Short-chain chlorinated paraffins in soil, paddy seeds (Oryza sativa) and snails (Ampullariidae) in an e-waste dismantling area in China: Homologue group pattern, spatial distribution and risk assessment

Exploring long-term global environmental impacts of chlorinated paraffins (CPs) in waste: Implications for the Stockholm and Basel Conventions and the global plastic treaty

Chlorinated paraffins (CPs), mainly short-chain CPs (SCCPs) and medium-chain CPs (MCCPs), are currently the most produced and used industrial chemicals related to persistent organic pollutants (POPs) globally. These chemicals are widely detected in the environment and in the human body. As the release of SCCPs and MCCPs from products represents only a small fraction of their stock in products, the potential long-term release of CPs from a large variety of products at the waste stage has become an issue of great concern. The results of this study showed that, by 2050, SCCPs and MCCPs used between 2000 and 2021 will cumulatively generate 226.49 Mt of CP-containing wastes, comprising 8610.13 kt of SCCPs and MCCPs. Approximately 79.72 Mt of CP-containing wastes is predicted to be generated abroad through the international trade of products using SCCPs and MCCPs. The magnitude, distribution, and growth of CP-containing wastes subject to environmentally sound disposal will depend largely on the relevant provisions of the Stockholm and Basel Conventions and the forthcoming global plastic treaty. According to multiple scenarios synthesizing the provisions of the three conventions, 26.6-101.1 Mt of CP-containing wastes will be subject to environmentally sound disposal as POP wastes, which would pose a great challenge to the waste disposal capacity of China, as well as for countries importing CP-containing products. The additional 5-year exemption period for MCCPs is expected to see an additional 10 Mt of CP-containing wastes subject to environmentally sound disposal. Thus, there is an urgent need to strengthen the Stockholm and Basel Conventions and the global plastic treaty.

Advances and challenges in biocathode microbial electrolysis cells for chlorinated organic compounds degradation from electroactive perspectives

Microbial electrolysis cell (MEC) is a promising in-situ strategy for chlorinated organic compound (COC) pollution remediation due to its high efficiency, low energy input, and long-term potential. Reductive dechlorination as the most critical step in COC degradation which takes place primarily in the cathode chamber of MECs is a complex biochemical process driven by the behavior of electrons. However, no information is currently available on the internal mechanism of MEC in dechlorination from the perspective of the whole electron transfer procedure and its dependent electrode materials. This review addresses the underlying mechanism of MEC on the fundamental of the generation (electron donor), transmission (transfer pathway), utilization (functional microbiota) and reception (electron acceptor) of electrons in dechlorination. In addition, the vital role of varied cathode materials involved in the entire electron transfer procedure during COC dechlorination is emphasized. Subsequently, suggestions for future research, including model construction, cathode material modification, and expanding the applicability of MECs to removal gaseous COCs have been proposed. This paper enriches the mechanism of COC degradation by MEC, and thus provides the theoretical support for the scale-up bioreactors for efficient COC removal.

An alkali-enhanced subcritical water treatment strategy of short-chain chlorinated paraffins: Dechlorination and hydrocarbons recovery

As persistent organic pollutants, short-chain chlorinated paraffins (SCCPs) have attracted wide attention in the field of environmental health risk and hazardous waste management. Efficient dechlorination of high content of SCCPs in plastic waste is the committed step for its detoxification and safety treatment. In this study, a high-efficiency and low-temperature process for dechlorination and hydrocarbons recovery from typical SCCPs (52#SCCPs) by subcritical water (SubCW) with alkali enhancer was developed. The introduction of alkali enhancer in the SubCW process had significantly enhanced effect on the dechlorination of 52#SCCPs, and the order of the enhanced effect of alkali enhancer for the dechlorination was NaOH > Na2CO3 > NaHCO3 > NH3·H2O > KOH. The dechlorination behaviors of 52#SCCPs in the NaOH-enhanced SubCW process were studied systematically under different conditions including temperature, residence time, alkali concentration, and volume ratio. The results showed that high-efficiency dechlorination (100 %) of 52#SCCPs could be achieved by the NaOH-enhanced SubCW process at low temperature for a short time (250 °C, 5 min). All of the chlorine released from the molecular chain of 52#SCCPs was transferred to the aqueous phase in the form of inorganic chlorine. The continuous HCl elimination reaction was the primary dechlorination mechanism for 52#SCCPs in the NaOH-enhanced SubCW process. After the dechlorination of 52#SCCPs, high value-added hydrocarbons such as 2,4-hexadiyne (31.74 %) could be obtained. The alkali-enhanced SubCW process proposed in this study is believed to be an environmentally friendly and high-efficiency method for dechlorination/detoxification and resource recovery of SCCPs.

Biomonitoring, exposure routes and risk assessment of chlorinated paraffins in humans: a mini-review

Chlorinated paraffins (CPs), which were conventionally classified into short- (SCCPs), medium- (MCCPs) and long- (LCCPs) chain CPs, have received growing attention due to their wide usage and extensive detection in environmental samples and biota. The number of studies regarding the biomonitoring of CPs in human beings increased rapidly and their health risk gained great concern. This review summarized their occurrence and homologue patterns in human matrices including blood/serum, placenta, cord serum and breast milk. As the production and usage of SCCPs was progressively banned after being listed in Annex A of the Stockholm Convention, the production of MCCPs and LCCPs was stimulated. Accordingly, the ratio of MCCPs/SCCPs in human samples has increased rapidly in the last 5 years. The current understanding of exposure routes and risk assessments of CPs was also reviewed. Oral dietary intake is the most predominant source of daily CP intake, but dust ingestion, inhalation and dermal exposure is also nonnegligible, especially for MCCPs and LCCPs. Furthermore, the reported upper bound of the estimated daily intakes (EDIs) in various risk assessment studies was close to or exceeded the tolerable daily intakes (TDIs). Considering the bioaccumulation and long-lasting exposure of CPs, their health impacts on humans and the ecosystem required continuous monitoring and evaluation.

Disparate toxicity mechanisms of parabens with different alkyl chain length in freshwater biofilms: Ecological hazards associated with antibiotic resistome

As emerging organic pollutants, parabens are of global concern because of their ubiquitous presence and adverse effects. However, few researchers have addressed the relationship between parabens' structural features and toxicity mechanisms. This study conducted theoretical calculations and laboratory exposure experiments to uncover the toxic effects and mechanisms of parabens with different alkyl chains in freshwater biofilms. The result demonstrated that parabens' hydrophobicity and lethality increased with their alkyl-chain length, whereas the possibility of chemical reactions and reactive sites were unchanged despite the alkyl-chain length alteration. Due to the hydrophobicity variation, parabens with different alkyl-chain presented different distribution patterns in cells of freshwater biofilms and consequently induced distinct toxic effects and led to diverse cell death modes. The butylparaben with longer alkyl-chain preferred to stay in the membrane and altered membrane permeability by non-covalent interaction with phospholipid, which caused cell necrosis. The methylparaben with shorter alkyl-chain preferred to enter into the cytoplasm and influence mazE gene expression by chemically reacting with biomacromolecules, thereby triggering apoptosis. The different cell death patterns induced by parabens contributed to different ecological hazards associated with antibiotic resistome. Compared with butylparaben, methylparaben was more likely to spread ARGs among microbial communities despite its lower lethality.

