Complex Mixture Analysis of Emerging Contaminants Generated from Coal Tar- and Petroleum-Derived Pavement Sealants: Molecular Compositions and Correlations with Toxicity Revealed by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry.

Pavement sealants are of environmental concern because of their complex petroleum-based chemistry and potential toxicity. Specifically, coal tar-derived sealants contain high concentrations of toxic/carcinogenic polycyclic aromatic hydrocarbons (PAHs) that, when weathered, can be transferred into the surrounding environment. Previous studies have demonstrated the effects of coal tar sealants on PAH concentration in nearby waterways and their harmful effects in aquatic ecosystems. Here, we investigate and compare the molecular composition of two different pavement sealants, petroleum asphalt- and coal tar-derived, and their photoproducts, by positive-ion (+) atmospheric pressure photoionization (APPI) and negative-ion (-) electrospray ionization (ESI) coupled with ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry to address species (high-boiling and/or high oxygen content) that lie outside the analytical window of other techniques due to ultra-high molecular complexity. In addition, we evaluate the toxicity of the water-soluble photoproducts by use of Microtox bioassay. The results demonstrate that the coal tar sealant contains higher amounts of PAHs and produces abundant water-soluble compounds, relative to unweathered materials, with a high abundance of PAH-like molecules of high toxicity. By comparison, the asphalt sealant produces fewer toxic water-soluble species, with molecular compositions that are consistent with natural dissolved organic matter. These results capture the mass, chemical diversity, toxicity, and source/photoproduct relationship of these compositionally complex emerging contaminants from the built environment.

Detoxification modification of coal-tar pitch by ultraviolet & microwave radiation-enhanced chemical reaction and toxicity evaluation by chemical index and cytotoxicity assay in vitro.

Although coal tar pitch (CTP) has a large yield in China, its large-scale and effective utilization is significantly hindered because of existing and possibly releasing polycyclic aromatic hydrocarbons (PAHs). Therefore, it is an imminent problem how to prepare an environmentally friendly CTP by detoxification modification. In the investigation, a typical CTP was subjected to structural characterization via solid-state 13C NMR and gas chromatograph/mass spectrometer, which confirmed the existence of dominant PAHs such as fluoranthene, pyrene, as well as benzo[a]pyrene, and few heterocyclic compounds. Subsequently, the CTP was modified using 10-undecenal via alkylation reaction enhanced by ultraviolet & microwave radiation. Compared with the original CTP, the total content of 16 toxic PAHs in the modified CTP decreased with a reduction efficiency of above 90%. According to different environmental standards, toxic equivalent quotient of CTP after modification was reduced by above 90%. In order to veritably and fully evaluate the toxicity of CTP, a living vascular smooth muscle cell (A-10 cell) in vitro was used in the cell counting kit-8 assay. The viability of A-10 cell was always higher when exposed to modified CTP than the original CTP. These results powerfully indicated that the enhanced modification was actually effective and efficient for reducing the toxicity of CTP.

Identification and analysis of key lncRNAs in malignant-transformed BEAS-2B cells induced with coal tar pitch by microarray analysis.

This study aims to explore the key and differentially expressed long non-coding RNAs (lncRNAs) and elucidates their possible mechanisms in malignant-transformed Human bronchial epithelial (BEAS-2B) cells induced by coal tar pitch extracts (CTPE). BEAS-2B cells were stimulated with 2.4 µg/ml CTPE, then passaged for three times which were named CTPE1 and then passaged until passage 30 (CTPE30). The results showed that cells of CTPE30 appeared abnormal morphology. Furthermore, migration, clonality and proliferation of cells in CTPE group were significantly increased compared with those in control groups. However, the apoptosis of cells in CTPE group was inhibited. A total of 569 differentially expressed mRNAs and 707 differentially expressed lncRNAs were screened out, among which four lncRNAs were validated and were consistent with the microarray results. 32 target genes were screened out by Co-expression network. The study suggests that differentially expressed lncRNAs may play a potential role in lung carcinogenesis.

Epigenetic-Based Biomarkers in the Malignant Transformation of BEAS-2B Cells Induced by Coal Tar Pitch Extract.

