Equilibria, kinetics, and spectroscopic analyses on the uptake of aqueous arsenite by two-line ferrihydrite.

Arsenite sorption from aqueous solutions was investigated using two-line ferrihydrite at room temperature, as a function of solution pH and arsenite loading. The isotherms, pH envelopes, and kinetics of arsenite sorption were characterized and its mechanism was elucidated via X-ray absorption spectroscopic studies. Arsenite sorption showed only slight pH dependence with a sorption maximum centered around pH 8.0. The Langmuir isotherm is most appropriate for arsenite sorption over the wide range of pH, indicating the homogenous and monolayer sorption of arsenite. The kinetic study demonstrated that arsenite sorption onto two-line ferrihydrite is considerably fast and the equilibrium is achieved within the reaction time of 3 h. X-ray absorption near-edge structure spectroscopy elucidated a slight change in oxidation state of arsenite for the initial concentration of 13.35 mM at pH 4. The extended X-ray absorption fine structure (EXAFS) spectroscopy results indicate that types of surface complexes of arsenite appeared to be very similar to those proposed by the previous studies in that the bidentate binuclear corner-sharing (2C) complex is predominant at all the surface loadings. However, our EXAFS results suggest that regardless ofpH, the mixed complexes of2C and bidentate mononuclear edge-sharing surface complex (2E) as well as the 2C complex are favoured at low and intermediate surface loadings, but only the 2C complex is dominant at high surface loading. Overall, the EXAFS results support the efficient removal of arsenite by the two-line ferrihydrite through the formation of highly stable inner-sphere surface complexes, such as 2C complex.

Differentiating anthropogenic effects from natural metal(loid) levels in residential soil near a zinc smelter in South Korea.

Metal(loid)s pose a significant hazard due to inherent toxicity. Individuals are particularly exposed to metal(loid)s in soil through direct or indirect contact. Identifying metal(loid) sources in soil is required for exposure mitigation to anthropogenic metal(loid)s, while metal(loid)s are natural constitutes of soil. Metal(loid) concentrations and Pb isotopes were determined in residential soil profiles impacted by a Zn smelter to distinguish the anthropogenic effect from natural levels. One hundred sixty-nine core soil samples were collected from depths down to 5.5 m below ground level at 19 sites and were divided into Zn-Cd-As- and As-contaminated groups based on the worrisome level (WL) of soil contamination. The Zn-Cd-As-contaminated group (n = 62) was observed at depths < 1 m, showed high Zn levels (mean of 1168 mg/kg) and Cd and As frequently exceeding WLs, and had low 206Pb/207Pb ratios close to the Zn smelter. In contrast, the As-contaminated group (n = 96) was observed at depths > 1 m, did not have other metals exceeding WLs, and showed a wide range of 206Pb/207Pb ratios far away from the Zn smelter. The results indicated that the pollution sources of Zn-Cd-As- and As-contaminated soils were fugitive dust emissions from smelter stacks and geology, respectively. The metal(loid)s in host rock set geochemical baselines in soil profiles, while smelting activities affected the upper layers over 50 years. This study demonstrated the effectiveness of utilizing the vertical distribution of metal(loid) concentrations and Pb isotopes in soil profiles for distinguishing between anthropogenic and geogenic origins, in combination with baseline assessment.

Evaluation of the toxic effects of arsenite, chromate, cadmium, and copper using a battery of four bioassays.

The sensitivities of four different kinds of bioassays to the toxicities of arsenite, chromate, cadmium, and copper were compared. The different bioassays exhibited different sensitivities, i.e., they responded to different levels of toxicity of each of the different metals. However, with the exception of the α-glucosidase enzyme activity, arsenite was the most toxic compound towards all the tested organisms, exhibiting the highest toxic effect on the seeds of Lactuca, with an EC(50) value of 0.63 mg/L. The sensitivities of Lactuca and Raphanus were greater than the sensitivities of two other kinds of seeds tested. Therefore, these were the seeds appropriate for use in a seed germination assay. A high revertant mutagenic ratio (5:1) of Salmonella typhimurium was observed with an arsenite concentration of 0.1 µg/plate, indicative of a high possibility of mutagenicity. These different results suggested that a battery of bioassays, rather than one bioassay alone, is needed as a more accurate and better tool for the bioassessment of environmental pollutants.

Mobility of metal(loid)s in roof dusts and agricultural soils surrounding a Zn smelter: Focused on the impacts of smelter-derived fugitive dusts.