Short- and medium-chain chlorinated paraffins in fish from an anthropized south-western Atlantic estuary, Bahía Blanca, Argentina

Chlorinated paraffins (CPs) are synthetic organic compounds of growing environmental and social concern. Short-chain chlorinated paraffins (SCCPs) were listed under the Stockholm Convention on Persistent Organic Pollutants (POPs) in 2017. Further, in 2021, medium-chain chlorinated paraffins (MCCPs) were proposed to be listed as POPs. We investigated SCCP and MCCP amounts and homolog profiles in four wild fish species from Bahía Blanca Estuary, a South Atlantic Ocean coastal habitat in Argentina. SCCPs and MCCPs were detected in 41% and 36% of the samples, respectively. SCCP amounts ranged from <12 to 29 ng g^-1 wet weight and <750-5887 ng g^-1 lipid weight, whereas MCCP amounts ranged from <7 to 19 ng g^-1 wet weight and <440-2848 ng g^-1 lipid weight. Amounts were equivalent to those found in fish from the Arctic and Antarctic Oceans and from some North American and Tibetan Plateau lakes. We performed a human health risk assessment and found no direct risks to human health for SCCP or MCCP ingestion, according to present knowledge. Regarding their environmental behavior, no significant differences were observed among SCCP amounts, sampling locations, species, sizes, lipid content, and age of the specimens. However, there were significant differences in MCCP amounts across species, which could be attributed to fish size and feeding habits. Homolog profiles in all fish were dominated by the medium-chlorinated (Cl₆ and Cl₇) CPs and shorter chain length CPs were the most abundant, with C₁₀Cl₆ (12.8%) and C₁₁Cl₆ (10.1%) being the predominant SCCPs and C₁₄Cl₆ (19.2%) and C₁₄Cl₇ (12.4%) the predominant MCCPs. To the best of our knowledge, this is the first study on the presence of CPs in the environment in Argentina and the South Atlantic Ocean. CP occurrence in the environment, particularly in the food chain, promotes the need for further research on their occurrence and behavior, and the impact of CPs in marine ecosystems in Argentina.

The potential health risks of short-chain chlorinated paraffin: A mini-review from a toxicological perspective

Short-chain chlorinated paraffins (SCCPs) are ubiquitously distributed in various environmental matrics due to their wide production and consumption globally in the past and ongoing production and use in some developing countries. SCCPs have been detected in various human samples including serum, milk, placenta, nail, and hair, and internal SCCP levels were found to be positively correlated with biomarkers of some diseases. While the environmental occurrence has been reported in a lot of studies, the toxicity and underlying molecular mechanisms of SCCPs remain largely unknown. The current tolerable daily intakes (TDIs) recommended by the world health organization/international programme on chemical safety (WHO/IPCS, 100 μg/kg bw/d) and the UK Committee on Toxicity (COT, 30 μg/kg bw/d) were obtained based on a no observed adverse effect level (NOAEL) of SCCP from the repeated-dose study (90 d exposure) in rodents performed nearly 40 years ago. Importantly, the health risks assessment of SCCPs in a variety of studies has shown that the estimated daily intakes (EDIs) may approach and even over the established TDI by UK COT. Furthermore, recent studies revealed that lower doses of SCCPs could also result in damage to multiple organs including the liver, kidney, and thyroid. Long-term effects of SCCPs at environmental-related doses are warranted.

Bioaccumulation and Biotransformation of Chlorinated Paraffins

Chlorinated paraffins (CPs), a class of persistent, toxic, and bioaccumulated compounds, have received increasing attention for their environmental occurrence and ecological and human health risks worldwide in the past decades. Understanding the environmental behavior and fate of CPs faces a huge challenge owing to the extremely complex CP congeners. Consequently, the aims of the present study are to summarize and integrate the bioaccumulation and biotransformation of CPs, including the occurrence of CPs in biota, tissue distribution, biomagnification, and trophic transfer, and biotransformation of CPs in plants, invertebrates, and vertebrates in detail. Biota samples collected in China showed higher CP concentrations than other regions, which is consistent with their huge production and usage. The lipid content is the major factor that determines the physical burden of CPs in tissues or organs. Regarding the bioaccumulation of CPs and their influence factors, inconsistent results were obtained. Biotransformation is an important reason for this variable. Some CP congeners are readily biodegradable in plants, animals, and microorganisms. Hydroxylation, dechlorination, chlorine rearrangement, and carbon chain decomposition are potential biotransformation pathways for the CP congeners. Knowledge of the influence of chain length, chlorination degree, constitution, and stereochemistry on the tissue distribution, bioaccumulation, and biotransformation is still scarce.

Distribution, behavior, and risk assessment of chlorinated paraffins in paddy plants throughout whole growth cycle

Paddy plants provide staple food for 3 billion people worldwide. This study explores the environmental fate and behavior of a high-volume production emerging contaminants chlorinated paraffins (CPs) in the paddy ecosystem. Very-short-, short-, medium-, and long-chain CPs (vSCCPs, SCCPs, MCCPs, and LCCPs, respectively) were analyzed in specific tissue of paddy plants at four main growth stages and soils from the Yangtze River Delta, China throughout a full rice growing season. The total CP concentrations in the paddy roots, stalks, leaves, panicles, hulls, rice, and soils ranged from 181 to 1.74 × 10³, 21.7-383, 19.6-585, 108-332, 245-470, 59.6-130, and 99.6-400 ng/g dry weight, respectively. The distribution profile indicated the translocation of SCCPs and MCCPs from soils to paddy tissue, highlighting their elevated bioaccumulative potential. The evolution of CP level/mass/pattern during the whole growth cycle suggested atmospheric CPs deposition on leaves and hulls, as well as stalk-rice transfer. CSOIL plant uptake model well predicted the level, distribution pattern, and bioconcentration factors (BCFs) of SCCPs and MCCPs in paddy shoot and recognized the soil-air-shoot pathway as the major contributor. Moreover, risk evaluation indicated that MCCPs intake and subsequent risks dominated the total exposure to CPs via rice ingestion. This is the first report on the occurrence, fate and risk assessment of all CPs classes in paddy ecosystems, and the results underline the potential health effects caused by the in-use MCCPs via rice ingestion.

Occurrence, Distribution and Health Risk of Short-Chain Chlorinated Paraffins (SCCPs) in China: A Critical Review

With being listed in the Stockholm Convention, the ban on short-chain chlorinated paraffins (SCCPs) has been put on the agenda in China. Based on the literature over the past decade, this study comprehensively analyzed the occurrence, distribution of and human exposure to SCCPs in China, aiming to provide a reference for the changes in SCCPs after the ban. SCCPs were ubiquitous in environmental matrices, and the levels were considerably higher than those in other countries. SCCPs from the emission region were 2–4 orders of magnitude higher than those in the background area. Environmental processes may play an important role in the SCCP profiles in the environment, and C10 and Cl6 were identified as potential factors distinguishing their spatial distribution. River input was the dominant source in the sea areas, and atmospheric transport was the main source in the remote inland areas. Ingestion and dermal absorption and food intake may pose potential risk to residents, especially for children and infants. More studies are needed on their temporal trend, source emission and environmental degradation. The enactment of the restriction order will have a great impact on China’s CP industry; nevertheless, it will play a positive role in the remediation of SCCP pollution in the environment.