Background and objectives: The carcinogenicity of coal tar pitch (CTP) to occupational workers has been confirmed by the International Agency for Research on Cancer, especially for lung cancer. Herein, we explored the dynamic changes of epigenetic modifications in the malignant transformation process of CTP-induced BEAS-2B cells and also provided clues for screening early biomarkers of CTP-associated occupational lung cancer. Methods: BEAS-2B cells treated with 3.0 µg/mL CTP extract (CTPE) were cultured to the 30th passage to set up a malignant transformation model, which was confirmed by platelet clone formation assay and xenograft assay. DNA methylation levels were determined by ultraviolet-high performance liquid chromatography. mRNA levels in cells and protein levels in supernatants were respectively detected by Real-Time PCR and enzyme-linked immunosorbent assay. Results: The number of clones and the ability of tumor formation in nude mice of CTPE-exposed BEAS-2B cells at 30th passage were significantly increased compared to vehicle control. Moreover, genomic DNA methylation level was down-regulated. The mRNA levels of DNMT1, DNMT3a and HDAC1 as well as the expression of DNMT1 protein were up-regulated since the 10th passage. From the 20th passage, the transcriptional levels of DNMT3b, let-7a and the expression of DNMT3a, DNMT3b, and HDAC1 proteins were detected to be higher than vehicle control, while the level of miR-21 increased only at the 30th passage. Conclusion: Data in this study indicated that the changes of epigenetic molecules including DNMT1, DNMT3a, DNMT3b, HDAC1, and let-7a occurred at the early stages of BEAS-2B cell malignant transformation after CTPE exposure, which provided critical information for screening early biomarkers of CTP-associated occupational lung cancer.

A Review of the Literature on Potential Effects of Runoff from Refined Coal-Tar-Based Sealant Coating on Aquatic Organisms.

Pavement sealants are frequently applied to parking lots and driveways to improve their appearance and protect the integrity of the underlying asphalt. We performed a comprehensive literature review to summarize the potential impacts of refined coal-tar-based sealant (RCTS) runoff to aquatic organisms and to evaluate the strengths and weaknesses of the lines of evidence presented in the literature. The studies reviewed included both laboratory and field exposures, with and without exposure to UV light, and measured effects on multiple endpoints associated with bacteria, benthic macroinvertebrates, and fish. Several studies demonstrated that constituents in RCTS runoff can affect survival, growth, behavior, development, and molecular responses of aquatic organisms in controlled laboratory settings. However, translating effects observed in the laboratory to field settings, where runoff is diluted and constituents interact with particulate and dissolved stream constituents (e.g., organic matter), has proven difficult. In this review, we identify the strengths and weaknesses of the existing literature and provide recommendations for study designs and methods to fill the most critical data gaps in understanding the risk of this material to aquatic organisms. Our review highlights the need for environmentally relevant study designs that demonstrate cause-effect relationships under field conditions. Integr Environ Assess Manag 2019;00:1-11. © 2019 SETAC.

Assessing natural clays of a contaminated site to stabilize and reduce the ecotoxicity of a coal tar.

Stabilization/solidification is widely used for the immobilization of pollutants in matrices. This work addresses the effect of illite amendment to a liquid coal tar on organic compounds (OCs) immobilization, especially PAHs and BTEX. For practical purpose, illite was selected as raw clay material available on the coal tar contaminated site. Contaminants availability and ecotoxicity of clay/tar matrices at various ratios and considering several treatments were assessed. Varying the tar mass fraction from 1 to 0.12, strongly viscous pastes, pellets and powders were obtained successively, with minimal contaminant mobility observed for tar fractions ranging from 0.28 to 0.80. Pellets obtained for the tar fraction of 0.33 were particularly studied for toxicity tests, because of their ease of handling. Using the land snail Cantareus aspersus as an ecotoxicity probe, mechanisms of PAHs bioavailability considering several treatments were studied. Considering either land snails for direct contact or exposed to vapors, or Lymnaea stagnalis for contact with leachates, toxicity of matrices decreased with ageing or even better with incineration.

LncRNA-ENST00000501520 promotes the proliferation of malignant-transformed BEAS-2B cells induced with coal tar pitch mediated by target genes.

