263 resultados para Occuational Exposure


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BACKGROUND: In May 2010, Switzerland introduced a heterogeneous smoking ban in the hospitality sector. While the law leaves room for exceptions in some cantons, it is comprehensive in others. This longitudinal study uses different measurement methods to examine airborne nicotine levels in hospitality venues and the level of personal exposure of non-smoking hospitality workers before and after implementation of the law. METHODS: Personal exposure to second hand smoke (SHS) was measured by three different methods. We compared a passive sampler called MoNIC (Monitor of NICotine) badge, to salivary cotinine and nicotine concentration as well as questionnaire data. Badges allowed the number of passively smoked cigarettes to be estimated. They were placed at the venues as well as distributed to the participants for personal measurements. To assess personal exposure at work, a time-weighted average of the workplace badge measurements was calculated. RESULTS: Prior to the ban, smoke-exposed hospitality venues yielded a mean badge value of 4.48 (95%-CI: 3.7 to 5.25; n = 214) cigarette equivalents/day. At follow-up, measurements in venues that had implemented a smoking ban significantly declined to an average of 0.31 (0.17 to 0.45; n = 37) (p = 0.001). Personal badge measurements also significantly decreased from an average of 2.18 (1.31-3.05 n = 53) to 0.25 (0.13-0.36; n = 41) (p = 0.001). Spearman rank correlations between badge exposure measures and salivary measures were small to moderate (0.3 at maximum). CONCLUSIONS: Nicotine levels significantly decreased in all types of hospitality venues after implementation of the smoking ban. In-depth analyses demonstrated that a time-weighted average of the workplace badge measurements represented typical personal SHS exposure at work more reliably than personal exposure measures such as salivary cotinine and nicotine.

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Horses (Equus caballus) belong to the group of seasonally polyestrous mammals. Estrous cycles typically start with increasing daylight length after winter, but mares can differ greatly in the timing of onset of regular estrus cycles. Here, we test whether spatial proximity to a stallion also plays a role. Twenty-two anestrous mares were either exposed to one of two stallions (without direct physical contact) or not exposed (controls) under experimental conditions during two consecutive springs (February to April). Ovarian activity was monitored via transrectal ultrasound and stallion's direct contact time with each mare was determined three times per week for one hour each. We found that mares exposed to a stallion ovulated earlier and more often during the observational period than mares that were not exposed to stallions. Neither stallion identity nor direct contact time, mare age, body condition, size of her largest follicle at the onset of the experiment, or parasite burden significantly affected the onset of cyclicity. In conclusion, the timing of estrous cycles and cycle frequency, i.e., crucial aspects of female reproductive strategy, strongly depend on how the mares perceive their social environment. Exposing mares to the proximity of a stallion can therefore be an alternative to, for example, light programs or elaborated hormonal therapies to start the breeding season earlier and increase the number of estrous cycles in horses.

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Agricultural workers are among the professional groups most at risk of developing acute or chronic respiratory problems. Despite this fact, the etiology of these occupational diseases is poorly known, even in important sectors of agriculture such as the crops sector. A chronic exposure to multiple microorganisms, such as different bacterial and fungal species, has been proposed to be the cause of these multiple respiratory pathologies. Nevertheless, these microbial communities are still partially known. The aim of this study is to characterize all fungal species inhaled by the crops workers during different grain related activities and identify the abiotic and biotic factors that reduce the growth of the toxigenic, irritative or allergenic microbial species. Here, we are presenting the factors promoting the exposure to bioaerosols during different wheat related activities: harvesting, grain unload, baling straw, the cleaning of harvesters and silos. Total dust has been quantified following NIOSH 0500 method. Reactive endotoxin activity has been determined with Limulus Amebocyte Lysate Assay. All molds have been identified by the pyrosequencing of ITS2 amplicons generated from bioaerosol.

