On the composition of the Arizona test dust: A comprehensive characterization of an analog for atmospheric mineral dust

In order to study the current situation and sources of heavy metal pollution in Zhangbei County， Bashang Grassland， 69 surface soil samples， 16 ancient weathering crust soil samples， and 35 rock samples were collected to test and analyze the contents of eight heavy metals such as Cd， Pb， Hg， Zn， Cu， As， Cr， and Ni. The enrichment factor method and potential ecological risk index method were used to study the characteristics of heavy metal enrichment and ecological risk assessment. Multivariate statistical analysis and the positive matrix factorization （PMF） model were combined to analyze the sources of heavy metals in the soil. The results showed that the average content of eight heavy metal elements in the soil of the study area was lower than the screening value for soil pollution risk in agricultural land and the average content of surface soil in Hebei Province. Only Cd showed slight enrichment in heavy metals， while the rest of the heavy metal elements were not enriched overall. The potential ecological risks of a single indicator were ranked from high to low as follows： Cd>Hg>Pb>As>Ni>Cu>Zn>Cr. The comprehensive index of potential ecological risks showed that the study area was mainly mild， with only two samples reaching a moderate risk level， and the main contributing factors were Cd and Hg. The results of multivariate statistical analysis and PMF model source analysis indicated that heavy metals in the soil of the study area were mainly controlled by the weathering of the parent rock. The high-value areas of Cr， Ni， Cu， Zn， and Cd were mainly controlled by the basalt parent rock， while the high-value areas of Pb and As were mainly controlled by parent rocks such as detrital rocks and granite. Hg was a composite pollution source of multiple factors such as coal burning， atmospheric dust deposition， and parent rock weathering. As， Cr， Pb， and Zn were also affected by industrial activities， agricultural activities， transportation， and household waste.

Impact of atmospheric dust on phytoplankton dynamics and primary productivity in the tropical marine ecosystem of the Eastern Arabian Sea.

Abstract The Hawaii Aerosol Time‐Series (HATS) was a coordinated effort to simultaneously monitor atmospheric and water column dust dynamics in the North Pacific Subtropical Gyre. Throughout 2022 and 2023, HATS measured the composition of water column particles and made complementary measurements of aerosol chemistry and deposition fluxes. Here we report the inventories, elemental composition, dust‐relative residence times, and internal dynamics of size‐fractionated marine particles at Station ALOHA from four expeditions between September 2022 and August 2023. Mixed layer inventories of lithogenic particulate elements (Al, Fe, and Ti) varied by factors of 9 and 5 in small (0.2–51 μm) and large (>51 μm) particles, respectively, and by factors of 3 and 2 through 300 m depth; much less than the factor of 25–42 variations of these elements observed in aerosols. Mixed layer residence times of small lithogenic particles, relative to dust fluxes, ranged from <1 day to 12 days and from 1 week to 6 months through 300 m, demonstrating persistent rapid packaging into large particles near the surface. Fractional lability of Fe and Al in marine particles ranged from 6% to 89% and 22%–80%, respectively, in the upper 200 m, with Fe showing greater variability across size fractions. Scavenged Fe was more abundant below 200 m than at the surface, coincident with longer particulate residence times and larger lithogenic inventories in the upper mesopelagic. Ti‐normalized lithogenic ratios of marine particles were mostly lower than the aerosol time‐series, suggesting loss of Fe and Al from minerals post‐deposition and/or unquantified lateral inputs of Ti‐rich material.

Abstract MAVEN's 10 Deep Dip campaigns, when periapsis altitude was lowered from 150 km to 120 km for short periods in 2015–2019, have made major contributions to current understanding of the thermosphere and ionosphere of Mars, as well as of present escape and implications for past climate. Yet the available literature on the Deep Dip campaigns is fragmentary, naturally tending to emphasize the scientific results of the individual research project being reported. In order to view the Deep Dip campaigns in their totality, to integrate their main findings coherently, and to identify promising opportunities for further exploitation of their data, here we present a comprehensive overview of MAVEN's Deep Dip campaigns. For the thermosphere, MAVEN Deep Dip observations have revealed: the homopause altitude and its notable variability; gravity waves and their dissipation; thermospheric composition, its day‐to‐day variability (exemplified by the O/C ratio), and its response to changing solar irradiance; and the thermal structure of the lower thermosphere between the cold mesopause and the hot, isothermal upper thermosphere. For the ionosphere, MAVEN Deep Dip observations have revealed: ionospheric composition, its day‐to‐day variability (exemplified by the /C ratio), and its response to changing solar irradiance; the dependence of ionization efficiency upon altitude; electron and ion temperatures; and the presence of multiple species of metal ions. Solar conditions and atmospheric dust conditions, relevant observations by MAVEN remote sensing instruments and by other missions, and potential avenues for future analyses of Deep Dip data are also addressed.

