Bitumen fumes and PAHs in asphalt road paving: Emission characteristics, determinants of exposure and environmental impact.

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 characterised 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 hydrocarbons (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 proportion, 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 exposures. 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 negligible contribution of paving emissions to global environmental pollution. CONCLUSION: The present study confirmed the complex nature of bitumen fumes and characterised the main determinants 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.

Influence of exposure dose, complex mixture, and ultraviolet radiation on skin absorption and bioactivation of polycyclic aromatic hydrocarbons ex vivo.

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.

[Assessing the impact of psychological and organizational constraints on caregivers]. / Evaluer l'impact des contraintes psychologiques et organisationnelles chez les soignants.

Through a national cohort of more than 4000 nurses and nursing assistants in 14 university hospital centres, a study has developed a tool to assess the health of nursing staff within nursing units. This tool enables the general health condition of caregivers, as well as their working conditions, to be gauged. On this basis, preventative measures in terms of work organisation can be drawn up.

Validation of an instrument for measuring psychosocial and organisational work constraints detrimental to health among hospital workers: the NWI-EO questionnaire.

BACKGROUND: Quality of care, job satisfaction and the health of registered nurses (RNs) are associated with their exposure to psychosocial and organisational work factors (POWFs). OBJECTIVES: To develop and validate an extended version of the Revised Nursing Work Index (NWI-R), the NWI-EO (Extended Organisation) tool specifically designed for occupational physicians and those involved in prevention programmes in healthcare institutions to assess the perception of POWFs, and then to determine priorities for preventive action to improve work organisation at the hospital staff level. METHODS: The tool was validated in the ORSOSA study, a multicentre French cohort of RNs and NAs (n=4085) recruited in 214 work units of 7 French university hospitals. A total of 34 items (19 candidate items developed by a focus group and 15 items from the NWI-R) were analysed using principal component analysis (PCA) based on a randomised split-half of the data. In addition, construct validity, test-retest reliability, internal consistency and concurrent validity were assessed. RESULTS: Response rate was 91%. Twenty-two items were selected (9 of the 15 NWI-R items and 13 of the 19 candidate items) by PCA, resulting in an 8-factor solution that explained 53% of the common variance. The stability of the factorial structure of this 22-item NWI-EO questionnaire was confirmed by PCA on the other half-sample as well as by PCA on subgroups (age, gender, occupational group, specialty area, hospital). Reliability, assessed by internal consistency and test-retest, was satisfactory. Concurrent validity with two external measurements of organisational characteristics of work units was also observed. CONCLUSION: The NWI-EO was found to have good psychometric properties. Several POWFs accessible to prevention programmes can be evaluated with this tool: poor communication in the work unit, lack of support from senior nurses, inadequate staffing to perform duties, poor relationships between workers, frequency of interruptions during tasks, low level of shared values within the team with regard to work, lack of support from the administration, and changes in planned vacations and time off. We believe the NWI-EO is a useful tool for assessing POWFs among RNs and NAs in order to determine priorities for preventive action to improve work organisation at the unit level.

Linking hospital workers' organisational work environment to depressive symptoms: A mediating effect of effort-reward imbalance? The ORSOSA study.

Few studies have analysed the association between the organisational work environment and depression in hospital workers and we still have little understanding of how processes in the practice environment are related to depressive disorders. However, individual perception of an imbalance between efforts made and expected rewards has been associated with incident depression. The main goal of this study was to test the hypothesis that some organisational constraints at the work-unit level may be related to depressive symptoms in hospital workers, either directly or through individual perceptions of effort-reward imbalance (ERI). In 2006, 3316 female registered nurses and nursing aids working in 190 work units in seven French university hospitals, recruited from the baseline screening of an epidemiological cohort study (the ORSOSA study), responded in 2006 to valid self-report questionnaires (CES-D, ERI). The organisational work environment was assessed with the self-rated Nursing Work Index - Extended Organisation (NWI-EO) aggregated at the work unit level. Multilevel models were used. We found that poor relations between workers within work units were associated with higher CES-D score, independently of perceived ERI. Low level of communication between workers in the unit was associated with individual perceptions of ERI and indirectly associated with depressive symptoms. Understaffing and non-respect of planned days off and vacations were associated with perceived ERI but these organisational constraints were not associated with depressive symptoms. Our study allowed us to identify and quantify organisational factors that have a direct effect on hospital workers' depressive symptoms, or an indirect effect through perceived ERI. Better understanding of the effect of organisational factors on health through perceived ERI would provide targets for successful interventions. Organisational approaches may be more effective in improving mental health at work and may also have a longer-lasting impact than individual approaches.

Urinary levels of oxidative DNA and RNA damage among workers exposed to polycyclic aromatic hydrocarbons in silicon production: comparison with 1-hydroxypyrene.

Polycyclic aromatic hydrocarbons (PAH) are ubiquitous occupational and environmental pollutants and the urinary excretion of 1-hydroxypyrene (1-OHP) is classically measured for the determination of PAH exposure internal dose. Some of PAH are tumorigenic due to their metabolites ability to generate DNA adducts and oxidative DNA damage through the production of reactive oxygen species during metabolism. 8-hydroxy-7,8-dihydro-2'-deoxyguanosine (8-OHdGuo) is one of the major oxidative DNA lesions and its use as a potential biomarker of genotoxic PAH occupational exposure should be evaluated. Indeed conflicting results are frequently reported in occupational studies in terms of correlation between 8-OHdGuo urinary levels and PAH exposure. The aim of our study was therefore to determine the potential for PAH occupational exposure to increase urinary oxidative DNA damage. The population consisted of 68 male workers employed in silicon production. The urinary concentrations of 8-OHdGuo and its homologue in RNA, 8-hydroxy-7,8-dihydroguanosine (8-OHGuo) were determined using high performance liquid chromatography (HPLC) coupled to tandem mass spectrometry, whereas those of 1-OHP were measured using HPLC with fluorescence detection. Individual variation rates were calculated on a working day and a working week. The results indicated that, while 1-OHP levels strongly increased on a working day and even more on a working week, 8-OHdGuo and 8-OHGuo urinary levels did not show similar significant increases. Moreover, no correlation between 1-OHP and oxidative DNA and RNA lesions was found. Consequently, urinary 8-OHdGuo and 8-OHGuo did not seem to be relevant biomarkers of genotoxic PAH exposure in the case of the silicon plant studied.