Impact of atmospheric deposition on the dynamics of ultraphytoplanktonic populations in the Gulf of Gabès during an intense dust event (MERITE-HIPPOCAMPE campaign)

The ultraphytoplankton composition and dynamics were assessed during a Saharan dust event occurring off the southern Tunisian coasts during the MERITE-HIPPOCAMPE Trans-Mediterranean oceanographic cruise. The composition of atmospheric dust was characterized in terms of nutriments and trace metals. Data-assimilative hydrodynamic model revealed no differences in the hydrological features along the sampling track and almost no water transport occurred during the period of atmospheric deposition. Dust deposition increased the growth rates and the productivity of the major phytoplanktonic cytometric groups, resulting in the highest surface biomass along the Mediterranean transect. One group, distinguished by low fluorescence and nanoplanktonic size, reacted to dust deposition within hours, exhibiting the highest growth rate and net productivity. The dust composition showed a substantial enrichment with organic phosphorous representing (56 % of Total phosphorus) and trace metals mainly Fe, Mn and V.

Modeling of soiling losses on photovoltaic module based on transmittance loss effect

The photovoltaic modules are mostly installed outdoors, exposing them to different conditions. These conditions significantly affect their performance. One of the most influential factors on photovoltaic modules is the soiling phenomenon from dust deposition. Dust deposition on the surface of the modules causes transmittance loss. Some studies in different parts of the world have tried to find mathematical correlations between particulate deposition and transmittance. These correlations are a function of dust characteristics and environmental factors. This study proposes a new methodology to mathematically combine the photovoltaic model and transmittance loss correlations. The proposed model could examine and predict the effect of soiling on photovoltaic modules' performance. Three photovoltaic modules with different capacities are selected. Using the proposed model, they are modeled by assuming clean and dirty photovoltaic surfaces depending on the installation conditions. This study is based on actual data from the center of Tehran, located at 35° 41' north latitude and 51° 23' east longitude for 12 months in the year 2020. The module's performance was investigated in the presence of dust. The presented results are validated by comparing them with other studies. The results show that the soiling effect is not dependent on the modules' capacity.

Dust deposition mechanism and output characteristics of solar bifacial PV panels

The utilization of solar photovoltaic (PV) power generation represents a highly promising technological solution for addressing environmental challenges and energy crises. Dust deposition on the front and back surfaces of solar bifacial PV panels greatly decreases the optical performance and power generation. In this study, the dust deposition characteristics and mechanism of solar bifacial PV panels are investigated using the CFD-DEM method. The effects of the dust deposition rate on the output characteristics of bifacial PV panels are discussed. The research results show that the particle deposition behaviors on the back and front surfaces of bifacial PV panels are influenced by the deposition and separation forces at the left or right inlets. The dust deposition rate of windward surfaces can be 1.48-7.60 times that of the leeward surfaces of bifacial PV panels. The particle motion trajectories on the windward and leeward sides can be mainly divided into five and three kinds, respectively. The dust deposition rate of bifacial PV panels increases when the air inlet velocity decreases and the particle size and concentration and relative humidity increase. The open circuit voltage and short circuit current of bifacial PV panels decreased by 26.7% and 16.4%, respectively, when the dust deposition rate increases by 45.8%. The attenuation rate of the maximum output power of PV panels has a positive linear correlation with the dust deposition rate, as shown in Eq. 22. The bifacial PV panels have better output characteristics than the mono-facial PV panels with consideration of dust deposition.

Neodymium isotopes in peat reveal past local environmental disturbances

Over the past decade, the neodymium (Nd) isotope composition of mineral matter from peat cores has seen increasingly common use as a tracer of dust influx associated with major changes in the Holocene atmospheric circulation. However, the incomplete understanding of the local controls on the sources of the sediment supplied to peatlands remains a key difficulty in the interpretation of the archived Nd isotope signals. Here, we used neodymium isotopes to reconstruct environmental disturbances in peatlands. We performed a multi-proxy study of two peatlands that experienced peatland burning and validated the recorded peat Nd signatures using reference surface sampling. Our data show a link between the Nd isotope signals and local environmental disturbances: peat burning, local fire activity and pollution fluxes. Our study illustrates the crucial role of identifying local events that influence the supply of mineral material to peatlands. Insufficient recognition of such local controls may either obscure the large-scale variations in the atmospheric circulation patterns, or introduce artefacts to the Holocene climate record. We also provide recommendations for the use of Nd isotopes in palaeoecological studies of peatlands.

