Phenanthrene Metabolites Research Articles

Low-level exposure to polycyclic aromatic hydrocarbons is associated with reduced lung function among Swedish young adults

BackgroundExposure to polycyclic aromatic hydrocarbons (PAHs) has been linked to adverse pulmonary effects. However, the impact of low-level environmental PAH exposure on lung function in early adulthood remains uncertain. ObjectivesTo evaluate the associations between urinary PAH metabolites and lung function parameters in young adults. MethodsUrinary metabolites of pyrene, phenanthrene, and fluorene were analysed in 1000 young adults from Sweden (age 22–25 years) using LC-MS/MS. Lung function and eosinophilic airway inflammation were measured by spirometry and exhaled nitric oxide fraction (FeNO), respectively. Linear regression analysis was used to evaluate associations between PAH metabolites and the outcomes. ResultsMedian urinary concentrations of 1-OH-pyrene, ∑OH-phenanthrene, and ∑OH-fluorene were 0.066, 0.36, 0.22 μg/L, respectively. We found inverse associations of ∑OH-phenanthrene and ∑OH-fluorene with FEV1 and FVC, as well as between 1-OH-pyrene and FEV1/FVC ratio (adjusted P < 0.05; all participants). An increase of 1% in ∑OH-fluorene was associated with a decrease of 73 mL in FEV1 and 59 mL in FVC. In addition, ∑OH-phenanthrene concentrations were, in a dose-response manner, inversely associated with FEV1 (B from −109 to −48 compared with the lowest quartile of ∑OH-phenanthrene; p trend 0.004) and FVC (B from −159 to −102 compared with lowest quartile; p-trend <0.001). Similar dose-response associations were also observed between ∑OH-fluorene and FEV1 and FVC, as well as between 1-OH-pyrene and FEV1/FVC (p-trend <0.05). There was no association between PAH exposure and FeNO, nor was there an interaction with smoking, sex, or asthma. ConclusionLow-level PAH exposure was, in a dose-response manner, associated with reduced lung function in young adults. Our findings have public health implications due to i) the widespread occurrence of PAHs in the environment and ii) the clinical relevance of lung function in predicting all-cause and cardiovascular disease mortality.

Toxicity evaluation of the metabolites derived from the degradation of phenanthrene by one of a soil ubiquitous PAHs-degrading strain Rhodococcus qingshengii FF

Rhodococcus qingshengii strain FF is a soil ubiquitous strain that has a high polycyclic aromatic hydrocarbons (PAHs) biodegradation capability. In this work, phenanthrene was used as a PAH model compound. The accumulated pattern of the metabolites of phenanthrene by strain FF was investigated, and their toxicity to Vibrio fischeri, effect on microbiota diversity of farmland soil and influence on seed of wheat were evaluated. Total of 29 main intermediates were observed for the phenanthrene degradation process. Pyrogallol was the predominant accumulated metabolite, and 59% of the accumulated metabolites were oxygen-containing PAHs that have only one benzene ring. The acute toxicity assessment showed the accumulated metabolites in later phase were more toxic to Vibrio fischeri. Microbe and wheat seed response to the different stages of phenanthrene metabolites indicated pollution significantly decreased microbial richness and evenness of farmland soil and lower germinal length, root length or root number of wheat seed. These results indicated that not only the elimination of PAHs, but also the easily accumulated metabolites produced during the PAHs degradation process should be paid enough attention. The comprehensive evaluation of toxicity during the degradation process would provide useful information for the use of microbe-orientated strategies in PAHs bioremediation.

Trends in urinary metabolites of polycyclic aromatic hydrocarbons (PAHs) in the non-smoking U.S. population, NHANES 2001–2014

