Ecophysiological response of Eucalyptus camaldulensis to dust and lead pollution

Background: Air and soil pollution are among the main concerns in urban areas worldwide, and dust and heavy metals are major contributors to environmental pollution. Lead (Pb) is a highly toxic heavy metal that badly affects human health as well as plant's survival and growth. Vegetation can play an important role in ameliorating the effects of these pollutants. Eucalyptus camaldulensis is well adapted and cultivated throughout a wide range of urban environments from temperate to tropical climates. Methods: A 90 days experiment was conducted to investigate the effects of lead (Pb) and dust pollution on the growth performance of young E. camaldulensis plants. Four months old seedlings were treated with a factorial combinations of Pb (0,10 and 20 mg/l applied in irrigation) and dust levels (0,5 and 10 g applied on foliage). Results: All morphological traits (root length, shoot length, stem diameter) and biomass (root and shoot, fresh and dry mass) of E. camaldulensis were significantly reduced when exposed to higher Pb and dust levels. The highest Pb treatments exhibited greater Pb accumulation in plant roots (23.54 ± 1.61 mg/kg), shoots (15.53 ± 1.98 mg/kg), and leaves (13.89 ± 1.49 mg/kg). Dust load on leaves was greater (72.78 ± 8.1 mg/cm2) for those treatments with higher dust and Pb additions compared to the control (16.11 ± 2.0 mg/cm2). Chlorophyll content was greater at the start of the experiment (68.78 ± 0.74 mg.g-1FW) and progressively decreased over time consistently with the increase of Pb and dust levels applied. Conclusions: The results of the experiment, suggest that E. camaldulensis could be successfully grown in minimum to moderate Pb and dust polluted urban environments.

Less atmospheric radiative heating by dust due to the synergy of coarser size and aspherical shape

Mineral dust aerosols cool and warm the atmosphere by scattering and absorbing solar (shortwave: SW) and thermal (longwave: LW) radiation. However, significant uncertainties remain in dust radiative effects, largely due to differences in the dust size distribution and spectral optical properties simulated in Earth system models. Dust models typically underestimate the coarse dust load (more than 2.5 µm in diameter) and assume a spherical shape, which leads to an overestimate of the fine dust load (less than 2.5 µm) after the dust emissions in the models are scaled to match observed dust aerosol optical depth at 550 nm (DAOD550). Here, we improve the simulated dust properties with data sets that leverage measurements of size-resolved dust concentration, asphericity factor, and refractive index in a coupled global chemical transport model with a radiative transfer module. After the adjustment of size-resolved dust concentration and spectral optical properties, the global and annual average of DAOD550 from the simulation increases from 0.023 to 0.029 and falls within the range of a semi-observationally based estimate (0.030 ± 0.005). The reduction of fine dust load after the adjustment leads to a reduction of the SW cooling at the top of the atmosphere (TOA). To improve agreement against a semi-observationally based estimate of the radiative effect efficiency at TOA, we find that a less absorptive SW dust refractive index is required for coarser aspherical dust. Thus, only a minor difference is estimated for the net global dust radiative effect at TOA (−0.08 vs. −0.00 W m−2 on a global scale). Conversely, our sensitivity simulations reveal that the surface warming is substantially enhanced near the strong dust source regions (less cooling to −0.23 from −0.60 W m−2 on a global scale). Thus, less atmospheric radiative heating is estimated near the major source regions (less heating to 0.15 from 0.59 W m−2 on a global scale), because of enhanced LW warming at the surface by the synergy of coarser size and aspherical shape.

Development and testing of a tool for the decontamination of corners and inner edges on concrete surfaces