Identification and characteristic analysis of urban vegetation spectra under different dust deposition

Urban atmospheric environmental problems have raised increasing attention in recent years. To confirm the impact of plant dust deposition capacity on urban atmosphere and spectral characteristics, this study carried out experiments in Xuhui District and Minhang District of Shanghai, and 4 common greening species were selected as research objects. In order to explore the changes in vegetation spectral characteristics, ASD FieldSpec 3 Spectrometer and 1/10000 electronic balance were used to measure the spectral data and dust data of samples. The results show as follows: (1) 380-680 nm and 750-1350 nm are the best spectral wavelengths to analyze the influence of dust deposition on spectrum. (2) The canopy reflectance spectra of tree species decrease with the increase of dust deposition, especially in the wavelength range of 750-1350 nm. (3) The first derivative and the second derivative are beneficial to observe the spectral changes and judge the position of the red edge. The red edge position of some tree species is easy to move under the interference of dust deposition. (4) Among the four tree species, the spectrum of Osmanthus fragrans is relatively undisturbed by dust deposition, and Osmanthus fragrans is a great tree species for urban greening. The research made a foundation for the future use of spectral information to estimate vegetation dust.

The effect of various industrial dust particles on the performance of photovoltaic panels in Turkey

The accumulation of dust is one of the main causes of power loss in photovoltaic (PV) farms, and the effect of dust particles' size and chemistry on system performance is often overlooked. This study has focused on a comprehensive analysis of the effect of different dust particles collected from common industrial production facilities in Turkey on the performance of PV panels in the indoor laboratory environment. The collected dust samples were analyzed to determine the dust sample particles' chemical properties, size, character, and topography. The data for dust samples at different weights with changes in maximum power point (MPP) of PV panel has been collected using the artificial solar irradiation source system. Thus, the mathematical correlations (R2≥0.965) between the PV panel Thevenin resistance (RTH), fill factor (FF), MPP, and pollution rate were obtained using these collected data and particle swarm optimization (PSO). According to the results of the obtained mathematical correlations, marble dust is 2.3, 3.4, and 4.2 times less polluting than cement, fly ash, and silica fume, respectively. Additionally, it was observed that smaller dust particles block more light than larger ones of the same weight and reduce MPP, FF while increasing the RTH.

Computational prediction of dust deposition on solar panels

This research is concerned with performing computational fluid dynamics (CFD) simulations to investigate the air flow and dust deposition behavior around a ground-mounted solar PV panel. The discrete phase model (DPM) is adopted to model the gas-solid flow. The influence of the wind speed, the dust particle size, and the dust material on the dust deposition rate was investigated based on the environment of Cairo, Egypt. The wind speeds range between 1 and 11.5 m/s with an average of 3.7 m/s. It is found that increasing the wind speed decreases the dust deposition rate. For wind speeds higher than 2 m/s, it is found that increasing the dust particle diameter or the dust density increases the dust deposition rate. For wind speeds lower than 2 m/s, it is found that there is a critical particle size before which increasing the dust density causes dust deposition rate to increase and after which increasing the dust density decreases the dust deposition. The maximum percentage of deposition rate equals 10.8% and occurs for the dolomite dust material at a wind speed of 2 m/s and particles diameter of 150 μm.

