Ecotoxicity assessment of short- and medium-chain chlorinated paraffins used in polyvinyl-chloride products for construction industry

Occurrence and fate of atmospheric short/medium chain chlorinated paraffins: Size distribution and inhalation exposure

Chlorinated paraffins (CPs) are intricate industrial compounds synthesized through alkane chlorination. Researches on the size distribution of short-chain (SCCPs) and medium-chain chlorinated paraffins (MCCPs) in atmospheric particulate matter (PM) are limited. Here, we conducted a thorough investigation on the size-dependent distribution characteristics, deposition behavior in respiratory tract, and health risks associated with CPs in atmospheric PM. The concentration of SCCPs in atmospheric particulate matter (PM10) was much higher than MCCPs, with concentration ranges of 2.53-31.8 and 1.07-4.62 ng m-3, respectively. Concentrations of CPs increase with decreasing PM size, peaking at aerodynamic diameters (Dp) < 0.49 μm. Physicochemical properties influence the distribution of CP homologs in PM. Those with lower vapor pressure, higher octanol-air and octanol-water partition coefficients tended to accumulate in PM with larger geometric mean diameters. Most of the inhaled CPs in PM deposited in the upper airways, with a small amount in the trachea and alveolar regions. The estimated daily intakes values were highest when Dp < 0.49 μm. Particle size is an essential determinant for the deposition of inhaled CPs in PM and should be considered in health risk assessments.

Paraffin waxes in the North-Western Mediterranean Sea: A comprehensive assessment in the Pelagos Sanctuary, a Specially Protected Area of Mediterranean Importance

Paraffin waxes are widely recognized as emerging marine pollutants, even their classification by the recent monitoring programs and the knowledge of their occurrence, and sources of contamination in marine ecosystems are poorly defined and reported. Wax presence and distribution have been evaluated in different environmental compartments in the Pelagos Sanctuary (Mediterranean Sea) floating on the sea surface and stranded on beaches, focussing on their characterization, accumulation areas and pollution inputs. More than 2500 yellow paraffin residues were detected and analysed in the study area showing a prevailing dimension smaller than 5 mm. The Genoa Canyon and the waters facing Gorgona Island resulted in the more polluted areas representing two distinct hotspots of wax accumulation potentially related to the high density of tanker vessels sailing to and from the harbour of Genova and Livorno. Higher concentrations of beached particles were found along the Tuscan coast (11 items/100 m) and on Pianosa Island (110 items/m2). This study gives valuable insights into paraffin wax pollution in the Pelagos Sanctuary, emphasizing the need for harmonized monitoring and detection methods to elucidate the potential impacts on marine organisms. Moreover, mitigating actions are crucial to prevent and curb the waxes pollution of marine ecosystems.

Short- and medium-chain chlorinated paraffins in sediment from the Haihe River Basin: Sources, distributions, and ecological risk assessment

Chlorinated paraffins (CPs) can accumulate in sediment and pose risks to ecological systems and human health. The Haihe River Basin is one of the seven main river basins in China and is mainly in the Beijing-Tianjin-Hebei region, which is densely populated and very urbanized. There is therefore a high probability of CP pollution in the Haihe River Basin. However, CP pollution and the environmental risks posed by CPs in the Haihe River are not well understood. In this study, the concentrations of short-chain CPs (SCCPs) and medium-chain CPs (MCCPs) in sediment from six rivers in the Haihe River Basin system were determined using two-dimensional gas chromatography electron-capture negative ionization mass spectrometry. The total SCCP and MCCP concentrations in the sediment samples ranged from 131.83 to 1767.71 and from 89.72 to 1442.82 ng/g dry weight, respectively. The total organic carbon content did not significantly correlate with the CP concentrations. The dominant SCCP congener groups were C10Cl6-7 and the dominant MCCP congener groups were C14Cl7-8. Significant relationships (R = 0.700, p < 0.05) were found between the SCCP and MCCP concentrations, indicating that SCCPs and MCCPs may have similar sources. Hierarchical cluster analysis and principal component analysis indicated that sediment in the study area was contaminated with CPs through the use of the CP-42 and CP-52 commercial products in industrial processes and human activities. The ecological risks posed by CPs were assessed and SCCPs were found to pose high risks in the Yongding New River but moderate risks in the other rivers. MCCPs were found to pose minimal risks to the aquatic environment at most of the sampling points.

