1-3 bromine atoms on an alkane chain. Long-chain C18 chlorinated paraffins are also present, although they represent a relatively minor component. Experimental log KOW (6.9 to 8.6) and estimated log KOA (10.5 to 13.5) and log KAW (-5.1 to -0.6) partition coefficients suggest that this chemical will behave similarly to medium- and long-chain CPs as well as other persistent organic pollutants, such as highly chlorinated pesticides and polychlorinated biphenyls. The results of this study provide an initial step toward understanding the environmental behavior and persistence of Br-Cl PXAs, highlighting the need for further assessment and re-evaluation of the current structure(s) assigned to these compounds.

Chlorinated paraffins (CPs) are complex mixtures of polychlorinated n-alkanes of different chain length. Despite their environmental relevance, quantification is still a challenge. Moreover, the individual structures of the molecules in technical CP mixtures are largely unknown. Here, we synthesized 21 and studied 29 single chain length CP mixtures ranging from C10- to C17-CPs with different chlorine contents between 41.8% and 62.6% Cl and analyzed them by means of nuclear magnetic resonance spectroscopy (NMR). Discrete ranges of chemical shifts were observed in one-dimensional 1H and 13C NMR spectra. Two dimensional heteronuclear single quantum coherence spectroscopy (HSQC) enabled to assign nine substructures. These measurements also verified the presence of [-CCl2-] groups and chlorine atoms on terminal carbons in highly chlorinated (>59% Cl) mixtures. 1H NMR spectra of different chain length and the same degree of chlorination looked virtually the same. However, with increasing degree of chlorination the observed patterns in the spectra were slightly shifted downfield. Based on these findings, a calculation mode was developed to estimate the chlorine content (%) of the single chain length CP mixtures. The results agreed well (

Most emitters of short chain chlorinated paraffins (SCCPs) in China are located in eastern China, posing potential risks to the marine environment and food web. Here we employed a comprehensive atmospheric transport model combined with multiple environmental compartment exchange modules and a marine food web model to simulate levels and risks of SCCPs in the marine environment and fish in the Yellow Sea (YS), East China Sea (ECS), and South China Sea (SCS). Results unveiled a decreasing SCCP level in seawaters and sediments towards offshore. The modeled SCCP total (dry + wet) loadings to the three seawater bodies ranged from 0.0013 to 0.1635 mg/m2/season and gaseous diffusive deposition ranged from 43 to 4443 kg/month. The meteorological factors and secondary emission contributing to seasonal changes in SCCPs were also discussed. A tagging technique was used to trace origins of SCCPs, demonstrating that source proximity contributes most in SCCP contamination to these seawater bodies. Modeled SCCP levels in 5 marine fish in the YS, ECS, and SCS ranged from 23 to 111 ng/g. Our results showed the current SCCP levels in the marine environment and fish did not pose exposure risks to fish consumers for different age groups and genders. However, if consumed fish were harvested and imported from more seriously contaminated seawaters by SCCPs, the estimated dietary intake (EDI) would considerably increase.

Short-chain chlorinated paraffins (SCCPs, C10–13) were listed as persistent organic pollutants (POPs) by the Stockholm Convention in 2017 and pose extensive exposure risks to humans. To our knowledge, there have been no studies reporting the immmunomodulatory effects of SCCPs until now. C9-CPs have also been shown to be present in the environment. In this study, adult male C57BL/6 mice were exposed to 1, 10, or 100 mg/kg/d C9–13-CPs by gavage for 28 d. The results showed that compared to those of the controls, exposure to C9–13-CPs led to increased spleen weight, delimited germinal centers, enhanced energy metabolism, and elevated glutathione content, but no variation in the malonaldehyde level in the spleen was observed. Exposure to C9–13-CPs also increased the populations of splenic lymphocytes, T lymphocytes, NK cells, and the ratio of the CD3+/CD19+ subsets and CD4+/CD8+ subsets compared to those of the controls. RNA-seq revealed 424 differentially expressed genes (DEGs) (fold change ≥ 1.5, FDR

Short-chain chlorinated paraffins (SCCPs) are a series of new persistent organic pollutants, posing a risk of significant adverse effects to biota. Increasing attention has been paid to SCCP pollution in China as large amounts of chlorinated paraffin (CP) products containing SCCPs have been produced and used there. However, knowledge of the bioaccumulation of SCCPs in marine organisms from the Pearl River Estuary (PRE), Southern China, is still scarce. In this study, SCCP concentrations were measured in seawater, sediments, and marine organisms from the PRE. SCCP concentrations ranged from 180 to 460 ng/L in seawater, from 180 to 620 ng/g dry weight (dw) in sediments, and from 870 to 36,000 ng/g lipid weight (lw) in marine biota samples. C10–11 SCCPs were the predominant homologues in all the samples, with an average abundance of 68% in seawater, 57% in sediments, and 56–77% in marine organisms. However, chlorine patterns of SCCPs in seawater, sediments, and marine organisms were different. Cl8–10 SCCPs dominated in sediments, whereas Cl5–7 SCCPs were the predominant SCCP homologues in water and most organism species. The logarithm bioaccumulation factors (BAFs) of SCCPs ranged from 1.6 to 3.0, and increased significantly with the increase of Kow values for most marine biota species, indicating that Kow was the major factor controlling the bioaccumulation of SCCPs and that SCCPs with higher lipophilicity were more prone to being bioaccumulated from water. Opposite to that observed for log BAFs, biota-sediment accumulation factors of specific SCCPs (range: 0.01–30) decreased significantly with the increase of Kow values. The biomagnification factor of total SCCPs for oyster–mangrove crab was 2.40, implying the potential biomagnification of SCCPs for benthos in the PRE.

