Polycyclic aromatic hydrocarbons skin exposure among coke workers and skin cancer correlation: local data bank and case study.

To date, studies about historic PAH (polycyclic aromatic hydrocarbons) deposition at a regional scale have rarely been published. To address this research gap, we sampled 17 ombrotrophic peatlands across eastern Canada. The peat cores from hollows were dated with 210Pb for the period of about 1850-2000 and analyzed fortheir PAH concentration, so PAH deposition could be reconstructed. Peat samples were extracted by accelerated solvent extraction (ASE). The extracts were purified by column chromatography with aluminum oxide and silica gel. PAH were measured by gas chromatography-tandem mass spectrometry (GC-MS/MS). Overall reconstructed deposition rates of sigma-11 PAH ranged from 4 to 1432 microg m(-2) year(-1). Three different long-term trends in PAH deposition could be distinguished: sites with two separated periods of maximum PAH deposition, sites with one period of maximum PAH deposition, and sites with no clearly separated period of maximum PAH deposition. Increasing PAH depositions were caused by rapid industrialization accompanied by extensive use of fossil fuels; decreasing PAH depositions were caused by substitution of these fuels and movements of PAH emitting industry to different regions. At all sites either phenanthrene (20-60%) or benzo[b+k]fluoranthene (10-40%) was the predominant PAH. Detailed analysis of three bogs suggested that combustion of coal and vehicle exhausts mainly contributed to the peat PAH burden. The temporal trends of PAH deposition indicated that increases in the PAH deposition rates followed the industrial development in Canada, particularly in the periods 1880-1910 and 1940-1960. Recent abatement efforts were reflected in decreased PAH deposition rates to about 15% of the maximum.

Risk Factors for the Development of Skin Cancers in Patients with Chronic Lymphocytic Leukemia: A Retrospective Cohort Study

Atmospheric deposition and vegetable uptake of polycyclic aromatic hydrocarbons (PAHs) based on experimental and computational simulations

This study investigated the dry and wet deposition fluxes of atmospheric polycyclic aromatic hydrocarbons (PAHs) in Shanghai, China. The flux sources were traced based on composition and spatio-temporal variation. The results show that wet deposition concentrations of PAHs ranged from 0.07 to 0.67 mg·L–1 and were correlated with temperature (P<0.05). Dry deposition of PAHs concentrations ranged from 3.60–92.15 mg·L–1 and were higher in winter and spring than in summer and autumn. The annual PAH average fluxes were 0.631 mg·m–2·d–1 and 4.06 mg·m–2·d–1 for wet and dry deposition, respectively. The highest wet deposition of PAH fluxes was observed in summer, while dry deposition fluxes were higher in winter and spring. Atmospheric PAHs were deposited as dry deposition in spring and winter, yet wet deposition was the dominant pathway during summer. Total atmospheric PAH fluxes were higher in the northern areas than in the southern areas of Shanghai, and were also observed to be higher in winter and spring. Annual deposition of atmospheric PAHs was about 10.8 t in across all of Shanghai. Wet deposition of PAHs was primarily composed of two, three, or four rings, while dry deposition of PAHs was composed of four, five, or six rings. The atmospheric PAHs, composed of four, five, or six rings, primarily existed in the form of particulates. Coal combustion and vehicle emissions were the dominant sources of PAH in the observed area of downtown Shanghai. In suburban areas, industrial pollution, from sources such as coke oven, incinerator, and oil fired power plant, was as significant as vehicle emissions in contributing to the deposition of PAHs.

Atmospheric deposition of polycyclic aromatic hydrocarbons near New England coastal waters

The risk of skin cancer in solid organ transplant recipients (SOTR) is 50 to 100 times as great as in those without a transplant. Multiple factors, including immunosuppression, influence the development of post-transplantation skin cancer. Individuals with cardiac transplant are serially screened for organ rejection and immunosuppressive regimen effectiveness. Gene expression profiling of peripheral blood mononuclear cells has been established as a noninvasive test for monitoring cardiac rejection. We examined individuals with cardiac transplant monitored using peripheral gene expression profiling to determine whether the profile of peripheral blood mononuclear cell activity could correlate with the development of post-transplantation skin cancer. Sixty-one patient records were examined for initial endomyocardial biopsy results, gene expression profiling data, immunosuppressive regimens, and post-transplantation skin cancer. There was no relationship between acute rejection and the development of skin cancer. No relationship between peripheral gene expression profiling and the development of post-transplantation skin cancer was observed. The most common skin cancer in the population was squamous cell carcinoma. SOTR suppressed with azathioprine had a significantly higher incidence of squamous cell carcinoma. Although gene expression tests have advanced transplant surveillance, they were not associated with post-transplantation skin cancer.

