Authorized in the European Union as a novel food, Tenebrio molitor larvae are gaining attention as a sustainable protein source. This study aimed to characterize potential contamination of T.molitor larvae flour with environmental pollutants and to assess its bioaccumulation capacity.To account for potential variability linked to rearing conditions and/or substrate origin, T.molitor larvae were raised on eight different cereal-based substrates, resulting in eight distinct flours. Eleven trace elements, six mycotoxins, seven PCBs, and 650 pesticide residues were analyzed. For each substance detected, a bioaccumulation factor (BAF) was calculated. Of the substances analyzed, forteen substances were found in T.molitor larvae flour: piperonyl butoxide (<0.0025 to 0.017 mg/kg), 2,4-D (<0.005 to 0.073 mg/kg), glyphosate (0.013 to 0.032 mg/kg), lead (<0.04 to 0.075 mg/kg), cadmium (0.058 to 0.097 mg/kg), total arsenic (0.045 to 0.21 mg/kg), total mercury (<0.005 mg/kg), aluminium (2.2 to 36 mg/kg), nickel (0.54 to 1.11 mg/kg), copper (18.2 to 23.3 mg/kg), zinc (102 to 149 mg/kg), cobalt (<0.05 to 0.14 mg/kg), chromium (0.13 to 0.64 mg/kg) and manganese (14.6 to 44.2 mg/kg). Among these, T.molitor exhibits bioaccumulation of 2,4-D (median BAF = 4.60), glyphosate (1.74), copper (1.50), zinc (1.56), chromium (3.68) and total arsenic (2.19). No bioaccumulation was observed for eight pesticides, four mycotoxins and seven trace elements. Contamination levels were below the specifications of this novel food but, in some cases, higher than the maximal limit authorized for meat and fish. Replacing conventional animal proteins with T.molitor could alter the population’s exposure, requiring specific risk assessments.

INTRODUCTION:Biomonitoring of exposure to carcinogenic Benzo(a)Pyrene is generally based on measurement of urinary 3-hydroxybenzo(a)pyrene (3-OHBaP), but its analysis is complex and only reflects the BaP detoxification pathway. TetraolBaP, another BaP metabolite resulting from the metabolic activation pathway, is now available but has not yet been studied in occupational settings or compared with 3-OHBaP. METHODS:Biomonitoring was carried out on 118 subjects working in the aluminium smelting industry. 3 urine samples were collected from each subject at the beginning and end of the working week. Pyrene metabolite (1-hydroxypyrene) and the two BaP biomarkers (3-OHBaP and TetraolBaP) were analysed using LC-Fluorescence and GC-NCI-MS-MS. RESULTS:The workers studied were found to be highly exposed, with 1-OHP and 3-OHBaP frequently exceeding maximum recommended values in occupational settings. Maximum concentrations were measured at end of shift+16h for all biomarkers, highlighting dermal exposure and/or temporary storage. Correlations were strong between 1-OHP and 3-OHBaP (r = 0.68-0.75) as well as between 3-OHBaP and TetraolBaP (r = 0.67-0.78), and moderate between 1-OHP and TetraolBaP (r = 0.59-0.76). While TetraolBaP levels were higher at low PAH exposures, TetraolBaP increased much more slowly at high exposures, indicating progressive saturation of the bioactivation pathway. The [3-OHBaP]/[TetraolBaP] ratio was found to be significantly lower in chronically exposed workers. Urinary TetraolBaP levels corresponding to 1-OHP (2.5 μg/L or 1 μmol/mol creatinine) or 3-OHBaP (0.4 nmol/mol creatinine) guidance values were found to range between 0.84 and 0.95 nmol/mol creatinine. CONCLUSIONS:TetraolBaP, resulting from carcinogenic BaP's metabolic activation pathway, was shown to be a diagnostically specific and sensitive biomarker for determining subjects' toxic internal exposure to PAHs in different contexts (occupational settings, environment) and assessing health risks.