As high-production-volume chemicals, chlorinated paraffins (CPs) have raised an increasing environmental concern in recent years. However, their accurate analysis and quantification is still a huge challenge due to the high complexity of their technical formulations and the interference from CPs congeners and other polychlorinated products. In this study, a novel method for the simultaneous analysis of short-chain (SC) and medium-chain (MC) CPs in a single injection has been developed using ultra-high-performance liquid chromatography coupled with Orbitrap Fusion Tribrid mass spectrometry (UHPLC-Orbitrap Fusion TMS). Compared with other analytical methods for CPs, this novel method can greatly shorten the measurement time and provides a lower limit of detection. A high resolution of 120,000 FWHM was set to avoid the self-interference of CPs congeners and to eliminate interferences from chlorinated olefins (COs). Accuracies for SCCPs and MCCPs standards were evaluated at 75-103% and 83-118%, respectively. The developed method was further validated by determining CPs in sediment, soil, and indoor dust samples. This novel method gives higher CPs concentrations than those achieved by gas chromatography-electron capture negative ionization low-resolution mass spectrometry (GC-ECNI-LRMS), with factors of 1.1-12.5 for SCCPs and 0.7-2.7 for MCCPs, respectively. Some new CPs, such as C8Cl7-8 and C9Cl5-8, have been determined in soil samples for the first time, indicating great potential of this novel method for routine CP analysis in various environmental samples.

While short-chain chlorinated paraffins (SCCPs) comprise a myriad of components whose physicochemical properties are extremely diverse, many previous studies characterized the SCCP mixtures collectively using a single set of physicochemical properties when modeling the global environmental fate and risk. In this work, we explore whether a discrepancy exists between simulations based on a single set of physicochemical properties and multiple component-specific ones in global fate and risk modeling, and the environmental condition (e.g., proximity to emission source vs. temperature) in which such a discrepancy is most notable. We simulated the environmental concentrations and compartmental distribution of SCCPs, using a mechanistic fugacity-based multimedia BETR-Global model. We observed a discrepancy between modeled concentrations based on a single and multiple sets of properties, which is more notable in regions with a low temperature and negligible emissions, e.g., the remote and cold background Arctic region. The modeled compartmental distribution differs slightly between simulations based on different sets of physicochemical properties. While using a single set of properties minimizes input data required for model-based evaluation of the risk of SCCPs, it tends to underestimate the environmental occurrence and risk in remote and cold regions, which are vulnerable and hence deserve a more conservative evaluation conclusion, and prevents us from drawing conclusions on which SCCP component is of greatest concern. The current work can be a relevant step towards improving the methodology for global environmental modeling and risk assessment of SCCPs and other complex halogenated chemical mixtures.

Short chain chlorinated paraffins (SCCPs) have attracted worldwide attention in recent years, due to their high production volume, persistent, bioaccumulative and toxic properties. In this study, 1-chlorodecane (CD) was selected as a model of SCCPs to explore its photochemical degradation behavior under UV irradiation. The results found that CD could be completely photochemical degradation within 120 min, and the •OH was found to be the main reactive species from both quenching experiments and electron paramagnetic resonance (EPR) results. However, the contribution of triple excited state of CD (3CD*) was still nonnegligible from the results with the absorption peak at 480 nm obtained by laser flash photolysis. Based on the identified intermediates as well as the data from theoretical chemical calculation, the detailed photochemical degradation mechanism of CD was tentatively proposed that CD firstly was excited and photo-ionized under UV irradiation, and the released Cl• in water could result in generating •OH. Then •OH initiates CD degradation mainly through the H-abstraction pathway, leading to the generation of several dehydrogenation radicals, which further generated alcohols or long chain intermediates through radical-radical reactions. The results will provide a comprehensive understanding of the degradation mechanism and environmental fates of SCCPs in water under UV irradiation.

