Exposure of hairdressing apprentices to airborne hazardous substances

BACKGROUND: Few studies have investigated exposure of hairdressing apprentices to airborne irritants. This study describes exposure levels of apprentices to chemical products used in hairdressing salons in relation with their activity. METHODS: Following a two stages study design, a group of 300 students completed a questionnaire on their work activities and environment. Among these, a group of 28 subjects volunteered to undergo personal exposure and workplace concentrations measurements over a work shift, during a cold and a hot season, with the agreement of the salon owners. Three chemical substances were studied (ammonia, hydrogen peroxide and persulfates) because they are respiratory tract irritants and because their concentrations could be quantified within a 5 to 8 hour shift period. RESULTS: Personal exposure values for H(2)O(2)and NH(3) (averages [standard deviations] are 0.05 [0.04] and 0.90 [0.76] mg.m(-3), respectively) were greater than workplace ambient air concentrations (corresponding values of 0.04 [0.03] and 0.68 [0.42] mg.m(-3)) for H(2)O(2 )and NH(3), with no significant seasonal variation. By contrast, workplace concentrations of persulfates (0.019 [0.018] mg.m(-3)) were greater than personal exposure (0.016 [0.021] mg.m(-3), a finding that is consistent with the fact that bleaching is more often undertaken by senior hairdressers. However, all exposure values were lower than the current TLV TWA values. This study also shows that over half of technical spaces where chemical substances used for dying, permanenting or bleaching are manipulated, have no ventilation system, and not even a door or a window opening outside. CONCLUSION: The study hairdressing salons, on average, were small, the most probable reason why occupational hygiene measures such as appropriate ventilation were too seldom implemented. As a consequence, young apprentices and senior hairdressers experience substantial exposure to known airways irritants

What do brain endocasts tell us? A comparative analysis of the accuracy of sulcal identification by experts and perspectives in palaeoanthropology

Palaeoneurology is a complex field as the object of study, the brain, does not fossilize. Studies rely therefore on the (brain) endocranial cast (often named endocast), the only available and reliable proxy for brain shape, size and details of surface. However, researchers debate whether or not specific marks found on endocasts correspond reliably to particular sulci and/or gyri of the brain that were imprinted in the braincase. The aim of this study is to measure the accuracy of sulcal identification through an experiment that reproduces the conditions that palaeoneurologists face when working with hominin endocasts. We asked 14 experts to manually identify well-known foldings in a proxy endocast that was obtained from an MRI of an actual in vivo Homo sapiens head. We observe clear differences in the results when comparing the non-corrected labels (the original labels proposed by each expert) with the corrected labels. This result illustrates that trying to reconstruct a sulcus following the very general known shape/position in the literature or from a mean specimen may induce a bias when looking at an endocast and trying to follow the marks observed there. We also observe that the identification of sulci appears to be better in the lower part of the endocast compared to the upper part. The results concerning specific anatomical traits have implications for highly debated topics in palaeoanthropology. Endocranial description of fossil specimens should in the future consider the variation in position and shape of sulci in addition to using models of mean brain shape. Moreover, it is clear from this study that researchers can perceive sulcal imprints with reasonably high accuracy, but their correct identification and labelling remains a challenge, particularly when dealing with extinct species for which we lack direct knowledge of the brain

Exposure of bakery and pastry apprentices to airborne flour dust using PM2.5 and PM10 personal samplers

<p>Abstract</p> <p>Background</p> <p>This study describes exposure levels of bakery and pastry apprentices to flour dust, a known risk factor of occupational asthma.</p> <p>Methods</p> <p>Questionnaires on work activity were completed by 286 students. Among them, 34 performed a series of two personal exposure measurements using a PM_2.5and PM₁₀personal sampler during a complete work shift, one during a cold ("winter") period, and the other during a hot ("summer") period.</p> <p>Results</p> <p>Bakery apprentices experience greater average PM_2.5and PM₁₀exposures than pastry apprentices (p < 0.006). Exposure values for both particulate fractions are greater in winter (average PM₁₀values among bakers = 1.10 mg.m^-3[standard deviation: 0.83]) than in summer (0.63 mg.m^-3[0.36]). While complying with current European occupational limit values, these exposures exceed the ACGIH recommendations set to prevent sensitization to flour dust (0.5 mg.m^-3). Over half the facilities had no ventilation system.</p> <p>Conclusion</p> <p>Young bakery apprentices incur substantial exposure to known airways allergens, a situation that might elicit early induction of airways inflammation.</p

Early incidence of occupational asthma among young bakers, pastry-makers and hairdressers: design of a retrospective cohort study