Exposure to polycyclic aromatic hydrocarbons (PAHs), ubiquitously environmental contaminant, leads to the development of major toxic effects on human health, such as carcinogenic and immunosuppressive alterations reported for the most studied PAH, i.e., benzo(a)pyrene (B(a)P). In order to assess the risk associated with this exposure, it is necessary to have predictive biomarkers. Thus, extracellular vesicles (EVs) and their microRNA (miRNA) contents, have recently been proposed as potentially interesting biomarkers in Toxicology. Our study here explores the use of vesicles secreted and found in blood fluids, and their miRNAs, as biomarkers of exposure to B(a)P alone and within a realistic occupational mixture. We isolated EVs from primary human cultured blood mononuclear cells (PBMCs) and rat plasma after PAH exposure and reported an increased EV production by B(a)P, used either alone or in the mixture, in vitro and in vivo. We then investigated the association of this EV release with the blood concentration of the 7,8,9,10-hydroxy (tetrol)-B(a)P reactive metabolite, in rats. By performing RNA-sequencing (RNA-seq) of miRNAs in PBMC-derived EVs, we analyzed miRNA profiles and demonstrated the regulation of the expression of miR-342-3p upon B(a)P exposure. We then validated B(a)P-induced changes of miR-342-3p expression in vivo in rat plasma-derived EVs. Overall, our study highlights the feasibility of using EVs and their miRNA contents, as biomarkers of PAH exposure and discusses their potential in environmental Toxicology.

Polycyclic aromatic hydrocarbons (PAHs) are interesting environmental pollutants for understanding cocktail effects. High-molecular-weight-PAHs (HMW–PAHs) are classified as probable or possible carcinogens; only benzo[a]pyrene (B[a]P) is a certain carcinogen in humans. Their toxicity depends on their metabolic activation. While 3-hydroxybenzo[a]pyrene (3-OHB[a]P) represents its detoxification pathway, trans-anti-7,8,9,10-tetrahydroxy-7,8,9,10-tetrahydrobenzo[a]pyrene (tetrol-B[a]P) represents the carcinogenicity pathway. The objective was to study the metabolism of B[a]P and HMW–PAHs during chronic low-dose exposure to B[a]P or a PAH mixture. Rats were exposed orally 5 times/week for 10 weeks to low-levels of B[a]P (0.02 and 0.2 mg.kg−1.d−1) or to an industrial mixture extracted from coal tar pitch (CTP) adjusted to 0.2 mg.kg−1.d−1 B[a]P. Urinary levels of monohydroxy-, diol-, and tetrol-PAH were measured during weeks 1 and 10 by HPLC-fluorescence and GC‒MS/MS. After 1 week, the percentages of B[a]P eliminated as 3-OHB[a]P and tetrol-B[a]P were not different depending on the dose of B[a]P, whereas they were reduced by half in the CTP group. Repeated exposure led to an increase in the percentages of the 2 metabolites for the 0.02-B[a]P group. Moreover, the percentage of B[a]P eliminated as 3-OHB[a]P was equal in the 0.2-B[a]P and CTP groups, whereas it remained halved for tetrol-B[a]P in the CTP group. The percent elimination of HMW–PAH metabolites did not vary between weeks 1 and 10. Thus, dose, duration of exposure and chemical composition of the mixture have a major influence on PAH metabolism that goes beyond a simple additive effect. This work contributes to the reflection on determination of limit values and risk assessments in a context of poly-exposures.

