992 resultados para AIR-EXPOSURE


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The aim of this study was to verify the duration of the development period, number of parasitoids produced per pupa, parasitism rate and sex ratio of Nasonia vitripennis (Hymenoptera, Pteromalidae), when they were exposed to a single host: Chrysomya megacephala (Diptera, Calliphoridae). One pupa was exposed in glass tubes to different numbers of female parasitoids (1, 3, 5, 7, 9 and 11) during 48 h. Twenty replications/treatment were used, under controlled conditions (T= 27 °C day/ 25 °C night, 60 ± 10% RH). Statistical analysis of the data was made using the ANOVA test and the "a posteriori" comparisons were made using the Tukey-HSD test (both tests with a significance level of 5%). The duration of the development period was longer in treatments where a higher density of females per host was used. When five females per host were used, the mean number of parasitoids that emerged per pupa was higher. The data showed a tendency to a decrease in the amount of parasitoids emerged per host, especially of female, when used high quantities of female per host. Higher parasitism rates were observed in the 3:1 and 5:1 treatments and an increase in the percentage of unviable pupae was observed, probably due to an increase of female densities in the treatments, possibly a consequence of superparasitism.

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Children psychological abuse is difficult to identify. However, its consequences on child development can be as serious as physical and sexual abuses. It is therefore essential, to implement in our hospitals, structures whose missions are successively to detect victims, evaluate them on somatic and psychological levels, and elaborate a therapy. We propose a model for the achievement of these objectives through collaboration between the Medical Unit of Violence, the Pediatric CAN Team and the Unit of Les Boréales.

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AIM: To describe outdoor activities, sun protection behaviours and the experience of sunburn in a sample of New Zealanders during summer weekends of 1994. METHODS: 1243 respondents to a telephone survey provided information regarding their outdoor activities for the 5 hour period around midday of the previous Saturday and Sunday. The sample was drawn from those aged 15 to 65 years in the five centres of Auckland, Hamilton, Wellington, Christchurch and Dunedin. Respondents provided information on sun exposure, sunburn, sun protection and beliefs about tanning, as well as background demographic information, skin type and previous experience of sunburn. RESULTS: 12% of the sample (or 17% of all those outdoors) reported being sunburned on the preceding weekend, and those sunburned tended to be men, and to be under age 35 years. The face, neck and limbs were the areas most frequently reported as burned. Sporting activities and beach or water activities were associated with the highest number of episodes of burning. Overall 38% of those outside reported wearing a hat and 32% reported the use of a sunscreen. Positive attitudes to tanning were quite common and probably present the main target for change in the community. CONCLUSION: On any sunny weekend in summer about three-quarters of adult New Zealanders will be out in the sun for relatively long periods of time, and many will get sunburned. The reduction of such harmful sun exposures remains an important public health goal.

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The Iowa Department of Economic Development (IDED) is committed to assisting economic developers as they advise businesses with new projects and expansions. IDED and the Iowa Department of Natural Resources (IDNR) have developed this fact sheet as a guide to help a business or project meet state and federal air quality regulations.

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The Work Package 4 of the ORAMED project, a collaborative project (2008-11) supported by the European Commission within its seventh Framework Programme, is concerned with the optimisation of the extremity dosimetry of medical staff in nuclear medicine. To evaluate the extremity doses and dose distributions across the hands of medical staff working in nuclear medicine departments, an extensive measurement programme has been started in 32 nuclear medicine departments in Europe. This was done using a standard protocol recording all relevant information for radiation exposure, i.e. radiation protection devices and tools. This study shows the preliminary results obtained for this measurement campaign. For diagnostic purposes, the two most-used radionuclides were considered: (99m)Tc and (18)F. For therapeutic treatments, Zevalin(®) and DOTATOC (both labelled with (90)Y) were chosen. Large variations of doses were observed across the hands depending on different parameters. Furthermore, this study highlights the importance of the positioning of the extremity dosemeter for a correct estimate of the maximum skin doses.

