FeNO levels increase with degree of sensitisation in apprentices at risk of occupational asthma.

BACKGROUND: Atopy has emerged as a major determinant of airway inflammation. OBJECTIVE: To examine whether early markers of occupational asthma increase with degree of sensitisation. METHOD: This study was a prospective follow-up study of apprentices in baking, pastry-cooking and hairdressing during their 2-year apprenticeship. Four visits were conducted to administer a standardised questionnaire, a methacholine challenge test to assess bronchial hyperresponsiveness (BHR) and to measure fractional exhaled nitric oxide (FeNO). Degree of sensitisation was estimated based on the number of positive skin prick tests (SPTs) for 12 common allergens. Mixed-effect models were applied to examine the association between the degree of sensitisation and FeNO levels, BHR and eosinophilic status (more than 3% of cells in nasal lavage fluid). RESULTS: Of the 441 apprentices who agreed to take part in the study, 417 had at least one SPT session providing usable results. Degree of sensitization was related to BHR and FeNO levels. Compared to non-sensitised subjects, FeNO levels were 83% higher (P < 0.01) in highly sensitised subjects and 30% higher (P < 0.01) in weakly sensitised subjects. However, the degree of sensitisation was not predictive of the evolution of these markers. CONCLUSION: Degree of sensitisation is related to early markers of airway inflammation.

Multiple exposures to indoor contaminants: Derivation of benchmark doses and relative potency factors based on male reprotoxic effects.

Semi-Volatile Organic Compounds (SVOCs) are commonly present in dwellings and several are suspected of having effects on male reproductive function mediated by an endocrine disruption mode of action. To improve knowledge of the health impact of these compounds, cumulative toxicity indicators are needed. This work derives Benchmark Doses (BMD) and Relative Potency Factors (RPF) for SVOCs acting on the male reproductive system through the same mode of action. We included SVOCs fulfilling the following conditions: detection frequency (>10%) in French dwellings, availability of data on the mechanism/mode of action for male reproductive toxicity, and availability of comparable dose-response relationships. Of 58 SVOCs selected, 18 induce a decrease in serum testosterone levels. Six have sufficient and comparable data to derive BMDs based on 10 or 50% of the response. The SVOCs inducing the largest decrease in serum testosterone concentration are: for 10%, bisphenol A (BMD10 = 7.72E-07 mg/kg bw/d; RPF10 = 7,033,679); for 50%, benzo[a]pyrene (BMD50 = 0.030 mg/kg bw/d; RPF50 = 1630), and the one inducing the smallest one is benzyl butyl phthalate (RPF10 and RPF50 = 0.095). This approach encompasses contaminants from diverse chemical families acting through similar modes of action, and makes possible a cumulative risk assessment in indoor environments. The main limitation remains the lack of comparable toxicological data.

Volatile and semi-volatile organic compounds of respiratory health relevance in French dwellings.

Over the last decades, the prevalence of childhood respiratory conditions has dramatically increased worldwide. Considering the time spent in enclosed spaces, indoor air pollutants are of major interest to explain part of this increase. This study aimed to measure the concentrations of pollutants known or suspected to affect respiratory health that are present in dwellings in order to assess children's exposure. Measurements were taken in 150 homes with at least one child, in Brittany (western France), to assess the concentrations of 18 volatile organic compounds (among which four aldehydes and four trihalomethanes) and nine semi-volatile organic compounds (seven phthalates and two synthetic musks). In addition to descriptive statistics, a principal component analysis (PCA) was used to investigate grouping of contaminants. Formaldehyde was highly present and above 30 µg/m(3) in 40% of the homes. Diethyl phthalate, diisobutyl phthalate, and dimethylphthalate were quantified in all dwellings, as well as Galaxolide and Tonalide. For each chemical family, the groups appearing in the PCA could be interpreted in term of sources. The high prevalence and the levels of these compounds, with known or suspected respiratory toxicity, should question regulatory agencies to trigger prevention and mitigation actions.