Spatial and temporal variations of polycyclic aromatic hydrocarbons (PAHs) deposition fluxes and sources may significantly facilitate risk evaluation and pollution control of super megacity in China. A study on PAHs of wet and dry deposition in Shanghai was conducted from January to December of 2019. Seventeen sampling sites located in four functional areas were set, including the Baoshan iron and steel industry area (BS), Jinshan petrochemical industry area (JS), city center (CC), and Chongming agricultural area (CM). A total of 15 PAHs were determined by gas chromatography-mass spectrometry (GC-MS, Agilent 7890A/5975C). PAHs atmospheric deposition flux in winter was highest (3.12 ± 1.98μg/(m2·day), mostly attributed to local emissions accumulation under adverse meteorological diffusion conditions, as well as pollutants transport from northern China during heating season. PAHs deposition fluxes in industrial area (BS and JS) were 3.75 ± 4.08μg/(m2·day) and 3.18 ± 3.62μg/(m2·day) respectively, which were greater than those in CC and CM, accounting for 1.91 ± 1.06μg/(m2·day) and 1.41 ± 0.61μg/(m2·day) respectively. Proportional composition and isomer ratios of PAHs indicated that the PAHs deposition in winter and spring samples were more homogeneous, whereas those of summer and autumn seemed to be more variable and dispersed. Positive matrix factorization model were employed to identify the potential sources of PAHs in specific functional areas. A dominance of contribution was attributed to coal combustion (46%) at BS, petroleum volatilization (48%) at JS, biomass burning (55%) at CM, and vehicle emission (49%) at CC. This study highlighted that local urbanization and industrialization have a significant contribution to PAHs deposition to specific functional regions in Shanghai.

Polycyclic aromatic hydrocarbons (PAH) are ubiquitous environmental carcinogens (Connell et al. 1997; Conney, 1982; Dipple, 1985; Lesko, 1984). They are produced during forest fire, volcanic eruption, incomplete burning of fuel and other materials, tobacco smoke, and food processing (Baum, 1978; Connell et al. 1997). Exposure to PAHs has been linked to the development of skin and lung cancers as it is summarized in the 8th Report on Carcinogens (National Toxicology Program, 1998). PAHs are considered relatively nontoxic themselves, but they can be activated after entering the cell. The first activation pathway is metabolism. PAH metabolic products, diol-epoxides or diones, are known to be carcinogenic through DNA covalent product formation (Connell et al. 1997; Conney, 1982; Devanesan et al. 1996; Dipple, 1985; Lesko, 1984). The diol-epoxides can alkylate DNA, usually form a bond to the exocyclic amino group of the guanine residue in duplex DNA (Geacintov et al. 1997). The diones are able to oxidatively damage DNA by generation of free radicals, which either cause DNA damages or form DNA covalent products (Chen et al. 1996; Devanesan et al. 1996). Another pathway that enhances PAH toxicity is light activation. There have been studies on the photo-induced toxicity of PAH mixtures or individuals in the marine sediment toward micro-organisms and plants in the aquatic systems (Pelletier et al. 1997; Swartz et al. 1997). It is found that PAHs are generally more toxic when the system is exposed to the simulated solar radiation (ssr) than if it is kept in the dark. The increase in toxicity due to ssr can exceed 100 times (Swartz et al., 1997). It is suggested that PAHs act as photosensitizers (Pelletier et al. 1997). After absorbing UV light energy, PAHs in the excited-state may transfer its energy to molecular oxygen to produce reactive oxygen species that can cause a variety of damages to the cell. The phototoxicity can also be due to DNA covalent product formation from earlier studies. These works showed that, under light irradiation, benzo[a]pyrene can form DNA covalent adducts or cause DNA strand breakage (Blackburn et al. 1977; Brooks and Lawley, 1964; Hoard et al. 1981; Santamaria et al. 1966; Striste et al. 1980). The presence of benzo[a]pyrene can also increase the formation of 8-hydroxy-2′-deoxyguanine (Liu et al., 1998), a compound generated by oxidative damage of DNA. These DNA damage mechanisms have been suggested to relate to tumor induction and other adverse effects (Brooks and Lawley, 1964; Camalier et al. 1981; Santamaria et al. 1966). However, the studies so far have mostly focused on benzo[a]pyrene alone. In this research, we will examine light-induced DNA cleavage by the environmental contaminants: a series of 3, 4, 5-ring PAHs and their derivatives.