Abstract The Arabian Gulf, connected to the Indian Ocean by a narrow strait, is an inverse estuary for which surface heating and evaporation are the primary mechanisms for the formation of warm, salty bottom water. Frequent dust storms over the Gulf reflect and absorb solar insolation and cause a significant reduction of surface radiative forcing. Previous studies have mainly investigated the effects of dust storms by considering corrections at climatological time scales. Shorter time-scale variations of air–sea fluxes due to dust aerosols in the meteorological reanalysis products were not easily represented until the recent introduction of the National Aeronautics and Space Administration’s (NASA’s) Modern‐Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2), product that incorporates the dust aerosol transport directly. In this study, we investigate the time-dependent sea surface temperature (SST) response of the Gulf to the dust concentration over the Gulf by combining satellite-based SST, in situ SST collected by biologging devices attached to cormorants (diving seabirds), and a series of numerical experiments comparing shortwave radiative forcings with and without dust from the MERRA-2 reanalysis. Model results show that high dust concentration decreases the Gulf-averaged daily SST by up to 0.9°C, due to reduced shortwave radiation. A linearized forcing–response model is used to generalize and interpret the model results. Specifically, by fitting the numerical results to the linearized model, we found that the response time of the SST to the variation of shortwave radiation is about 13 days, with a clear seasonal variation due to the change of mixed layer depth. The SST response to dust and winds is also captured by applying the linearized model to satellite-based observational SST measurements. Significance Statement The Arabian Gulf is characterized by high evaporations and frequent dust storms and exhibits a unique inverse estuary circulation. We validated satellite-based sea surface temperature (SST) observations using in situ data from biologging devices on cormorants, confirming minimal bias from elevated dust concentrations. We found a significant SST response to dust storms in the Gulf by numerical experiments and satellite-based SST observations. Furthermore, we evaluated the relative contribution of wind and dust during dust storms and found that about 30%–50% of the SST variations are attributed to the dust in the Gulf. This study deepens our understanding of how atmospheric dust aerosols influence surface ocean dynamics in high-dust regions, with implications for local and global ocean processes.

Abstract Surface temperature is a key component of the Martian climate system, modulating energy and momentum exchange between the atmosphere and surface. However, temporal shifts in the local time of Mars Climate Sounder (MCS) observations complicate comparisons of interannual variations. In this paper, we correct the observation‐time bias in MCS‐derived surface temperature records from Mars Years (MY) 29 to 36 using the Mars Climate Database. After correction, a statistically significant nighttime surface warming trend and tentative daytime warming are detected over the 8‐year period. A multiple linear regression analysis reveals that variations in atmospheric dust opacity are the dominant driver of surface temperature variability, with dust, albedo, and thermal inertia (TI) together explaining 45.0% (29.1%–76.4%) of the daytime and 68.3% (55.4%–80.6%) of the nighttime global temperature variance. To assess the spatial response to each forcing, Martian surface temperature variations are simulated using the Mars Planetary Climate Model under variable surface albedo and TI scenarios. Simulations that incorporate surface property changes better reproduce observed spatial patterns, particularly during the daytime. Attribution using the optimal fingerprinting method shows that daytime warming can be explained primarily by surface albedo (0.52 K) and dust (0.24 K) changes, with TI exerting a slight cooling effect (−0.24 K). These findings emphasize the importance of correcting observational artifacts and highlight the roles of surface and atmospheric processes in recent Martian climate variability.