Exhaled nitric oxide and screening for occupational asthma in two at-risk sectors: bakery and hairdressing.

BACKGROUND: Fractional exhaled nitric oxide (FENO) levels are increasingly being used in the diagnosis and management of asthma. However, this indicator has rarely been used to detect occupational asthma. OBJECTIVE: To examine non-invasive methods to estimate airway inflammation. METHODS: A nested case-control study was conducted among a retrospective cohort of young workers in the bakery, pastry-making and hairdressing industries. Subjects underwent a clinical examination during a medical visit. Blood samples were collected and FENO levels measured. Cases were subjects diagnosed as suffering from 'confirmed' or 'probable' occupational asthma. RESULTS: Of the 178 workers included in the study, 19 were cases. In univariate analysis, FENO was associated with case/control status, and height and smoking status. In a multiple linear regression model, case/control status (P < 0.001), height (P = 0.006) and smoking status (P < 0.001) remained independent risk factors for variations in FENO levels. Good or fair sensitivity of respectively around 80% and 70% can be achieved using low FENO thresholds (8.5 and 10.5 ppb, respectively). FENO >8.5 ppb and a positive clinical examination increases specificity without loss of sensitivity (to 80.5% and 79.0%, respectively). CONCLUSION: This study suggests that FENO measurements alone cannot be considered a useful screening test for occupational asthma. Further investigations are needed to investigate the use of combined FENO and questionnaire or repeated measures.

The role of anxiety in the perception of technological hazards - a cross-sectional study on cell phones and masts.

BACKGROUND: Risk perception is determined by parameters related to the nature of the risk, as well as inherent to the individual perceiving this risk. This study was designed to provide a better understanding of the role of personality, especially anxiety traits, on risk perception. It compared representations of two different risks, smoking (with known and generally accepted adverse health effects) and cell phones (whose hazardous potency is still controversial), each presented in two different forms of exposure, active (smokers and cell phone users) and passive (passive smoking and exposure to cell phone masts). METHODS: A self-administered questionnaire sent to volunteer subjects collected sociodemographic and exposure data. It measured the perceived risk as well as 11 psychometric properties of risk using visual analogue scales (values ranging from 0 to 10). An anxiety trait was evaluated by the Spielberger questionnaire. RESULTS: In all, 72% of the questionnaires sent were returned. Mean declared risk scores attributed to passive and active smoking were higher (8.75 and 8.31 respectively) than those attributed to cell phones and masts (4.44 and 4.73 respectively). However, scores for the 11 psychometric properties of the risk attributed to cell phones were higher than those associated with smoking, especially for dissatisfaction with information (6.71 and 7.36 respectively for cell phones and masts versus 1.75 and 2.18 for passive and active smoking) and the capacity of authorities to master the risk (6.45 and 6.65 for cell phones and masts versus 4.72 and 4.40 for passive and active smoking). Anxiety did not directly influence the risk scores attributed to these 4 forms of exposure but was predictive of the way in which subjects perceived the risk in terms of two essential properties: uncertainty concerning the effects on health and the potential to trigger health catastrophes. Indeed anxious subjects are more certain about the hazards of cell phones and masts than non-anxious subjects (P=0.008 et P≤0.001) and attributed a higher catastrophic potential (P=0.02 and P=0.004). CONCLUSION: This study suggests that subjects with an anxious profile are affected by the destabilizing nature of uncertain knowledge concerning the hazardous potency of new technologies and of the controversies concerning this hazard.

Prevalence of IgE against neuromuscular blocking agents in hairdressers and bakers.