The mobility of Zn, Cd, Pb, Cu, and As was assessed in an atmospheric environment and soil system near a Zn smelter by performing sequential extraction as well as Pb isotopic and mineralogical analyses for fugitive and roof dusts and agricultural soils. Transmission electron microscopy observations with selected area electron diffraction patterns confirmed that micron-sized roof dusts originated from the Zn smelter. Both fugitive and roof dusts contained zincite, massicot, franklinite, anglesite, and willemite. The sequential extraction of the fugitive dust from the Zn smelter stacks showed that Zn, Cd, and Pb were predominantly bound to the exchangeable (FI), carbonate (FII), and reducible (FIII) fractions, whereas Cu and As were significantly associated with the residual (FV) fraction and had low mobility. The estimation of remobilized concentrations of Zn, Cd, and Pb bound to labile fractions (FI and FII) in the fugitive dust implied their severe environmental and human health risks. In contrast, the studied metal(loid)s in the roof dust had low mobility except for Pb, implying the insignificant risks of roof dusts, although anthropogenic dusts from the Zn smelter significantly impacted FV as well as the non-residual fractions based on the Pb isotopic compositions of geochemical fractions. Similarly, the mobility and bioavailability of the studied metal(loid)s were low in agricultural soils, except for Cd, suggesting a low adverse effect on crops cultivated in the soil. The decrease in labile Cd fractions with depth indicated that the agricultural soil did not retain anthropogenic Cd in the soil subsurface. The mineralogical investigation combined with sequential extraction revealed that the different mobility of Zn, Cd, and Pb between fugitive dusts, roof dusts and agricultural soils resulted from the different solubility of metal-bearing minerals, e.g., zincite, willemite, simonkolleite which were not detected in the residuals of the fugitive dust collected after FIII extraction.

Recent pollution and source identification of metal(loid)s in a sediment core from Gunsan Reservoir, South Korea.

We assessed the contributions of Cu smelting and Asian dust influx to metal(loid) pollution over the last century based on metal(loid) concentrations, Pb isotope ratios, and 210Pb dating of sediments from Gunsan Reservoir, South Korea. During the pre-industrial period (1827-1936), heavy metal pollutants were predominantly geogenic. Local smelting activity was dominant between 1936 and 2008. Between 1936 and 1971, Cu and Pb contamination was not significant, with contributions from smelting activities accounting for < 6.2% of the measured concentrations. In contrast, anthropogenic Cu and Pb inputs increased between 1971 and 2008 due to intense smelting activity. Based on the similar 206Pb/207Pb ratios of the reservoir sediments and smelter bottom ash, anthropogenic contributions reached 95% during 1987-1995. In comparison, the sediments deposited between 2008 and 2018 were characterized by a higher Zn and Cd geoaccumulation index and enrichment factor values and less-radiogenic Pb signals than the regional geogenic Pb signal. These trends are attributed to the long-range transport of pollutants from China, the contribution of which gradually increased from 11.0% in 2008 to 19.2% in 2018. Our results show that reservoir sediments are valuable archives for reconstructing metal(loid) contamination histories and changes in pollution sources over time.

Assessment of trace metal pollution in roof dusts and soils near a large Zn smelter.

The spatial extent of dust emissions from a Zn smelter was assessed based on metal concentrations in roof dust samples. In addition, the vertical mobility of metal loads in soils was assessed from metal concentrations and Pb isotopic compositions. Moreover, the source apportionment of metals in the roof dusts and soils was estimated using Pb isotopes. A total of 13 roof dust and 11 smelter dust samples were collected respectively from residential houses and smelter stacks. The vertical distribution in soils was assessed at 10 cm intervals in four sites along the predominant wind direction. High metal concentrations were found in the roof dusts, which were enriched in Zn, Pb, Cd, and Cu by a factor of 48-937, 13-169, 161-3400 and 10-135, respectively, compared to the regional background values of soils, depending on the distance from the smelter. Horizontal extents of the airborne metal transport were estimated to exceed the impact radius (<4 km) calculated by a numerical model. As for soils, the metal concentrations were high in the surface layer and decreased abruptly with depth. The vertical extent of the metal contamination was found up to 60 cm. Considering the operational period of the smelter, the Pb migration rate was 0.4-1.3 cm/year and the farmlands showed higher penetration rates than the other sites, probably due to agricultural practices. The Pb isotope compositions for the contaminated soils lay on a mixing line between the anthropogenic Pb of the smelter and the geogenic Pb of the background soils, which confirmed that the emission and deposition of the airborne particles produced by the smelter contributed to 49-83% of trace metals in the surface soils. Similarly, the Pb isotopic compositions of the roof dusts indicated that most of Pb was derived from the smelter, in particular, from the casting and leaching stacks.