Impact of dust deposition on phytoplankton biomass in the Northwestern Pacific: A long-term study from 1998 to 2020

Dust deposition can supply nutrients to the ocean and affect phytoplankton growth. However, the impact of dust deposition on phytoplankton biomass in varying trophic regions remains poorly evaluated. The Northwestern Pacific is located in the downwind area of East Asian dust and includes eutrophic regions (Yellow Sea, YS; East China Sea, ECS), high-nutrient low-chlorophyll waters (subarctic Northwestern Pacific, SNWP) and low-nutrient low-chlorophyll waters (Northwestern Pacific subtropical gyre, NWPSG), which is an ideal region to explore the spatial heterogeneity of the dust fertilization effect. Here, the distribution and variation of dust deposition, high dust deposition events (HDDE) and Chlorophyll-a concentration (Chl-a, mg m^-3) in the Northwestern Pacific during spring from 1998 to 2020 were investigated. The differences in the response of phytoplankton biomass (using Chl-a as a proxy) to HDDE in the YS, the ECS, the SNWP and the NWPSG were explored. Our results indicated that a large amount of dust was deposited into the Northwest Pacific during spring, resulting in numerous HDDE. The HDDE could stimulate the increase of phytoplankton biomass in the whole area of the Northwestern Pacific during spring. The response probabilities of Chl-a to HDDE were most significant (~80%) in the SNWP and the duration of response was the longest, even lasting for up to 40 days. While the response probabilities of Chl-a to HDDE were lowest in the YS and ECS (~65%), increasing from north to south, and most of the responses were less than 20 days. The response of Chl-a to HDDE was also detected in NWPSG, confirming the dust fertilization effect in oligotrophic waters, with response probabilities of 70% and duration less than 30 days. Overall, this study provides a more comprehensive understanding of the differences of phytoplankton response to dust deposition in varying trophic regions.

Leaf reflectance and functional traits as environmental indicators of urban dust deposition

BACKGROUND

How to quickly predict and evaluate urban dust deposition is the key to the control of urban atmospheric environment. Here, we focus on changes of plant reflectance and plant functional traits due to dust deposition, and develop a prediction model of dust deposition based on these traits.

RESULTS

The results showed that (1) The average dust deposition per unit area of Ligustrum quihoui leaves was significantly different among urban environments (street (18.1001 g/m2), community (14.5597 g/m2) and park (9.7661 g/m2)). Among different urban environments, leaf reflectance curves tends to be consistent, but there were significant differences in leaf reflectance values (park (0.052-0.585) > community (0.028-0.477) > street (0.025-0.203)). (2) There were five major reflection peaks and five major absorption valleys. (3) The spectral reflectances before and after dust removal were significantly different (clean leaves > dust-stagnant leaves). 695 ~ 1400 nm was the sensitive range of spectral response. (4) Dust deposition has significant influence on slope and position of red edge. Red edge slope was park > community > street. After dust deposition, the red edge position has obviously "blue shift". The moving distance of the red edge position increases with the increase of dust deposition. The forecast model of dust deposition amount established by simple ratio index (y = 2.517x + 0.381, R2 = 0.787, RMSE (root-mean-square error) = 0.187. In the model, y refers to dust retention, x refers to simple ratio index.) has an average accuracy of 99.98%. (5) With the increase of dust deposition, the specific leaf area and chlorophyll content index decreased gradually. The leaf dry matter content, leaf tissue density and leaf thickness increased gradually.

CONCLUSION

In the dust-polluted environment, L. quihoui generally presents a combination of characters with lower specific leaf area, chlorophyll content index, and higher leaf dry matter content, leaf tissue density and leaf thickness. Leaf reflectance spectroscopy and functional traits have been proved to be effective in evaluating the changes of urban dust deposition.