BACKGROUND: Allergic IgE-mediated reactions to neuromuscular blocking agents (NMBAs) are the main cause of immediate hypersensitivity reactions in anaesthesia; their predominant occurrence in the absence of previous exposure to NMBAs suggests a risk related to environmental exposure. OBJECTIVE: To investigate the prevalence of specific IgE to quaternary ammonium ions in two populations professionally exposed to quaternary ammonium compounds, in the north-eastern France. METHODS: The study had a retrospective follow-up design whereby apprentices were assessed after their 2-year training period as apprentices. The professionally exposed hairdresser populations (n = 128) were compared with baker/pastry makers (n = 108) and 'non-exposed' matched control subjects (n = 379). RESULTS: We observed a 4.6-fold higher frequency of positive IgE against quaternary ammonium ions in hairdressers (HD), compared with baker/pastry makers (BP) and control (C) groups. The competitive inhibition of quaternary ammonium Sepharose radioimmunoassay (QAS-IgE RIA) with succinylcholine was significantly higher in HD, compared with BP and C groups, with inhibition percentage of 66.2 ± 7.4, 39.7 ± 6.0 and 43.8 ± 9.9, respectively (P < 0.001). The specific IgE against quaternary ammonium ions recognized also two compounds widely used by hairdressers, benzalkonium chloride and polyquaternium-10, in competitive inhibition of IgE RIA. When considering the whole study population, hairdresser professional exposure and total IgE > 100 kU/L were the two significant predictors of IgE-sensitization against quaternary ammonium ions in the multivariate analysis of a model that included age, sex, professional exposure, increased concentration of total IgE (IgE > 100 kU/L) and positive IgE against prevalent allergens (Phadiatop(®) ; P = 0.019 and P = 0.001, respectively). CONCLUSION AND CLINICAL RELEVANCE: The exposure to hairdressing professional occupational factors increases IgE-sensitization to NMBAs and quaternary ammonium ion compounds used in hairdressing. Besides the pholcodine hypothesis, our study suggests that repetitive exposure to quaternary ammonium compounds used in hairdressing is a risk factor for NMBAs sensitization.

Early incidence of occupational asthma is not accelerated by atopy in the bakery/pastry and hairdressing sectors.

SETTING: Occupational asthma (OA) is most likely to develop in the very early years of exposure. OBJECTIVE: To describe the early incidence of OA among bakers/pastry-makers (BP) and hairdressers and to explore the role of atopy. DESIGN: Following a retrospective follow-up design, subjects were invited to undergo telephone interviews. Those who declared work-related respiratory or rhinitis symptoms and a sample group of others were offered a medical visit for OA investigations. Data from interviews and from medical visits were used to estimate the incidence of OA according to increasing durations of exposure. RESULTS: A total of 866 subjects were interviewed (mean age 25.3 years, 43.8% females), of whom 282 underwent a medical visit. Total estimated incidence rates of 'confirmed or probable' OA during the first 12 years of exposure were high in BP (2.63 per 100 person-years [py]) and in hairdressers (0.58/100 py), particularly in the first 4 years. Atopy is a strong risk factor for incidence among BP but, irrespective of the occupational sector, it does not influence the timing of OA symptoms. CONCLUSION: OA symptoms occur soon after the start of exposure. Our results suggest that atopy does not precipitate the occurrence of symptoms in two different allergen exposure settings.

Pontiac fever among retirement home nurses associated with airborne legionella.

The aim of this study was to ascertain incidence of symptoms compatible with Pontiac fever (PF) and to assess their association with exposure to legionella bacteria among retirement home nurses who help residents take their shower. Within a non-epidemic framework, 104 nurses of 19 retirement homes were followed up during an average period of four months. Data on symptoms, number and location of showers they attended were recorded daily by each participant. Water and aerosol bacterial quality was characterised at the end of follow-up using the culturable and the in-situ hybridisation techniques. Among 11 Pontiac-like episodes, eight cases complied with the study definition of PF. Water concentrations >10(3) cfu legionella per litre were associated with an increased risk of PF, with dose-response patterns. No association was established between the aerosol legionella concentrations and PF events. A threshold value of 103 cfu legionella per litre of water might be used with a view to protection from legionella-associated occupational conditions.

[Tobacco use characteristics among apprentices in Vocational Centers]. / Caractéristiques du tabagisme chez les adolescents en Centre de formation des apprentis.