The Rise of Trichlorides Enabling an Improved Chlorine Technology

Chlorine plays a central role for the industrial production of numerous materials with global relevance. More recently, polychlorides have been evolved from an area of academic interest to a research topic with enormous industrial potential. In this minireview, the value of trichlorides for chlorine storage and chlorination reactions are outlined. Particularly, the inexpensive ionic liquid [NEt₃ Me][Cl₃ ] shows a similar and sometimes even advantageous reactivity compared to chlorine gas, while offering a superior safety profile. Used as a chlorine storage, [NEt₃ Me][Cl₃ ] could help to overcome the current limitations of storing and transporting chlorine in larger quantities. Thus, trichlorides could become a key technique for the flexibilization of the chlorine production enabling an exploitation of renewable, yet fluctuating, electrical energy. As the loaded storage, [NEt₃ Me][Cl₃ ], is a proven chlorination reagent, it could directly be employed for downstream processes, paving the path to a more practical and safer chlorine industry.

The impact of three related emission industries on regional atmospheric chlorinated paraffins pollution

Identifying the contributions of various chlorinated paraffins (CPs) sources in the environment plays an important practical role in the prevention and control of the CPs contamination. However, little is known about how main CP-related emission industries affect the regional atmospheric characteristics of CPs, including CP products industry, metal working industry, and polyvinyl chloride (PVC) industry. In this study, 60 passive air samples were collected from five typical cities in Henan Province, China, which had serious CP pollution and different structures of CP-related emission industry. Short chain CPs (SCCPs) and medium chain CPs (MCCPs) were detected in all samples in concentrations ranging of 2.6-7.7 × 10² and 2.1-4.3 × 10² ng m^-3, respectively, which were higher than those in most reports. Moreover, Luoyang (LY) is different from other cities, showing a relatively severe MCCP contaminations. The CP pollution characteristics between different cities are obviously affected by the proportion of local CP-related industries. According to the results of cluster heatmaps, the local CP-related emission industrial structure had a greater impact on MCCPs pollution than SCCPs. Additionally, the contribution of metal working industry was beyond that of PVC production industry and CP products industry.

Semiquantitative Characterization of Bromo-chloro Paraffins and Olefins in the Australian Environment

A semiquantitative high-resolution mass spectrometry method was developed and applied to assess the occurrence of bromo-/chloro paraffins (BCPs) and olefins (BCOs) in the environment. More than 400 possible BCPs and BCO congener groups were detected in dust, air, and sewage sludge samples collected from Australia. Median chain analytes with the number of halogen atoms <7 (C_nH_mCl_xBr_y, 14 ≤ n ≤ 17, x + y < 7) prevailed in the dust and sludge samples, while short chain analytes (C_nH_mCl_xBr_y, 10 ≤ n ≤ 13, x + y < 7) predominated the air samples. The estimated concentrations of ∑BCPs and ∑BCOs in dust and sludge were approximately 20% that of the chlorinated paraffins (CPs) present, with the median concentrations of 5.4 μg/g (dust) and 0.18 μg/g (sludge) for ∑BCPs and 22 μg/g (in dust) and 0.50 μg/g (sludge) for BCOs. In the air samples, the concentrations of BCPs (0.020 pg/m³) and BCOs (0.032 pg/m³) were 3-4 orders of magnitudes lower than the concentrations of CPs (790 pg/m³). Significant correlations (P < 0.001) were found between the concentration of CPs, BCPs, and BCOs in all the matrices.