Background: Asphalt road paving and its subsequent complex airborne emissions have raised concerns about occupational exposures and environmental impacts. Although several studies described bitumen fumes or Polycyclic Aromatic Hydrocarbons (PAH) emissions at specific worksites, no comprehensive studies have char-acterised road paving emissions and identified the main determinants of exposure.Methods: A 10-year study from 2012 to 2022 was performed to examine the pollutants resulting from bitumen fume emissions and covering the main processes used in road paving (asphalt production, mechanical rolled asphalt paving, manual paving, mastic asphalt paving, emulsion paving, and coal-tar asphalt milling). A total of 623 air samples were collected at 63 worksites (on 290 workers, in the environment and near emission sources), and bitumen fumes, PAHs, aldehydes and volatile organic compounds were analysed. Biomonitoring campaigns were performed on 130 workers to assess internal exposure to PAHs.Results: Fume emissions revealed complex mixtures of C10-C30 compounds, including linear saturated hydro-carbons (C6-C12), alicyclic hydrocarbons and aliphatic ketones. PAHs were dominated by 2-3 aromatic ring compounds (naphthalene, fluorene, and phenanthrene), and C1-C13 aldehydes were identified. Binder propor-tion, paving temperature, outdoor temperature, workload and job category influenced airborne concentrations. A significant temporal trend was observed over the time period of the study, with decreasing BF and PAH expo-sures. PAH biomonitoring was consistent with air samples, and urinary metabolites of 2-3 ring PAHs dominated over 4-5 ring PAHs. Occupational exposures were generally far lower than exposure limits, except coal-tar asphalt milling activities. Very low environmental concentrations were measured, which highlights a negli-gible contribution of paving emissions to global environmental pollution.Conclusion: The present study confirmed the complex nature of bitumen fumes and characterised the main de-terminants of exposure. The results highlight the need to reduce the paving temperature and binder proportion. Recycled asphalt pavement use was not associated with higher emissions. The impact of paving activities on environmental airborne pollution was deemed negligible.

A new gas chromatography–tandem mass spectrometry method for the determination of mono- and dihydroxylated polycyclic aromatic hydrocarbon metabolites (OH-PAHs and diol-PAHs) in urine was developed and validated. Various sample preparation procedures were compared, namely liquid–liquid extraction (LLE), dispersive solid-phase extraction (dSPE), and SPE, alone or combined. A novel two-stage derivatization approach using 2 silylation reagents was developed, and an experimental procedure design was used to optimize the programmed temperature vaporization–solvent vent injection (PTV-SV) GC parameters. The method focused on 11 target compounds resulting from four- to five-ring suspected carcinogenic PAHs. SPE was identified as an acceptable and more convenient extraction method for all tested metabolites, with extraction rates ranging from 63 to 86% and relative standard deviations lower than 20%. The two-stage derivatization approach successfully allowed first the derivatization of OH-PAHs by MTBSTFA (N-tert-butyldimethylsilyl-N-methyltrifluoroacetamide) and then diol-PAHs by BSTFA (N,O-bis(trimethylsilyl)trifluoroacetamide) in a single run. The limits of quantification were in the range of 0.01–0.02 μg l−1 for OH-PAHs and 0.02–0.2 μg l−1 for diol-PAHs. The intra- and interday precisions were lower than 10%. The method was applied to determine PAH metabolites in urine collected at the beginning and at the end of the working week from 6 workers involved in aluminum production. The mean diol-PAH levels at the end of the week were 10 to 20 times higher (0.86–2.34 μg g−1 creatinine) than those of OH-PAHs (0.03–0.30 μg g−1). These results confirmed the usefulness of this new analytical technique for detecting and characterizing metabolic patterns of PAHs in urine and assessing carcinogenic occupational exposures.

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.