Trace element contaminants associated with historic gold mining in sediments of dams and pans across Benoni, South Africa

As a historic gold mining area, the City of Benoni has numerous water bodies close to major tailings dams and mine dumps. Here we assess spatial patterns in the sediment geochemistry of five dams and four natural pans within a 5-km radius of the core mining area to determine the degree of contamination7 by mining-associated pollutants. XRF analysis was used with a geoaccumulation index to assess the degree of contamination above background levels. Prevailing winds blow from the north and north-west with less dominant winds from the east. Sediment concentrations of As, Cu, Pb, Ni and Zn are highly correlated across the region, suggestive of a common source. Except for one pan showing evidence of local industrial pollution, the most contaminated sites are the dams to the west of the mine dumps where concentrations of As, Cu, Pb and Zn increase towards the central mining area, with highest trace metal concentrations in Kleinfontein Dam, adjacent to a reworked mine dump. Sites upwind of the central mining area showed little evidence of mining-related contamination. Trace contaminant concentrations in sediments of these dams are much greater than those found in the nearby Springs-Blesbokspruit wetlands adjacent to more recently active mines. The potential risks to aquatic ecosystems and recreational users of these urban and suburban water bodies from these wind-blown, legacy mining contaminants merit further investigation.

Tree responses to foliar dust deposition and gradient of air pollution around opencast coal mines of Jharia coalfield, India: gas exchange, antioxidative potential and tolerance level

Atmospheric pollution by opencast mining activities affects tree species around the mining area. The present study evaluated the responses of five native tree species to air pollution in Jharia coalfield. Sites were selected as closest to farthest from the mining area. Foliar dust deposition and foliar sulphate content affected stomatal conductance, superoxide dismutase activity and ascorbic acid and, thus, increased the susceptibility of sensitive species. Ficus benghalensis and Butea monosperma showed maximum dust deposition, while Adina cordifolia showed minimum deposition. Maximum dust deposition in Ficus benghalensis lowered stomatal conductance and, thus, checked the flux of other acidic gaseous pollutants which led to minimum variation in leaf extract pH. Higher stomatal conductance in Adina cordifolia and Aegle marmelos, on the other hand, facilitated the entry of acidic pollutants and disrupted many biological functions by altering photosynthesis and inducing membrane damage. Low variations in Ficus religiosa, Ficus benghalensis and Butea monosperma with sites and seasons suggest better physiological and morphological adaptations towards pollution load near coal mining areas. Tree species with better adaptation resisted variation in leaf extract pH by effectively metabolising sulphate and, thus, had higher chlorophyll content and relative water content.

Study of a dust deposition mechanism dominated by electrostatic force on a solar photovoltaic module

Solar energy is one of the most promising renewable energy sources to solve the energy crisis. Dust deposition on solar photovoltaic (PV) modules significantly reduces the power generation of PV power plants. In this paper, the motion characteristics of the gas phase and charging mechanism of dust particles and solar PV glass are investigated by means of the computational fluid dynamics-discrete element model (CFD-DEM) method. In addition, the mechanism and characteristics of dust deposition on a solar PV module as dominated by electrostatic force are discussed. The research results show that frequent collisions between dust particles and PV glass or between dust particles lead to charging. The dust deposition mechanism on a solar PV module is a gas-solid-electrical multi-directional coupling process. There is a great electrostatic field near the solar PV glass, causing charged dust particle deposition. The dust deposition density decreases when the air inlet velocity increases and when the tilt angle of the solar PV module or the number of particle collisions decreases. Different particle dynamics have different dust deposition ratios for different predominant deposition forces (such as the electrostatic force, van der Waals force, and gravity force). The research findings provide an important theoretical basis for dust deposition prevention and removal from solar PV modules.

Dynamics of phytoplankton and nutrient uptake following dust additions in the northwest Pacific