BackgroundRecent studies indicate airborne PAH levels have decreased in the U.S., but it is unclear if this has resulted in PAH exposure changes in the U.S. population. ObjectiveExamine temporal trends in urinary metabolites of Naphthalene, Fluorene, Phenanthrene, and Pyrene in U.S. non-smokers, 6+ years old. MethodsWe used biomonitoring data from the National Health and Nutrition Examination Survey (NHANES) program, 2001–2014, (N = 11,053) using survey weighted linear regression. Models were adjusted for age, sex, race/ethnicity, creatinine, BMI, income, diet, and seasonality. Stratified models evaluated the effect of age, sex, and race/ethnicity on trends. ResultsBetween 2001 and 2014, Naphthalene exposure increased 36% (p < 0.01); Pyrene exposure increased 106% (p < 0.01); Fluorene and Phenanthrene exposure decreased 55% (p < 0.01), and 37% (p < 0.01), respectively. Naphthalene was the most abundant urinary PAH, 20-fold higher than Fluorene and Phenanthrene, and over 50-fold higher than Pyrene compared to reference groups, effect modification was observed by age (Naphthalene, Pyrene), sex (Fluorene, Pyrene), and race/ethnicity (Naphthalene, Fluorene, Phenanthrene, Pyrene). SignificanceThis study shows exposure to Naphthalene and Pyrene increased, while exposure to Fluorene and Phenanthrene decreased among the non-smoking U.S. general population between 2001 and 2014, suggesting environmental sources of PAHs have changed over the time period.

Indoor wood combustion, carcinogenic exposure and esophageal cancer in southwest Kenya

BackgroundExposure to polycyclic aromatic hydrocarbons (PAHs) is a risk factor for esophageal squamous cell carcinoma (ESCC) in high-incidence areas of China, Iran and Brazil, but PAH assessments have not been conducted in East Africa, another ESCC hot spot. ObjectiveTo evaluate demographic or lifestyle factors associated with the PAH biomarker concentrations in the study population, and whether PAH metabolite concentrations showed any associations with esophageal precancerous lesions. MethodsWe recruited a community-based sample of 289 asymptomatic adults from a rural area of Kenya and performed Lugol’s chromoendoscopy to detect esophageal squamous dysplasia (ESD); participants completed a questionnaire and provided a spot urine specimen. We analyzed urine for seven hydroxylated metabolites of naphthalene, fluorene, phenanthrene, and pyrene at the U.S. National Center for Environmental Health, and compared creatinine-corrected PAH metabolite concentrations with questionnaire data and the presence of ESD. ResultsPAH metabolite concentrations among never tobacco users in these rural Kenya residents were 2.4–28.1 times higher than those reported from never tobacco users in Iran, Brazil and the USA. Female sex, cooking indoors, having no post-primary education, and age <50, but not tobacco use, were positively and significantly associated with PAH metabolite concentrations. Almost all participants used wood as cooking fuel. Nine participants had advanced ESD. Adjusted logistic regression showed a significant association between 2-hydroxynaphthalene (OR = 4.19, 95%CI: 1.01–17.47) and advanced ESD. All other PAH metabolites had positive but non-significant associations with advanced ESD. ConclusionsUrinary PAH metabolite concentrations among never tobacco users are markedly higher in this group from Kenya than in other populations and are associated with indoor cooking with wood on open, unvented stoves. These metabolite concentrations were also associated with the presence of advanced esophageal dysplasia. Our findings underline the importance of assessing alternative cooking conditions to reduce PAH exposure in this population.

Untangling mechanisms of crude oil toxicity: Linking gene expression, morphology and PAHs at two developmental stages in a cold-water fish

Early life stages of fish are highly sensitive to crude oil exposure and thus, short term exposures during critical developmental periods could have detrimental consequences for juvenile survival. Here we administered crude oil to Atlantic haddock (Melanogrammus aeglefinus) in short term (3-day) exposures at two developmental time periods: before first heartbeat, from gastrulation to cardiac cone stage (early), and from first heartbeat to one day before hatching (late). A frequent sampling regime enabled us to determine immediate PAH uptake, metabolite formation and gene expression changes. In general, the embryotoxic consequences of an oil exposure were more severe in the early exposure animals. Oil droplets on the eggshell resulted in severe cardiac and craniofacial abnormalities in the highest treatments. Gene expression changes of Cytochrome 1 a, b, c and d (cyp1a, b, c, d), Bone morphogenetic protein 10 (bmp10), ABC transporter b1 (abcb1) and Rh-associated G-protein (rhag) were linked to PAH uptake, occurrence of metabolites of phenanthrene and developmental and functional abnormalities. We detected circulation-independent, oil-induced gene expression changes and separated phenotypes linked to proliferation, growth and disruption of formation events at early and late developmental stages. Changes in bmp10 expression suggest a direct oil-induced effect on calcium homeostasis. Localized expression of rhag propose an impact on osmoregulation. Severe eye abnormalities were linked to possible inappropriate overexpression of cyp1b in the eyes. This study gives an increased knowledge about developmentally dependent effects of crude oil toxicity. Thus, our findings provide more knowledge and detail to new and several existing adverse outcome pathways of crude oil toxicity.