Atmospheric occurrences and health risk assessment of polycyclic aromatic hydrocarbons and their derivatives in a typical coking facility and surrounding areas

Background concentration, risk assessment and regulatory threshold development: Polycyclic aromatic hydrocarbons (PAH) in Milwaukee, Wisconsin surface soils.

Inflammation and the inflammatory infiltrate essentially contribute to tumor development and progression. For skin cancer, the observation that tumors arise in sites of chronic irritation and inflammation dates back to 1828 and has stimulated a whole field of research. Numerous animal models such as models of UV-induced or chemically induced skin carcinogenesis but also trangenic models support the role of a deregulated inflammation in the development of skin cancer. These models have greatly contributed to our understanding of the multistage process of carcinogenesis and have given important insights in the differences between physiological inflammation in a healing wound and the functional contribution of the deregulated tumor-associated inflammation to skin cancer growth and progression. Data from these models are supported by epidemiological studies that emphasize a connection of inflammatory conditions with the development of melanoma and epithelial skin cancer and give first indications for a beneficial effect of anti-inflammatory treatments in reducing the risk for skin cancer. Consequently, anti-inflammatory drugs might represent a highly interesting approach in the prevention and treatment of skin cancers.

Nonmelanoma skin cancer is one of the most frequently occurring cancers in the United States. Chronic exposure to UVB irradiation is a major cause of this cancer. Daidzein, along with genistein, is a major isoflavone found in soybeans; however, little is known about the chemopreventive effects of daidzein and its metabolites in UVB-induced skin cancer. Here, we found that 7,3',4'-trihydroxyisoflavone (THIF), a major metabolite of daidzein, effectively inhibits UVB-induced cyclooxygenase 2 (COX-2) expression through the inhibition of NF-κB transcription activity in mouse skin epidermal JB6 P+ cells. In contrast, daidzein had no effect on COX-2 expression levels. Data from Western blot and kinase assays showed that 7,3',4'-THIF inhibited Cot and MKK4 activity, thereby suppressing UVB-induced phosphorylation of mitogen-activated protein kinases. Pull-down assays indicated that 7,3',4'-THIF competed with ATP to inhibit Cot or MKK4 activity. Topical application of 7,3',4'-THIF clearly suppressed the incidence and multiplicity of UVB-induced tumors in hairless mouse skin. Hairless mouse skin results also showed that 7,3',4'-THIF inhibits Cot or MKK4 kinase activity directly, resulting in suppressed UVB-induced COX-2 expression. A docking study revealed that 7,3',4'-THIF, but not daidzein, easily docked to the ATP binding site of Cot and MKK4, which is located between the N- and C-lobes of the kinase domain. Collectively, these results provide insight into the biological actions of 7,3',4'-THIF, a potential skin cancer chemopreventive agent.

ABSTRACTBulk atmospheric deposition of Polycyclic Aromatic Hydrocarbons (PAHs) in Guwahati city of the Brahmaputra Valley have been characterised for a period of one year. The ∑PAHs (USEPA’s priority 16) and benzo(s)pyrene (BaP) concentrations in the collected bulk deposit ranged between 2.2 and 1035 ng mL–1, and BDL and 5.6 ng mL–1 respectively. Greater deposition of PAHs was observed during the dry season and the deposition of low molecular weight PAHs (LMWPAHs) were particularly high. The study revealed explicit effect of the prevailing meteorology on the bulk atmospheric deposition characteristics of PAHs. Greater number of inversion days and lowering of inversion height during the dry season were found to enhance deposition of PAHs. Diagnostic ratios indicated pyrogenic origin of the PAHs derived from combustion of diesel, coal and wood combustion. The deposition of LMWPAHs was greatly influenced by temperature. The diurnal variation of relative humidity, and wind pattern were found to affect deposition of PAHs