<p>Abstract</p> <p>Background</p> <p>Occupational exposures are thought to be responsible for 10-15% of new-onset asthma cases in adults, with disparities across sectors. Because most of the data are derived from registries and cross-sectional studies, little is known about incidence of occupational asthma (OA) during the first years after inception of exposure. This paper describes the design of a study that focuses on this early asthma onset period among young workers in the bakery, pastry making and hairdressing sectors in order to assess early incidence of OA in these "at risk" occupations according to exposure duration, and to identify risk factors of OA incidence.</p> <p>Methods/Design</p> <p>The study population is composed of subjects who graduated between 2001 and 2006 in these sectors where they experience exposure to organic or inorganic allergenic or irritant compounds (with an objective of 150 subjects by year) and 250 young workers with no specific occupational exposure. A phone interview focusing on respiratory and 'Ear-Nose-Throat' (ENT) work-related symptoms screen subjects considered as "possibly OA cases". Subjects are invited to participate in a medical visit to complete clinical and lung function investigations, including fractional exhaled nitric oxide (FE_NO) and carbon monoxide (CO) measurements, and to collect blood samples for IgE (Immunoglobulin E) measurements (total IgE and IgE for work-related and common allergens). Markers of oxidative stress and genetic polymorphisms exploration are also assessed. A random sample of 200 "non-cases" (controls) is also visited, following a nested case-control design.</p> <p>Discussion</p> <p>This study may allow to describ a latent period between inception of exposure and the rise of the prevalence of asthma symptoms, an information that would be useful for the prevention of OA. Such a time frame would be suited for conducting screening campaigns of this emergent asthma at a stage when occupational hygiene measures and adapted therapeutic interventions might be effective.</p> <p>Trial registration</p> <p>Clinical trial registration number is NCT01096537.</p

Lasers a centres colores dans les domaines: 1,0-1,3 #mu#m et 1,5-1,75 #mu#m, pompes par lampe flash

SIGLEINIST T 76591 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Exposition des apprentis de la coiffure et de la boulangerie-pâtisserie à des facteurs de risque d'asthme

La coiffure et la boulangerie sont des professions à risque d'asthme. Les études visant à apprécier l'exposition des apprentis dans ces métiers sont rares. Ce travail s'intéresse aux expositions personnelle et aux concentrations ambiantes pour des agents chimiques utilisés par les apprentis coiffeurs (ammoniac, peroxyde d'hydrogène et persulfates), aux expositions personnelles d'apprentis boulangers et pâtissiers aux poussières de farine (PM2,5 et PM1O), et à leurs déterminants. A cet effet, un questionnaire rempli par 586 apprentis décrit leurs profils d'activités et l'environnement de travail. Les mesurages ont été réalisés auprès de 34 apprentis boulangers ou pâtissiers et 28 apprentis coiffeurs sur un poste de travail au cours de deux saisons. Les expositions personnelles à H202 et NH3 sont légèrement plus élevées que les concentrations d'ambiance, ce contraste étant inversé pour les persulfates, sans différence saisonnière. L'exposition des boulangers et pâtissiers aux poussières de farine est plus élevée en hiver. Les résultats satisfont les valeurs limites règlementaires françaises (NH3, H202, poussières non spécifique inhalables et alvéolaires). Les valeurs moyennes chez les boulangers excèdent cependant les recommandations de l'ACGIH. Il en est de même pour certaines valeurs maximales des persulfates. Des facteurs prédictifs expliquant les valeurs hautes d'exposition ont été mis en évidence; la fréquence de la ventilation insuffisante des locaux est soulignée. Ce travail apporte des enseignements de nature à contribuer à une diminution des niveaux d'exposition et ainsi à réduire le risque d'asthme professionnel.Hairdressing and bakery are weIl known as occupations at risk of asthma. Exposure studies of apprentie es in hairdressing salons and bakeries are scarce, however. This work describes exposure levels and workplace air concentrations to airbome chemical products (ammonia, hydrogen peroxide, persulfates) used in hairdressing salons and personal exposure of flour dust used in bakery and pastry (PM2,5 et PM1O), and associated apprentices' exposure determinants. A questionnaire was completed by 586 apprentie es on their work activities and environment. 28 hairdressers and 34 bakery or pastry apprentices volunteered to undergo personal exposure and workplace concentrations measurements, during a cold and a hot season. Personal H202 and NH3 exposure values are greater than workplace concentrations, while the reverse holds for persulfates, with no seasonal variation. Exposure to flour dust (PM 10, PM2,5) is greater in winter than during the hot season. Results do not exceed the French limit values for NH3, H202, non specifie inhalable and respirable particulate matter. Average bakers' results were greater than the ACGIH recommendations, as were persulfates values. Few factors explained the high values of exposure; appropriate ventilation is showed as rarely implemented, however. This research suggests that reduction of exposure levels can be achieved, that would result in abatement of the risk of occupational asthma.NANCY1-SCD Medecine (545472101) / SudocSudocFranceF

Design of High Performance Scroll Microcoils for Nuclear Magnetic Resonance Spectroscopy of Nanoliter and Subnanoliter Samples

The electromagnetic properties of scroll microcoils are investigated with finite element modelling (FEM) and the design of experiment (DOE) approach. The design of scroll microcoils was optimized for nuclear magnetic resonance (NMR) spectroscopy of nanoliter and subnanoliter sample volumes. The unusual proximity effect favours optimised scroll microcoils with a large number of turns rolled up in close proximity. Scroll microcoils have many advantages over microsolenoids: such as ease of fabrication and better B1-homogeneity for comparable intrinsic signal-to-noise ratio (SNR). Scroll coils are suitable for broadband multinuclei NMR spectroscopy of subnanoliter sample

Chronique climatologique : Interprétation de la circulation atmosphérique d'après les images de satellites géostationnaires GEO-EST et METEOSAT

National audienc

Chronique climatologique : Interprétation de la circulation atmosphérique d'après les images de satellites géostationnaires GEO-EST et METEOSAT

National audienc