Cytotoxic phenanthrenes and phenolic constituents from the tubers of Dioscorea persimilis

Abstract The tubers of Dioscorea persimilis have been widely consumed as a food and for the treatment of sonasthenia, intestinal disease, diarrhea, long-term dysentery, spermatorrhea, metritis, kidney failure, back pain, dizziness, and night sweats. The present study describes the isolation of 11 secondary metabolites, including three new phenanthrenes namely diospersimilosides A (1) and B (2) and diosbiphenanthrene (3), and eight known phenolic compounds: 2,4,6,7-tetrahydroxy-9,10-dihydrophenanthrene (4), aerosin (5), gastrodin (6), 2-phenylethyl-β- d -glucopyranoside (7), afzelechin (8), catechin (9), eucomic acid (10), and vanillic acid-4-O-β- d -glucopyranoside (11) from the tubers of D. persimilis. Their chemical structures were elucidated based on comprehensive analyses of the NMR and mass spectra. Evaluation of their cytotoxicity against three human cancer cell lines, including liver (HepG2), breast (MCF7), and melanoma (SK-Mel-2) revealed that the phenanthrene metabolites (3-5) possess cytotoxicity toward all the cell lines, with IC50 values ranging from 8.2–68.4 μM. Our results revealed that the free of the hydroxy groups plays an important role in cytotoxicity of the phenanthrenes and suggests that pohydroxylated dihydrophenanthrene and biphenanthrene metabolites could be considered as promising cytotoxic agents against human cancer cells.

Identification and quantification of phenanthrene ortho-quinones in human urine and their association with lipid peroxidation

Although human exposure to polycyclic aromatic hydrocarbons (PAH) has been associated with in vivo oxidative damage, and hydroxyPAH metabolites have been used as biomarkers to assess PAH-induced oxidative stress, few studies have looked at the likely causative compounds for oxidative stress in humans - PAH quinones. We developed a method using pre-column derivatization - liquid chromatography-heated electrospray ionization-tandem mass spectrometry (LC-HESI-MS/MS) to analyze ortho-phenanthrene quinones (PheQs) in human urine. 1,2-PheQ and 3,4-PheQ were identified and quantified in 3 mL of human urine; their total concentrations were higher in cigarette smokers (0.79 ± 0.98 nmol/6h urine) than in nonsmokers (0.20 ± 0.98 nmol/6h urine) (p < 0.01). The total of 1,2-PheQ and 3,4-PheQ were more strongly correlated with urinary (Z)-7-[1R,2R,3R,5S)-3,5-dihydroxy-2-[(E,3S)-3-hydroxyoct-1-enyl]cyclopentyl]hept-5-enoic acid (8-iso-PGF2α), a biomarker of lipid peroxidation (R2 = 0.53, p < 0.001), than the other phenanthrene metabolites including phenanthrene tetraol (PheT), phenanthrene-1,2-dihydrodiol (1,2-PheD), and total phenanthrene phenols (OHPhe), consistent with the concept that PheQs and likely other PAH quinones play a causal role in the generation of reactive oxygen species (ROS) in humans. Thus, PheQs may be suitable as biomarkers to assess human exposure to oxygenated PAH and the subsequent oxidative damage. This study provides unique support, by analysis of human urinary metabolites, for the PAH quinone mediated oxidative damage hypothesis of PAH carcinogenesis.

Urinary polycyclic aromatic hydrocarbons in relation to anthropometric measures and pubertal development in a cohort of Northern California girls.

Polycyclic aromatic hydrocarbons (PAHs) are a class of ubiquitous, environmental chemicals that may have endocrine disrupting capabilities. We investigated whether childhood exposure to PAHs was associated with adiposity and pubertal timing in a longitudinal study of 404 girls enrolled in the Northern California site of the Breast Cancer and the Environment Research Program cohort. Baseline urinary samples from girls aged 6-8-years-old were assayed for 2-naphthol, fluorene metabolites, phenanthrene metabolites, 1-hydroxypyrene, and sum of PAH metabolites. Mixed-effects linear models were used to estimate how concentrations of PAH metabolites were related to changes in girl's body mass index (BMI) and waist-to-height ratio from age 7 through 16 years old. Accelerated failure time models were used to estimate age of pubertal onset (Tanner stages 2 or higher for breast and pubic hair development). Higher adiposity measurements among high tertiles of baseline PAH metabolites were evident at age 7 years old and increased thereafter (i.e., BMI for all PAH metabolites, waist-to-height ratio for fluorene and phenanthrene metabolites) or leveled off (i.e., waist-to-height ratio for 2-naphthol, 1-hydroxypyrene, sum of PAHs). Among girls overweight/obese at baseline, median age of breast development onset for high tertiles was 9.1-9.4 years old compared with 10-10.2 years old for low tertiles for all PAH metabolites; in contrast, found no association or slightly later onset of breast development for girls with normal weight at baseline. These results suggest that exposure to specific PAHs during childhood may influence adiposity throughout adolescence and effect pubertal timing.