First ecotoxicological characterization of paraffin microparticles: a biomarker approach in a marine suspension-feeder, Mytilus sp

Microplastics are one of the main environmental pollutants in marine ecosystems, and their presence in seawater is a consequence of the widespread use of plastic materials in modern commodities. This wide usage of plastics includes the employment of microspheres in common personal care products, which end up being ultimately released into the aquatic compartment. Known ecotoxicological effects of microplastics favoured the search for technologically viable and environmentally safer alternatives, such as paraffin wax microparticles, whose ecotoxicological risks have not been entirely characterized. To address this gap, the present study exposed mussels (Mytilus sp.) for 96 h to three densities (5 mg/L, 20 mg/L and 80 mg/L) of four size ranges (100-300 μm, 300-500 μm, 400-850 μm, and 800-1200 μm) of paraffin wax particles. Toxicological endpoints were the activities of four enzymes involved in key cellular processes, including antioxidant defence (catalase (CAT), glutathione reductase (GRed) and glutathione peroxidase (GPx)) and phase II metabolism (glutathione S-transferases (GSTs)), as well as lipid content and fatty acid profiles of the digestive gland. Significant interactions between the presence/absence of food and paraffin particle density were found, as food sometimes worked as a confounding factor in the analysed biomarkers. Despite this uncertainty, some overall patterns emerged. In general, smaller paraffin wax particles (100-300 μm) caused little effects on the activity of the four enzymes tested, whereas larger particles (800-1200 μm) caused significant effects on almost all biomarkers. CAT activity was enhanced in animals exposed to larger paraffin particles, whilst GPx activity was depressed; GRed activity was not affected by the exposure to paraffin particles. The activity of GSTs was enhanced, but only in one tested condition. No effects were observed in terms of the total lipid content and fatty acids of exposed animals. Overall, data obtained in this work suggest that, at densities of paraffin wax particles comparable to the levels found in the environment for microplastic beads, no toxicity is expected to occur in the tested mussel species, by measuring the here-assessed toxicological endpoints.

Blood partitioning and whole-blood-based maternal transfer assessment of chlorinated paraffins in mother-infant pairs from South China

As a new group of persistent organic pollutants of concern, chlorinated paraffins (CPs) have been widely detected in the environment and biota, but their occurrence, partitioning, and transfer in humans have been not well documented. In this study, 32 pairs of maternal blood, cord blood, and placenta samples were collected from pregnant women in South China, and the blood was further separated into plasma and red blood cells (RBCs) for blood partitioning study. Short- and medium-chain CPs (SCCPs and MCCPs, respectively) were detected in all the five human biological matrices, suggesting prevalent exposure and maternal transfer of CPs in the pregnant women. Discrepant congener group profiles of CPs were observed in different human biological matrices. Significant differences in the plasma-RBC partitioning of CPs in the maternal and cord bloods were identified (p < 0.001). CP partitioning to plasma was stronger than that to RBCs in maternal blood, but the converse was true for cord blood. Mass fractions in plasma (F_p) for SCCPs (mean, 0.78) and MCCPs (0.74) in maternal blood were significantly higher than the values in cord blood. Transplacental transfer efficiencies (TTEs) were evaluated based on the whole blood concentrations of CPs in the maternal and cord bloods, and the TTEs ranged from 0.50 to 0.69 (first to third quartiles) for SCCPs and MCCPs, indicating that the placenta can partially restrict maternal transfer. The extent of CP retention in the placenta was assessed by the concentration ratio (R_PM) of matched placenta and maternal blood, and interestingly, a U-shaped trend for placental retention (R_PM) with increasing chain length was observed for individual congener groups. Significant relationships of the CP concentrations among the maternal blood, cord blood, and placenta were observed (p < 0.001). To our knowledge, this is the first study to report the plasma-RBC partitioning of CPs in human maternal and cord bloods, as well as the first study to evaluate TTEs based on whole blood concentrations. Our study confirmed that whole blood is the preferred matrix for accurately assessing human internal exposure and transplacental transfer of CPs.

Short- and medium-chain chlorinated paraffins in aquatic organisms from an e-waste site: Biomagnification and maternal transfer