Short- and medium-chain chlorinated paraffins in soil from an urban area of northern China: Levels, distribution, and homolog patterns

Short-chain chlorinated paraffins (SCCPs) are persistent organic pollutants that are present in relatively high concentrations in various environmental media in China. Many studies have focused on chlorinated paraffins in soil from agricultural land and contaminated areas. There are limited data on the levels of chlorinated paraffins in soil from urban areas. In this study, to investigate the levels, distribution, and homolog patterns of chlorinated paraffins (CPs) in soil from a typical urban area, 130 soil samples were collected and combined to form 26 pooled samples. The samples were analyzed for 50 CP congener groups (C_9-17Cl_5-10). The concentration ranges for SCCPs, medium-chain CPs (MCCP), and chlorinated nonane paraffin (C₉-CP) were 19-1456 ng/g (average: 234 ng/g), <10-385 ng/g (average: 54 ng/g), and 1-39 ng/g (average: 11 ng/g), respectively. The CP concentrations were not significantly correlated with the total organic carbon content (P > 0.05). Compared with other areas worldwide, the SCCP and C₉-CP concentrations in soil in this area were at the medium level, and the concentrations of MCCPs were at a low level. The CP concentrations were higher in soil samples collected near factories and domestic garbage disposal sites. C₁₀Cl_6-7 were the main SCCP homologs and C₁₄Cl_7-8 were the main MCCP homologs. Principal component analysis showed that the sources of C₉-CPs, SCCPs, and MCCPs in the soils were similar. Risk assessment showed that the concentrations of SCCPs and MCCPs in soil in this area did not pose a significant risk to soil organisms or human health.

Status of short-chain chlorinated paraffins in matrices and research gap priorities in Africa: a review

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.

Medium- and Short-Chain Chlorinated Paraffins in Mature Maize Plants and Corresponding Agricultural Soils

For the most complex artificial chlorinated environmental contaminants, much less is known for medium-chain CPs than short-chain CPs. In this research, the spatial distributions of MCCPs and SCCPs in farmland soil and maize leaves near a CP production facility were found marginally influenced by seasonal winds. The levels of ∑MCCPs and ∑SCCPs were in the ranges of <1.51-188 and 5.41-381 ng/g dw for soils; and 77.6-52930 and 119-61999 ng/g dw for maize leaf, respectively. Bioaccumulation and tissue distributions of the CPs within maize plants were specifically analyzed. Most of the CPs were contained in the tissues directly exposed to airborne CPs. Though the estimated risk of CPs to humans through ingestion of kernels appears to be minimal, the edible safety of MCCPs in maize plants for cattle was nearly in the designated range of adverse effects. To our knowledge, this is the first report on bioaccumulation of CPs in mature maize plants, especially in the parts eaten by humans and domestic animals. It provides a baseline reference to the edible risks of CPs in agricultural food plants and alerts us to the problematic environmental behavior of MCCPs, a probable future replacement for SCCPs commercially.

Human exposure to halogenated and organophosphate flame retardants through informal e-waste handling activities - A critical review

Informal electrical and electronic waste (e-waste) handling activities constitute a potentially important source of halogenated (HFRs) and organophosphate flame retardants (OPFRs) to the environment and humans. In this review, two electronic databases (ScienceDirect and Web of Science Core Collection) were searched for papers that addressed this topic. A total of 82 relevant studies (including 72 studies selected from the two databases and 10 studies located from the references of the first 72 selected studies) were identified that reported on human external and internal exposure to HFRs and OPFRs arising as a result of informal e-waste handling activities. Compared to the general population, higher levels of external exposure (i.e., inhalation, ingestion, and dermal absorption) and internal exposure (i.e., blood serum, hair, breast milk, urine, and other human matrices) to HFRs and OPFRs were identified for e-waste recyclers and residents inhabiting e-waste dismantling and recycling zones, especially for younger adults and children. Food intake and dust ingestion were the dominant exposure pathways for the majority of brominated flame retardants (BFRs) and dechlorane plus (DP); while inhalation was identified as the most significant pathway of human exposure to OPFRs in informal e-waste sites. The majority of research to date has focused on China and thus future studies should be conducted in other regions such as Africa and South Asia. Other suggested foci of future research are: examination of exposure via dermal contact with e-waste, dietary exposure of local populations to OPFRs, confirmation of the existence of and cause(s) of the higher body burdens of females compared with males amongst populations impacted by informal e-waste handling, and characterisation of exposure of such populations to chlorinated paraffins.

Short-chain chlorinated paraffins in soils indicate landfills as local sources in the Tibetan Plateau

Background contamination levels of contemporary persistent organic pollutants (POPs) may be elevated due to local discharges, and hence it is of high importance to assess and monitor them in alpine and Polar Regions. This study investigated the role of waste disposal in the Tibetan plateau as the local source of short-chain chlorinated paraffins (SCCPs). SCCPs were determined in soils from the urban landfill and rural dumpsites, with a concentration range of 56.8-1348 ng/g dw. The gradient descent of SCCP levels from Lhasa landfill to the surrounding soils with increasing distances suggested a significant SCCP release from waste disposal. The transport pattern was well fitted by the Boltzmann equation after normalization in terms of soil organic carbon contents. Compared to the landfill cells closed in early years, the recently closed cells contained higher concentrations but lower proportions of the short-chain congener groups, likely reflecting the SCCP use history in Tibet. In open-burning dumpsites, higher SCCP levels and dominance of lighter congener groups indicates that such crude waste treatment process might cause an extra release of volatile SCCPs. This study elucidates local SCCP inputs to the background environment, and demonstrates that both urbanization and badly-managed landfill have been contributing to the presence of contemporary POPs in the Tibetan Plateau.