Biodegradation of polycyclic aromatic hydrocarbons by high-laccase basidiomycetes fungi isolated from tropical forest of Borneo

Abstract A total of 804 fungi isolate were subjected to the screening of high laccase activity by four different indicators test, Poly R-478, RBBR, guaiacol, and syringaldazine. The results presented the diversity of 6 order, belonging to 17 families, 25 genera and 29 species, and most of the isolated strain was reacted with laccase chemical indicators and categorized as saprophytic, parasitic and ectomycorrhizal. Three fungi (Coriolopsis caperata, Fomes fomentarius, Pluteus chysophaeus) that isolated from Niah National Park and Lambir Hill National Park were selected for further experiment due to their high positive reaction on all tested indicators. The maximum level on the laccase production during fungi exponential growth was impacted by the addition of carbon source. Diphenic acid, 1-hydroxy-2naphthoic acid, catechol, and salicylic acid, anthraquinone, benzoic acid, and phthalic acid were detected as metabolites of phenanthrene, anthracene, and pyrene.

Probing the Interaction between Human Serum Albumin and 9-Hydroxyphenanthrene: A Spectroscopic and Molecular Docking Study.

9-Hydroxyphenanthrene (9-OHPhe), the representative hydroxyl metabolite of phenanthrene, has generated increasing concern as it is potentially hazardous to organisms. Herein, multispectroscopic and molecular docking techniques were applied to investigate the molecular interaction of human serum albumin (HSA) with 9-hydroxyphenanthrene (9-OHPhe) under simulated physiological conditions. Steady-state fluorescence and time-resolved fluorescence spectral analysis showed that 9-OHPhe quenched HSA fluorescence through a mixed static and dynamic process. HSA can bind with 9-OHPhe to form a 1:1 complex, with binding constants of 1.28 × 105, 1.36 × 105, and 1.26 × 105 L·mol–1 at 298.15, 303.15, and 308.15 K, respectively. The strong binding between HSA and 9-OHPhe is spontaneous and entropy-driven. Molecular docking indicated that the optimal binding site of 9-OHPhe with HSA was located in the IA subdomain of HSA. Thermodynamic analysis and molecular docking results suggested that hydrophobic interactions and hydrogen bond force dominated the binding process of HSA with 9-OHPhe. Specifically, 9-OHPhe formed hydrophobic interactions with LEU134, LEU139, ILE142, LEU154, PHE157, ALA158, and TYR161 and formed a 1.86 Å hydrogen bond with LEU135. Circular dichroism spectral analysis showed that the α-helical content of HSA decreased from 52.3 to 50.9% after adding 9-OHPhe with a ratio of 1:1. The obtained results are hoped to provide basic data for understanding the potential effects of the hydroxyl metabolites of PAHs on functional biomacromolecules.

Fluorene exposure among PAH-exposed workers is associated with epigenetic markers related to lung cancer

ObjectivesExposure to high-molecular-weight polycyclic aromatic hydrocarbons (PAHs) may cause cancer in chimney sweeps and creosote-exposed workers, however, knowledge about exposure to low-molecular-weight PAHs in relation to cancer risk is limited....

Bioavailability of polycyclic aromatic hydrocarbons to penguins on the coast of southeastern Brazil

Bioavailability of polycyclic aromatic hydrocarbons on São Paulo state coast (southeastern Brazil) was evaluated through the analysis of biliary metabolites in Spheniscus magellanicus (n = 79). The animals analyzed in present study were either found dead during beach monitoring procedures or died at rehabilitation centers. Analyses of naphthalene (NAP), phenanthrene (PHE) and benzo[a]pyrene (BaP) metabolites were performed using a high-performance liquid chromatograph equipped with fluorescence detectors. Total metabolite (TM) concentrations ranged from below the method quantification limit to 270 μg g−1 of bile. TM concentrations were mainly composed of NAP metabolites, followed by PHE metabolites. BaP metabolites were detected in only two samples. This is the first study using PAHs metabolites in S. magellanicus to assess the bioavailability of these compounds in coastal regions.