<p>This study systematically analyzed the pollution characteristics, source apportionment, and health risks of 16 polycyclic aromatic hydrocarbons (PAHs) in atmospheric dust deposition, using Anqing City—a typical industrial city in China—as the research subject. Results indicate that the concentration range of Σ<sub>16</sub>PAHs in atmospheric dust in Anqing City is 85.22 – 21,351.03 ng g<sup>-1</sup>, with an average of 5,301.21 ng g<sup>-1</sup>, placing the pollution level in the lower-middle range nationally. Spatial distribution revealed significantly higher PAH concentrations in industrial clusters of Daguan District compared to other areas, indicating industrial emissions as a major point source of PAHs. The composition was dominated by high-ring (5–6 ring) PAHs (average proportion: 58.90%), indicating primary origin from high-temperature combustion processes. Integrated source apportionment using ring number distribution, characteristic ratio analysis, and positive matrix factorization (PMF) models identified fossil fuel combustion and industrial activities as the primary PAH sources. Health risk assessments revealed skin contact as the predominant exposure pathway for both adults and children, with carcinogenic risks approaching or exceeding acceptable thresholds under certain high-exposure scenarios.</p>

Carbonate minerals, as key components of atmospheric dust, play a critical role in neutralizing acidic pollutants. Their heterogeneous reaction behavior under ambient conditions, particularly at room temperature and without added oxidants, remains poorly understood. In this study, we found synergistic oxidation of NO and SO2 on carbonate surfaces, such as Na2CO3, K2CO3, etc. SO2 surprisingly activated O2 adsorbed on these carbonates, triggering significant adsorption and oxidation of NO under ambient temperature conditions. An intermediate species, [NO-SO5], was proposed to form on the surface of Na2CO3 and decompose to adsorbed NO2 and sulfate. Subsequently, adsorbed NO2 can react with surface oxygen sites to generate adsorbed nitrate. This finding fills the gap in the interaction mechanism between nitrogen and sulfur species on carbonate particles, revealing the significant catalytic role of carbonate in promoting oxidation processes within complex polluted atmospheric environments.

Droplet corrosion of steel with simulated atmospheric dust from mixtures of ammonium salts

Dustfall source-apportionment and source-oriented health risk assessment using unsupervised machine learning, PMF, and HYSPLIT: Insights from a hotspot area in Xinjiang, China.

Abstract Dust in the atmosphere of Mars, along with its radiative effects, is the central factor for understanding the Martian climate. Global circulation models and remote sensing observations are used to shed light on the evolution of Martian dust storms. Trajectories of Martian dust storms have been investigated by manual treatment of Mars daily global maps from the MARs Color Imager. However, the tracking of dust storms has neither been automated, nor systematically compared with modeled dust storm trajectories. We therefore developed a simple algorithm to detect regions with an enhanced atmospheric dust content and to attribute these regions to a trajectory. We applied this algorithm to daily global maps of measurements of the column dust optical depth for Mars Years 24–35, and found 20 dust storm trajectories lasting for at least 10 Sols. We compared these observation‐based trajectories with the corresponding model‐based trajectories from our own simulations using the global circulation model Mars Planetary Climate Model version 6. The obtained distributions of storm speed and direction of propagation show strong similarities between observations and model, demonstrating a reasonably good performance of the model with regard to dust storm trajectories. We find that most dust storms on Mars are traveling east‐ or westwards, but that dust storms propagating westwards are less well represented in the model. The developed algorithm can be used as a tool for model evaluation, but also for tracking meteorological conditions along dust storms' trajectories, allowing for further development of dust storm understanding.

Aim. To minimize atmospheric pollution during open-pit coal mining, which increases with growth in production volumes and involvement of lower-quality coals in the development. Methods. Analysis, mathematical modeling, discrete optimization, expert assessment, engineering forecasting, environmental and economic calculations and recommendations. Results. The author has carried out the quarry dust typification according to the danger to the environment. The paper introduces the results of assessing the condition of ledges as dust generators based on visual observations and graphical constructions. Based on the results of trapping by reference points the author measured the parameters of dust propagation and established the mechanism of its migration in the vicinity of the quarry. The author determined the dynamics of dust content depending on seasons and differentiated the atmospheric pollution zones. The sources of dust formation within the quarry were ranked according to the degree of danger, with the priority of explosive stripping of coal and rocks being established. The mechanism of formation of zones of regulated and unregulated crushing with the formation of large and mobile fractions was established on the example of the Bogatyr quarry. The author determined the integrating indicator of the state of the surface atmosphere of the quarry by dust sources and established the dependence approximating the data with a confidence probability. The paper introduces the model for describing the effects of a group of pollutants at a point in the controlled area and a model of the intensity of dust formation. The integral indicator of atmospheric dust content was measured. A technique for managing the atmosphere of a quarry is proposed. The author stated the matrix of financing the modernization of technologies with limited material resources. It is shown that the probability of good indicators of the atmosphere state is associated with the duration of reliability of technological processes.

