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19 result(s) for "Hoffmeyer, Frank"
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Effects of wearing different face masks on cardiopulmonary performance at rest and exercise in a partially double-blinded randomized cross-over study
The use of face masks became mandatory during SARS-CoV-2 pandemic. Wearing masks may lead to complaints about laboured breathing and stress. The influence of different masks on cardiopulmonary performance was investigated in a partially double-blinded randomized cross-over design. Forty subjects (19–65 years) underwent body plethysmography, ergometry, cardiopulmonary exercise test and a 4-h wearing period without a mask, with a surgical mask (SM), a community mask (CM), and an FFP2 respirator (FFP2). Cardiopulmonary, physical, capnometric, and blood gas related parameters were recorded. Breathing resistance and work of breathing were significantly increased while wearing a mask. During exercise the increase in minute ventilation tended to be lower and breathing time was significantly longer with mask than without mask. Wearing a mask caused significant minimal decreases in blood oxygen pressure, oxygen saturation, an initial increase in blood and inspiratory carbon dioxide pressure, and a higher perceived physical exertion and temperature and humidity behind the mask under very heavy exercise. All effects were stronger when wearing an FFP2. Wearing face masks at rest and under exercise, changed breathing patterns in the sense of physiological compensation without representing a health risk. Wearing a mask for 4-h during light work had no effect on blood gases.
Influence of face masks on the subjective impairment at different physical workloads
To quantify the subjective and cognitive impairment caused by wearing face masks at work, 20 men and 20 women (median age 47 years, range 19–65) were tested under different ergometer workloads while wearing surgical mask, community mask, FFP2 respirator or no mask in a randomized and partially double-blinded design. Masks were worn also at the workplace for four hours. Subjective impairment was recorded by questionnaires. Cognitive performance was tested before and after the workplace examination. Subjective feeling of heat, humidity, and difficult breathing increased with rising physical exertion and wearing time for all three mask types, most notably for FFP2. Even when blinded, participants with FFP2 reported difficult breathing already at rest. During physical exertion, individuals with low tolerance to discomfort reported significantly stronger impairment (OR 1.14, 95% CI 1.02–1.27). Regarding light work, older subjects (OR 0.95, 95% CI 0.92–0.98) and women (OR 0.84, 95% CI 0.72–0.99) showed significantly lower and atopic subjects stronger impairment (OR 1.16, 95% CI 1.06–1.27). No significant influence of mask wearing was detected on cognitive performance. Wearing a mask had no effect on cognitive performance, but led to discomfort which increased with physical exertion and wearing time. Individuals who tolerate discomfort poorly felt more impaired by wearing a mask during physical exertion.
Occupational health hazards of street cleaners – a literature review considering prevention practices at the workplace
Street cleaning is an integral part of the solid waste management system. There are different ways to achieve clean streets depending on the availability of equipment, the type and magnitude of dirt, the surface conditions encountered or traffic conditions. In general, hand sweeping by an individual worker or a group, hose flushing, or machine sweeping or flushing are applied. In order to obtain information about the occurrence and relevance of occupational health hazards of street cleaners, the current international literature, as well as corresponding German regulations, were reviewed and evaluated. Street cleaning includes a variety of health hazards for employees. These can be subdivided into effects of occupational tasks and effects of working conditions such as weather or road traffic. The hazards result from physical, chemical and biological exposures, but may also be due to physiological and psychological burden or inadequate safety aspects. The most commonly reported work-related complaints are musculoskeletal and respiratory disorders, cuts, slips, and road traffic accidents. In developing countries, street cleaners seem to be still heavily exposed to dust and, in most cases, no suitable protective measures are available. Especially in industrialized countries there exist a number of standards and recommendations for waste workers that aim to reduce their occupational health impacts. Int J Occup Med Environ Health. 2020;33(6):701-32.