Biodegradation and phytotoxicity assessment of phenanthrene by biosurfactant-producing Bacillus pumilus 1529 bacteria

ABSTRACTPhenanthrene is a toxic and mutagenic pollutant that can cause severe environmental and human health issues. The bioremediation of these polyaromatic hydrocarbons (PAHs) is possible with a biosurfactant by enhancing hydrophobicity. In this study, the production of a biosurfactant by Bacillus pumilus 1529 and its effects on the phenanthrene biodegradation pathway were examined. Biosurfactant production was determined using hemolytic activity, emulsification index, and surface tension. For phenanthrene metabolite detection, samples at 0, 7, 14, and 21 incubation days were analysed by gas chromatography-mass (GC-mass) spectrometry. The results showed that Bacillus pumilus 1529 can reduce surface tension to 22.83 ± 1.1 mN m−1. Furthermore, the GC-mass spectrometry analysis showed that 1-hydroxy-2-naphthoic acid, benzaldehyde, o-phthalic acid, and phenylacetic acid were notable phenanthrene metabolites produced during phenanthrene biodegradation. Biodegraded phenanthrene and its metabolites have a less toxic effect on the germination of safflower seeds than non-biodegraded phenanthrene. The IC50 of phenanthrene on seed germination after biodegradation was increased to approximately 113 mg L−1. In general, biodegradation aided by biosurfactant producing bacteria contributed to turning the toxic phenanthrene into less harmful metabolites with lower phytotoxicity effects, indicating that its application in the bioremediation of PAHs is promising.

Formation and distribution of phenanthrene and its metabolites (monohydroxy-phenanthrenes) in Korean rockfish (Sebastes schlegelii)

This study investigated the tissue distribution of phenanthrene (PHE) and the formation of monohydroxy-phenanthrene (OH-PHE) metabolites in Korean rockfish (Sebastes schlegelii). PHE was intragastrically administered to two groups of rockfish. The first group was exposed to PHE at a low dose (10 mg/kg body weight) and the second group was exposed at a high dose (30 mg/kg body weight). The rockfish were analyzed and the levels of PHE were higher in the liver, followed by muscle, and then bile. PHE concentrations in the liver, muscle, and bile were 1.4–26, 0.10–2.01, and not detected (ND)–0.13 μg/g wet weight, respectively. All five monohydroxylated PHE metabolites (1-OH-PHE, 2-OH-PHE, 3-OH-PHE, 4-OH-PHE, and 9-OH-PHE) were detected only in bile. Among these OH-PHE metabolites, 3-OH-PHE was found at the highest concentration from all fish bile samples in both PHE exposure groups, indicating that regioselective OH-PHE formation occurs in rockfish and 3-OH PHE could be a good biomarker of exposure of Korean rockfish to PHE. Suspect screening analysis of the rockfish bile was performed by LC-QTOF/MS, and the formation of two OH-PHE-DNA adducts (thymine–OH–PHE and cytosine–OH–PHE) were identified in the bile sample collected 6 h after rockfish were exposed to the high PHE dose, indicating that OH-PHE metabolites may be toxic to fish. This is the first report on the formation characteristics of OH-PHE metabolites in rockfish and their use as biomarkers of exposure of rockfish to parent PHE.

The influence of demographic and lifestyle factors on urinary levels of PAH metabolites-empirical analyses of Cycle 2 (2009-2011) CHMS data.