Lead isotopes combined with geochemical and mineralogical analyses for source identification of arsenic in agricultural soils surrounding a zinc smelter.

As-contaminated soil samples were chosen to identify As sources near a Zn smelter where Zn contamination in soils was found to be of smelter origin. Based on the As concentrations and Pb isotopic compositions, high As levels in soils were originated from the geogenic source. There was no consistent trend in As concentrations with either depth or distance from the smelter, while the Pb isotopic compositions in soils varied regardless of As levels and were quite different from those of smelter origin. Transmission electron microscopy (TEM) and selected area electron diffraction (SAED) suggested that the high As concentrations were due to arsenopyrite and its alteration minerals, which were easily found but heterogeneously distributed within host rocks. A detailed investigation of As levels and Pb isotropic compositions along the predominant wind direction also supported that the As contamination was of geogenic origin unlike the Zn contamination. The atmospheric emissions from the smelter increased the Zn concentrations and decreased the 206Pb/207Pb ratios at surface layers, while the As concentrations occasionally exceeded the worrisome level at deep layers. According to the Pb isotropic compositions, about 21% of the As-contaminated soils were impacted by the smelter, in particular at the surface layer.

Source identification of arsenic contamination in agricultural soils surrounding a closed Cu smelter, South Korea.

Arsenic sources were identified in As-contaminated soils 4 km-7 km from a closed Cu smelter. Host rocks, heavy minerals in contaminated soils, ore minerals in quartz veins (geogenic sources) and bottom ash from the Cu smelter (an anthropogenic source) were investigated as potential sources. As a result, heavy minerals and bottom ash were found to contain higher As concentrations than the contaminated soils. Some of the host rock samples also showed higher As levels than the contaminated soils. Arsenopyrite was one of the frequently detected ore minerals in quartz veins. The As concentrations in soils did not decrease with soil depth or distance from the smelter. These results imply that the atmospheric emission from the smelter was not a major arsenic source. Based on the geochemical investigation and Pb isotopic analysis, the As contamination was affected by both regional ore mineralization and the host rock, and the influence of the smelter was limited. The spatial analysis of As concentrations and Pb isotopic ratios suggested that As contamination was mainly due to regional ore mineralization. The 206Pb/207Pb and 206Pb/204Pb ratios of the contaminated soils were plotted on the mixing line between background soils and ore minerals. The source apportionment results indicated a significant contribution of regional ore mineralization (average 52.9 ±â€¯30.3%) to the As contamination. The contribution of this study is that we identified that the major source of soil contamination was of geologic origin despite an anthropogenic source nearby using geochemical and Pb isotopic investigation.

Assessment of Zn pollution sources and apportionment in agricultural soils impacted by a Zn smelter in South Korea.

This study was conducted to assess the anthropogenic impact on the metal concentration in agricultural soils in the vicinity of a Zn smelter. We determined Pb isotope ratios to trace source of metals and calculate source apportionment. 19.7% of the agricultural soil samples had Zn concentrations exceeding the Korean worrisome level (WL). The isotopic variation in the contaminated agricultural soils reflected the input of contaminants derived from the Zn smelter. The spatial distribution of Zn concentrations and Pb isotopes suggested that the Zn smelter dust fallout was the major source of heavy metal pollution in the agricultural soils. Lead isotope compositions of soil horizon I was comparable to those of soil horizon II, indicating that smelter-origin Zn had migrated vertically. Binary mixing between Zn concentrates and background soils could explain the variations in Pb isotope ratios in the contaminated agricultural soils. Source apportionment calculations showed that for agricultural soils that were found to exceed the Korean countermeasure standard (CS), the average proportion of smelter-origin Zn was 45.8%-83.3% while for agricultural soils that exceeded the WL but were below the CS, the average proportion of smelter-origin Zn was 36.3%-68.1%. The remainder was derived from a geogenic source.

Characterization of Cr (VI) - Containing solid phase particles in dry dust deposition in Daejeon, South Korea.