Combined exposure to complex mixtures of polycyclic aromatic hydrocarbons (PAHs) and ultraviolet radiation (UVR) is suspected to enhance PAH skin permeability and skin cancer risk depending on PAH bioactivation. The impact of PAH mixtures (exposure dose, composition, and complexity) and UVR was assessed for PAH cutaneous absorption and metabolism using realistic exposure conditions and human skin explants. PAH complex mixtures were extracted from the industrial products coal tar pitch (CTP-I) and petroleum coke (PC-I). The synthetic mixture (CTP-S) was identically reconstituted using PAH standards. The applied dose was adjusted to 1 (PC-I, CTP-I) or 10 nmol (CTP-I, CTP-S) of benzo[a]pyrene (B[a]P). Unmetabolized PAHs were recovered from the skin surface, skin and medium, and then quantified by HPLC-fluorescence detection. PAH metabolites were collected from the medium and analyzed by GC–MS/MS. B[a]P and PAH penetration was lower for the highest B[a]P dose, industrial mixtures, and CTP-I compared to PC-I. Skin irradiation increased PAH penetration only for CTP-I. PAH uptake was poorly influenced by the different experimental conditions. PAH metabolism markedly decreased in the application of mixtures, leading to unmetabolized PAH accumulation in human skin. PAH metabolism was similar between CTP-I and PC-I, but was lower for the highest dose and the industrial mixtures, suggesting a saturation of xenobiotic metabolizing enzymes, as confirmed in a time-course study. UVR strongly inhibited all PAH metabolism. Altogether, these results underline the necessity to consider the reality of human exposure (PAH complex mixtures and UVR) during in vitro experiments to properly estimate skin absorption and metabolism.

Cutaneous exposure to carcinogenic polycyclic aromatic hydrocarbons (PAH) occurs frequently in the industrialized workplace. In the present study, we addressed this topic in a series of experiments using human skin explants and organic extracts of relevant industrial products. PAH mixtures were applied topically in volumes containing either 10 or 1 nmol B[a]P. We first observed that although mixtures were very efficient at inducing expression of CYP450 1A1, 1A2, and 1B1, formation of adducts of PAH metabolites to DNA, like those of benzo[a]pyrene diol epoxide (BPDE), was drastically reduced as the complexity of the surrounding matrix increased. Interestingly, observation of a nonlinear, dose-dependent response with the least complex mixture suggested the existence of a threshold for this inhibitory effect. We then investigated the impact of simulated sunlight (SSL) on the effects of PAH in skin. SSL was found to decrease the expression of CYP450 genes when applied either after or more efficiently before PAH treatment. Accordingly, the level of DNA-BPDE adducts was reduced in skin samples exposed to both PAH and SSL. The main conclusion of our work is that both increasing chemical complexity of the mixtures and co-exposure to UV radiation decreased the production of adducts between DNA and PAH metabolites. Such results must be taken into account in risk management.

Introduction: High styrene exposures are still experienced in various occupational settings, requesting regular exposure assessments. The aims of this study were to study occupational exposures in various industrial sectors and to determine factors influencing styrene urinary metabolites levels. Methods: Biomonitoring was conducted in 141 workers from fiberglass-reinforced plastic (FRP) manufacture, thermoplastic polymers production, vehicle repair shops and cured-in-place pipe lining (CIPP). Urinary styrene (StyU) as well as Mandelic (MA) /Phenyglyoxylic Acids (PGA) were quantified at the beginning and at the end of week, and multivariate linear regression models were used. Results: StyU levels revealed very low, rarely exceeding 3 mu g.L-1. Highest concentrations of MA + PGA were observed in FRP sector, with levels reaching up to 1100 mg.g(-1) of creatinine. Factors influencing end-of-week MA + PGA concentrations were levels at the beginning of week, open molding processes, proximity to the emission source, respiratory protection, styrene content in raw materials. Elevated levels were also observed during CIPP process, whereas thermoplastic injection and vehicle repair shop workers exhibited much lower exposures. Conclusions: Intervention on process (decreasing styrene proportion, using closed molding), protective equipment (local exhaust ventilation, respiratory protection) and individual practices (stringent safety rules) are expected to decrease occupational exposures. Urinary MA+ PGA remain the most appropriate biomarkers for occupational biomonitoring.