Polycyclic aromatic hydrocarbons (PAHs) are a group of compounds formed during the incomplete combustion of organic matter. Several are mutagenic carcinogens; the magnitude of exposure can be assessed by examining urinary levels of PAH metabolites. Data from biomonitoring studies that record urinary PAH metabolite levels, as well as demographic and lifestyle information, can be used to investigate relationships between PAH exposure and variables, such as smoking status, workplace smoking restrictions, age, sex, household income, home age, and occupation. This study analysed creatinine-adjusted urinary PAH metabolite concentrations and questionnaire data from ~1200 individuals aged 16 years and older surveyed in Cycle 2 of the Canadian Health Measures Survey (CHMS). Statistical analyses revealed that smoking status, age, and sex are associated with urinary concentrations of a pyrene metabolite (1-OHP), phenanthrene metabolites (ΣOH-Phen), fluorene metabolites (ΣOH-Flu) and naphthalene metabolites (ΣOH-Nap). More specifically, smoking status, age and sex can collectively account for 30, 24, 52, and 34% of the observed variations in 1-OHP, ΣOH-Phen, ΣOH-Flu and ΣOH-Nap metabolites, respectively (p < 0.001). Analyses of non-smokers revealed weak but significant effects of age, sex, home age, and occupation on urinary levels of selected PAH metabolites (i.e., <7% of observed variation, p < 0.05). The unexplained variation in PAH metabolite levels is most likely related to diet, which was not examined. Although the results revealed significant relationships between urinary PAH metabolite levels and several lifestyle and/or demographic variables, robust examinations of selected effects (e.g., sex, home age, occupation) will require datasets that are balanced with respect to the other highlighted variables. The results can be used to identify remedial measures to reduce exposure and concomitant risk, and/or design follow-up studies to test hypotheses regarding the causes of exposure differences empirically related to sex, age, home age, and occupation.

Quantitation of phenanthrene dihydrodiols in the urine of smokers and non-smokers by gas chromatography-negative ion chemical ionization-tandem mass spectrometry

Polycyclic aromatic hydrocarbons (PAH) are well-established environmental carcinogens likely to be causative agents for some human cancers. Bay-region diol epoxides are ultimate carcinogenic metabolites of multiple PAH. Dihydrodiols are the important intermediate products of this pathway and can be further oxidized to form diol epoxides. We quantified two dihydrodiol metabolites of phenanthrene (Phe), the simplest PAH with a bay-region, in the 6 h urine of smokers (N = 25) and non-smokers (N = 25) using a newly developed and validated analytical method. After hydrolysis by ß-glucuronidase and sulfatase, and solid phase extraction, the sample was silylated and analyzed by gas chromatography-negative ion chemical ionization-tandem mass spectrometry (GC-NICI-MS/MS). Levels (nmol/6h urine) of Phe-1,2-dihydrodiol (Phe-1,2-D) and Phe-3,4-dihydrodiol (Phe-3,4-D) were 2.04 ± 1.52 and 0.51 ± 0.35 , respectively, in smokers, significantly higher than those in non-smokers (1.35 ± 1.11 of Phe-1,2-D, p < 0.05; 0.27 ± 0.25 of Phe-3,4-D, p < 0.005). Cigarette smoking also influenced the regioselective metabolism of Phe, presenting as a significant difference in the urinary distribution pattern of Phe-1,2-D and Phe-3,4-D between smokers and non-smokers: the ratio Phe-3,4-D: Phe-1,2-D increased from 0.20 in non-smokers to 0.28 in smokers (p < 0.01), which can be explained by the induction of the phenanthrene metabolizing enzymes CYP1A2 and CYP1B1 by cigarette smoke. The method described here is the first example of facile quantitation of an intact human dihydrodiol metabolite of any PAH with three or more aromatic rings and will be applicable in clinical and molecular epidemiology studies of PAH metabolism and cancer susceptibility.

Towards a recommended biomonitoring strategy for assessing the occupational exposure of roofers to PAHs

The aims of this work were to assess the PAH exposure among roofers and to identify relevant biomarkers for monitoring occupational exposure. Several campaigns were conducted between 2004 and 2017, with 28 individual air samples and 240 urinary samples collected from 73 roofers. Seventeen parent PAHs and 14 urinary biomarkers, metabolites of pyrene (1-OHP), benzo(a)pyrene (3-OHBaP and TetraolBaP), naphthalene (1- and 2-naphtols), fluorene (1- 2- 3- 9-fluorenols) and phenanthrene (1- 2- 3- 4- 9-phenanthrols), were analysed. Three exposure groups were considered: soft-applied roofing using polymer-modified bitumen ("PMB"), hot-applied roofing using oxidized bitumen ("OB") and the tearing off of old roof coatings containing coal tar ("CT"). The PAHs containing 2–3 rings were much more abundant, and the highest airborne levels were observed in the "CT" group. The biomonitoring results were consistent with these results, with a large predominance of 2–3 ring PAH metabolites. 1-OHP, 3-fluorenol and 2-phenanthrol were better correlated with airborne levels and less influenced by smoking than the other metabolites. Conversely, 1-/2-naphtol levels were heavily influenced by smoking and not correlated with airborne naphthalene levels. Moreover, 3-OHBaP and TetraolBaP levels were very low when applying bitumen membranes, and much higher exposures were observed during tear-off activities. In this context, the recommended strategy for roofer biomonitoring should include 1-OHP, fluorenols and phenanthrols, as well as carcinogenic BaP metabolites (3-OHBaP or TetraolBaP) when evaluating the occupational exposure of roofers that are tearing off old roof coatings.