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Hygiene practices in neonatal units require the use of disinfecting solutions containing ethanol or isopropanol. Newly disinfected hands or soaked swabs introduced inside the incubators may emit vapours leading to alcohol exposures to the neonates. Alcohol emissions from hands and other occasional sources (e.g. soaked disinfecting swabs) lead to measurable levels of vapours inside incubators. Average isopropanol and ethanol concentrations ranging from 33.1 to 171.4 mg/m(3) (13.8 to 71.4 ppm) and from 23.5 to more than 146 mg/m3 (9.8 to > 6 ppm) respectively were measured inside occupied incubators (n = 11, measurement time about 230 min) in a neonatal unit of the Centre Hospitalier Universitaire Vaudois in Lausanne during regular activity. Exposure concentrations in a wide range of possible situations were then investigated by modeling using the one-box dispersion model. Theoretical modeling suggested typical isopropanol peaks and average concentrations ranging between 10(2) and 10(3) mg/m(3) (4.10(1) to 4.10(2)ppm), and 10(1) to 10(2) mg/m(3) (4 to 4.10(1) ppm), respectively. Based on our results we suggest several preventive measures to reduce the neonates' exposures to solvent vapours.

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A passive sampling device called Monitor of NICotine or "MoNIC", was constructed and evaluated by IST laboratory for determining nicotine in Second Hand Tobacco Smoke (SHTS) or Environmental Tobacco Smoke (ETS). Vapour nicotine was passively collected on a potassium bisulfate treated glass fibre filter as collection medium. Analysis of collected nicotine on the treated filter by gas chromatography equipped with Thermoionic-Specific Detector (GC-TSD) after liquid-liquid extraction of 1mL of 5N NaOH : 1 mL of n-heptane saturated with NH3 using quinoline as internal standard. Based on nicotine amount of 0.2 mg/cigarette as the reference, the inhaled Cigarette Equivalents (CE) by non-smokers can be calculated. Using the detected CE on the badge for non-smokers, and comparing with amount of nicotine and cotinine level in saliva of both smokers and exposed non-smokers, we can confirm the use of the CE concept for estimating exposure to ETS. The regional CIPRET (Center of information and prevention of the addiction to smoking) of different cantons (Valais (VS), Vaud (VD), Neuchâtel (NE) and Fribourg (FR)) are going to organize a big campaign on the subject of the passive addiction to smoking. This campaign took place in 2007-2008 and has for objective to inform clearly the Swiss population of the dangerousness of the passive smoke. More than 3'900 MoNIC badges were gracefully distributed to Swiss population to perform a self-monitoring of population exposure level to ETS, expressed in term of CE. Non-stimulated saliva was also collected to determine ETS biomarkers nicotine/cotinine levels of participating volunteers. Results of different levels of CE in occupational and non-occupational situations in relation with ETS were presented in this study. This study, unique in Switzerland, has established a base map on the population's exposure to SHTS. It underscored the fact that all the Swiss people involved in this campaign (N=1241) is exposed to passive smoke, from <0.2 cig/d (10.8%), 1-2 to more than 10 cig/d (89.2%). In the area of high exposure (15-38 cig/d), are the most workers in public restaurant, cafe, bar, disco. By monitoring ETS tracer nicotine and its biomarkers, salivary nicotine and cotinine, it is demonstrated that the MoNIC badge can serve as indicator of CE passive smoking. The MoNIC badge, accompanied with content of salivary nicotine/cotinine can serve as a tool of evaluation of the ETS passive smoking and contributes to supply useful data for future epidemiological studies. It is also demonstrated that the salivary nicotine (without stimulation) is a better biomarker of ETS exposure than cotinine.