Chlorinated paraffins (CPs) are globally pervasive contaminants that are toxic to humans and wildlife. Inconsistent biomagnification behaviors in different food chains have been reported, and very few studies have been conducted to investigate the maternal transfer of CPs in ovoviviparous species. This study investigated the biomagnification of short- and medium-chain chlorinated paraffins (S/MCCPs) in two aquatic food chains, as well as maternal transfer of S/MCCPs in watersnakes collected from an e-waste polluted pond in southern China. The concentrations of SCCPs and MCCPs varied from 1.2 to 250 μg/g lipid weight (lw) and from 2.3 to 200 μg/g lw in the collected organisms. The SCCP homologue profiles in prey (fish and prawn) differed from those in predators (watersnake and waterbird egg), while MCCP homologue group patterns were homogeneous. All maternal transfer concentration ratios (egg to muscle) of S/MCCPs in the watersnakes were lower than 1 and negatively correlated with the octanol-water partition coefficients (log K_OW), different from the maternal transfer of halogenated aromatic pollutants in the watersnake. Biomagnification factors (BMFs) of S/MCCPs for fish-watersnake muscle food chain were larger than 1, while BMFs for the fish-waterbird egg food chain were less than 1. However, when watersnake egg was used to calculate BMF, no biomagnification was found. BMFs in the two food chains showed significant positive linear correlations with chlorine atoms, but no significant correlation with carbon atom numbers, which suggested that a congener-group-specific elimination and excretion process for S/MCCPs exist.

C12-30 α-Bromo-Chloro "Alkenes": Characterization of a Poorly Identified Flame Retardant and Potential Environmental Implications

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, C_12-30 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 K_OW (6.9 to 8.6) and estimated log K_OA (10.5 to 13.5) and log K_AW (-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.

Altitude-dependent accumulation of short chain chlorinated paraffins in fish from alpine lakes and Lhasa river on the Tibetan Plateau

High mountain cold-trapping effects can play important roles in the global long-range transport of persistent organic pollutants (POPs). Short chain chlorinated paraffins (SCCPs) have recently been included into the Stockholm Convention as a new class of POPs. However, the long-range transport behavior and environmental fate of SCCPs still remain largely unknown in high-altitude mountain areas. In this study, a total of 51 fish samples were collected from five high-altitude mountain lakes and Lasha river across the Tibetan Plateau. SCCPs were positively detected in all fish samples, and the concentrations ranged from 3.9 to 107 ng g^-1 dry weight (dw) with an average of 26.6 ng g^-1 dw. Compared to aquatic organisms from the Artic and Antarctica, the SCCP levels found in alpine fish from the Tibetan Plateau were lower. A significant increasing trend in accumulation levels of SCCPs in alpine fish with the increasing altitude was found on the Tibetan Plateau (r = 0.98, p < 0.001). Shorter chain congener group C10 showed a significant increase in percentage contribution to total SCCPs with increasing altitude, but a contrary tendency was found for longer chain congener group C13. The widespread occurrence of SCCPs in Tibetan fish was mainly sourced from the long-range atmospheric transport, and the altitude-dependent distribution of SCCPs was due to the mountain cold-trapping effects and potential susceptibility to bioaccumulation. To our knowledge, this is the first report regarding the altitude-dependent accumulation of SCCPs in biota in the polar 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.

Size-dependent distribution and inhalation exposure characteristics of particle-bound chlorinated paraffins in indoor air in Guangzhou, China

Chlorinated paraffins (CPs) are now attracting special concerns worldwide as one type of new persistent toxic substances as classified by the Stockholm Convention. CPs are extensively applied in household goods and indoor decoration materials, but information on their occurrence and exposure risk in such environments is still very scarce. In this study, the current concentrations, particle size distributions, and inhalation exposure characteristics and risk of CPs were investigated in regard to indoor air particulate matter. Both short chain (SCCPs) and medium chain CPs (MCCPs) were determined in all size-fractioned particle samples with a range of 6.20-17.8 and 5.98-40.5 ng m^-3, respectively. MCCPs were more abundant than SCCPs. Size distributions revealed that individual homologs, SCCPs, and MCCPs exhibited a similar unimodal distribution peaking in the fine particles with a diameter of 0.56-1.0 μm. The relative abundance of longer-chain or more heavily chlorinated homologs tend to gradually increase with particle size shift from coarse to fine mode. Vapor pressure may be a critical factor governing the size-dependent distribution of CPs. Deposition of particulate CPs in the human respiratory tract is also size-dependent. The contributions of fine particles to the regional depositions of CPs in the human respiratory tract increase with increasing carbon chain length or chlorine content. Based on the size-dependent distributions of CPs, inhalation exposure assessment from the ICRP model indicated no significant health risk due to CPs in current indoor environments.

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.