Polycyclic aromatic hydrocarbons (PAHs) levels in urine samples collected in a subarctic region of the Northwest Territories, Canada.

Traditional food consumption for Indigenous peoples is associated with improved nutrition and health but can also pose potential risks via exposure to contaminants. Polycyclic aromatic hydrocarbons (PAHs) are compounds of interest due to their widespread presence (e.g., their metabolites are detected in up to 100% of the Canadian population) and their toxicological potential. To better understand the range of exposures faced by Indigenous populations in northern Canada and to address a contaminant of emerging concern identified by the Arctic Monitoring and Assessment Programme, a multi-year biomonitoring study investigated levels of PAH exposure in subarctic First Nations communities of the Northwest Territories, Canada. Secondary data analysis of banked samples from a subset of the cross-sectional study was done. PAHs and cotinine markers in the urine samples (n = 97) of participants from two regions from the Mackenzie Valley (Dehcho and Sahtú) was completed by liquid and gas chromatography coupled with mass spectrometry. Also, participants completed a 24-hr recall food survey. When compared according to age/sex categories, the GM of several biomarkers (1-hydroxypyrene, 1-naphthol, 2-hydroxyfluorene, 2-hydroxyphenanthrene, 2-naphthol, 3-hydroxyfluorene, 3-hydroxyphenanthrene, 4-hydroxyphenanthrene, 9-hydroxyfluorene, 9-hydroxyphenanthrene) appeared higher than observed for the general Canadian population. The PAHs levels observed were, however, below clinical levels associated with adverse health outcomes. Altogether, these elevated biomarkers are metabolites of pyrene, naphthalene, fluorene and phenanthrene. Statistically significant non-parametric associations were observed between several biomarkers and i) the consumption of cooked meat in the last 24 h; and, ii) smoking status (self-reported status and adjusted on urine cotinine level). This work is the first to report PAH levels in a northern Canadian population and provides local baseline data for monitoring the effects of changes to climate and lifestyle over time. These findings will support regional and territorial decision makers in identifying environmental health priorities.

Accumulation of phenanthrene and its metabolites in lettuce (Lactuca sativaL.) as affected by magnetic carbon nanotubes and dissolved humic acids

Accumulation and metabolites of phenanthrene in lettuce as affected by magnetic carbon nanotubes and dissolved humic acids were investigated under hydroponic conditions.

Association of urinary polycyclic aromatic hydrocarbons and obesity in children aged 3-18: Canadian Health Measures Survey 2009-2015.

Polycyclic aromatic hydrocarbons (PAHs) may contribute to obesity. Childhood obesity is a strong predictor of adult obesity and morbidity; however, the relationship between PAHs and obesity in young children (e.g., aged 3-5) has not been studied. We examined the association between urinary PAH metabolites and measures of obesity in children. We analyzed data from 3667 children aged 3-18 years who participated in the Canadian Health Measures Survey (CHMS, 2009-2015). We ran separate multivariable linear models to estimate the association between quartiles of PAH metabolites and each of body mass index (BMI) percentile, waist circumference (WC), and waist-to-height ratio (WHtR) in the total population, as well as in the age subgroups 3-5, 6-11, and 12-18, adjusting for age, sex, ethnicity, education, income quintile, diet, creatinine, and exposure to environmental tobacco smoke. A multinomial logistic regression model estimated adjusted odds ratios for risk of central obesity. BMI, WC, and WHtR were positively associated with total PAH and naphthalene metabolites in the total population aged 3-18 and in age groups 6-11 and 12-18. In 3-5 year olds, WHtR, but not BMI, was significantly associated with total PAH, naphthalene, and phenanthrene metabolites. Overall, those in the highest quartile for naphthalene or total PAH metabolites had three times greater odds of having central obesity compared with those in the lowest quartile. Urinary PAH metabolites are associated with WHtR, an indicator of central obesity and predictor of health risks associated with obesity, in children as young as 3-5.