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The use of urinary hexane diamine (HDA) as a biomarker to assess human respiratory exposure to hexamethylene diisocyanate (HDI) aerosol was evaluated. Twenty-three auto body shop workers were exposed to HDI biuret aerosol for two hours using a closed exposure apparatus. HDI exposures were quantified using both a direct-reading instrument and a treated-filter method. Urine samples collected at baseline, immediately post exposure, and every four to five hours for up to 20 hours were analyzed for HDA using gas chromatography and mass spectrometry. Mean urinary HDA (microg/g creatinine) sharply increased from the baseline value of 0.7 to 18.1 immediately post exposure and decreased rapidly to 4.7, 1.9 and 1.1, respectively, at 4, 9, and 18 hours post exposure. Considerable individual variability was found. Urinary HDA can assess acute respiratory exposure to HDI aerosol, but may have limited use as a biomarker of exposure in the workplace. [Authors]

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Because of the development of modern transportation facilities, an ever rising number of individuals including many patients with preexisting diseases visit high-altitude locations (>2500 m). High-altitude exposure triggers a series of physiologic responses intended to maintain an adequate tissue oxygenation. Even in normal subjects, there is enormous interindividual variability in these responses that may be further amplified by environmental factors such as cold temperature, low humidity, exercise, and stress. These adaptive mechanisms, although generally tolerated by most healthy subjects, may induce major problems in patients with preexisting cardiovascular diseases in which the functional reserves are already limited. Preexposure assessment of patients helps to minimize risk and detect contraindications to high-altitude exposure. Moreover, the great variability and nonpredictability of the adaptive response should encourage physicians counseling such patients to adapt a cautionary approach. Here, we will briefly review how high-altitude adjustments may interfere with and aggravate/decompensate preexisting cardiovascular diseases. Moreover, we will provide practical recommendations on how to investigate and counsel patients with cardiovascular disease desiring to travel to high-altitude locations.

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Objective: To investigate the association between common carotid artery intima-media thickness (cIMT) and exposure to secondhand smoke (SHS) in children. Methods: Data were available at baseline in the Quebec Adiposity and Lifestyle investigation in Youth (QUALITY) study, an ongoing longitudinal investigation of Caucasian children aged 8e10 years at cohort inception, who had at least one obese parent. Data on exposure to parents, siblings and friends smoking were collected in interviewer-administered child, and self-report parent questionnaires. Blood cotinine was measured with a high sensitivity ELISA. cIMTwas measured by ultrasound. The association between blood cotinine and cIMT was investigated in multivariable linear regression analyses controlling for age, body mass index, and child smoking status. Results: Mean (SD) cIMT (0.5803 (0.04602)) did not differ across age or sex. Overall 26%, 6% and 3% of children were exposed to parents, siblings and friends smoking, respectively. Cotinine ranged from 0.13 ng/ml to 7.38 ng/ml (median (IQR)¼0.18 ng/ml)). Multivariately, a 1 ng/ml increase in cotinine was associated with a 0.090 mm increase in cIMT (p¼0.034). Conclusion: In children as young as age 8e10 years, exposure to SHS relates to cIMT, a marker of pre-clinical atherosclerosis. Given the wide range of health effects of SHS, increased public health efforts are needed to reduced exposure among children in homes an private vehicles.

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The aim of the study was to quantify the variability on biological indicators of exposure between men and women for three well known solvents: methyl ethyl ketone, 1-methoxy-2-propanol and 1,1,1-trichloroethane. Another purpose was to explore the effect of selected CYP2E1 polymorphisms on the toxicokinetic profile. Controlled human exposures were carried out in a 12m(3) exposure chamber for each solvent separately, during 6h and at half of the threshold limit value. The human volunteers groups were composed of ten young men and fifteen young women, including ten women using hormonal contraceptive. An analysis of variance mainly showed an effect on the urinary levels of several biomarkers of exposure among women due to the use of hormonal contraceptive, with an increase of more than 50% in metabolites concentrations and a decrease of up to 50% in unchanged substances concentrations, suggesting an increase in their metabolism rate. The results also showed a difference due to the genotype CYP2E1*6, when exposed to methyl ethyl ketone, with a tendency to increase CYP2E1 activity when volunteers were carriers of the mutant allele. Our study suggests that not only physiological differences between men and women but also differences due to sex hormones levels can have an impact on urinary concentrations of several biomarkers of exposure. The observed variability due to sex among biological exposure indices can lead to misinterpretation of biomonitoring results. This aspect should have its place in the approaches for setting limits of occupational exposure. [Authors]