Solid phase speciation of chromium in dry dust deposition and road paint was determined using transmission electron microscopy (TEM) and X-ray absorption spectroscopy (XAS). Spherical black carbon aggregates in dry dust deposition contained discrete nano-sized lead chromate (PbCrO4) and zinc chromate (ZnCrO4), which likely originated from yellow traffic paint and zinc chromate primer (corrosion resistant pigment), respectively based on their main applications. Road marking paint samples from auto roads included lead chromate particles whose size, shape, composition and crystal structure were similar to those in dry dust deposition. A slight difference was found at the particle boundary. Namely, lead chromate in traffic paint was encapsulated by silica-bearing matrix, while discrete lead chromate in the black carbon of dry deposition was rarely enclosed within silica-bearing matrix. The Cr K edge X-ray absorption near edge structure (XANES) spectrum for dry deposition showed the characteristic pre-edge resonance peak similar to the spectra for the Cr(VI) standard and road paint, but the lower intensity. The amount of Cr(VI) accounted for approximately 45% of the total Cr in the dust sample. The solid phase speciation of Cr observed using TEM and their valence states determined using XANES were consistent with the chemical speciation determined using the sequential extraction. The contribution of this study is that XANES was applied to identify Cr valance states in urban dust deposition and zinc chromate was found as a Cr(VI) phase in dry dust deposition using TEM. These study results provide novel data on Cr speciation and Cr(VI)-containing mineral phases in dry dust deposition and their potential sources. Based on the wide use of lead and zinc chromate, atmospheric contamination with these solid phase speciation of Cr(VI) is expected in other cities in the world.

Bauxite residue neutralization with simultaneous mineral carbonation using atmospheric CO2.

Simultaneous carbon mineralization during neutralization of bauxite residue, a caustic alkaline by-product of alumina refining, was tested using laboratory batch and a field pilot study in contact with atmospheric CO2. Since CO2 sequestration is limited by the Ca concentration in the bauxite residue, extra Ca sources were added in a semi-soluble mineral and salt form (flue gas desulfurization gypsum or CaCl2) to verify whether this Ca addition accelerated and enlarged the CO2 sequestration obtained as a consequence of neutralization. The results of 55 days of batch and longer-term field tests were in good agreement, and the neutralization rate was accelerated through the addition of both Ca sources. Without the addition of the extra Ca source, atmospheric CO2 contributed to neutralization of pore water alkalinity alone, while Ca addition induced further neutralization through mineral carbonation of atmospheric CO2 to CaCO3. This simple addition of environmentally benign Ca to bauxite residue may provide a feasible bauxite residue management practice that is cost-effective and easy to apply in the field.

Enrichment and geochemical mobility of heavy metals in bottom sediment of the Hoedong reservoir, Korea and their source apportionment.

Physicochemical characteristics of bottom sediment in the Hoedong reservoir were studied to evaluate the effectiveness of the reservoir as traps for trace metals. Roadside soil, stream sediment and background soil were also studied for comparison. Sequential extractions were carried out, and lead isotopic compositions of each extraction were determined to apportion Pb sources. Besides, particle size distribution of roadside soil, and metal concentrations and Pb isotopes of each size group were determined to characterize metal contamination. In result, Zn and Cu were enriched in sediment through roadside soil. The data on metal partitioning implied that Zn posed potential hazards for water quality. Meanwhile, the noticeable reduction of the 206Pb/207Pb isotopic ratio in the acid-soluble fraction in the size group 200 µm - 2 mm of national roadside soil indicated that this size group was highly contaminated by automotive emission with precipitation of acid-soluble secondary minerals during evaporation. Based on the Pb isotopic ratios, the dry deposition of Asian dust (AD) and non-Asian dust (NAD) affected roadside soil, while the effects of AD and NAD on bottom sediment appeared to be low given the low metal concentrations in sediment. Metal concentrations and Pb isotopic compositions indicated that sediments were a mixture of background and roadside soil. Source apportionment calculations showed that the average proportion of traffic Pb in bottom and stream sediments was respectively 34 and 31% in non-residual fractions, and 26 and 28% in residual fraction. The residual fraction of sediments appeared to be as contaminated as the non-residual fractions.

Lead isotopes combined with a sequential extraction procedure for source apportionment in the dry deposition of Asian dust and non-Asian dust.