Skin cancer is a well-recognized long-term complication of transplantation and immunosuppression. Although risk factors for the development of skin cancer in the general population are well defined, risk factors for the development of these lesions have not been identified clearly in the liver transplant population. We surveyed 151 liver transplant (LTx) recipients for risk factors associated with cutaneous malignancies in the general population. Variables included were: demographics, primary liver disease, severity of disease at LTx, immunosuppression history, complexion, hair color, eye color, tanning profile, number of moles, occupational history, sun exposure history, sunburn history, family history of skin cancer, and any history of removed skin lesions. All skin cancers were confirmed histologically. There were 86 documented skin cancers in 34 patients: 56 squamous cell, 23 basal cell and 7 melanomas. Median follow-up was 1490 days. In a univariate analysis, age, male gender, red hair, brown eyes, primary sclerosing cholangitis (PSC), primary biliary cirrhosis (protective), cyclosporine, number of second degree sunburns, and frequent lifetime sun exposure were associated with the development of new skin cancers. In a multivariate model, age, male gender, red hair, brown eyes, PSC, and cyclosporine remain the strongest predictors. The incidence of skin cancer after liver transplantation is underestimated. In particular, there is a higher incidence of squamous cell carcinoma compared with the general population. Recipients with identified risk factors may be candidates for prophylactic treatment and should be followed more intensively after liver transplantation.

Abstract. Polycyclic aromatic hydrocarbons (PAHs) were analysed in bulk atmospheric deposition samples collected at four European high-mountain areas, Gossenköllesee (Tyrolean Alps), Redon (Central Pyrenees), Skalnate Pleso (High Tatra Mountains), and Lochnagar (Grampian Mountains) between 2004 and 2006. Sample collection was performed monthly in the first three sites and biweekly in Lochnagar. The number of sites, period of study and sampling frequency provide the most comprehensive description of PAH fallout in high mountain areas addressed so far. The average PAH deposition fluxes in Gossenköllesee, Redon and Lochnagar ranged between 0.8 and 2.1 µg m−2 month−1, and in Skalnate Pleso it was 9.7 µg m−2 month−1, showing the influence of substantial inputs from regional emission sources. The deposited distributions of PAHs were dominated by parent phenanthrene, fluoranthene and pyrene, representing 32 %–60 % of the total. The proportion of phenanthrene, the most abundant compound, was higher at the sites of lower temperature, Gossenköllesee and Skalnate Pleso, showing higher transfer from gas phase to particles of the more volatile PAHs. The sites with lower insolation, e.g. those located at lower altitude, were those with a higher proportion of photooxidable compounds such as benz[a]anthracene. According to the data analysed, precipitation is the main driver of PAH fallout. However, when rain and snow deposition were low, particle settling also constituted an efficient driver for PAH deposition. Redon and Lochnagar were the two sites receiving the highest amounts of rain and snow and the fallout of PAH fluxes was related to this precipitation. No significant association was observed between long-range backward air trajectories and PAH deposition in Lochnagar, but in Redon PAH fallout at higher precipitation was essentially related to air masses originating from the North Atlantic, which were dominant between November and May (cold season). In these cases, particle-normalised PAH fallout was also associated with higher precipitation as these air masses were concurrent with lower temperatures, which enhanced gas to particle partitioning transfer. In the warm season (June–October), most of the air masses arriving at Redon originated from the south and particle deposition was enhanced as consequence of Saharan inputs. In these cases, particle settling was also a driver of PAH deposition despite the low overall PAH content of the Saharan particles. In Gossenköllesee, the site receiving lowest precipitation, PAH fallout was also related to particle deposition. The particle-normalised PAH fluxes were significantly negatively correlated to temperature, e.g. for air masses originating from central and eastern Europe, showing a dominant transfer from gas phase to particles at lower temperatures, which enhanced PAH fallout, mainly of the most volatile hydrocarbons. Comparison of PAH atmospheric deposition and lacustrine sedimentary fluxes showed much higher values in the latter case of 24–100 µg m−2 yr−1 vs. 120–3000 µg m−2 yr−1. A strong significant correlation was observed between these two fluxes, which is consistent with a dominant origin related to atmospheric deposition at each site.