Polycyclic aromatic hydrocarbons (PAH) are ubiquitous pollutants, among which benzo[a]pyrene (B[a]P) is the only compound classified carcinogenic to humans. Besides pulmonary uptake, skin is the major route of PAH absorption during occupational exposure. Health risk due to PAH exposure is commonly assessed among workers using biomonitoring. A realistic human ex vivo skin model was developed to explore B[a]P diffusion and metabolism to determine the most relevant biomarker following dermal exposure. Three realistic doses (0.88, 8.85 and 22.11 nmol/cm2) were topically applied for 8, 24, and 48 h. B[a]P and its metabolites were quantified by liquid chromatography coupled with fluorimetric detection. The impact of time, applied dose, and donor age were estimated using a linear mixed-effects model. B[a]P vastly penetrated the skin within 8 h. The major metabolites were 3-hydroxybenzo[a]pyrene (3-OHB[a]P) and 7,8,9,10-tetrahydroxy-7,8,9,10-tetrahydrobenzo[a]pyrene (B[a]P-tetrol). This latter predominantly derives from the most carcinogenic metabolite of B[a]P, benzo[a]pyrene-7,8-diol-9,10-epoxide (BPDE), as well as benzo[a]pyrene-9,10-diol-7,8-epoxide (reverse-BPDE). Benzo[a]pyrene-trans-7,8-dihydrodiol (B[a]P-7,8-diol) was a minor metabolite, and benzo[a]pyrene-trans-4,5-dihydrodiol (B[a]P-4,5-diol) was never quantified. Unmetabolized B[a]P bioavailability was limited following dermal exposure since less than 3% of the applied dose could be measured in the culture medium. B[a]P was continuously absorbed and metabolized by human skin over 48 h. B[a]P-tetrol production became saturated as the applied dose increased, while no effect was measured on the other metabolic pathways. Age had a slight positive effect on B[a]P absorption and metabolism. This work supports the relevance of B[a]P-tetrol to assess occupational exposure and carcinogenic risk after cutaneous absorption of B[a]P.

Skin is a major barrier against external insults and is exposed to combinations of chemical and/or physical toxic agents. Co-exposure to the carcinogenic benzo[a]pyrene (B[a]P) and solar UV radiation is highly relevant in human health, especially in occupational safety. In vitro studies have suggested that UVB enhances B[a]P genotoxicity by activating the AhR pathway and overexpressing the cytochrome P450 enzymes responsible for the conversion of B[a]P into DNA damaging metabolites. Our present work involved more realistic conditions, namely ex vivo human skin explants and simulated sunlight (SSL) as a UV source. We found that topically applied B[a]P strongly induced expression of cutaneous cytochrome P450 genes and formation of DNA adducts. However, gene induction was significantly reduced when B[a]P was combined with SSL. Consequently, formation of BPDE-adducts was also reduced when B[a]P was associated with SSL. Similar results were obtained with primary cultures of human keratinocytes. These results indicate that UV significantly impairs B[a]P metabolism, and decreases rather than increases immediate toxicity. However, it cannot be ruled out that decreased metabolism leads to accumulation of B[a]P and delayed genotoxicity.

