Trace Elements In Aerosols Research Articles

Aerosol trace element solubility determined using ultrapure water batch leaching: an intercomparison study of four different leaching protocols

Abstract. Solubility of aerosol trace elements, which determines their bioavailability and reactivity, is operationally defined and strongly depends on the leaching protocol used. Ultrapure water batch leaching is one of the most widely used leaching protocols, while the specific leaching protocols used in different labs can still differ in agitation methods, contact time, and filter pore size. It is yet unclear to which extent the difference in these experimental parameters would affect the aerosol trace element solubility reported. This work examined the effects of agitation methods, filter pore size, and contact time on the solubility of nine aerosol trace elements and found that the difference in agitation methods (shaking vs. sonication), filter pore size (0.22 vs. 0.45 µm), and contact time (1 vs. 2 h) only led to small and sometimes insignificant difference in the reported solubility. We further compared aerosol trace element solubility determined using four ultrapure water leaching protocols, which are adopted by four different labs and vary in agitation methods, filter pore size, and/or contact time, and observed good agreement in the reported solubility. Therefore, our work suggests that although ultrapure water batch leaching protocols used by different labs vary in specific experimental parameters, the determined aerosol trace element solubility is comparable. We recommend that ultrapure water batch leaching be one of the reference leaching schemes and emphasize that additional consensus in the community on agitation methods, contact time, and filter pore size is needed to formulate a standard operating procedure for ultrapure water batch leaching.

Concentration, seasonality, and sources of trace elements in atmospheric aerosols from Godavari in the southern Himalayas

Atmospheric pollution has detrimental effects on human health and ecosystems. The southern region of the Himalayas, undergoing rapid urbanization and intense human activities, faces poor air quality marked by high aerosol loadings. In this study, we conducted a two-year PM10 sampling in the suburban area (Godavari) of Kathmandu, a representative metropolis situated in the southern part of the central Himalayas. The trace elements were measured to depict aerosol-bound element loadings, seasonality, and potential sources. The mean concentrations of trace elements varied considerably, ranging from 0.27 ± 0.19 ng m−3 for Tl to 1252.78 ng m−3 for Zn. The average concentration of Co and Ni was 1.2 and 22.4 times higher, respectively, than those in Lhasa city in Tibet in the northern Himalayas. The concentration of Pb was 38 times lower than that in Lahore, Pakistan, and 9 times lower than urban sites in India. For the seasonality, the trace element concentrations displayed remarkable variation, with higher concentrations during the non-monsoon seasons and lower concentrations during the monsoon season. This trend was primarily influenced by anthropogenic activities such as low-grade fuel combustion in vehicles, coal combustion in brick kilns, and biomass burning, along with seasonal rainfall that induced aerosol washout. The enrichment factors (EFs) analysis revealed that Cd, Zn, Sb, Ni, Cu, Cr, and Pb had higher EFs, indicating their significant contributions from anthropogenic sources. In contrast, elements like Tl, Co, V, Cs, U, Ba, Th, and Sr, characterized by lower EFs, were mainly associated with natural sources. The Pb isotopic ratio profiles exhibited the Pb in PM10 are derived major contribution from legacy lead. Biomass burning contributed to the Pb source in winter. These findings provide policymakers with valuable insights to develop guidelines and strategies aimed at improving air quality and mitigating the impact of aerosol pollution on human health in the Himalayan region.

Preface to the inter-journal special issue “RUSTED: Reducing Uncertainty in Soluble aerosol Trace Element Deposition”

Preface to the inter-journal special issue “RUSTED: Reducing Uncertainty in Soluble aerosol Trace Element Deposition”

GEOTRACES: Fifteen Years of Progress in Marine Aerosol Research

The international GEOTRACES program has allowed unprecedented access to aerosols in the remote marine environment, moved the community toward standardized methodologies, and contributed to expanding research capabilities around the globe. A key aspect of GEOTRACES aerosol research is the quantification of deposition fluxes of trace elements and isotopes to the surface ocean as a source for biolimiting nutrients and anthropogenic contaminants. New methods for quantifying flux have been developed that leverage radioisotope tracers in the surface ocean to estimate bulk deposition rates on longer and more relevant timescales. The question as to what fraction of aerosols is soluble remains and is a source of continuing uncertainty. To that end, the community has engaged in coordinated study to address questions regarding the fractional solubility of aerosol trace elements and isotopes through the evaluation of widely used dissolution and extraction techniques. Intercalibration efforts, method standardization, and normalization of open-access data archiving will be the legacy of GEOTRACES-era aerosol research.