Dust deposition can supply nutrients that affect marine phytoplankton, but changing trophic statuses of the surface ocean increase the complexity of interpreting the process. In this study, four onboard incubation experiments amended with various nutrients and dust were performed in the Kuroshio Extension (KE) and Kuroshio-Oyashio transition (TR) of the northwest Pacific (NWP), which are characterised by lower and higher trophic statuses, respectively. According to the nutrient-addition experiments, phytoplankton were limited by nitrogen (N) in the KE, and limited by iron (Fe) or co-limited by Fe and phosphorus (P) in the TR. Dust additions supplied a considerable amount of N and Fe but negligible amount of P to stimulate phytoplankton growth, as indicated by chlorophyll a (Chl a) concentration. In the KE incubations, dust additions enhanced the shift of phytoplankton size structure towards larger cells from dominantly pico-sized (0.2-2 μm) Chl a to comparable contributions from each size class (i.e. pico-, nano-: 2-20 μm, micro-: >20 μm). On the basis of the large shift of size structure towards nano- or micro-phytoplankton in the unamended control treatments in the TR, dust additions furtherly promoted the shift towards micro-phytoplankton becoming the dominant contributor to the total Chl a. The collective analysis of the data from experiments in both regions revealed that, the extent of phytoplankton growth stimulation and the shift towards larger cells were enhanced gradually with increasing amounts of nutrient uptake (including N, P, and silicon). The nutrient uptake ratios of phytoplankton converged towards the Redfield ratio in comparison to the wider range of nutrient ratios in the dust-amended seawater. This study suggested consistencies in the dynamic of phytoplankton growth, shift of size structure, and nutrient uptake following dust additions in the KE and TR, although the trophic status and limiting nutrient varied between these two regions.

Changing nature of Saharan dust deposition in the Carpathian Basin (Central Europe): 40 years of identified North African dust events (1979-2018)

Several billion tonnes of mineral dust is emitted, and transported through winds every year from arid-semiarid areas. North African dust hot spots located in the Sahara are responsible for 50-70% of the global mineral dust budget. Dust-loaded air-masses originated from these sources can be transported over long distances and can also affect remote areas, such as North and South Americas, Europe, and the Middle East. In this study, we analysed 218 identified Saharan dust events (SDEs) in the Carpathian Basin (Central Europe) during 1979 to 2018. Systematic identification of SDEs and analyses of dust emission, dust source area activity, dust transporting wind systems, and transport routes revealed that different synoptic meteorological patterns are responsible for SDEs, and these are occurring mostly in spring and summer. The characteristic synoptic meteorological background of episodes was also identified, and three major types of atmospheric pressure-system patterns were distinguished. In recent years, several intense wintertime dust deposition events have been recorded in Central Europe. All of the identified unusual episodes were characterised by severe washout of mineral dust material and were related to very similar synoptic meteorological situations. Enhanced southward propagation of a high-latitude upper-level atmospheric trough to north-western Africa and orographic blocking of Atlas Mountains played an essential role in the formation of severe dust storms, whereas the long-range transport was associated with the northward branch of the meandering jet. The occurrence and southerly penetration of high-latitude upper-level atmospheric trough to low-latitudes and the increased meridionality of the dominant flow patterns may be associated with enhanced warming of the Arctic, leading to more meandering jet streams. Particles size of sampled dust material of some intense deposition episodes were very coarse with a considerable volumetric proportion of > 20 µm particles.

Variations in the phytoplankton community due to dust additions in eutrophication, LNLC and HNLC oceanic zones

Dust deposition can bring nutrients and trace elements to the upper ocean and affect phytoplankton growth and community structure. We conducted a comparative study using on-board microcosm experiments amended with varying amounts of dust (0.2, 1, and 2 mg L^-1) in the East China Sea (eutrophic zone), the subtropical gyre (low-nutrient and low-chlorophyll zone, LNLC), and the Kuroshio-Oyashio transition region (high-nutrient and low-chlorophyll zone, HNLC) of the Northwest Pacific Ocean. The additions of dust supplied a considerable amount of nitrogen (N) and negligible phosphorus (P) relative to the seawater collected for incubation experiments (baseline), contributing to increases in Chlorophyll a with increasing dust additions. Significant linear correlations were observed between the net growth rates of larger cells (i.e., micro-size: >20 μm and nano-size: 2-20 μm) and available N (sum of baseline and added N) at each zone, demonstrating that phytoplankton size structure shifts towards larger cells with the increasing dust additions. In the experiments conducted in LNLC and HNLC zones, micro-sized phytoplankton (primarily consisting of diatoms) benefited most from dust additions. In the experiments conducted in eutrophic zone, however, the primary beneficiary was the nano-sized phytoplankton (primarily consisting of dinoflagellates). When a time lag of one day in relative abundance of diatoms (RAD, the abundance of diatoms divided by the sum of diatoms and dinoflagellates) relative to the N:P ratio was considered, we found the RAD increased substantially with increases in the N:P ratio until the ratio approached the Redfield ratio (N:P = 16:1), and then the RAD decreased gradually as the N:P ratio increased. This was ascribed to the lower sensitivity of dinoflagellates to nutrient shortage, relative to diatoms. Overall, our results suggested that the overwhelming input of N relative to P by dust deposition might cause significant ecological impacts by altering the N:P ratio of varying trophic seawaters.