La dépollution des sols est en expansion en France du fait de la réhabilitation d’anciens sites industriels et de l’action des pouvoirs publics. L’impact environnemental des sols pollués a été beaucoup étudié, en revanche l’impact sanitaire pour les travailleurs assurant la réhabilitation de sites pollués est peu documenté. L’objectif de cette étude était d’évaluer les expositions professionnelles aux polluants chimiques lors d’activité de dépollution des sols. Quatre sites regroupant chacun des pollutions variées liées à d’anciennes activités (fonderie, mines, stockage de gaz, équarrissage) ont été inclus dans l’étude, représentant 9 chantiers. Sur chaque chantier ont été réalisés des prélèvements de sol, ainsi que des prélèvements individuels atmosphériques et urinaires sur les 25 opérateurs impliqués dans la réhabilitation. Les polluants analysés incluaient les hydrocarbures aromatiques polycycliques (HAP) et les métaux (sols, air, urines), les particules (air), les hydrocarbures totaux (HCT) et PCB (sols). Des fiches de renseignements ont été renseignées systématiquement et incluaient l’historique des sites, les co-expositions, les équipements de protection et les conditions météorologiques. Les prélèvements de sols ont mis en évidence des pollutions variables, avec des métaux lourds (Arsenic, Plomb) et des HCT (C10–C40) prépondérants, à des taux pouvant atteindre jusqu’à 1000 (métaux) à 10 000 (HCT) mg/kg. Les concentrations atmosphériques étaient proportionnellement plus faibles en HAP et métaux et pas toujours corrélées aux niveaux dans les sols. Les concentrations urinaires de métaux toxiques et de métabolites des HAP étaient faibles, en cohérence avec les niveaux atmosphériques et les protections collectives (cabines ventilées) ou individuelles (masques) utilisées. Les expositions ne dépassaient pas les valeurs maximales admissibles et en majorité similaires ou légèrement supérieures aux valeurs observables en population générale, indiquant une bonne protection. Seul un chantier était associé à des expositions élevées en HAP dont l’origine supposée était une co-exposition à des poussières de créosote issues de traverses de chemin de fer manipulées lors de la réhabilitation du site. Cette étude a permis d’évaluer l’exposition professionnelle des travailleurs des sites de dépollution, jusqu’à présent peu décrite. Nos 1er résultats montrent que les niveaux de pollution dans les sols donnent une indication précieuse sur les familles de polluants concernés, mais ne sont pas nécessairement prédictifs de l’exposition professionnelle des agents sur les sites de réhabilitation des sols, nécessitant un suivi métrologique individuel.

Le raffinage du pétrole génère des hydrocarbures aromatiques polycycliques (HAP) qui doivent être mesurés du fait de leur toxicité potentielle (effets cancérogènes, irritatifs, immunotoxiques). Une SBEP est réalisée chez des sujets assurant le nettoyage de bacs ayant contenu des résidus de fuels lourds. Quatorze sujets (6 non-fumeurs et 8 fumeurs) ont été inclus. Les sujets étaient équipés de masques à adduction d’air. Trois prélèvements d’urines ont été recueillis, en début de poste le 1er jour de travail, en fin de poste le 4e jour et en début de dernier poste. Ont été analysés le 1-hydroxypyrène (1-OHP, issu du pyrène), le 3-hydroxybenzo(a)pyrène (3-OHBaP, issu du BaP cancérogène) et les métabolites de 3 HAP gazeux majoritaires (naphtalène, fluorène et phénanthrène). En complément, un échantillon du résidu a été analysé. Le résidu contenait 600 μg d’HAP par gramme de résidu sec, avec une majorité (70 %) d’HAP légers à 2/3 cycles aromatiques (naphtalène, fluorène, phénanthrène, pyrène) et peu d’HAP lourds (BaP notamment). Les concentrations urinaires d’1-OHP (0,01 à 0,27 μmol/mol de créatinine) étaient largement inférieures aux valeurs maximales recommandées en milieu professionnel et ne dépassaient que rarement celles de témoins. Une accumulation était néanmoins retrouvée, avec des concentrations significativement supérieures en fin de semaine (p = 0,05). Le 3-OHBaP était indétectable dans près de 40 % des échantillons et au maximum de 0,15 nmol/mol hormis chez un sujet fumeur au niveau de base anormalement élevé. Les niveaux des métabolites des HAP gazeux (naphtols, fluorénols et phénanthrols) en fin de semaine étaient majoritairement similaires à ceux de la population générale (non analysés sur le 1er prélèvement). Malgré une tendance, aucune différence statistiquement significative n’est mise en évidence entre les sujets fumeurs et non-fumeurs pour l’ensemble des biomarqueurs, probablement en raison du faible effectif. Les expositions mesurées sont faibles et cohérentes avec le niveau de protection des sujets et la source (dérivés de distillation de pétrole). Le 3-OHBaP, bien qu’issu d’un HAP cancérogène, n’apparaît pas comme le biomarqueur exclusif à privilégier ici du fait de valeurs souvent indétectables. Le 1-OHP et les métabolites des HAP gazeux, plus abondants et davantage influencés par les émissions, paraissent utiles pour suivre l’imprégnation des travailleurs aux HAP. Il serait néanmoins nécessaire de pratiquer des biométrologies à d’autres postes du raffinage pour confirmer cette stratégie de SBEP incluant les HAP gazeux, ces derniers reflétant mieux le mélange auquel sont exposés les travailleurs.