The association of liver function biomarkers with internal exposure of short- and medium-chain chlorinated paraffins in residents from Jinan, China

Chlorinated paraffins (CPs) are pervasive environmental pollutants which have been reported to be hepatotoxic by laboratory cell and animal studies. However, the related epidemiological reports on their hepatotoxic effects to humans are sparse. In this study, we evaluated the associations between six liver enzymes and serum short-chain CP (SCCP) or medium-chain CP (MCCP) concentrations of 197 residents in Jinan, China. Serum S/MCCPs were detected by quadrupole time-of-flight high-resolution mass spectrometry coupled with atmospheric pressure chemical ionization source (APCI-QTOF-HRMS), and quantified by pattern deconvolution method. The associations between total serum S/MCCP concentrations (ΣS/MCCPs) and continuous liver enzyme levels were assessed by linear regression. Odds ratios (ORs) for the effects of serum ΣS/MCCPs concentrations on liver function biomarkers dichotomized by clinical reference intervals were predicted by logistic regression, either treating ΣS/MCCPs as continuous or categorical dependents. After multivariable adjustment, linear regression results illustrated that 1-ln unit increase in serum ΣSCCPs was negatively associated with male PA levels [-6.08, 95% confidence interval (CI): -11.90, -3.25, p < 0.05], positively associated with male TB levels (1.80, 95% CI: 0.28, 3.31, p < 0.05), and positively associated with female AST levels (1.39, 95% CI: 0.07, 2.70, p < 0.05). One-ln unit increase in serum ΣMCCPs was negatively associated male PA levels (-7.56, 95% CI: -17.15, -4.03, p < 0.05). Logistic regression results suggested that male serum ΣSCCPs were associated with increased prevalence of abnormal PA (OR = 1.47 per 1 ln-unit increase, CI = 1.18, 1.82) and TB (OR = 1.75, 95% CI = 1.12, 2.76) levels, and male serum ΣMCCPs were significantly associated with increased prevalence of abnormal PA (OR = 1.43, 95% CI = 1.03, 1.97) levels. In addition, male participants with concentrations above the median ΣS/MCCPs were associated with increased risk for abnormal PA levels [SCCPs, 2.11-fold (95% CI = 1.15, 3.87); MCCPs, 1.94-fold (95% CI = 1.24, 3.03)]. Male participants with concentrations above the median ΣSCCPs were also associated with increased risk for abnormal TB levels (OR = 1.75, 95% CI = 1.12, 2.76). Conclusively, our results revealed that CP internal exposure was associated with disturbed liver biomarker levels, suggesting the hepatotoxicity of both SCCPs and MCCPs to humans.

Occurrence of short- and medium-chain chlorinated paraffins in soils and sediments from Dongguan City, South China

As a group of emerging organic pollutants, chlorinated paraffins (CPs) have attracted rising global attention due to their persistence and toxicity. In this study, we have investigated the concentration levels and profiles of short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) in soils and sediments from Dongguan City, an industrial area in South China, and have also screened very short-chain chlorinated paraffins (vSCCPs) by means of ultra-high resolution liquid chromatograph coupled with an Orbitrap Fusion Tribrid mass spectrometer. The results indicated that total SCCP concentrations ranged from 6.75 to 993 ng/g (mean 172 ng/g) in soils and from 4.00 to 613 ng/g (mean 153 ng/g) in sediments, respectively. Higher MCCP levels were observed with a range of 23.9-2427 ng/g (mean 369 ng/g) in soils and 14.0-1581 ng/g (mean 493 ng/g) in sediments, respectively. The results indicated that MCCPs dominated over SCCPs in the studied region. The dominant homologues in soils and sediments were C₁₃Cl_6-7 and C₁₄Cl_7-8, C₁₃Cl₇, and C₁₄Cl_7-8, respectively. Furthermore, six vSCCP homologues (C₈Cl_7-8 and C₉Cl_5-8) in soils and four vSCCPs (C₉Cl_5-8) in sediments have been identified. Because of their higher detection frequencies, further studies should focus on the transformation mechanisms and toxicities of these vSCCPs in environmental media and biota.

Metabolism of SCCPs and MCCPs in Suspension Rice Cells Based on Paired Mass Distance (PMD) Analysis

Short-chain and medium-chain chlorinated paraffins (SCCPs and MCCPs) are mixtures of complex chemical compounds with intensive usage. They are frequently detected in various environmental samples. However, the interaction between CPs and plants, especially the biotransformation behaviors of CPs within plants, is poorly understood. In this study, 1,2,5,6,9,10-hexachlorodecane (CP-4, a typical standard of individual SCCP congeners) and 52%-MCCP (a commercial mixture standard of MCCPs with 52% chlorine content by mass) were selected as representative chemicals to explore the metabolic behaviors of SCCPs and MCCPs using suspension rice cell culture exposure systems. Both 79.53% and 40.70% of CP-4 and 52%-MCCP were metabolized by suspension rice cells, respectively. A complementary suspected screening strategy based on the pair mass distances (PMD) analysis algorithm was used to study the metabolism of CPs mediated by the plant cells. Forty and 25 metabolic products for CP-4 and 52%-MCCP, respectively, were identified, including (multi-) hydroxylation, dechlorination, -HCl- elimination metabolites, (hydroxylation-) sulfation, and glycosylation conjugates. Here, we propose a comprehensive metabolic molecular network and provide insight on degradation pathways of SCCPs and MCCPs in plants for the first time, aiding in further understanding of the transformation behaviors of CPs.

Short and medium-chain chlorinated paraffins in serum from residents aged from 50 to 84 in Jinan, China: Occurrence, composition and association with hematologic parameters

Human exposure to chlorinated paraffins (CPs) has been expected and assessed by external pathways considering their pervasive environmental occurrence. However, the deficiency of external exposure assessment in characterizing human burden is unavoidable. In addition, the associations between health outcomes and CP contents in human biospecimen are rarely assessed. In this study, we reported the occurrence and homologue profiles of short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) in serum samples from 145 residents aged from 50 to 84 in Jinan, Shandong Province of China using quadrupole time-of-flight high-resolution mass spectrometry coupled with atmospheric pressure chemical ionization source operated in negative ion mode (APCI-qTOF-HRMS). The associations between serum CP concentrations and hematologic parameters were further analyzed by linear regression. We identified high level of ∑SCCPs (median = 107 ng/g wet weight, ww; 13,800 ng/g lipid, lw), ∑MCCPs (median = 134 ng/g ww; 15,200 ng/g lw) and elevated ∑MCCPs/∑SCCPs (median = 1.12) in serum of the studied population. C₁₃-CPs and C₁₄-CPs were the most abundant SCCP and MCCP groups, respectively. While the predominant chlorine homologues among SCCPs and MCCPs were Cl_7-8-CPs. ∑SCCPs, ∑MCCPs, ∑MCCPs/∑SCCPs and the homologue patterns presented no significant variance among age, sex and BMI groups. Further explorations suggested that perturbation of hematologic homeostasis could be induced by CP exposure in a sex-specific way, reflected by significant negative associations of serum SCCP and MCCP concentrations in lipid weight basis with sex-specific hematologic parameters. This study suffered from some limitations and should be interpreted with caution. However, the CP burdens of residents in China and the subsequent health risks must be underscored.

A typical derivative and byproduct of tetrabromobisphenol A: Development of novel high-throughput immunoassays and systematic investigation of their distributions in Taizhou, an e-waste recycling area in eastern China

Environmental distribution and concentration of tetrabromobisphenol A bis- (2-hydroxyethyl) ether (TBBPA-DHEE) and tetrabromobisphenol A mono- (hydroxyethyl) ether (TBBPA-MHEE), are obscure due to the lack of available analytical methods. Here two novel immunoassays were established to systematically investigate their distributions in Taizhou, Eastern China. Five monoclonal antibodies against pollutants were generated with two designed haptens through animal immunization. After matched with different coating antigens/antibodies, ELISAs were established (LOD for TBBPA-DHEE, 0.12 ng/mL, based on OVA-M3/mAb-D4G6; LOD for TBBPA-MHEE, 0.79 ng/mL, based on OVA-M3/mAb-D2G6) and applied for investigation of their occurrences at a typical e-waste recycling area after 2-year samples collection, where the total 33 water, 32 soil and 16 biological samples were collected with the highest concentrations of 3.46 ng/mL, 2.76 ng/g (dry weight, dw) and 5.01 ng/g (dw), respectively. Meanwhile, our study also indicated that at the centralizing e-waste recycling sites the serious pollution for both chemicals still existed despite of various efforts. Besides, obvious improvements were observed at an abandoned e-waste recycling region treated and remedied for many years by the local Chinese government. These findings highlight the importance of policy decisions in treatment of pollutants to reduce organic pollutant-related health risks.