The field experiments and model of the natural dust deposition effects on photovoltaic module efficiency

The maximisation of the efficiency of the photovoltaic system is crucial in order to increase the competitiveness of this technology. Unfortunately, several environmental factors in addition to many alterable and unalterable factors can significantly influence the performance of the PV system. Some of the environmental factors that depend on the site have to do with dust, soiling and pollutants. In this study conducted in the city centre of Kraków, Poland, characterised by high pollution and low wind speed, the focus is on the evaluation of the degradation of efficiency of polycrystalline photovoltaic modules due to natural dust deposition. The experimental results that were obtained demonstrated that deposited dust-related efficiency loss gradually increased with the mass and that it follows the exponential. The maximum dust deposition density observed for rainless exposure periods of 1 week exceeds 300 mg/m² and the results in efficiency loss were about 2.1%. It was observed that efficiency loss is not only mass-dependent but that it also depends on the dust properties. The small positive effect of the tiny dust layer which slightly increases in surface roughness on the module performance was also observed. The results that were obtained enable the development of a reliable model for the degradation of the efficiency of the PV module caused by dust deposition. The novelty consists in the model, which is easy to apply and which is dependent on the dust mass, for low and moderate naturally deposited dust concentration (up to 1 and 5 g/m² and representative for many geographical regions) and which is applicable to the majority of cases met in an urban and non-urban polluted area can be used to evaluate the dust deposition-related derating factor (efficiency loss), which is very much sought after by the system designers, and tools used for computer modelling and system malfunction detection.

Growth impacts of Saharan dust, mineral nutrients, and CO2 on a planktonic herbivore in southern Mediterranean lakes

Rising levels of CO₂ can boost plant biomass but reduce its quality as a food source for herbivores. However, significant uncertainties remain as to the degree to which the effect is modulated by other environmental factors and the underlying processes causing these responses in nature. To address these questions, we carried out CO₂-manipulation experiments using natural seston from three lakes under nutrient-enriched conditions (mimicking eutrophication and atmospheric dust-input processes) as a food source for the planktonic Daphnia pulicaria. Contrary to expectations, there were no single effects of rising CO₂ on herbivorous growth. Instead, synergistic CO₂ × nutrient interactions indicated that CO₂ did not support higher zooplankton growth rates unless supplemented with dust or inorganic nutrients (nitrogen, N; phosphorus, P) in two of three studied lakes. The overall positive correlation between zooplankton growth and seston carbon (C), but not seston C:P, suggested that this was a food quantity-mediated response. In addition, we found that this correlation improved when the data were grouped according to the nutrient treatments, and that the response was largest for dust. The synergistic CO₂ × nutrient effects reported here imply that the effects of rising CO₂ levels on herbivorous growth may be strongly influenced by eutrophication processes and the increase in dust deposition predicted for the Mediterranean region.

