Spatiotemporal distribution and risk assessment of short-chain chlorinated paraffins in 30 major rivers in Taiwan

Multivariate statistical characterization of analytical methods for C10-C13 polychlorinated alkanes (PCAs) using interlaboratory comparison data of a reference material as a common quantification standard

Polychlorinated alkanes (PCAs) are persistent environmental pollutants with numerous congeners and homologues, making their analysis challenging. Among these, carbon chain length congener groups (i.e., C10-C13) can be analysed using both gas chromatography (GC) and liquid chromatography (LC), but differences in ionization methods between these techniques can introduce analytical biases. To address this issue, we reanalysed data from the earlier interlaboratory comparisons using a common quantification standard and applied multivariate statistical analysis to elucidate methodological differences. First, we characterized the common quantification standard across different ionization methods and identified its distinctive features. Subsequently, we extracted results from participating laboratories that employed identical analytical methods in the earlier interlaboratory comparison and conducted a multivariate statistical analysis. Our case study with limited analytical samples revealed that specific chain length congener and homologue groups are associated with different ionization techniques. Recognizing these homologue group patterns is crucial for accurate source identifications in environmental monitoring and appropriate estimations of key ecological factors such as biomagnification.

Fate and ecological risk of legacy and emerging POPs in coastal waters in China

Short-chain chlorinated paraffins (SCCPs) and dechlorane plus (DPs) are persistent organic pollutants of emerging concern, however, little is known of their fate and ecological risks in coastal waters compared to legacy contaminants in marine environment. Here, we analyzed SCCPs, 2 DP isomers as well as legacy contaminants including 24 organochlorine pesticides and polychlorinated biphenyls (PCBs) in seawater from Hangzhou Bay (HZB) and Liaodong Bay (LDB) for comparison using GC-Orbitrap MS. The total contaminant load in seawater was dominated by SCCPs with the highest detection frequency, in concentrations ranging from 25.38 to 388.23 ng/L in HZB and 7.45 to 144.48 ng/L in LDB, respectively. The congener patterns of SCCPs differed significantly, where HZB was predominated by C11-13-CPs (accounted for 83 %) and C10-CPs (40.4 %) was the most abundant in LDB. SCCPs were positively correlated with legacy contaminants in HZB, indicating similar sources. In terms of legacy contaminants, HZB exhibited higher levels of hexachlorobenzene, whereas LDB showed a prevalence of hexachlorocyclohexane. The ocean current in HZB and direct terrestrial input with the impact of intensive human activities around LDB were suggested to attribute to their spatial distribution characteristics, respectively. The contaminants were identified to have medium risks to aquatic organisms by using the risk quotient method. SCCPs contributed most with proportions of 45 % and 80 % for HZB and LDB, the monitoring of which needs to be strengthened in the future.

Investigating the research landscape of chlorinated paraffins over the past ten decades

Chlorinated paraffins (CPs) are classified as emerging persistent organic pollutants (POPs). Due to their associated environmental and health impacts, these groups of chemicals have been a subject of interest among researchers in the past decades. Here we used a scientometric approach to understand the research landscape of CPs using literature published in the Web of Science and Scopus database. RStudio and VOSviewer programs were employed as scientometric tools to analyze the publication trends in global CP-related research from 1916 to 2024. A total of 1,452 articles were published over this period, with a publication/author and co-author/publication ratio of 0.43 and 5.49, respectively. China ranked first in publication output (n = 556, 43.3%), and the highest total citations (n = 12,007), followed by Sweden (n = 90), Canada (n = 77), and Germany (n = 75). Publications from developing countries were limited, with most contributions from Africa originating from Egypt (n = 7), South Africa (n = 5), and Nigeria (n = 3), primarily through international collaborations. The average annual growth rate of 4.3% suggests a significant future article output. This scientometric analysis allowed us to infer global trends in CPs, identify tendencies and gaps, and contribute to future research. Despite having similar toxicity to short-chain chlorinated paraffin (SCCP), long-chain chlorinated paraffin (LCCP) has received less attention. Therefore, future research should prioritize studying LCCP bioaccumulation and toxicity in diverse food webs, focusing on aquatic species vulnerable to CPs and effective toxicological models. Additionally, collaborative research with developing countries should be encouraged to enhance meeting the Stockholm Convention's demand.