Distributions and Congener Group Profiles of Short-Chain and Medium-Chain Chlorinated Paraffins in Cooking Oils in Chinese Markets

Chlorinated paraffins (CPs) are organic pollutants that have caused widespread concerns in recent years. Because of their lipophilic characteristics, CPs may enter into the body through diet or other routes and exert adverse effects on human health. In this study, we investigated the occurrence and congener profiles of short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) in 176 cooking oils and 19 oil containers collected from various markets in China. The concentrations of SCCPs and MCCPs in cooking oils were in the range of not detected (ND) to 16,055 ng/g and ND to 11,612 ng/g, respectively, and the geomean concentrations of MCCPs were lower than those of SCCPs. The concentrations of CPs in sesame oil, rapeseed oil, and camellia oil were higher than those in other types of oils, and different oil processing methods had different effects on the presence of CPs in the oils. CPs were detected in 5 out of 20 oil containers, although their concentrations were much lower than those detected in the oil samples, indicating that containers are not the main sources of CPs detected in the oils. The mean SCCP and MCCP intakes through cooking oils of the general Chinese population were 8.83 and 6.09 μg/kg/d, respectively.

Short- and medium-chain chlorinated paraffins in multi-environmental matrices in the Tibetan Plateau environment of China: A regional scale study

Research on the environmental fate and behavior of short- and medium-chain chlorinated paraffins (SCCPs and MCCPs, respectively), especially in high-altitude remote mountain areas, has rarely been conducted. In this study, the distribution and profiles of SCCPs and MCCPs in soils, barks, needles, lichens, and mosses in the Tibetan Plateau area were investigated during the period from 2010 to 2016. The total CP concentrations in soils, barks, needles, lichens, and mosses increased with increasing altitude from 1983 to 5147 m a.s.l. (above sea level), covering a range of 1843.5 km × 370.6 km. Generally, the mean SCCP levels were higher than mean MCCP levels in different environmental matrices. Moreover, as-obtained linear relationships between CP concentrations in different environmental matrices and altitudes (p < 0.05) indicated that the mountain cold-trapping could affect the presence and congener patterns of both SCCPs and MCCPs in the Tibetan Plateau environment. C_10-11 and C₁₄ congener groups were found to be the dominant groups in SCCPs and MCCPs in the environmental samples, respectively. Finally, the back-trajectory model was employed to reveal the differences of the potential sources in different regions of the Tibetan Plateau.

Exploratory analysis and ranking of analytical procedures for short-chain chlorinated paraffins determination in environmental solid samples

Short-chain chlorinated paraffins are ones of the most recent chemical compounds that have been classified as persistent organic pollutants. They have various applications and are emitted to the environment. Despite the fact, that the content levels of these compounds in the environmental compartments should be monitored, there is still a lack of well-defined and validated analytical procedures, proposed or suggested by the national or international environmental protection agencies. Finding an appropriate analytical procedure (sensitive and green at the same time) from many available ones is very often a difficult task. Therefore it can be supported with multicriteria decision analysis. The dataset consisting of 22 procedures was described by 7 criteria, mainly referring to procedures greenness. The data treatment with cluster analysis and principal component analysis revealed the internal structure of the dataset. Moreover, both statistical tools allowed for reduction of dataset criteria to three. This was used for applying ternary plot to show the multicriteria decision analysis results within all possible weights. With the aid of chemometric and multicriteria decision analysis tools it was easy to assess the set of analytical procedure. Depending on the applied weights to assessment criteria different analytical procedures are the most appropriate (winners).

Transformation of 1,1,1,3,8,10,10,10-octachlorodecane in air phase increased by phytogenic volatile organic compounds of pumpkin seedlings

Short chain chlorinated paraffins (SCCPs) are widely distributed persistent organic pollutants (POPs). Airborne chlorodecanes were hypothesized to be transformed by reactive phytogenic volatile organic compounds (PVOCs) in our previous work. To test this hypothesis, PVOCs of pumpkin (Cucurbita maxima x C. moschata) were collected and reacted with 1,1,1,3,8,10,10,10-octachlorodecane in the air phase of a sealed glass bottle under illumination for 10 days (reaction system I, simulating atmospheric reaction conditions with PVOCs). The reaction control group (reaction system II) was set at the same conditions but only had chlorodecane (without PVOCs) inside the bottle. Transformation of SCCPs in the air phase of reaction control group was unexpectedly found. Results showed that 1,1,1,3,8,10,10,10-octachlorodecane was transformed to a great extent to C₁₀Cl_5-8, C₉Cl_6-8, and C₈Cl_7-8 in the air phase after 10-d illumination in both with and without the presence of PVOCs, which is explained by carbon chain decomposition, dechlorination and chlorine rearrangement products of the parent SCCP. Those transformation processes were increased to some extent by the PVOCs from pumpkin seedlings. This study provides the first experimental data on atmospheric transformation of SCCPs and also the first evidence that plant emissions (PVOCs) can increase the transformation of SCCPs in air under light and experimental conditions. It provides new insight into the potential transformation and fate of CPs in the environment.

The environmental distribution and toxicity of short-chain chlorinated paraffins and underlying mechanisms: Implications for further toxicological investigation

Short-chain chlorinated paraffin (SCCP) pollution has become a global threat. Much attention has been paid to their environmental occurrence and toxicity. In this review, we summarized the wide distribution of SCCPs in various environmental matrices and biota, including human beings. Toxicokinetics and the toxicities of SCCPs, including lethality, hepatotoxicity, developmental toxicity, carcinogenicity, endocrine- and metabolism-disrupting effects, and immunomodulatory effects have been considered. The mechanisms of SCCP toxicity are mainly related to oxidative stress, metabolic disturbance, endocrine disruption and binding to biomacromolecules. In the future, further studies of SCCPs should focus on searching for their novel toxicity targets, and uncovering their toxic effects using transcriptomics, proteomics, metabolomics, and mutigenerational toxicity.

Shorter than short-chain: Very short-chain chlorinated paraffins (vSCCPs) found in wildlife from the Yangtze River Delta

Very short-chain chlorinated paraffins (vSCCPs, C_6-9) occurred in 94% of wildlife samples from the Yangtze River Delta (YRD), China, with C_nCl_m comparable to that of a local CP product, CP-52. Therefore, we determined the content of vSCCPs in CP-52 using a mathematical deconvolution technique. Then with CP-52 and several other reference standards, vSCCPs together with short-, medium-, and long-chain CPs were quantified in 21 wildlife species from an artificial wetland ecosystem and a freshwater ecosystem in the YRD. Concentrations of vSCCPs ranged from 2.6 to 8400 ng/g lipid. These concentrations were 1.2-380 fold lower than SCCPs, but were significantly correlated with those of SCCPs. vSCCP concentrations were comparable to or higher than reported for brominated flame retardants in the same samples. Bioaccumulation tendency of vSCCPs was identified in two benthic species, indicating congener-specific accumulation of vSCCPs in the environment.