Trends of metals enrichment in deposited particulate matter at semi-arid area of Iran

The presence and enrichment of heavy metals in dust depositions have been recognized as an emerging environmental health issues in the urban and industrial areas. In this study, the deposition of some metals was found in Qom, a city located in a semi-desert area in Iran that is surrounded by industrial areas. Dust deposition samples were collected using five sampling stations during a year. Dust samples were digested applying acidic condition and then, the metal content was analyzed using inductively coupled plasma technology (ICP-OES). Comparative results showed the following order, from the maximum to the minimum concentration (mg/kg dust) of elements: Ca > Al > Fe > Mg > Ti > Si > K > B > Sr > Mn > P > Ba > Cr > Zn > Ni > Sn > Pb > V > Na > Cu > Co > U > Li > Ce > Ag. The differences among the average concentrations of metals in the five stations were not significant (p value > 0.05). The average concentration of some metals increased significantly during cold seasons. In this study, the cluster analysis (CA) and princicipal component analysis (PCA) were applied, and relationships among some elements in different clusters were found. In addition, the geo-accumulation and enrichment analysis revealed that the following metals had been enriched more than the average values: boron, silver, tin, uranium, lead, zinc, cobalt, chromium, lithium, nickel, strontium, and coper. The presence of thermal power plant, pesticide manufacturing plants, publishing centers, traffic jam, and some industrial areas around the city has resulted in the enrichment of some metals (particularly in cold seasons with atmospheric stable conditions) in dust deposition.

Airborne dust absorption by semi-arid forests reduces PM pollution in nearby urban environments

Dust storms are a major source of global atmospheric particulate matter (PM), having significant impacts on air pollution and human health. During dust storms, daily averages of atmospheric PM concentrations can reach high levels above the World Health Organization (WHO) guideline for air quality. The objective of this study was to explore the impact of forests on PM distribution following dust events in a region that is subjected to frequent dust storms (Northern Negev, Israel). Dust was measured in a forest transect including urban environments that are nearby the forest and at a distal location. During a background period, without dust events, the forest with its surrounding areas were characterized by lower monthly average of PM concentrations (38μg/m³) compared with areas that are not affected by the forest (54μg/m³). Such difference can be meaningful for long-term human health exposure. A reduction in PM levels in the forest transect was evident at most measured dust events, depending on the storm intensity and the locations of the protected areas. A significant reduction in PM_2.5/PM₁₀ during dust events, indicates the high efficiency of the forest trees to absorb airborne PM_2.5. Analysis of dust particles absorbed on the foliage revealed a total dust deposits of 8.1-9.2g/m², which is equal to a minimum of 418.2tons removed from the atmosphere per a forest foliage area (30km²). The findings can support environmental strategies to enhance life quality in regions that are subjected to dust storms, or under potential risk of dust-related PM due to land use and/or climate changes.

Environmental arsenic, cadmium and lead dust emissions from metal mine operations: Implications for environmental management, monitoring and human health

Although blood lead values in children are predominantly falling globally, there are locations where lead exposure remains a persistent problem. One such location is Broken Hill, Australia, where the percentage of blood lead values >10 μg/dL in children aged 1-4 years has risen from 12.6% (2010), to 13% (2011) to 21% (2012). The purpose of this study was to determine the extent of metal contamination in places accessible to children. This study examines contemporary exposure risks from arsenic, cadmium, lead, silver and zinc in surface soil and dust, and in pre- and post-play hand wipes at six playgrounds across Broken Hill over a 5-day period in September 2013. Soil lead (mean 2,450 mg/kg) and zinc (mean 3,710 mg/kg) were the most elevated metals in playgrounds. Surface dust lead concentrations were consistently elevated (mean 27,500 μg/m(2)) with the highest lead in surface dust (59,900 μg/m(2)) and post-play hand wipes (60,900 μg/m(2)) recorded close to existing mining operations. Surface and post-play hand wipe dust values exceeded national guidelines for lead and international benchmarks for arsenic, cadmium and lead. Lead isotopic compositions ((206)Pb/(207)Pb, (208)Pb/(207)Pb) of surface dust wipes from the playgrounds revealed the source of lead contamination to be indistinct from the local Broken Hill ore body. The data suggest frequent, cumulative and ongoing mine-derived dust metal contamination poses a serious risk of harm to children.