This study investigates the elemental composition of atmospheric dust collected from both outdoor (roadside) and indoor environments across five distinct geographic areas in Lagos State, Nigeria, to assess environmental contamination and associated health risks. Surface dust was collected using a soft brush and dustpan, followed by acid digestion and analysis using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). A total of 34 elements were quantified, with results indicating significant spatial variation in concentrations. Notably, elevated levels of lead (Pb) and cadmium (Cd) were detected, suggesting contributions from industrial activities, vehicular emissions, and other anthropogenic sources. In contrast, concentrations of zinc (Zn), copper (Cu), and nickel (Ni) remained within permissible limits, reflecting lower pollution levels in certain areas. Health risk assessments revealed that the incremental lifetime cancer risk (ILCR) for both adults and children exceeded the U.S. EPA's acceptable thresholds (10⁻⁶ to 10⁻⁴), particularly in high-traffic zones. The findings underscore the need for targeted pollution control measures and provide essential data to inform air quality management and public health strategies in Lagos State.

Abstract On Mars, neighboring craters of similar diameter show variations in rim thermal inertia. In this study, thermal inertia (TI) was calculated using Mars Odyssey Thermal Emission Imaging System (THEMIS) nighttime images acquired during the southern hemisphere Martian autumn, a period with minimal fine dust influence. One hundred and thirty‐seven craters of different diameters across 21 TI scenes were analyzed, encompassing Gale Crater and its surroundings. Morphological parameters such as depth‐diameter ratio (d/D), radii variation (RV), rim irregularity (RI), and mantle rim percentage (MRP) were derived using Mars Reconnaissance Orbiter (MRO) Context camera (CTX) images. Two hypotheses were tested: Hypothesis I—Crater rim thermal inertia influenced by crater degradation during the southern hemisphere Martian autumn, and Hypothesis II—Crater rim thermal inertia influenced by crater rim regolith mantling during the southern hemisphere Martian autumn. Multilevel regression models were used to test the hypotheses. Hypothesis I was rejected, and Hypothesis II was found to be statistically significant ( p < 0.05), indicating crater rim TI variations are largely influenced by regolith mantling, reflecting dominant depositional activity. During the southern hemisphere autumn on Mars, atmospheric dust levels are relatively low; however, significant surface dust remains, likely redistributed by dust storms from the preceding summer season.

The Arabian Peninsula (AP) is an epicenter of global dust activity, shaped by both local emissions and long-range transport. Recent observational studies suggest that the Tigris–Euphrates river basin (TE) is the dominant contributor to the intense dust periods over the AP. This study, for the first time, quantifies the influence of TE during these periods using a regionally tuned Weather Research and Forecasting model coupled with chemistry (WRF-Chem). Two simulations were conducted with WRF-Chem for three extreme dust seasons (March–August; 2009, 2011, and 2012): one with dust emissions from all sources, including TE, and the other with TE emissions excluded. Results show that excluding TE emissions significantly reduces mean atmospheric dust loading and decreases dust concentrations across atmospheric layers over the AP. Reduced dust concentrations enhance surface shortwave radiation, increasing solar energy potential and improving regional particulate air quality. This also contributes to cooler nighttime temperatures by limiting trapping of longwave radiation.Critically, our findings indicate that the dust transport from TE controls the intensity and frequency of dust events in the AP during the study period. Suppressing TE dust emissions leads to a substantial reduction over 50% in the occurrence of extreme dust events over the AP. At the same time, it increases the prevalence of moderate and heavy dust events across most of the region. The Kingdom of Saudi Arabia (KSA) is pursuing ambitious strategies to mitigate dust extremes. Effective action depends on identifying dominant sources and their contributions. This study quantifies the impact of the remote TE source on KSA dust extremes, offering a strong basis for targeted control measures.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-31244-2.