Lead isotopic compositions were determined in leachates that were generated using sequential extractions of dry deposition samples of Asian dust (AD) and non-Asian dust (NAD) and Chinese desert soils, and used to apportion Pb sources. Results showed significant differences in (206)Pb/(207)Pb and (206)Pb/(204)Pb isotopic compositions in non-residual fractions between the dry deposition samples and the Chinese desert soils while (206)Pb/(207)Pb and (206)Pb/(204)Pb isotopic compositions in residual fraction of the dry deposition of AD and NAD were similar to the mean (206)Pb/(207)Pb and (206)Pb/(204)Pb in residual fraction of the Alashan Plateau soil. These results indicate that the geogenic materials of the dry deposition of AD and NAD were largely influenced by the Alashan Plateau soil, while the secondary sources of the dry deposition were different from those of the Chinese desert soils. In particular, the lead isotopic compositions in non-residual fractions of the dry deposition were homogenous, which implies that the non-residual four fractions (F1 to F4) shared the primary anthropogenic origin. (206)Pb/(207)Pb values and the predominant wind directions in the study area suggested that airborne particulates of heavily industrialized Chinese cities were one of the main Pb sources. Source apportionment calculations showed that the average proportion of anthropogenic Pb in the dry deposition of AD and NAD was 87% and 95% respectively in total Pb extraction, 92% and 97% in non-residual fractions, 15% and 49% in residual fraction. Approximately 81% and 80% of the anthropogenic Pb was contributed by coal combustion in China in the dry deposition of AD and NAD respectively while the remainder was derived from industrial Pb contamination. The research result proposes that sequential extractions with Pb isotope analysis are a useful tool for the discrimination of anthropogenic and geogenic origins in highly contaminated AD and NAD.

Lead chromate detected as a source of atmospheric Pb and Cr (VI) pollution.

Spherical black carbon aggregates were frequently observed in dust dry deposition in Daejeon, Korea. They were tens of micrometers in diameter and presented a mixture of black carbon and several mineral phases. Transmission electron microscopy (TEM) observations with energy-dispersive X-ray spectroscopy (EDS) and selected area diffraction pattern (SADP) analyses confirmed that the aggregates were compact and included significant amounts of lead chromate (PbCrO4). The compositions and morphologies of the nanosized lead chromate particles suggest that they probably originated from traffic paint used in roads and were combined as discrete minerals with black carbon. Based on Pb isotope analysis and air-mass backward trajectories, the dust in Daejeon received a considerable input of anthropogenic pollutants from heavily industrialized Chinese cities, which implies that long-range transported aerosols containing PbCrO4 were a possible source of the lead and hexavalent chromium levels in East Asia. Lead chromate should be considered to be a source of global atmospheric Pb and Cr(VI) pollution, especially given its toxicity.

A novel method of utilizing permeable reactive kiddle (PRK) for the remediation of acid mine drainage.

Numerous technologies have been developed and applied to remediate AMD, but each has specific drawbacks. To overcome the limitations of existing methods and improve their effectiveness, we propose a novel method utilizing permeable reactive kiddle (PRK). This manuscript explores the performance of the PRK method. In line with the concept of green technology, the PRK method recycles industrial waste, such as steel slag and waste cast iron. Our results demonstrate that the PRK method can be applied to remediate AMD under optimal operational conditions. Especially, this method allows for simple installation and cheap expenditure, compared with established technologies.

Metal contamination and solid phase partitioning of metals in urban roadside sediments.

This study was undertaken to assess the anthropogenic impact on metal concentrations of urban roadside sediments (N = 633) in Seoul city, Korea and to estimate the potential mobility of selected metals (Zn, Cu, Pb, Cr, Ni, and Cd) using sequential extraction. Comparison of metal concentrations in roadside sediments with mean background values in sediments collected from first- or second-order streams in Korea shows that Zn, Cu and Pb are most affected by anthropogenic inputs. The 206Pb/207Pb ratios of roadside sediments (range = 1.1419-1.1681; mean 1.1576 +/- 0.0068) suggest that Pb is mainly derived from industrial sources rather than from leaded gasoline. A five-step sequential extraction of roadside sediments showed that Zn, Cd and to a lesser degree Ni occur predominantly in the carbonate bound fraction, while Pb is highest in the reducible fraction, Cu in the organic fraction, and Cr in the residual fraction. It was found that the concentrations in the readily available exchangeable fraction were generally low for most metals examined, except for Ni whose exchangeable fraction was appreciable (average 15.2%). Considering the proportion of metals bound to the exchangeable and carbonate fractions, the comparative mobility of metals probably decreases in the order of Zn > Ni > Cd > Pb > Cu > Cr. As potential changes of redox state and pH may remobilize the metals bound to carbonates, reducible, and/or organic matter, and may release and flush them through drain networks into streams, careful monitoring of environmental conditions appears to be very important. With respect to ecotoxicity, it is apparent the Zn and Cu pollution is of particular concern in Seoul city.