For the decontamination of flat concrete surfaces, a wide variety of tools are available; however, these tools cannot be used for the decontamination of corners, inner edges, gaps and other geometrical discontinuities. Currently, these areas are worked by hand-held tools with a connected vacuum exhaust system to reduce dust emissions. The combination of using heavy hand-operated tools with exhaust systems on difficult to access areas as well as the forces and vibration of the tools, make the task of decontamination a burden and add additional physical stress for the operator. The goal of the research project called EKont, funded by the German Ministry for Education and Research, BMBF), is, to develop an innovative semi-automated demonstrator for dry mechanical decontamination of corners, edges and geometrical discontinuities in nuclear facilities. The tool will have a flexible housing with an integrated exhaust system to reduce the dust load. This specialized tool should make the decontamination of corners and inner edges more effective regarding time and the generation of secondary waste and should further spare the musculoskeletal system of the operator physical stress by lowering the vibrations and weight of the tool. For this task, a test bench for testing and evaluating different methods of surface decontamination has been set up. The test bench enables the measurement of forces and vibrations of the machine during the decontamination and the dust emissions. Based on the analysis of different decontamination methods and tools, four prototypes are being developed. This project also aims at the scientific investigation of experimentally collected performance parameters, such as feed rate, removal depth per operation, surface roughness and removal rate, in order to determine the relevant parameters of the developed prototypes. A field test of the prototypes together with decommissioning companies is scheduled. The prototype is not limited to use in nuclear facilities but later can also be used in conventional fields, for example in the decontamination of materials containing PCBs and asbestos. In this presentation the EKont test bench and prototypes will be explained and the test results will be presented.

Research and Analysis of the Sources of Emission of Respirable Fraction of Dust at the Coal Mines

At the deposits of the Krasnoyarsk Territory, the actual concentration of the suspended dust is 60–83 mg/m3. The search for efficient ways of reducing dust emission and dust suppression remains an urgent task, since fine dust has a negative effect on the health of enterprise employees and on mining equipment reducing its service life. Full-scale measurements were conducted related to the dust content and dispersed composition of the aerosols. The dust content was measured by counting method with the use of CEM DT-9880 dust particle counter. The measurements were conducted at the points located at different distances from the road of the section. The content of the most dangerous fraction PM2.5 was 48 % of the total amount of fine dust or 30–40 mg/m3, while the maximum permissible concentration for this fraction is 0.16 mg/m3. The employees who constantly work near the automotive haul roads and the ruins of an exploded rock mass are exposed to the strongest effects of dust emissions on the respiratory organs. To reduce the dust load on the employees of the mining enterprise, it is most appropriate to deal primarily with the dust emitted from the open pit roads, since this will help to reduce the dust load by 30–40 %. The permissible length of service for the operator of the loading equipment of one of the open-pit mines of the Krasnoyarsk Territory was calculated: it will be 9 years, and not 17, as was obtained earlier — without considering the actual content of the respirable dust. With the most rational parameters of drilling and blasting operations and using all methods to reduce dust formation, it is possible to reduce the dust emission by 15–20 %.

Assessment of Photosynthetic Pigments and Dust Load in Selected Avenue Plants of Saharanpur and Herbertpur Areas of India

The paper depicts impact of SO2, NO2, ozone and CO in chosen road plants of Saharanpur and Herbertpur regions in Indian dominion. Plant species falling in and around the area of modern territory and street side were chosen for examining purpose. Different morphological attributes and impact of business and vehicular residue on chlorophyll shade were contemplated and noticed the impact of residue molecule on development of the plant species (Ficus religiosa, Mangifera indica). In the examination the impacts of residue on chosen tree species was noticed and which will help in overseeing advancement of green belt to lessen the air contamination in the investigation area. Treatment with dust fundamentally expanded the fixation on leaves and the impacts were more extreme in significant degree of residue medicines. Contrasted with control, chlorophyll and porphyrin in substance were essentially diminished in the residue treated gatherings. This investigation propounds that business and vehicular residue statements affect photosynthetic shades, with broad impacts on development and improvement of plant.

Position correction in dust storm forecasting using LOTOS-EUROS v2.1: grid-distorted data assimilation v1.0

When calibrating simulations of dust clouds, both the intensity and the position are important. Intensity errors arise mainly from uncertain emission and sedimentation strengths, while position errors are attributed either to imperfect emission timing or to uncertainties in the transport. Though many studies have been conducted on the calibration or correction of dust simulations, most of these focus on intensity solely and leave the position errors mainly unchanged. In this paper, a grid-distorted data assimilation, which consists of an image-morphing method and an ensemble-based variational assimilation, is designed for realigning a simulated dust plume to correct the position error. This newly developed grid-distorted data assimilation has been applied to a dust storm event in May 2017 over East Asia. Results have been compared for three configurations: a traditional assimilation configuration that focuses solely on intensity correction, a grid-distorted data assimilation that focuses on position correction only and the hybrid assimilation that combines these two. For the evaluated case, the position misfit in the simulations is shown to be dominant in the results. The traditional emission inversion only slightly improves the dust simulation, while the grid-distorted data assimilation effectively improves the dust simulation and forecasting. The hybrid assimilation that corrects both position and intensity of the dust load provides the best initial condition for forecasting of dust concentrations.