BACKGROUND: Most smokers start smoking during adolescence and become dependent before 20 years old. In France, vocational trainees are a population not much explored. The objective of our study is to present tobacco use characteristics among apprentices in Vocational Centers (VC). METHODS: This cross-sectional exhaustive study covered 1814 students (among whose 943 smokers) entering in a 1st year of the eight participating Vocational Centers in the Lorraine region (Eastern France, 2.3 million inhabitants, 16,500 vocational trainees), during the school years 2007-2008 and 2008-2009. Data collection concerned the sociocultural environment, tobacco use habits, degree of dependency to tobacco and co-addictions. RESULTS: Among the study population, 52.0% declared they were smokers among whom 89.4% daily smokers, and 5.7% were ex-smokers. The average age of tobacco use initiation was 12.1 years (standard deviation [SD]=2.1) and the average age at inception of regular cigarette smoking was 13.8 years (SD=1.6). Current consumption of the smokers was 12.8 cigarettes per day (SD=7.8). The average score of smoking addiction was 6.1 (SD=2.8), according to the Hooked On Nicotine checklist test (score from 0 to 10=strongly dependent). Finally, 37.1% of students (58.9% among smokers) smoked or have smoked cannabis. CONCLUSION: The high prevalence of smoking in Vocational Centers, the early start of tobacco use and the high tobacco consumption among apprentices show that they are overexposed compared to the general population of adolescents. In addition, these young people are already dependant to tobacco use. This underlines the need of specific measures dedicated to this population that amounts to 361,500 individuals in France.

Exhaled nitric oxide and spirometry in respiratory health surveillance.

BACKGROUND: Exposure to pollutants in bakeries and hairdressing salons can cause airway syndromes varying from bronchial irritation to asthma. Workplace respiratory health surveillance aims to identify possible cases requiring further investigation. AIMS: To compare the performance of fractional exhaled nitric oxide (FE(NO)) and spirometry for health surveillance of apprentice bakers (ABs) and apprentice hairdressers (AHDs). Determinants of FE(NO) were also identified. METHODS: Symptoms and physician-diagnosed asthma were evaluated by questionnaire. FE(NO) was measured and spirometry was carried out. Subjects with elevated FE(NO) (FE(NO) > upper limit normal), airway obstruction [forced expiratory volume in 1 s (FEV(1))/forced vital capacity (FVC) < 95th percentile] and atopy (history of allergies) were identified. RESULTS: A total of 126 apprentices (59 ABs and 67 AHDs) participated. Twenty-nine (23%) apprentices had abnormal tests: 4 had associated high FE(NO) and airway obstruction, while 25 had either high FE(NO) (n = 15) or airway obstruction (n = 10) alone. Compared with ABs (n = 16), AHDs (n = 13) had more asthma (38 versus 0%; P < 0.05) and atopy (62 versus 6%; P < 0.05). There was no difference in symptoms, smoking FE(NO) or airways obstruction. Among 97 subjects with normal tests, no differences existed between ABs (n = 53) and AHDs (n = 44). Average FE(NO) was increased in atopic non-smokers compared with atopic smokers and non-atopic subjects (P < 0.05). Smoking, a history of allergies, FEV(1)/FVC % observed and respiratory symptoms were the main determinants of FE(NO). CONCLUSIONS: FE(NO) and spirometry were not overlapping dimensions in ABs and hairdressers, each test contributing unique information on the physiological status of the respiratory system. FE(NO) may provide added information on airway inflammation not provided by spirometry.

Legionella bacteria in shower aerosols increase the risk of Pontiac fever among older people in retirement homes.