Unveiling the Presence of Short- and Medium-Chain Chlorinated Paraffins in the Hadal Trenches of the Western Pacific Ocean

This study delves into the unexplored distribution and accumulation of chlorinated paraffins (CPs), pervasive industrial contaminants used as flame retardants and plasticizers, within the hadal trenches, some of Earth's most isolated marine ecosystems. Analysis of sediments from the Mussau (MS) and Mariana trench (MT) reveals notably high total CP concentrations (∑SCCPs + ∑MCCPs) of 10,963 and 14,554 ng g-1 dw, respectively, surpassing those in a reference site in the western Pacific abyssal plain (8533 ng g-1 dw). In contrast, the New Britain Trench (NBT) exhibits the lowest concentrations (2213-5880 ng g-1 dw), where CP distribution correlates with clay content, δ13C and δ15N values, but little with total organic carbon and depth. Additionally, amphipods from these trenches display varying CP levels, with MS amphipods reaching concerning concentrations (8681-16,138 ng g-1 lw), while amphipods in the MT-1 site show the lowest (4414-5010 ng g-1 lw). These bioaccumulation trends appear to be primarily influenced by feeding behaviors (δ13C) and trophic levels (δ15N). Utilizing biota-sediment accumulation factor values and principal component analysis, we discern that CPs in sediment may come from surface-derived particulate organic matters, while those in amphipods may come from the above carrion. Our findings elucidate the profound impacts of the emerging pollutants on the Earth's least explored marine ecosystems.

Spatial distribution and ecological risk assessment of short and medium chain chlorinated paraffins in water and sediments of river Ravi, Pakistan

Short (SCCPs) and medium (MCCPs) chain chlorinated paraffins being the emerging organic pollutants have raised serious concerns due to their widespread use and related human health risks. However, their occurrence in aquatic bodies like rivers and associated damage to ecological integrity is yet unknown in some regions of the world. The current study is the first ever assessment of SCCPs and MCCPs in sediment and water of river Ravi, Pakistan. Spatial occurrence and associated ecological risks were investigated from sediments (n = 16) and composite water samples (n = 8) collected at eight locations along the stretch of river Ravi. The concentrations of SCCPs and MCCPs varied from below limit of detection ( Collapse

Key Words

• Aquatic body
• Partitioning coefficient
• Risk assessment
• Source identification
• Total organic carbon

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MESH Headings

• Humans
• Animals
• Chlorine
• Hydrocarbons, Chlorinated/analysis
• Paraffin/analysis
• Rivers
• Pakistan
• Environmental Monitoring
• Risk Assessment
• Carbon
• China

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Grants Collapse

Affiliation(s)

Areej Tahir College of Earth and Environmental Sciences, University of the Punjab, Lahore 54590, Pakistan
Naeem Akhtar Abbasi College of Earth and Environmental Sciences, University of the Punjab, Lahore 54590, Pakistan.
Chang He Queensland Alliance for Environmental Health Science, The University of Queensland, Brisbane 4102, Australia; Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, PR China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, PR China
Sajid Rashid Ahmad College of Earth and Environmental Sciences, University of the Punjab, Lahore 54590, Pakistan
Mujtaba Baqar Sustainable Development Study Centre, Government College University, Lahore 54000, Pakistan
Abdul Qadir College of Earth and Environmental Sciences, University of the Punjab, Lahore 54590, Pakistan

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Chlorinated Paraffin Pollution in the Marine Environment

Chlorinated paraffins (CPs) are ubiquitous in the environment due to their large-scale usage, persistence, and long-range atmospheric transport. The oceans are a critical environment where CPs transformation occurs. However, the broad impacts of CPs on the marine environment remain unclear. This review describes the sources, occurrence and transport pathways, environmental processes, and ecological effects of CPs in the marine environment. CPs are distributed in the global marine environment by riverine input, ocean currents, and long-range atmospheric transport from industrial areas. Environmental processes, such as the deposition of particle-bound compounds, leaching of plastics, and microbial degradation of CPs, are the critical drivers for regulating CPs' fate in water columns or sediment. Bioaccumulation and trophic transfer of CPs in marine food webs may threaten marine ecosystem functions. To elucidate the biogeochemical processes and environmental impacts of CPs in marine environments, future work should clarify the burden and transformation process of CPs and reveal their ecological effects. The results would help readers clarify the current research status and future research directions of CPs in the marine environment and provide the scientific basis and theoretical foundations for the government to assess marine ecological risks of CPs and to make policies for pollution prevention and control.

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.