On the issue of assessing the occupational risk of diseases of dust aetiology

Introduction. In the Russian Federation, occupational diseases associated with exposure to industrial aerosols occupy third place in the structure of occupational pathology. The predominant forms of occupational diseases included chronic dust bronchitis, pneumoconiosis( silicosis), chronic obstructive (asthmatic) bronchitis. For an objective assessment of dust exposure and calculation of the occupational health risk of employees of “dust” professions, it is advisable to clarify the criteria and methodology for assessing dust exposure as an independent and informative hygienic characteristic. The purpose of the study is to formulate additional criteria for assessing the risk of exposure to industrial aerosol; to substantiate the methodology for calculating the accumulation of dust particles in the lungs as an informative characteristic of inhaled dust that is subject to hygienic assessment when calculating the dust load, to clarify the methodology for managing the health risk of dust professions workers. Material and methods. The paper uses the technique of mathematical modelling. The calculation of the time of finding dust particles, taking into account their dispersion in various parts of the tracheobronchial tree, was carried out. Results. Taking into account the methodology for calculating the dust exposure by the value of the inhaled dust mass, additional criteria for assessing the hazard of exposure to industrial aerosol were formulated; the methodology for calculating the accumulated dust mass (ADM) was justified, the formation of ADM in tracheobronchial tree sites was estimated, taking into account the time dependence of the removal of dust particles of various dispersities from the tracheobronchial tree was estimated. The results of the study contribute to the improvement of hygienic criteria for the danger and harmfulness of working conditions according to the dust factor, the justification of preventive measures. Conclusions. The choice of the ADM index to clarify the information content of the calculated dust load value is justified. Improving the methodology of dust control helps to preserve employees’ health and reduce the level of occupational and production-related diseases.

Elemental composition of dust aerosols near cement plants based on the study of samples of the solid phase of the snow cover

This study is focused on the quantification of dust load on snow cover and chemical elements content in the solid phase of snow cover in the impacted areas of cement plants (the south of Western Siberia). Applying the instrumental neutron activation analysis, we identified chemical composition in the samples of the solid phase of snow cover. The results demonstrated that the dust load corresponded to the permissible pollution levels in the living zones. Dust pollution level varied from moderately hazardous to highly hazardous in the north-western impacted zone of the cement plants and raw material open pits. It was found that the predominant chemical element is Ca, as well as a group of rare-earth (Yb, Tb, Sm, La, Ce, etc.) elements in the solid phase of snow cover from the impacted zone of the cement plants.

An Assessment on Average Pressure Drop and Dust-Holding Capacity of Hollow-Fiber Membranes in Air Filtration

In this work, we tried to analyze dust loading behavior of polypropylene hollow fiber membranes using average pressure drop models. Hollow fiber membranes varying in fiber diameter were loaded with a standardized test dust to simulate particle-polluted air. We measured pressure drop development of the membranes at different flowrates and dust concentrations, and, after each experiment, the dust deposited on the membrane fibers was weighed to obtain dust holding capacity (DHC). The obtained experimental data was analyzed using various average pressure drop models and compared with average pressure drop obtained from pressure drop/dust load dependence using a curve fit. Exponential and polynomial fitting was used and compared. Pressure drop in relation to the dust load followed different trends depending on the experimental conditions and inner fiber diameter. At higher flowrate, the dependence was polynomial no matter what the fiber diameter. However, with higher fiber diameter at lower permeate velocities, the dependence was close to exponential curve and followed similar trends as observed in planar filter media. Dust-holding capacity of the membranes depended on the experimental conditions and was up to 21.4 g. However, higher dust holding capacity was impossible to reach no matter the experiment duration due to self-cleaning ability of the tested membranes.