Assessment of mobility and bio-availability of heavy metals in dry depositions of Asian dust and implications for environmental risk.

We assess the potential mobility and bio-availability of selected metals (As, Cd, Co, Cr, Cu, Ni, Mo, Pb, S, Zn, and Zr) in the dry depositions of Asian and non-Asian dust from the city of Daejeon, Korea. For this study, we applied Pb isotopes, total extraction and chemical sequential extraction methods to the dry depositions. In addition, microscopic analysis was performed using X-ray diffraction (XRD) and focused ion beam (FIB)-scanning electron microscopy (SEM-EDS). FIB-SEM cross-section observations and Pb isotope data showed a black carbon is an important carrier of associated heavy metals originating from China. A five-step sequential extraction performed on the dry depositions showed that S and Cd are the most abundant elements in the water-soluble and cation-exchangeable fraction. In addition, Zn and Pb appeared predominantly in the carbonate and reducible fractions. On the other hand, Cu, Mo and, to a lesser degree, As were significantly associated with the organic fraction, while Co, Ni, Cr and Zr were bound to the residual fraction. These results showed that S, Cd, Zn and Pb, which were highly concentrated in potentially mobile fractions, have potential environmental risk because potential changes in redox state and pH may remobilize these metals. In addition, the estimated remobilization concentrations of these metals were significant. Thus, this study shows that frequent and careful monitoring of S, Cd, Z, Pb and, to a lesser degree, Cu, Mo and As is very important for assessing environmental risk in Korea.

Atmospheric versus lithogenic contribution to the composition of first- and second-order stream waters in Seoul and its vicinity.

The spatial variations in the chemistry of first- and second-order stream waters (N = 65) were investigated in the easterly bound of Seoul in order to assess the effects of urban air pollution on surface water chemistry. The sulfate (SO4(2-)) was high (range 3.9-17.8 mg l(-1), mean 11.8 mg l(-1)) within 30 km away from the center of Seoul, compared to the levels (range 1.1-7.7 mg l(-1), mean 4.3 mg l(-1)) observed in remote areas (30-70 km away). Both graphical examination and statistical evaluation (variogram) of sulfate concentration data consistently showed the decrease of sulfate concentration with increasing distance. The results of mass balance modeling also indicate that the concentrations of SO4(2-), Cl- and Na+ may be affected mainly by dry/wet deposition. However, the spatial variations of major cations such as Ca2+ and Na+ are well explained by the reaction of rainwater with diverse rocks in the watercourse. The water type was found to change from Ca(-Na)-SO4) type to Ca(-a)-HCO3 type with the increasing distance. It is thus inferred that the pollutants like SO2 emitted from strong man-made source areas of Seoul are transported to the considerable distance (at least 30 km away) by westerlies and that such mechanism may lead to the changes of the anion composition in surface water. In the remote area (> 30 km away from Seoul), the stream water chemistry appears to be influenced more effectively by the weathering of rock-forming minerals.

Heavy metal concentrations and contamination levels from Asian dust and identification of sources: a case-study.

The aims of this study were to determine concentrations of selected metals (As, Cd, Cr, Co, Cu, Ni, Sb, Pb and Zn) in Asian and non-Asian dust collected in Daejeon, Korea between February 2007 and December 2007 and to estimate the pollution sources. The geoaccumulation index (Igeo) and the enrichment factor (EF) show that the pollution levels of Cd, Pb, Zn, Sb, Cu, and As are much higher than those of Cr, Co and Ni. As, Cd, Cu, Sb, Pb, and Zn are the ones most strongly affected by anthropogenic inputs such as airborne pollutants. The (206)Pb/(207)Pb ratios of Asian and non-Asian dust are similar to those of the airborne particles in some heavily industrialized Chinese cities and the soils of the Alashan desert. To address the highly elevated levels of heavy metals found in Asian and non-Asian dust, studies should be performed to assess the potential impacts of settled particles on surface ecosystems, water resources, and human health in Korea.