Analytical procedures for short chain chlorinated paraffins determination - How to make them greener?

The aim of the following paper was to gather current scientific information about the analytical protocols dedicated to measuring the content level of short-chain chlorinated paraffins (SCCPs) in various types of environmental samples. Moreover, the data about the basic validation parameters of applied procedures for SCCPs determination are listed. The main issue which is highlighted in the paper is the possibility of the application of green analytical chemistry (GAC) principals in the SCCPs measuring process to reduce the environmental impact of the applied methodology. Analytical methods dedicated to SCCPs determination contain a significant number of steps and require advanced analytical equipment during the quantitative and qualitative analysis. In addition, there is a substantial issue associated with the reliability of the obtained results, especially in the case of the quantification of individual SCCPs in the studied samples. Due to this fact, the paper attempts to discuss the various stages of the analytical procedure, in which appropriate changes in the formula or equipment solutions might be introduced to ensure a better quality of the analytical results, as well as to meet the requirements of the philosophy of green analytical chemistry. The most important case which concerns this subject is finding an optimal consensus between the economic and logistic aspects and the quality and "greenness" of the analytical procedure employed in SCCPs determination process.

Migration of chlorinated paraffins from plastic food packaging into food simulants: Concentrations and differences in congener profiles

Human exposure to chlorinated paraffins (CPs) is of increasing concern for human health. Previous studies have focused on human CP exposure through food intake; however, the migration behaviors of CPs from food packaging into food are yet to be assessed. Herein, we used four food simulants (water, 3% acetic acid, 15% ethanol, and hexane) to investigate the migration of CPs from food packaging into food. The average migration efficiencies of short-chain chlorinated paraffins (SCCPs) (12.15%) were significantly higher than medium-chain chlorinated paraffins (MCCPs) (1.51%) except in hexane food simulants (ANOVA, p < 0.05). Differences in congener profiles of CPs were found in food simulants, compared with in food packaging. In food simulants, C₁₀-congener groups were predominant in SCCP carbon homologues and Cl₆-and Cl₇-congener groups were predominant in chlorine homologues. The shorter chain and lower chlorinated congener groups of CPs had higher migration efficiencies. Moreover, the average estimated dietary intakes of SCCPs and MCCPs due to migration were 12.8 and 10.3 ng/kg·bw/day, respectively. These results revealed that migration of CPs from food packaging into food does not pose immediate risks to human health.

Accumulation of Short-, Medium-, and Long-Chain Chlorinated Paraffins in Marine and Terrestrial Animals from Scandinavia

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.

Methods for trace analysis of short-, medium-, and long-chain chlorinated paraffins: Critical review and recommendations

Many methods for quantifying chlorinated paraffins (CPs) yield only a total concentration of the mixture as a single value. With appropriate analytical instrumentation and quantification methods, more reliable and detailed analysis can be performed by quantifying total concentrations of short-, medium-, and long-chain CPs (SCCPs, MCCPs, and LCCPs), and in the current optimal situation by quantifying individual carbon-chlorine congener groups (C_nCl_m). Sample extraction and clean-up methods for other persistent organochlorines that have been adapted for recovery of CPs must be applied prior to quantification with appropriate quality assurance and quality control to ensure applicability of the methods for SCCPs, MCCPs, and LCCPs. Part critical review, part tutorial, and part perspective, this paper provides practical guidance to analytical chemists who are interested in establishing a method for analysis of CPs in their lab facilities using commercial reference standards, or for expanding existing analysis of total CPs or SCCPs to analysis of SCCPs, MCCPs, and LCCPs, or to analysis of C_nCl_m congener groups.

Polychlorinated biphenyls in apple snails from an abandoned e-waste recycling site, 2010-2016: A temporal snapshot after the regulatory efforts and the bioaccumulation characteristics

The rudimentary recycling of electronic waste (e-waste) has been banned in China since the late 2000s, leaving many abandoned e-waste sites. However, knowledge is limited on the concentrations and fates of the e-waste derived contaminants such as polychlorinated biphenyls (PCBs) in these abandoned sites. In this work, we assessed the temporal trend of PCB concentrations in the year 2010, 2012, and 2016 at an abandoned e-waste site in South China, using apple snail as a bioindicator. The mean ∑PCBs concentrations in apple snails sampled in 2016 (53.2 ng/g dry weight) was approximately 11-fold higher than that (4.68 ng/g dry weight) in apple snails from a reference site. The result suggested that the abandoned e-waste recycling site was still heavily polluted by PCBs, despite of the fact that crude e-waste recycling processes have been prohibited for nearly 10 years. The concentrations of ∑PCBs were significantly decreased in 2016 compared to those in 2010 (mean: 115 ng/g dry weight) and 2012 (mean: 92.3 ng/g dry weight), but there were no significant differences in the concentrations between 2010 and 2012. Regarding the congener profiles, the contributions of lower chlorinated congeners (tri- and tetra-PCBs) in the snails tended to be higher over the years. The ∑PCBs in snails were significantly correlated with those in soils. Additionally, PCB profiles in snails resembled those in soils. These results suggested that apple snails can be used as an ideal bioindicator for PCBs in the paddy soils. Field determined biota-soil accumulation factors (BSAFs) for PCBs ranged from 0.31 to 1.9, with most of the values being 1-2; indicating that theoretical BSAFs can be used to predict the bioaccumulation of PCBs in the snails with a reasonable degree of certainty.

Spatial distributions and transport implications of short- and medium-chain chlorinated paraffins in soils and sediments from an e-waste dismantling area in China

To investigate the spatial distributions, potential transport and ecological risks of chlorinated paraffins (CPs) in and around e-waste dismantling area, we collected soil samples within 5 km of the e-waste dismantling centers and sediment samples in the surrounding area from the lower reaches of Jiaojiang River. Short- and medium-chain chlorinated paraffins (SCCPs and MCCPs) were analyzed by two-dimensional gas chromatography coupled with electron-capture negative-ionization mass spectrometry (GC × GC-ECNI-MS). The SCCP and MCCP concentration ranges in soils were 68.5 to 2.20 × 10⁵ ng/g dry weight (dw) and 507 to 4.40 × 10⁶ ng/g dw, respectively. The ranges for the levels of SCCPs and MCCPs in sediments were 32.5-1.29 × 10⁴ ng/g dw and 271-2.72 × 10⁴ ng/g dw, respectively. No significant correlation was observed between total organic carbon (TOC) and CP concentrations (P > 0.05). The spatial distributions showed that the CP levels were closely related to e-waste pollution. Correspondence analysis revealed that shorter-chain and less chlorinated congeners were enriched in sediments from sites distant from e-waste pollution source, while longer-chain and higher chlorinated congeners were concentrated in soils and sediments collected near the pollution source, which indicated that complex environmental processes, such as transportation via atmosphere and/or water, and deposition, resulted in different CP profiles in different sampling locations and environment matrixes (e.g., soil and sediments). Principal component analysis (PCA) indicated that e-waste pollution could be the same source of SCCPs and MCCPs. The preliminary risk assessment indicated that CPs in soils within 1 km of e-waste dismantling centers at current levels posed a considerable risk to soil-dwelling organisms, and the sediment MCCPs in Jiaojiang estuary at present levels also posed a risk to sediment-dwelling organisms.