Trace elements in ambient aerosols and size-resolved fog droplets: Trends, enrichment, and risk assessment

Ambient particulate matter (PM) is composed of inorganic and organic components. The contribution of each component is impacted by various factors such as emission sources, atmospheric aging process, and size of the PM or droplets. This study mainly focuses on the effect of the PM and droplet size on trace elemental concentrations, for which various size fractions of ambient PM (PM1, PM2.5) were collected on quartz filters along with fog water (FW) samples during winter. Simultaneous, online measurements of the mass concentrations of PM1 and PM2.5 were also carried out. At the time of the collection, the mass concentration of PM2.5 ranged from 19 to 890 μg/m3, and its mean value was 227 μg/m3. During the sampling period, 17 fog events occurred and caused a 27% reduction in the mean pre-fog PM2.5 concentration. All the PM and FW samples were analyzed for 12 trace elements: Ca, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Zn, V. The concentrations of the various trace elements in the PM1, PM2.5, and FW samples encompassed a wide range: 10 (V)–2432 (Na) ng/m3, 34 (Mn)–13810 (Na) ng/m3, and 8 (Cr)–19870 (Ca) μg/l, respectively. The concentrations of the trace elements in the FW samples indicated a droplet-size-dependent trend: the small droplets (diameter <16 μm) had several times (3–10 times) higher concentrations than the coarser droplets (diameter >22 μm). The enrichment factor (EF) analysis revealed that the EF values for almost all the trace elements were an order of magnitude higher in the FW samples than in PM1 and PM2.5. Risk assessment based on toxic elements suggested a very high inhalation carcinogenic risk (231 per million) for the exposed population during foggy periods. This study will facilitate decision-making by policymakers regarding air quality and health concerns.

Characteristics and seasonality of trace elements in fine aerosols from Tianjin, North China during 2018-2019

To better understand the characteristics and seasonality of trace elements in fine aerosols (PM2.5) in the Tianjin region, North China, we conducted a long-term PM2.5 sampling during July 2018 to July 2019 (n = 121) at an urban location in Tianjin. We measured 28 trace elements in PM2.5 using inductively coupled plasma mass spectroscopy (ICP-MS). Zn, As, Cd, V, and Ni, which are mainly emitted from anthropogenic sources, found to be abundant followed by the elements of natural origin and of dust, respectively. Concentrations of most of the elements varied substantially from season to season, indicating the seasonal differences in emission sources. However, V, Ni, and Cr did not show any significant seasonal variation during the whole campaign, which suggested that the impact of local emissions from the industry was significant throughout the year at Tianjin. The positive matrix factorization (PMF) analysis of the data resulted six factors, representing the sources: emissions of coal combustion, industries, biomass burning, soil dust, vehicle exhaust and secondary formation, with the relative contributions of 17.3%, 12.5%, 14.3%, 18.8%, 25.3% and 11.9%, respectively. Although the annual contribution to PM2.5 from vehicle exhaust was higher, the contributions from biomass burning, secondary formation, coal combustion and the vehicle exhaust were dominated in spring, summer, autumn and winter, respectively. This study provides insights on PM2.5 seasonal characteristics and to develop a controlling strategy for air pollution in mid-latitude coastal cities, especially in northeastern Asia.

Does Sea Spray Aerosol Contribute Significantly to Aerosol Trace Element Loading? A Case Study From the U.S. GEOTRACES Pacific Meridional Transect (GP15)