BACKGROUND: 828 elderly subjects residing in nursing homes were followed up during 4 months to ascertain incidence of symptoms associated with Pontiac fever (PF) in a non-epidemic setting. METHODS: The exposure situation was inhalation of Legionella bacteria while showering. An audit of the hot water system in all institutions allowed ascribing each subject to a water quality area wherefrom one shower was sampled for Legionella assays at the end of the follow-up period. Legionella were detected in water and aerosols using the culture (CFU, colony forming units) and in situ hybridization (FISH) techniques. RESULTS: Among 32 Pontiac-like episodes, 29 cases complied with the operational definition of PF elaborated for this study. Incidence density was 0.11 case/person-year (95% CI 0.07 to 0.15). Water concentrations greater than 105 Legionella FISH/l and 104 Legionella CFU/l were associated with an increased risk of PF (respectively RR 2.23, p = 0.05 and RR 2.39, p = 0.11, with significant dose-response patterns: p for trend <0.04). The condition also seems associated with aerosol concentrations above 103 Legionella FISH/l of air. A significantly higher risk of Pontiac-like episodes (RR 6.24, 95% CI 2.12 to 18.38) was seen for elderly subjects receiving corticosteroid therapy. CONCLUSION: The water and threshold values identified in this research could be used to inform guidance measures aimed at protecting institutionalised older people from Legionnaires' disease. Immunosuppressive therapy in the same population group can significantly enhance susceptibility to Legionella bacteria.

[Democracy and science advice: the case of environmental health risks]. / De la démocratie en expertise. Le cas des risques sanitaires environnementaux.

Science advice, in the context of environmental health, is an activity consisting in bringing together and evaluating available scientific data at a given moment on a particular question or concern regarding the hazardous nature of an agent or substance--whether it be of a physical, chemical or microbiological nature. Science advice also relates to assessing health risks linked to the quality of the environment, in vue of rendering this information useful to those in charge of decision making and risk management. Naturally, many groups are interested by a potential hazard or risk, and they all would like to effectively intervene over the course of the process in order to influence the decision or measure taken. In this article, the author recalls that risk is an entity which is both scientific and political by nature. Hence, this demand is well founded. Nevertheless, he proposes and explicates a series of different steps, whether concurrent or successive, throughout the entire process of science advice in support of decision-making on matters related to environmental risk. He justifies why hazard and risk assessment, followed by risk analysis, requisites a clear delineation of the roles of the various actors so that their own responsibilities could be clearly attributed. The "procedural" approach of science advice, which is more and more frequently implemented within international expert groups in the international arena, satisfactorily achieves the target of objectivity, transparency and accountability.

Waterborne microbial risk assessment: a population-based dose-response function for Giardia spp. (E.MI.R.A study).

BACKGROUND: Dose-response parameters based on clinical challenges are frequently used to assess the health impact of protozoa in drinking water. We compare the risk estimates associated with Giardia in drinking water derived from the dose-response parameter published in the literature and the incidence of acute digestive conditions (ADC) measured in the framework of an epidemiological study in a general population. METHODS: The study combined a daily follow-up of digestive morbidity among a panel of 544 volunteers and a microbiological surveillance of tap water. The relationship between incidence of ADC and concentrations of Giardia cysts was modeled with Generalized Estimating Equations, adjusting on community, age, tap water intake, presence of bacterial indicators, and genetic markers of viruses. The quantitative estimate of Giardia dose was the product of the declared amount of drinking water intake (in L) by the logarithm of cysts concentrations. RESULTS: The Odds Ratio for one unit of dose [OR = 1.76 (95% CI: 1.21, 2.55)] showed a very good consistency with the risk assessment estimate computed after the literature dose-response, provided application of a 20 % abatement factor to the cysts counts that were measured in the epidemiological study. Doing so, a daily water intake of 2 L and a Giardia concentration of 10 cysts/100 L, would yield an estimated relative excess risk of 12 % according to the Rendtorff model, against 11 % when multiplying the baseline rate of ADC by the corresponding OR. This abatement parameter encompasses uncertainties associated with germ viability, infectivity and virulence in natural settings. CONCLUSION: The dose-response function for waterborne Giardia risk derived from clinical experiments is consistent with epidemiological data. However, much remains to be learned about key characteristics that may heavily influence quantitative risk assessment results.