Short-chain chlorinated paraffin (SCCP) pollution from a CP production plant in China: Dispersion, congener patterns and health risk assessment

China is the largest chlorinated paraffin (CP) producer in the world. Given that CP production is a major source of short-chain CP (SCCP) pollution in China, the effects of CP production on the environment inside and outside of CP production plants are worth revealing. The concentrations and specific congener group patterns of SCCPs in various environmental matrices, such as air, soil and dust, inside and outside of a chosen CP production plant surrounded by farmlands and villages were analyzed to explore SCCP pollution and transportation behaviors. SCCP concentrations in air (129-1442 ng/m³) and soil (28-554 μg/g) samples inside the CP production plant were dramatically higher than those in air (91-333 ng/m³) and soil (102-441 ng/g) samples outside the CP production plant. Based on the congener abundance patterns among these samples, lighter groups (C_10-11 and Cl_5-6) were dominant in atmospheric environment, with greater long-range transport potential, whereas heavier groups (C_12-13 and Cl_7-10) were inclined toward deposition. It was clear that substantial amounts of SCCPs were released from the CP production plant, which contaminated the environment inside and outside of the plant. The daily occupational SCCP exposure of employees in the production hall (21.8 μg/day-kg) exceeded the tolerable daily intake (TDI, 10 μg/day-kg) given by Canadian Environmental Protection Act, suggesting that production employees were confronted with high health risk from SCCP exposure; while daily SCCP exposure of employees in office areas (0.57 μg/day-kg) and residents near the CP plant (1.22-25.5 × 10^-2 μg/day-kg) were significantly lower, representing low health risk.

Combined Effects of Dust and Dietary Exposure of Occupational Workers and Local Residents to Short- and Medium-Chain Chlorinated Paraffins in a Mega E-Waste Recycling Industrial Park in South China

Four types of dust samples and nine categories of locally produced staple foods were collected from a mega e-waste recycling industrial park and its surrounding regions, and simultaneously analyzed for short-chain and medium-chain chlorinated paraffins (CPs) to estimate dust and dietary exposure and their combined effects on occupational workers and local residents. All samples related to e-waste activities contained considerably high concentrations of CPs. The highest dust concentration was found in e-waste workshops. CPs were highly accumulated in local plant and animal origin foods, most markedly in fish, vegetables, and rice. The main contribution to CP intake under a median exposure scenario was from the diet, and vegetables, fish, and rice were the three largest dietary intake sources. Only the combined dust and food exposure from the present study has approached or even exceeded the highest tolerable daily intake (TDI) set up by the International Program on Chemical Safety (IPCS). However, due to lack of official threshold values for CP exposure on adverse human health, there are limitations on accurate risk assessment. Considering the presence of other exposure pathways, CPs' endocrine disrupter properties, as well as the multicomponent chemical "cocktails" effects, potential high risks from CP exposure may be posed to e-waste workers and local residents.

Partitioning of Chlorinated Paraffins (CPs) to Daphnia magna Overlaps between Restricted and in-Use Categories

Chlorinated paraffins (CPs) are high-production volume industrial chemicals consisting of n-alkanes (with 10 to 30 carbon atoms in the chain) with chlorine content from 30 to 70% of weight. In Europe, the use of short chain chlorinated paraffins (SCCPs) has been restricted by the Stockholm Convention on POPs due to their PBT (persistent, bioaccumulative and toxic) properties. Medium (MCCPs) and long chain (LCCPs) chlorinated paraffins are used as substitution products. In this work we studied the partitioning behavior of five different CP technical mixtures from the established categories (2 SCCPs, 1 MCCP, 1 LCCP and 1 CP technical mixture covering all categories) using passive dosing, by determining the partitioning coefficient of CP technical mixtures between silicone and water ( K_{silicone-water}) as well as between organic matter and water ( K_oc-water). We show that both silicone-water and organic carbon-water partition coefficients overlap between different categories of CP technical mixtures. These results indicate that in-use MCCPs and LCCPs may be equally or more bioaccumulative than restricted SCCPs. For the tested mixtures, both chlorine content and carbon chain length showed a significant correlation with both K_{silicone-water} and K_oc-water.

Concentrations and congener profiles of chlorinated paraffins in domestic polymeric products in China

Chlorinated paraffins (CPs) are widely used in domestic polymeric products as plasticizers and fire retardants. In this study, concentrations and congener profiles of short-chain and medium-chain chlorinated paraffins (SCCPs and MCCPs) were investigated in domestic polymeric products, including plastics, rubber and food packaging in China. The average concentrations of SCCPs in polyethylene terephthalate (PET), polypropylene (PP), polyethylene (PE) and food packaging were 234, 3968, 150 and 188 ng/g, respectively and the corresponding average concentrations of MCCPs in these samples were 37.4, 2537, 208 and 644 ng/g, respectively. The concentrations of CPs in rubber and polyvinylchloride (PVC) were significantly higher than in other matrices. The highest concentrations of SCCPs and MCCPs were found in a PVC cable sheath with 191 mg/g and 145 mg/g, respectively. Congener group profiles analysis indicated C₁₁- and C₁₃-congener groups were predominant in carbon homologues of SCCPs, and C₁₄-congener groups were predominant in MCCPs. High levels of SCCPs and MCCPs in domestic polymeric products implied that they might be a significant source to the environment and human exposure.

Has the question of e-waste opened a Pandora's box? An overview of unpredictable issues and challenges