Background: Millions of workers are exposed to polycyclic aromatic hydrocarbons (PAHs), a well-known family of carcinogens, but occupational exposure data about PAH mixture compositions are scarce. Objectives: To provide a detailed picture of airborne PAH exposures encountered in the French industrial landscape over the previous 20 years and to identify determinants driving exposures. Methods: Results from 1643 airborne samples of 16 gaseous and particulate PAHs implemented into the Exporisq HAP database from 1995 to 2014 were used to describe exposure levels and aerosol chemical composition in many industries and activities. Compliance of benzo[a]pyrene (BaP) levels with several existing occupational exposure limits for long-term exposure was assessed. Results: BaP levels were lower than those reported in the literature, but the level and composition of PAH mixtures were highly variable between and within industries. Numerous exposure determinants (e.g., product composition, type and temperature of process, ventilation and confinement) were assumed to explain these differences. The highest levels were found in industries using products derived from coal (aluminum, silicon, and coke production, manufacturing of carbon products and foundries), with mean BaP levels up to 23 times higher than the French recommended value of 150 ng/m(3). Forty-seven percent of the occupational activities exceeded this value. Conversely, exposures resulting from petroleum-derived products were relatively low. Conclusions: As health effects depend on PAH levels but also on the composition of the mixture, exposure assessments must characterize the entire mixtures and record specific determinants to define homogeneous exposure groups and to accurately assess health risks.

Polycyclic aromatic hydrocarbons (PAH) are ubiquitous pollutants present as complex mixtures in the environment. Among them, benzo(a)pyrene (BaP) is classified as carcinogenic to humans by the International Agency of Research on Cancer. Taking into account all absorption ways, human biomonitoring allows PAH exposure assessment, but biomarkers both specific to carcinogenic effect and sufficiently sensitive are lacking. In this work, we proposed the urinary 7,8,9,10-tetrahydroxy-7,8,9,10-tetrahydrobenzo(a)pyrene (7,8,9,10-OHBaP) stemming from hydrolysis of BaP-7,8-diol-9,10-epoxide, the ultimate carcinogenic BaP metabolite, as biomarker of PAH exposure. A simple and highly sensitive analytical method, with a limit of quantification (LQ) reaching 0.06 pmol/L (0.02 ng/L), was described and validated. The relevance of urinary 7,8,9,10-OHBaP concentrations adjustment by creatinine was demonstrated. In a group of 24 non-occupationally PAH exposed subjects, only 15% of 7,8,9,10-OHBaP levels was below the LQ and the last daily void has been found as the best sampling time. Tobacco consumption had a significant positive effect on 7,8,9,10-OHBaP concentrations with a 90e percentile equal to 0.05 nmole/mole creatinine (nmol/mol) and 0.03 nmol/mol for smokers and non-smokers, respectively. In case of occupational PAH exposure, all the pre- and post-shift urinary 7,8,9,10-OHBaP levels of 7 non-smoking workers in a prebaked electrodes production plant were above the LQ. Concentrations ranged from 0.05 to 0.91 nmol/mol and accumulation of 7,8,9,10-OHBaP into organism of workers during the working week was clearly observed. The best sampling time was the post-shift at the end of week but samples should also be collected at pre-shift the beginning of week to assess the background level. Finally, the urinary 7,8,9,10-OHBaP elimination kinetic through the weekend was studied using non-linear mixed effect modelling. Mean apparent urinary half-life was 31.5 h with low inter-individual variability. Describing key characteristics of urinary 7,8,9,10-OHBaP as PAH exposure biomarker, this work should promote its use for future large-scale biomonitoring campaigns.