As a human carcinogen, coal tar pitch (CTP) can significantly increase the risk of lung cancer. However, the mechanism underlying CTP-induced lung carcinogenesis has not been well understood. This study aims to explore the role of the LncRNA-ENST00000501520 in the proliferation of malignant-transformed human bronchial epithelial cells (BAES-2B) induced by CTP extract for the first time. BEAS-2B cells were stimulated with 2.4 µg/mL CTP extract, and then passaged for three times, which were named passage 1 and then passaged until passage 30 (named as CTP group). The ENST000001520 of cells in CTP group was interfered using siRNA. The results showed that ENST000001520 located in cell nucleus (>80%) had no or weak ability of protein encoding. After interference of ENST000001520, the migration and proliferation of cells in CTP group were inhibited, and the cell cycle was arrested in the G0/G1 phase; however, the apoptosis of cells in CTP group was promoted. The target genes (SKB1, CLTB, TAP2, PIPK2, and SOCS3) of ENST000001520 were screened out, and the mRNA and protein expression of SBK1 and SOCS3 was significantly decreased after ENST000001520 interference. SBK1 and SOCS3 may play a promoting role in occurrence and development of cancers. The study suggests that LncRNA-ENST00000501520 could promote the proliferation in malignant-transformed BEAS-2B cells induced with CTP extract which may be mediated by target genes. This study may provide a new target for prevention and treatment of lung cancer.

NLRP3 inflammasome activation involved in LPS and coal tar pitch extract-induced malignant transformation of human bronchial epithelial cells.

Inflammatory microenvironment has been found as a new characteristic of cancer; however, the mechanisms of inflammation-related lung cancer remain unclear. To explore the role of NLRP3 inflammsome activation in inflammation-related lung carcinogenesis, a cell model was set up. Human bronchial epithelial cells (BEAS-2B) were stimulated with 1 µg/mL lipopolysaccharide (LPS) for 24 hours, and then treated with 2.4 µg/mL coal tar pitch extract (CTPE) for 24 hours, after removal of LPS and CTPE, the cells were numbered passage 1 and were passaged and treated in this way until passage 30, which was called LPS + CTPE group. DMSO and Saline were used as vehicle controls. Malignant transformation of cells in passage 30 was evaluated by morphological change, platelet clone formation assay, and tumor formation in nude mice. The mRNA levels of NLRP3 and IL-1ß were detected by real time-PCR. The combination of NLRP3 and caspase-1 were determined using immunofluorescence and confocal. The protein expression of NLRP3, cleaved caspase-1(p10), and cleaved IL-1ß was detected using Western blot. It was shown that CTPE, LPS + CTPE-stimulated BEAS-2B cells of passage 30 changed a lot morphologically. The clone formation rates, the rates of positive cells of NLRP3 and caspase-1 combination, the mRNA levels of NLRP3 and IL-1ß, the protein expression of NLRP3, cleaved caspase-1(p10) and cleaved IL-1ß of cells exposed with CTPE and LPS + CTPE at passage 30 were significantly increased compared to vehicle controls. Furthermore, the ability of tumor formation in nude mice, the rates of clone formation and positive cells, mRNA and protein levels of NLRP3 inflammasome activation-related factors in LPS + CTPE-induced cells were all higher than those in cells stimulated with CTPE alone. In conclusion, the cell model of inflammation-related lung cancer is set up successfully, and NLRP3 inflammasome activation may be involved in the malignant transformation of BEAS-2B cells which induced by CTPE alone or LPS combined with CTPE.

Evaluation of ocular irritancy of coal-tar dyes used in cosmetics employing reconstructed human cornea-like epithelium and short time exposure tests.

Coal-tar dyes in cosmetics may elicit adverse effects in the skin and eyes. Countries, like the US, have banned the use of coal-tar dyes in cosmetics for the eye area due to the potential for ocular irritation. We evaluated the eye irritation potential of 15 coal-tar dyes permitted as cosmetic ingredients in reconstructed human cornea-like epithelium (RhCEs [EpiOcular™ and MCTT HCE™]) tests and the short time exposure (STE) test. Eosin YS, phloxine B, tetrachlorotetrabromofluorescein, and tetrabromofluorescein were identified as irritants in RhCEs; dibromofluorescein and uranine yielded discrepant results. STE enabled further classification in accordance with the UN Globally Harmonized System of Classification and Labelling of Chemicals, as follows: eosin YS as Cat 2; phloxine B, Cat 1; and tetrachlorotetrabromofluorescein and tetrabromofluorescein, Cat 1/2. STE indicated dibromofluorescein (irritant in EpiOcular™) and uranine (irritant in MCTT HCE™) as No Cat, resulting in the classification of "No prediction can be made." based on bottom-up approach with each model. These results demonstrated that in vitro eye irritation tests can be utilized to evaluate the potential ocular irritancy of cosmetic ingredients and provide significant evidence with which to determine whether precautions should be given for the use of coal-tar dyes in cosmetics or other substances applied to the eye area.