Frequent Detection of Latent Tuberculosis Infection among Aged Underground Hard Coal Miners in the Absence of Recent Tuberculosis Exposure
Miners are at particular risk for tuberculosis (TB) infection due to exposure to silica dust and silicosis. The objectives of the present observational cohort study were to determine the prevalence of latent TB infection (LTBI) among aged German underground hard coal miners with silicosis or chronic obstructive pulmonary disease (COPD) using two commercial interferon-gamma release assays (IGRAs) and to compare their performance with respect to predictors of test positivity. Between October 2008 and June 2010, miners were consecutively recruited when routinely attending pneumoconiosis clinics for an expert opinion. Both IGRAs, the QuantiFERON®-TB Gold In-Tube (QFT) and the T-SPOT®.TB (T-SPOT), were performed at baseline. A standardized clinical interview was conducted at baseline and at follow-up. The cohort was prospectively followed regarding the development of active TB for at least two years after inclusion of the last study subject. Independent predictors of IGRA positivity were calculated using logistic regression. Among 118 subjects (mean age 75 years), none reported recent exposure to TB. Overall, the QFT and the T-SPOT yielded similarly high rates of positive results (QFT: 46.6%; 95% confidence interval 37.6-55.6%; T-SPOT: 61.0%; 95% confidence interval 52.2-69.8%). Positive results were independently predicted by age ≥80 years and foreign country of birth for both IGRAs. In addition, radiological evidence of prior healed TB increased the chance of a positive QFT result fivefold. While 28 subjects were lost to follow-up, no cases of active TB occurred among 90 subjects during an average follow-up of >2 years. Considering the high prevalence of LTBI, the absence of recent TB exposure, and the currently low TB incidence in Germany, our study provides evidence for the persistence of specific interferon-gamma responses even decades after putative exposure. However, the clinical value of current IGRAs among our study population, although probably limited, remains uncertain.
Comparative analysis of selected exhaled breath biomarkers obtained with two different temperature-controlled devices
Background The collection of exhaled breath condensate (EBC) is a suitable and non-invasive method for evaluation of airway inflammation. Several studies indicate that the composition of the condensate and the recovery of biomarkers are affected by physical characteristics of the condensing device and collecting circumstances. Additionally, there is an apparent influence of the condensing temperature, and often the level of detection of the assay is a limiting factor. The ECoScreen2 device is a new, partly single-use disposable system designed for studying different lung compartments. Methods EBC samples were collected from 16 healthy non-smokers by using the two commercially available devices ECoScreen2 and ECoScreen at a controlled temperature of -20°C. EBC volume, pH, NOx, LTB 4 , PGE 2 , 8-isoprostane and cys-LTs were determined. Results EBC collected with ECoScreen2 was less acidic compared to ECoScreen. ECoScreen2 was superior concerning condensate volume and detection of biomarkers, as more samples were above the detection limit (LTB 4 and PGE 2 ) or showed higher concentrations (8-isoprostane). However, NOx was detected only in EBC sampled by ECoScreen. Conclusion ECoScreen2 in combination with mediator specific enzyme immunoassays may be suitable for measurement of different biomarkers. Using this equipment, patterns of markers can be assessed that are likely to reflect the complex pathophysiological processes in inflammatory respiratory disease.
Ethyl acrylate: influence of sex or atopy on perceptual ratings and eye blink frequency
Occupational exposure limits (OELs) are derived for protection from health hazards, assuming that exposed subjects are healthy adult workers. Whether differences in susceptibility to sensory irritation effects from airborne chemicals have to be taken into account is currently under discussion. Thus, we chose atopics as a healthy but possibly susceptible subpopulation that can be identified with a clinical test. To investigate the influence of sex or atopy on sensitivity to airborne chemicals, 22 subjects were exposed for 4 h to ethyl acrylate at three concentrations: 0.05 ppm (odor threshold; sham), 5 ppm (constant), and varying exposure between 0 and 10 ppm. Odor intensity decreased and eye irritation ratings increased in a dose-dependent manner, reflecting the time course of the exposure scenarios. The reports of moderate-to-strong eye irritation were verified by significant increases in eye blink frequency. Our results show that women reported subjective eye irritation to an increasing degree. However, these sex-related differences in ratings could not be verified by objective assessment of eye blink frequency. Atopic subjects reported higher odor intensity than non-atopic subjects, but only during the sham (odorous but not irritating) exposure condition. Differences in ratings on annoyance, and eye or nose irritation were not found. Furthermore, the study revealed that atopic subjects might belong to a group of subjects with frequent eye blink activity. Although the relative increase in blink rates was more pronounced in non-atopic subjects, atopic subjects had significant higher blink rates at the end of the exposure to varying ethyl acrylate concentrations. Our results do not support that atopy enhances chemosensory effects if only the increase of blink rates and not the absolute height are considered as adverse effect. Nevertheless, the results indicate that individuals with frequent eye blink activity should be distinguished from those with normal eye blink activity while investigating blink rates as objective parameter of eye irritation.