Exposure to Polycyclic Aromatic Hydrocarbons (PAHs) occurs by respiratory, digestive and dermal absorption. Biomonitoring takes all pathways into account but sensitive and specific biomarkers are required. Different gaseous PAHs metabolites were used due to their abundance in the atmospheric mixtures but none of them were selected as better biomarker than the others. To identify the best candidates for assessing occupational airborne exposure, relation between atmospheric levels of Naphtalene, Fluorene and Phenanthrene and urinary metabolites concentrations was studied in a carbon electrode workers group. Linear mixed effects models were built to select explanatory variables and estimate variance component. Urinary creatinine was a predictor of metabolites levels confirming the importance of diuresis for interpreting results. High significance of pre-shift sampling time combined with positive coefficients of post-shift indicated that urine should be sampled at the end of the workday in association with pre-shift urine to avoid misinterpretations. Among the 10 metabolites studied, urinary 2-hydroxyfluorene and 2-hydroxyphenanthrene showed the highest increase of variance explained by models after inclusion of individual atmospheric levels as explanatory variable. Priority could be given to 2-hydroxyfluorene due to higher excretion levels than 2-hydroxyphenanthrene.

Les bitumes issus du raffinage du pétrole sont utilisés pour l’application d’enrobés routiers. De nombreux HAP sont émis à partir des liants bitumineux, incluant des composés gazeux et particulaires (dont certains cancérogènes). Du fait de modifications récentes des conditions d’application des bitumes (enrobés tièdes, aspiration des fumées), une nouvelle évaluation de l’exposition professionnelle aux HAP a été conduite. Une surveillance des expositions a été réalisée par des métrologies atmosphériques individuelles (prélèvements et analyses de 17 HAP) en complément d’une surveillance biologique basée sur le recueil de 2 échantillons urinaires en début et fin de poste, avec analyse des métabolites du pyrène (1-OHP), benzo(a)pyrène (3-OHBaP), naphtalène (1- et 2-naphtols), fluorène (1- 2- 3- 9-fluorénols) et phénanthrène (1- 2- 3- 4- 9-phénanthrols). L’étude a été conduite sur 10 chantiers/36 travailleurs, dont 9 conducteurs de finisseur, 9 régleurs, 14 opérateurs râteau et 4 autres postes. Les analyses ont été réalisées par HPLC-fluorescence et GC-spectrométrie de masse au Laboratoire de toxicologie professionnelle et environnementale du CHU de Grenoble. Les concentrations urinaires de 1-OHP sont faibles, très influencées par tabagisme (moyennes géométriques MG de 0,05 et 0,10 μmol/mol de créatinine en fin de journée chez les non-fumeurs et fumeurs), et dans leur majorité largement inférieures aux valeurs recommandées en milieu professionnel (1 μmol/mol). Les niveaux de 3-OHBaP sont extrêmement faibles, souvent indétectables avec un maximum de 0,17 nmol/mol de créatinine (niveaux recommandés < 0,4 nmol/mol). Les naphtols sont retrouvés à des niveaux similaires à ceux de la population générale. Les fluorénols et phénanthrols bien que très faibles sont supérieurs à ceux de témoins. Les niveaux de fin de journée de 1-OHP, 3-OHBaP, et 2- 3-fluorénols sont supérieurs à ceux de début de journée. Les principaux paramètres expliquant la variabilité des concentrations des biomarqueurs sont le tabagisme, le % de liant bitumineux et la T° d’application des enrobés. Lors de l’application d’enrobés bitumineux, les expositions sont faibles pour les HAP gazeux et très faibles pour les particulaires (notamment BaP), avec une cohérence entre la surveillance biologique et la métrologie atmosphérique. L’utilisation de bitumes tièdes et le faible pourcentage de liants bitumineux permettent de diminuer encore les expositions aux HAP ce qui va dans le sens des recommandations ANSES (2013). L’efficacité des systèmes d’aspiration des fumées est en cours d’évaluation.