Despite regulatory efforts and position papers, electrical and electronic waste (e-waste) remains ill-managed as evidenced by the extremely low rates of proper e-waste recycling (e-recycling) worldwide, ongoing illegal shipments to developing countries and constantly reported human health issues and environmental pollution. The objectives of this review are, first, to expose the complexity of e-waste problems, and then to suggest possible upstream and downstream solutions. Exploring e-waste issues is akin to opening a Pandora's box. Thus, a review of prevailing e-waste management practices reveals complex and often intertwined gaps, issues and challenges. These include the absence of any consistent definition of e-waste to date, a prevalent toxic potential still involving already banned or restricted hazardous components such as heavy metals and persistent and bioaccumulative organic compounds, a relentless growth in e-waste volume fueled by planned obsolescence and unsustainable consumption, problematic e-recycling processes, a fragile formal e-recycling sector, sustained and more harmful informal e-recycling practices, and more convoluted and unpredictable patterns of illegal e-waste trade. A close examination of the e-waste legacy contamination reveals critical human health concerns, including significant occupational exposure during both formal and informal e-recycling, and persistent environmental contamination, particularly in some developing countries. However, newly detected e-waste contaminants as well as unexpected sources and environmental fates of contaminants are among the emerging issues that raise concerns. Moreover, scientific knowledge gaps remain regarding the complexity and magnitude of the e-waste legacy contamination, specifically, a comprehensive characterization of e-waste contaminants, information on the scale of legacy contamination in developing countries and on the potential environmental damage in developed countries, and a stronger body of evidence of adverse health effects specifically ascribed to e-waste contaminants. However, the knowledge accumulated to date is sufficient to raise awareness and concern among all stakeholders. Potential solutions to curb e-waste issues should be addressed comprehensively, by focusing on two fronts: upstream and downstream. Potential upstream solutions should focus on more rational and eco-oriented consumer habits in order to decrease e-waste quantities while fostering ethical and sustained commitments from manufacturers, which include a limited usage of hazardous compounds and an optimal increase in e-waste recyclability. At the downstream level, solutions should include suitable and pragmatic actions to progressively reduce the illegal e-waste trade particularly through international cooperation and coordination, better enforcement of domestic laws, and monitoring in both exporting and receiving countries, along with the supervised integration of the informal sector into the recycling system of developing countries and global expansion of formal e-waste collection and recycling activities. Downstream solutions should also introduce stronger reverse logistics, together with upgraded, more affordable, and eco-friendly and worker-friendly e-recycling technologies to ensure that benefits are derived fully and safely from the great economic potential of e-waste.

Chlorinated paraffins leaking from hand blenders can lead to significant human exposures

BACKGROUND

Chlorinated paraffins (CPs, polychlorinated n-alkanes) are versatile, high-production-volume chemicals. A previous study indicated that hand blenders leak CPs into prepared food.

OBJECTIVES

(1) to estimate exposure to CPs from hand blender use compared to background CP exposure from diet; (2) to assess the risk from human dietary exposure to CPs from hand blender use; (3) to investigate how hand blenders leak out CPs.

METHODS

CPs were analyzed in food market baskets, in cooking oil/water samples (1g oil/100mL water) mixed using 16 different hand blenders, and in dismantled components of the hand blenders.

RESULTS

Dietary intake of CPs from food market baskets was calculated to be 4.6μg/day per capita for Swedish adults. Total CP amounts in oil/water leakage samples ranged from <0.09 to 120μg using the hand blenders once. CP leakage showed no decreasing levels after 20 times of hand blender usage. CP profiles in the leakage samples matched those of self-lubricating bearings and/or polymer components disassembled from the hand blenders.

CONCLUSIONS

Usage of 75% of the hand blenders tested will lead to increased human exposure to CPs. The intake of CPs for Swedish adults by using hand blenders once a day can raise their daily dietary intake by a factor of up to 26. The 95th percentile intake of CPs via using the hand blenders once a day exceeded the TDI for Swedish infants with a body weight <7.2kg. CP leakage came from blender components which contain CPs. The leakage may last several hundred times of hand blender use.

Quantifying Short-Chain Chlorinated Paraffin Congener Groups

Accurate quantification of short-chain chlorinated paraffins (SCCPs) poses an exceptional challenge to analytical chemists. SCCPs are complex mixtures of chlorinated alkanes with variable chain length and chlorination level; congeners with a fixed chain length (n) and number of chlorines (m) are referred to as a "congener group" C_nCl_m. Recently, we resolved individual C_nCl_m by mathematically deconvolving soft ionization high-resolution mass spectra of SCCP mixtures. Here we extend the method to quantifying C_nCl_m by introducing C_nCl_m specific response factors (RFs) that are calculated from 17 SCCP chain-length standards with a single carbon chain length and variable chlorination level. The signal pattern of each standard is measured on APCI-QTOF-MS. RFs of each C_nCl_m are obtained by pairwise optimization of the normal distribution's fit to the signal patterns of the 17 chain-length standards. The method was verified by quantifying SCCP technical mixtures and spiked environmental samples with accuracies of 82-123% and 76-109%, respectively. The absolute differences between calculated and manufacturer-reported chlorination degrees were -0.9 to 1.0%Cl for SCCP mixtures of 49-71%Cl. The quantification method has been replicated with ECNI magnetic sector MS and ECNI-Q-Orbitrap-MS. C_nCl_m concentrations determined with the three instruments were highly correlated (R² > 0.90) with each other.

Occurrence, homologue patterns and source apportionment of short- and medium-chain chlorinated paraffins in suburban soils of Shanghai, China

In order to systematically investigate the spatial distribution, homologue profiles, and sources of short- and medium-chain chlorinated paraffins (SCCPs and MCCPs) in suburban soils in Shanghai, SCCPs and MCCPs in soils were analyzed using gas chromatography coupled with low resolution mass spectrometry in electron capture negative ion (ECNI) mode (GC-ECNI-MS). The CP concentrations in soils were between not detected (ND) - 697 ng g^-1 with a median value of 3.52 ng g^-1 for SCCPs, and ND - 666 ng g^-1 with a median value of 15.3 ng g^-1 for MCCPs, respectively. The concentrations of MCCPs in most soils were higher than that of SCCPs. The total CP concentrations (sum of SCCPs and MCCPs) in soils varied from ND to 964 ng g^-1 with a median value of 20.5 ng g^-1. The concentration of MCCPs was higher than that of SCCPs in most soils. The levels of SCCPs and MCCPs in suburban soils in Shanghai were at the medium level when compared to other areas around the world. No significant correlation was observed between soil CP concentrations and total organic carbon contents (p > 0.05). For different use type of soils, the median concentrations of CPs in soils were found higher in greenland than that in other areas probably due to busy traffic, sewage sludge application and/or wastewater irrigation. All soils were divided into two groups by hierarchical cluster analysis (HCA) both for SCCPs and MCCPs. Three discharge sources of CPs in suburban soil of Shanghai were identified by PMF model.

Side Chains of Parabens Modulate Antiandrogenic Activity: In Vitro and Molecular Docking Studies

Parabens have been widely used in packaged foods, pharmaceuticals, and personal-care products. Considering their potential hydrolysis, we herein investigated structural features leading to the disruption of human androgen receptor (AR) and whether hydrolysis could alleviate such effects using the recombinant yeast two-hybrid assay. Parabens with an aryloxy side chain such as benzyl paraben and phenyl paraben have the strongest antiandrogenic activity. The antiandrogenic activity of parabens with alkyloxyl side chains decreases as the side chain length increases from 1 to 4, and no antiandrogenic effect occurred for heptyl, octyl, and dodecyl parabens with the number of alkoxyl carbon atoms longer than 7. The antiandrogenic activity of parabens correlates significantly with their binding energies (R² = 0.84, p = 0.01) and were completely diminished after the hydrolysis, particularly for parabens with aryloxy side chains. The K_m for the hydrolysis of parabens with aromatic moiety side chain is 1 order of magnitude higher than that of the parabens with alkyl side chains. Both in vitro and in silico data, for the first time, suggest parabens with aromatic side chains are less prone to hydrolysis. Our results provide an insight into risk of various paraben and considerations for design of new paraben-related substitutes.