Club cell protein (CC16) in serum as an effect marker for small airway epithelial damage caused by diesel exhaust and blasting fumes in potash mining
ObjectiveThe effect marker club cell protein (CC16) is secreted by the epithelium of the small respiratory tract into its lumen and passes into the blood. Increased amounts of CC16 in serum are observed during acute epithelial lung injury due to air pollutants. CC16 in serum was determined as part of this cross-sectional study in underground potash miners on acute and chronic health effects from exposures to diesel exhaust and blasting fumes.MethodsNitrogen oxides, carbon monoxide, and diesel particulate matter were measured in 672 workers at a German potash mining site on a person-by-person basis over an early shift or midday shift, together with CC16 serum concentrations before and after the respective shift. CC16 concentrations and CC16 shift-differences were evaluated with respect to personal exposure measurements and other quantitative variables by Spearman rank correlation coefficients. CC16 shift-differences were modeled using multiple linear regression. Above-ground workers as reference group were compared to the exposed underground workers.ResultsSerum concentrations of CC16 were influenced by personal characteristics such as age, smoking status, and renal function. Moreover, they showed a circadian rhythm. While no statistically significant effects of work-related exposure on CC16 concentrations were seen in never smokers, such effects were evident in current smokers.ConclusionThe small airways of current smokers appeared to be vulnerable to the combination of measured work-related exposures and individual exposure to smoking. Therefore, as health protection of smokers exposed to diesel exhaust and blasting fumes, smoking cessation is strongly recommended.
The Influence of Humidity on Assessing Irritation Threshold of Ammonia
A large number of occupational exposure limit values (OELs) are based on avoiding of sensory irritation of the eyes and the upper respiratory tract. In order to investigate the chemosensory effect range of a chemical, odor and sensory irritation thresholds (lateralization thresholds, LTs) can be assessed. Humidity affects olfactory function and thus influences odor thresholds; however, a similar effect has not been shown for sensory irritation thresholds. The purpose of the present study was to explore whether LTs for ammonia vapor vary depending on the water vapor content of the inspired stimulus. Eight healthy nonsmoking volunteers were simultaneously exposed to ammonia vapor through one nostril and clean air through the other and were asked to determine which nostril received the chemical. Within experimental runs, ascending ammonia concentrations (60–350 ppm) that were either dry or humidified were administered at fixed time intervals. Geometric mean LTs obtained at wet (181 ppm) or dry (172 ppm) conditions did not differ significantly (P = 0.19) and were within the range of those reported by previous studies. These results suggest that humidity is not a critical factor in determining sensory irritation thresholds for ammonia, and future studies will examine if these findings are transferable to sensory irritation thresholds for other chemicals.
Exposure assessment of potash miners at elevated CO2 levels
Purpose In a potash mine in the center of Germany, stationary measurements 40 cm above ground level have revealed occasional increases in the carbon dioxide (CO 2 ) levels that exceed the 0.5 vol.% German occupational exposure limit (OEL). This study, therefore, aimed to examine the individual exposures of potash miners to CO 2 at their underground workplaces. Methods 119 miners were equipped with personal CO 2 detectors to log the individual CO 2 exposures during underground work. We decided to use electrochemical monitors due to their compactness and minimal mass. Furthermore, generated CO 2 measurements with precipitated overshooting and false positive CO 2 values were studied using diverse CO 2 test gases and different fumigation times. Results The personal detectors showed short-term CO 2 peak exposures at very high concentrations in a limited number of workers. Twenty-two threshold limit value violations were observed according to the present OEL, and the personal CO 2 monitoring allowed categorization into three exposure groups, low ( n  = 83), moderate ( n  = 26) and high burdens ( n  = 10) of CO 2 . Conclusions The electrochemical sensors used have numerous properties that can potentially influence the assessment of exposures. The current findings suggest that assessing similar exposure scenarios, with respect to elevated and strongly fluctuating CO 2 concentrations, the behavior of electrochemical sensors should be taken into consideration.
Exposure assessment of potash miners at elevated CO sub(2) levels
Purpose: In a potash mine in the center of Germany, stationary measurements 40 cm above ground level have revealed occasional increases in the carbon dioxide (CO sub(2)) levels that exceed the 0.5 vol.% German occupational exposure limit (OEL). This study, therefore, aimed to examine the individual exposures of potash miners to CO sub(2) at their underground workplaces. Methods: 119 miners were equipped with personal CO sub(2) detectors to log the individual CO sub(2) exposures during underground work. We decided to use electrochemical monitors due to their compactness and minimal mass. Furthermore, generated CO sub(2) measurements with precipitated overshooting and false positive CO sub(2) values were studied using diverse CO sub(2) test gases and different fumigation times. Results: The personal detectors showed short-term CO sub(2) peak exposures at very high concentrations in a limited number of workers. Twenty-two threshold limit value violations were observed according to the present OEL, and the personal CO sub(2) monitoring allowed categorization into three exposure groups, low (n = 83), moderate (n = 26) and high burdens (n = 10) of CO sub(2). Conclusions: The electrochemical sensors used have numerous properties that can potentially influence the assessment of exposures. The current findings suggest that assessing similar exposure scenarios, with respect to elevated and strongly fluctuating CO sub(2) concentrations, the behavior of electrochemical sensors should be taken into consideration.