Oral exposure to commercially available coal tar-based pavement sealcoat induces murine genetic damage and mutations.

Coal tar (CT) is a thick black liquid produced as a by-product of coal carbonization to produce coke or manufactured gas. It is comprised a complex mixture of polycyclic aromatic compounds, including a wide range of polycyclic aromatic hydrocarbons (PAHs), many of which are genotoxic and carcinogenic. CT is used in some pavement sealants (also known as sealcoat), which are applied to pavement in order to seal and beautify the surface. Human exposure is known to occur not only during application, but also as a result of the weathering process, as elevated levels of PAHs have been found in settled house dust in residences adjacent to CT-sealed surfaces. In this study we examined the genotoxicity of an extract of a commercially available CT-based sealcoat in the transgenic Muta™Mouse model. Mice were orally exposed to 3 doses of sealcoat extract daily for 28 days. We evaluated genotoxicity by examining: (1) stable DNA adducts and (2) lacZ mutations in bone marrow, liver, lung, small intestine, and glandular stomach, as well as (3) micronucleated red blood cells. Significant increases were seen for each endpoint and in all tissues. The potency of the response differed across tissues, with the highest frequency of adducts occurring in liver and lung, and the highest frequency of mutations occurring in small intestine. The results of this study are the first demonstration of mammalian genotoxicity following exposure to CT-containing pavement sealcoat. This work provides in vivo evidence to support the contention that there may be adverse health effects in mammals, and potentially in humans, from exposure to coal tar. Environ. Mol. Mutagen. 57:535-545, 2016. © 2016 Her Majesty the Queen in Right of Canada.

[The effect of occupational exposure to coal tar pitch workers' health].

Objective: To investigate the effect of occupational exposure to coal tar pitch on workers' health and metabolism. Methods: 805 workers exposed to coal tar pitch were selected as exposure group from the produce and em-ploy factory. Other people handle administrative and logistical affairs who not exposed to coal tar pitch were selected as control group. Fix-point sample of air were collected to detect the concentration of coal tar pitch. Do physical examination and questionnaire to collect workers' basic and healthy information. To detect the metabolic product of urine samples in laboratory. Results: Anomaly detection rate of the skin in exposure group is 10.61. The lung function indices (FEV1.0%) in exposure group were significantly lower than control group (P<0.05) . The monocyte count and monocyte rate in expo-sure group were significantly higher than control group (P<0.05) . The metabolic product content of PAHS in urine sam-ples is significantly higher in exposed group than control group (P<0.05) . Conclusion: The metabolic product content of polycyclic aromatic hydrocarbon is higher in exposed workers. Coal tar pitch damage workers' skin and lung function. It can cause pruritus chromatodermatosis and so on.

Severe Coal Tar Sealcoat Runoff Toxicity to Fish Is Prevented by Bioretention Filtration.

Coal tar sealcoats applied to asphalt surfaces in North America, east of the Continental Divide, are enriched in petroleum-derived compounds, including polycyclic aromatic hydrocarbons (PAHs). The release of PAHs and other chemicals from sealcoat has the potential to contaminate nearby water bodies, reducing the resiliency of aquatic communities. Despite this, relatively little is known about the aquatic toxicology of sealcoat-derived contaminants. We assessed the impacts of stormwater runoff from sealcoated asphalt on juvenile coho salmon (Oncorhynchus kisutch) and embryo-larval zebrafish (Danio rerio). We furthermore evaluated the effectiveness of bioretention as a green stormwater method to remove PAHs and reduce lethal and sublethal toxicity in both species. We applied a coal tar sealcoat to conventional asphalt and collected runoff from simulated rainfall events up to 7 months postapplication. Whereas sealcoat runoff was more acutely lethal to salmon, a spectrum of cardiovascular abnormalities was consistently evident in early life stage zebrafish. Soil bioretention effectively reduced PAH concentrations by an order of magnitude, prevented mortality in juvenile salmon, and significantly reduced cardiotoxicity in zebrafish. Our findings show that inexpensive bioretention methods can markedly improve stormwater quality and protect fish health.