Green roofs provide several ecosystem services, but due to the accumulation of atmospheric dust, they can be contaminated with heavy metals, which can reduce plant growth and pollute water runoff. In this study, we tested the original humic acids (HAo) isolated from black alder lowland peat and modified (HAmod) by reduction with sodium borohydride. The targeted chemical modification increased the phenolic group content in HAmod by 20% compared to HAo, increasing the ability of HAmod to reduce the toxic effect of heavy metal ions by binding them into non-toxic complexes. Testing with the “Ecolum” system showed that HAo and HAmod at concentrations of 50 and 100 mg L-1 did not have a toxic effect on microorganisms and can be used to reduce the toxicity of heavy metal ions. The addition of 50 mg L-1 HAmod reduced the toxicity of Cd2+ to an acceptable level, and the toxicity index for Zn2+ decreased by 2 times. The content of phenolic compounds in the test object (garden cress (Lepidium sativum)) grown on gray forest soil contaminated with cadmium (10 mg·kg-1) and zinc (100 mg·kg-1) ions decreased after the application of HAmod, indicating a reduction of plant stress. HAmod stimulated the root system of garden cress compared to the control; the total biomass increased by 90–120% compared to the substrate contaminated with Cd2+ and Zn2+ without the addition of HAmod. Thus, HAmod can be used to reduce the toxicity of heavy metal ions in substrates of green roofs.

Abstract We present the biogeochemical cycling of dissolved zinc (dZn) in marginal and open waters of the Indian Ocean using a high‐resolution dataset collected during multiple GEOTRACES‐India (GI) cruises. Atmospheric dust deposition is a minor source compared to continental shelf inputs for dZn in photic waters of the northern Indian Ocean. A strong linear relationship between dZn and silicate (Si) is noted across the Indian Ocean, with lower slope ratios (dZn : Si) in the Arabian Sea (0.045 ± 0.001 nM μ M −1 ) and Bay of Bengal (0.049 ± 0.001 nM μ M −1 ) relative to the southern tropical Indian Ocean (STIO, 0.062 ± 0.002 nM μ M −1 ). We investigated these regional differences using an inverse modeling approach by quantifying the fractional contribution of each water mass to the measured dZn concentrations in the water column. Our results indicate that water mass mixing and scavenging are the primary mechanisms controlling dZn distribution in the region. Scavenging of dZn in the intermediate waters is likely driving the lower dZn‐Si regression slopes in the northern Indian Ocean. Intense scavenging may result from zinc sulfide formation in anoxic microenvironments of poorly ventilated waters or adsorption onto sinking particles. Dissolved Zn in excess of its preformed component is nearly twice as high in deep waters of the northern Indian Ocean compared to the STIO, suggesting desorption of previously scavenged Zn and/or presence of regional deep sources. These findings advance our understanding of regional zinc cycling in the Indian Ocean.

Abstract This study focused on polychlorinated biphenyls (PCBs), a group of persistent toxic compounds with significant environmental and health risks, particularly in mining-impacted regions. PCB contamination was investigated at a mining site in Ibadan, Nigeria, by analyzing the distribution, concentrations and interrelationships of 18 PCB congeners. The mean total PCB concentration across all samples was 186.42 ng g −1 , ranging from 42.35 ng g −1 at site G3 to 451.27 ng g −1 at site G1, indicating severe contamination hotspots. Correlation analysis showed strong positive relationships, such as PCB161 vs PCB183 (r = 0.87, p < 0.01) and PCB99 vs PCB206 (r = 0.94, p < 0.01), suggesting common anthropogenic sources, likely linked to historical mining activities. In contrast, significant negative correlations, such as PCB5 vs PCB99 (r = − 0.71, p < 0.05), implied distinct environmental degradation pathways. Communalities analysis revealed that most congeners had variance explanations above 70%, with PCB180 (82%) and PCB138 (79%) being highly influenced by shared factors, while PCB161 (42%) and PCB168 (39%) were affected by unique sources. Human health risk assessments indicated that ingestion contributed the highest incremental lifetime cancer risk (ILCR). For example, at site G1, ingestion ILCR was 2.12 × 10 −5 , compared to 1.40 × 10 −5 for dermal exposure and 1.21 × 10 −6 for inhalation. These results highlight the urgent need for targeted remediation strategies, especially in hotspots like G1 and G2, and demonstrate the importance of understanding both shared and unique contamination pathways when managing PCB pollution in mining environments. Graphical Abstract

Contribution of dusts to trace element inventories in pioneering plants growing on a pilot-scale pit lake watershed.