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Given the adverse impact of image noise on the perception of important clinical details in digital mammography, routine quality control measurements should include an evaluation of noise. The European Guidelines, for example, employ a second-order polynomial fit of pixel variance as a function of detector air kerma (DAK) to decompose noise into quantum, electronic and fixed pattern (FP) components and assess the DAK range where quantum noise dominates. This work examines the robustness of the polynomial method against an explicit noise decomposition method. The two methods were applied to variance and noise power spectrum (NPS) data from six digital mammography units. Twenty homogeneously exposed images were acquired with PMMA blocks for target DAKs ranging from 6.25 to 1600 µGy. Both methods were explored for the effects of data weighting and squared fit coefficients during the curve fitting, the influence of the additional filter material (2 mm Al versus 40 mm PMMA) and noise de-trending. Finally, spatial stationarity of noise was assessed.Data weighting improved noise model fitting over large DAK ranges, especially at low detector exposures. The polynomial and explicit decompositions generally agreed for quantum and electronic noise but FP noise fraction was consistently underestimated by the polynomial method. Noise decomposition as a function of position in the image showed limited noise stationarity, especially for FP noise; thus the position of the region of interest (ROI) used for noise decomposition may influence fractional noise composition. The ROI area and position used in the Guidelines offer an acceptable estimation of noise components. While there are limitations to the polynomial model, when used with care and with appropriate data weighting, the method offers a simple and robust means of examining the detector noise components as a function of detector exposure.

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Road transport emissions are a major contributor to ambient particulate matter concentrations and have been associated with adverse health effects. Therefore, these emissions are targeted through increasingly stringent European emission standards. These policies succeed in reducing exhaust emissions, but do not address "nonexhaust" emissions from brake wear, tire wear, road wear, and suspension in air of road dust. Is this a problem? To what extent do nonexhaust emissions contribute to ambient concentrations of PM10 or PM2.5? In the near future, wear emissions may dominate the remaining traffic-related PM10 emissions in Europe, mostly due to the steep decrease in PM exhaust emissions. This underlines the need to determine the relevance of the wear emissions as a contribution to the existing ambient PM concentrations, and the need to assess the health risks related to wear particles, which has not yet received much attention. During a workshop in 2011, available knowledge was reported and evaluated so as to draw conclusions on the relevance of traffic-related wear emissions for air quality policy development. On the basis of available evidence, which is briefly presented in this paper, it was concluded that nonexhaust emissions and in particular suspension in air of road dust are major contributors to exceedances at street locations of the PM10 air quality standards in various European cities. Furthermore, wear-related PM emissions that contain high concentrations of metals may (despite their limited contribution to the mass of nonexhaust emissions) cause significant health risks for the population, especially those living near intensely trafficked locations. To quantify the existing health risks, targeted research is required on wear emissions, their dispersion in urban areas, population exposure, and its effects on health. Such information will be crucial for environmental policymakers as an input for discussions on the need to develop control strategies.

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Background: Fine particulate matter originating from traffic correlates with increased morbidity and mortality. An important source of traffic particles is brake wear of cars which contributes up to 20% of the total traffic emissions. The aim of this study was to evaluate potential toxicological effects of human epithelial lung cells exposed to freshly generated brake wear particles. Results: An exposure box was mounted around a car's braking system. Lung cells cultured at the air-liquid interface were then exposed to particles emitted from two typical braking behaviours ("full stop" and "normal deceleration"). The particle size distribution as well as the brake emission components like metals and carbons was measured on-line, and the particles deposited on grids for transmission electron microscopy were counted. The tight junction arrangement was observed by laser scanning microscopy. Cellular responses were assessed by measurement of lactate dehydrogenase (cytotoxicity), by investigating the production of reactive oxidative species and the release of the pro-inflammatory mediator interleukin-8. The tight junction protein occludin density decreased significantly (p < 0.05) with increasing concentrations of metals on the particles (iron, copper and manganese, which were all strongly correlated with each other). Occludin was also negatively correlated with the intensity of reactive oxidative species. The concentrations of interleukin-8 were significantly correlated with increasing organic carbon concentrations. No correlation was observed between occludin and interleukin-8, nor between reactive oxidative species and interleukin-8. Conclusion: These findings suggest that the metals on brake wear particles damage tight junctions with a mechanism involving oxidative stress. Brake wear particles also increase pro-inflammatory responses. However, this might be due to another mechanism than via oxidative stress. [Authors]

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The ill effects of second-hand smoke are now well documented. To protect the population from exposure to tobacco smoke, comprehensive smoking bans are necessary as expressed in the WHO Framework Convention on Tobacco Control and its guidelines. Switzerland has only a partial smoking ban full of exceptions which has been in effect since 2010, which reproduces the so-called Spanish model. In September 2012, the Swiss citizens refused a proposal for a more comprehensive ban. This case study examines the reasons behind this rejection and draws some lessons that can be learnt from it.