Gene regulation of filaggrin and other skin barrier proteins via aryl hydrocarbon receptor.

Aryl hydrocarbon receptor (AHR) is a ligand-dependent transcription factor that binds to structurally diverse chemicals including dioxins, coal tar, flavonoids and tryptophan photoproducts. Upon ligation, cytoplasmic AHR translocates to the nucleus, heterodimerizes with aryl hydrocarbon receptor nuclear translocator and mediates numerous biological effects by inducing the transcription of various AHR-responsive genes such as epidermal barrier proteins. The activation of AHR usually generates oxidative stress. However, AHR also mediates antioxidant signaling by a plethora of ligands via nuclear factor-erythroid 2-related factor-2. Both oxidative and antioxidant ligands upregulate the expression of the filaggrin gene. We review the role of AHR signaling in the gene regulation of epidermal barrier proteins.

Skin disease after occupational dermal exposure to coal tar: a review of the scientific literature.

For about a century, coal tar has been used in industry and has been applied in the therapeutic management of several skin diseases. However, in the last decades the benefits of coal tar exploitation for humans could not outweigh its harmful effects on health. The aim of this study is to present the main adverse effects of coal tar on skin, with the emphasis on occupational exposure. The scientific literature indicates that dermal exposure to coal tar and coal tar pitches can be the cause of phototoxic reactions, irritation and burn, allergic dermatitis, folliculitis, occupational acne, atrophy of the epidermis, and hyperpigmentation. Moreover coal tar has been implicated in tumorigenesis, a relationship shown in numerous studies but not confirmed yet as the mechanism has not been fully clarified. A common finding in most studies is that exposure over a long period is the main risk factor for malignancy development, even in low exposure levels. Additional prospective, well-designed studies need to be performed to confirm the validity of the carcinogenic, mutagenic, and cytotoxic potential of coal tar on skin.

Cytochrome P450 1b1 in polycyclic aromatic hydrocarbon (PAH)-induced skin carcinogenesis: Tumorigenicity of individual PAHs and coal-tar extract, DNA adduction and expression of select genes in the Cyp1b1 knockout mouse.

FVB/N mice wild-type, heterozygous or null for Cyp 1b1 were used in a two-stage skin tumor study comparing PAH, benzo[a]pyrene (BaP), dibenzo[def,p]chrysene (DBC), and coal tar extract (CTE, SRM 1597a). Following 20 weeks of promotion with TPA the Cyp 1b1 null mice, initiated with DBC, exhibited reductions in incidence, multiplicity, and progression. None of these effects were observed with BaP or CTE. The mechanism of Cyp 1b1-dependent alteration of DBC skin carcinogenesis was further investigated by determining expression of select genes in skin from DBC-treated mice 2, 4 and 8h post-initiation. A significant reduction in levels of Cyp 1a1, Nqo1 at 8h and Akr 1c14 mRNA was observed in Cyp 1b1 null (but not wt or het) mice, whereas no impact was observed in Gst a1, Nqo 1 at 2 and 4h or Akr 1c19 at any time point. Cyp 1b1 mRNA was not elevated by DBC. The major covalent DNA adducts, dibenzo[def,p]chrysene-(±)-11,12-dihydrodiol-cis and trans-13,14-epoxide-deoxyadenosine (DBCDE-dA) were quantified by UHPLC-MS/MS 8h post-initiation. Loss of Cyp1 b1 expression reduced DBCDE-dA adducts in the skin but not to a statistically significant degree. The ratio of cis- to trans-DBCDE-dA adducts was higher in the skin than other target tissues such as the spleen, lung and liver (oral dosing). These results document that Cyp 1b1 plays a significant role in bioactivation and carcinogenesis of DBC in a two-stage mouse skin tumor model and that loss of Cyp 1b1 has little impact on tumor response with BaP or CTE as initiators.

Acute toxicity of runoff from sealcoated pavement to Ceriodaphnia dubia and Pimephales promelas.