Short-, medium-, and long-chain chlorinated paraffins (SCCPs, MCCPs, and LCCPs) have a wide range of physical-chemical properties, indicating their varying bioaccumulation tendencies in marine and terrestrial ecosystems. However, there are few empirical data to reveal such bioaccumulation tendencies. In this study, we analyzed SCCPs, MCCPs, and LCCPs in samples from 18 species at both low and high trophic levels of marine and terrestrial ecosystems from the Scandinavian region collected during the past decade. These included fish, seabirds, marine mammals, and terrestrial birds and mammals. SCCPs, MCCPs, and LCCPs were present in all the species, with concentrations ranging from 26-1500, 30-1600, 6.0-1200 ng/g lipid, respectively. Although MCCPs and SCCPs predominated in most species, many terrestrial species had generally higher concentrations of LCCPs than marine species. Terrestrial raptors in particular accumulated higher concentrations of LCCPs, including C 24/25 - which are predominant among very-long-chain components. LCCP concentrations were highest and predominated (55% of total CPs) in peregrine falcons in this study, which is the first report where concentrations of LCCPs surpass those of SCCPs and MCCPs in wildlife. The results also indicate biomagnification of SCCPs, MCCPs, and LCCPs in both marine and terrestrial food chains, but in-depth studies of specific food webs are needed.

Chlorinated paraffins (CPs) are a new class of persistent organic pollutants and have aroused great concern of many environmental scientists, due to their ubiquity in various environmental media and biotas. Given their relative low levels in environmental samples, CPs need to be enriched and cleaned up before instrumental analysis. CPs consist of thousands of congeners and isomers, thus posing grand challenges to eliminate the mass interference by homologues and other organohalogen compounds during instrumental examination. Fortunately, high-resolution mass spectrometry (HRMS) owns the powerful ability to solve this key problem owing to its high mass resolution. This review introduces the methods of pretreatment and instrumental analysis of CPs-containing samples in the environment, mainly illustrating the application of gas chromatography and liquid chromatography coupled with HRMS (i.e. GC-HRMS and LC-HRMS). The existing issues and prospects of future study are also discussed.

Short-chain chlorinated paraffins (SCCPs) were added to the Stockholm Convention on Persistent Organic Pollutants (POPs) at the eighth meeting of the conference of the parties in 2017. As a consequence, increasing environmental attention and international regulation on SCCPs is expected in the future. Inhalation uptake of particulate matter (PM) was an important exposure pathway for POPs into the human body. In the present study, a total of eighty PM2.5 samples were collected in the four seasons of the year at an urban site (Shandong University, Jinan) in Shandong province to investigate the seasonal changes of SCCPs and their inhalation exposure risks to human health. The concentrations of SCCPs ranged from 9.80 to 105 ng m−3, with the mean value of 38.7 ng m−3. The highest concentrations of SCCPs were detected in winter, while the lowest concentrations were in summer. SCCPs concentrations were positively correlated with the mass concentrations of PM2.5 (r = 0.629, p

A comprehensive spatio-vertical survey of short-chain (SCCPs, C_(10-13)) and medium-chain (MCCPs, C_(14-17)) chlorinated paraffins (CPs) was performed in surface and core soils from Chinese nation-wide agricultural lands in 2016, and a total of 48 congener groups were measured. The shorter carbon chain C_(10-11) in SCCP and C_(14-15) in MCCP homologue groups, and the lower chlorinated congeners (Cl_(5-7)) for both CP groups were predominant. The ∑SCCP and ∑MCCP concentrations in surface soils ranged from 39 to 1609 ng/g and 127–1969 ng/g, dry weight (dw), respectively. The spatial distribution trend showed that SCCP congener groups with relatively low octanol-water partition coefficient (K_(OW)) and octanol-air partition coefficient (K_(OA)) are uniformly distributed across surface soils compared to MCCP congener groups. Significant relationships were observed between the spatial variation of SCCP concentrations and the driving factors responsible for dispersion and deposition. The distribution behavior of SCCPs and MCCPs in highland and plain surface soils showed an increasing trend of MCCP concentrations with elevation, indicating the “mountain cold-trapping effect”. Vertical distribution profile revealed similar homologue group composition patterns of SCCP and MCCP congener groups as those of surface soils. Furthermore, the penetration potential ratios (r) of chlorine and carbon atoms of CPs demonstrated that the lower chlorinated (Cl_(5-7)) and the shorter carbon chain (C_(10-13)) congener groups are more prone to vertical movement into deeper soil layers compared to the longer carbon chain (C_(14-17)) and highly chlorinated (Cl_(8-10)) congener groups.

Large amounts of short chain and medium chain chlorinated paraffins (SCCPs and MCCPs) are released into the environment during production and usage. However, compared to SCCPs, there is a significant lack of attention for MCCPs. In this work, 83 air samples, collected between 2012 and 2015 from the Tibetan Plateau, were analyzed to investigate the airborne levels and distributions of MCCPs, further to evaluate their potential long-range transport behavior on the alpine area. The total air MCCP concentrations at Shergyla Mountain and Lhasa were between 50 and 690 pg/m3 and 800–6700 pg/m3, respectively. At Shergyla Mountain, MCCP concentrations in the air appeared an increasing trend with altitude, which indicated that MCCPs could potentially possess the ability of “mountain cold trapping”. C14 and C15 congener groups were the dominant homologue groups. The mountain contamination potential (MCP) of different congener groups is closely related to their equilibrium partitioning coefficients between octanol and air (KOA), and water and air (KWA). Increasing MCCPs levels might be a potential threat to the environment and human exposure.