Runoff from coal-tar-based (CT) sealcoated pavement is a source of polycyclic aromatic hydrocarbons (PAHs) and N-heterocycles to surface waters. We investigated acute toxicity of simulated runoff collected from 5 h to 111 days after application of CT sealcoat and from 4 h to 36 days after application of asphalt-based sealcoat containing about 7% CT sealcoat (AS/CT-blend). Ceriodaphnia dubia (cladocerans) and Pimephales promelas (fathead minnows) were exposed in the laboratory to undiluted and 1:10 diluted runoff for 48 h, then transferred to control water and exposed to 4 h of ultraviolet radiation (UVR). Mortality following exposure to undiluted runoff from unsealed asphalt pavement and UVR was ≤10% in all treatments. Test organisms exposed to undiluted CT runoff samples collected during the 3 days (C. dubia) or 36 days (P. promelas) following sealcoat application experienced 100% mortality prior to UVR exposure; with UVR exposure, mortality was 100% for runoff collected across the entire sampling period. Phototoxic-equivalent PAH concentrations and mortality demonstrated an exposure-response relation. The results indicate that runoff remains acutely toxic for weeks to months after CT sealcoat application.

Exposure to runoff from coal-tar-sealed pavement induces genotoxicity and impairment of DNA repair capacity in the RTL-W1 fish liver cell line.

Coal-tar-based (CTB) sealcoat, frequently applied to parking lots and driveways in North America, contains elevated concentrations of polycyclic aromatic hydrocarbons (PAHs) and related compounds. The RTL-W1 fish liver cell line was used to investigate two endpoints (genotoxicity and DNA-repair-capacity impairment) associated with exposure to runoff from asphalt pavement with CTB sealcoat or with an asphalt-based sealcoat hypothesized to contain about 7% CTB sealcoat (AS-blend). Genotoxic potential was assessed by the Formamido pyrimidine glycosylase (Fpg)-modified comet assay for 1:10 and 1:100 dilutions of runoff samples collected from 5 h to 36 d following sealcoat application. DNA-repair capacity was assessed by the base excision repair comet assay for 1:10 dilution of samples collected 26 h and 36 d following application. Both assays were run with and without co-exposure to ultraviolet-A radiation (UVA). With co-exposure to UVA, genotoxic effects were significant for both dilutions of CTB runoff for three of four sample times, and for some samples of AS-blend runoff. Base excision repair was significantly impaired for CTB runoff both with and without UVA exposure, and for AS-blend runoff only in the absence of UVA. This study is the first to investigate the effects of exposure to the complex mixture of chemicals in coal tar on DNA repair capacity. The results indicate that co-exposure to runoff from CT-sealcoated pavement and UVA as much as a month after sealcoat application has the potential to cause genotoxicity and impair DNA repair capacity.

[Tumor necrosis factor-α and NF-κB play a role in macrophage-like THP-1 cells promoting coal tar pitch extract-induced tumorigenic transformation of human bronchial epithelial cells].

OBJECTIVE: To characterize the role of tumor necrosis factor-α (TNF-α) and NF-κB play a role in macrophage-like THP-1 cells promoting coal tar pitch extract (CTPE)-induced tumorigenic transformation of human bronchial epithelial cells (BEAS-2B). METHODS: From passage 10, CTPE-induced BEAS-2B cells cocultured with THP-1 cells were treated with NF-κB inhibitor-Pyrrolidine dithiocarbamate (PDTC) every 3 passages and TNF-α antibody every passage. Alterations of cell cycle, karyotype and colony formation in soft agar of BEAS-2B cells at passages 20, indicative of tumorigenicity, were determined, respectively. In addition, mRNA and protein levels of TNF receptor associated factor2 (TRAF2) and Cyclin D1 in BEAS-2B cells were measured with Real Time-PCR and Western blot, respectively. RESULTS: The percentages of S-phase BEAS-2B cells at passage 20 in PDTC group and TNF-α antibody group were (33.97±2.16)% and (34.29±2.04)% respectively, which were less than that in Co-culture+CTPE group of 20th passage [(44.46±0.83)%], P < 0.05; The number of cells with aneuploidy in 100 cells in 20th passage PDTC group and TNF-α antibody group were 40 and 37, and there were significantly different when comparing to that of 20th passage Co-culture+CTPE group (75); The number of colony formation and the rate of colony formation of BEAS-2B cells in soft agar at passage 20 in PDTC group were (15.17±2.48) and (1.51‰±0.25‰), (13.33±2.58)and (1.33‰±0.26‰) in TNF-α antibody group, which were less that those in 20th passage Co-culture+CTPE group [(172.33±12.09) and (17.23‰±1.20‰)], P < 0.05; at the same time, the mRNA and protein levels of TRAF2 and Cyclin D1 in BEAS-2B cells were decreased after PDTC and TNF-α antibody treatment. CONCLUSION: TNF-α and NF-κB could play an important role in THP-1 cells promoting coal tar pitch extract-induced tumorigenic transformation of BEAS-2B cells by influencing the expression of TRAF2 and Cyclin D1.

[The effects of monocyte-macrophages on malignant transformation of human bronchial epithelial cells induced by extracts from coal tar pitch].

OBJECTIVE: To study the effects of monocyte-macrophages (THP-1) in malignant transformation of human bronchial epithelial cells (BEAS-2B) cells induced by coal tar pitch (CTP) and the expression of TNF-α in the process of the cell malignant transformation. METHODS: BEAS-2B cells and THP-1 Cells were divided into four groups: coal tar pitch (CTP) group, benzo(a)pyrene [B(a)P] group, dimethyl sulfoxide (DMSO) group, BEAS-2B and THP-1 co-culture (co-culture group) group. Carcinogenesis model was established. The soft agar colony formation, chromosome aberrations and cell cycle tests were used to detect the cellular malignant transformation. The ELISA assay was utilized to measure the levels of TNF-α in the supernatant of CTP group and co-culture group. RESULTS: The chromosome number abnormalities could be observed in early stage of the experiment (the 10th generation cells), which showed the increased ratio of aneuploid to polyploid, and the decreased number of diploid. The colony formation rate of co-culture group (the 20th generation cells) was 17.63‰ ± 0.97‰, which was significantly higher than that (13.94‰ ± 0.84‰) of CTP group and that (12.96‰ ± 1.62‰) of B(a)P group (P < 0.05). The proportion of S phase cells in the co-culture group was 44.49% ± 0.68%, which was significantly higher than that (38.19% ± 1.26%) of CTP group and that (36.41% ± 1.19%) of B(a)P group (P < 0.05). The TNF-α level in the co-culture group was significantly higher than that in CTP group (P = 0.001). CONCLUSION: Monocyte-Macrophages can accelerate the malignant transformation of BEAS-2B cells induced by CTP and increase the expression level of TNF-α.

Importance of heterocylic aromatic compounds in monitored natural attenuation for coal tar contaminated aquifers: A review.

NSO heterocycles (HET) are typical constituents of coal tars. However, HET are not yet routinely monitored, although HET are relatively toxic coal tar constituents. The main objectives of the study is therefore to review previous studies and to analyse HET at coal tar polluted sites in order to assess the relevance of HET as part of monitored natural attenuation (MNA) or any other long-term monitoring programme. Hence, natural attenuation of typical HET (indole, quinoline, carbazole, acridine, methylquinolines, thiophene, benzothiophene, dibenzothiophene, benzofuran, dibenzofuran, methylbenzofurans, dimethylbenzofurans and xanthene) were studied at three different field sites in Germany. Compound-specific plume lengths were determined for all main contaminant groups (BTEX, PAH and HET). The results show that the observed plume lengths are site-specific and are above 250m, but less than 1000m. The latter, i.e. the upper limit, however mainly depends on the level of investigation, the considered compound, the lowest measured concentration and/or the achieved compound-specific detection limit and therefore cannot be unequivocally defined. All downstream contaminant plumes exhibited HET concentrations above typical PAH concentrations indicating that some HET are generally persistent towards biodegradation compared to other coal tar constituents, which results in comparatively increased field-derived half-lives of HET. Additionally, this study provides a review on physicochemical and toxicological parameters of HET. For three well investigated sites in Germany, the biodegradation of HET is quantified using the centre line method (CLM) for the evaluation of bulk attenuation rate constants. The results of the present and previous studies suggest that implementation of a comprehensive monitoring programme for heterocyclic aromatic compounds is relevant at sites, if MNA is considered in risk assessment and for remediation.