AbstractAtmospheric deposition represents a major input for micronutrient trace elements (TEs) to the surface ocean and is often quantified indirectly through measurements of aerosol TE concentrations. Sea spray aerosol (SSA) dominates aerosol mass concentration over much of the global ocean, but few studies have assessed its contribution to aerosol TE loading, which could result in overestimates of “new” TE inputs. Low‐mineral aerosol concentrations measured during the U.S. GEOTRACES Pacific Meridional Transect (GP15; 152°W, 56°N to 20°S), along with concurrent towfish sampling of surface seawater, provided an opportunity to investigate this aspect of TE biogeochemical cycling. Central Pacific Ocean surface seawater Al, V, Mn, Fe, Co, Ni, Cu, Zn, and Pb concentrations were combined with aerosol Na data to calculate a “recycled” SSA contribution to aerosol TE loading. Only vanadium was calculated to have a SSA contribution averaging &gt;1% along the transect (mean of 1.5%). We derive scaling factors from previous studies on TE enrichments in the sea surface microlayer and in freshly produced SSA to assess the broader potential for SSA contributions to aerosol TE loading. Maximum applied scaling factors suggest that SSA could contribute significantly to the aerosol loading of some elements (notably V, Cu, and Pb), while for others (e.g., Fe and Al), SSA contributions largely remained &lt;1%. Our study highlights that a lack of focused measurements of TEs in SSA limits our ability to quantify this component of marine aerosol loading and the associated potential for overestimating new TE inputs from atmospheric deposition.

Орчны дээжинд микроэлемент хортой хүнд метал, цацраг идэвхт изотоп тодорхойлох

The present report outlines the activities in Environmental studies at Nuclear Research Center, National University of Mongolia, Ulaanbaatar. The Nuclear and Related Analytical Techniques, which developed in this center, played on very important role in Environmental studies due to several advantageous features as multielemental, accuracy and low detection limits of these methods. The most appreciated advantageof Gamma Spectrometric, with HP Ge detector and Total Reflection X-Ray Fluorescence Techniques are briefly reviewed and • the results on determination toxic heavy metals, trace, natural and man-made radioactive elements in aerosols, soil, water, food and hair samples are discussed in detail. Also, in this report give some results of natural radioactive measurements of soil, building materials and indoor's radon data in Erdenet and Ulaanbaatar cities. In some soil samples of Western Mongolia observed man-made radioisotope Cs-137 14.7-64.8 Bk/kg. It means the Western Mongolia exposed ground and air nuclear explosions at Semipalatinsk (Russia) and Lobnor (China).

Bulk Aerosol Trace Element Concentrations and Deposition Fluxes During the U.S. GEOTRACES GP15 Pacific Meridional Transect

AbstractAtmospheric deposition of aerosols transported from the continents is an important source of nutrient and pollutant trace elements (TEs) to the surface ocean. During the U.S. GEOTRACES GP15 Pacific Meridional Transect between Alaska and Tahiti (September–November 2018), aerosol samples were collected over the North Pacific and equatorial Pacific and analyzed for a suite of TEs, including Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Pb. Sampling coincided with the annual minimum in dust transport from Asia, providing an opportunity to quantify aerosol TE concentrations and deposition during the low dust season. Nevertheless, peak concentrations of “crustal” TEs measured at ∼40–50°N (∼145 pmol/m3 Fe) were associated with transport from northern Asia, with lower concentrations (36 ± 14 pmol/m3 Fe) over the equatorial Pacific. Relative to crustal abundances, equatorial Pacific aerosols typically had higher TE enrichment factors than North Pacific aerosols. In contrast, aerosol V was more enriched over the North Pacific, presumably due to greater supply to this region from oil combustion products. Bulk deposition velocity (Vbulk) was calculated along the transect using the surface ocean decay inventory of the naturally occurring radionuclide, 7Be, and aerosol 7Be activity. Deposition velocities were significantly higher (4,570 ± 1,146 m/d) within the Intertropical Convergence Zone than elsewhere (1,764 ± 261 m/d) due to aerosol scavenging by intense rainfall. Daily deposition fluxes to the central Pacific during the low dust season were calculated using Vbulk and aerosol TE concentration data, with Fe fluxes ranging from 19 to 258 nmol/m2/d.

Amount, Sources, and Dissolution of Aerosol Trace Elements in the Canadian Arctic

Amount, Sources, and Dissolution of Aerosol Trace Elements in the Canadian Arctic

A Year-Round Measurement of Water-Soluble Trace and Rare Earth Elements in Arctic Aerosol: Possible Inorganic Tracers of Specific Events

This study presents the year-round variability of the water-soluble fraction of trace elements (wsTE) and rare earth elements (wsREE) among size segregated airborne particulate matter samples collected at Ny-Ålesund in the Svalbard Archipelago from 26 February 2018 to 26 February 2019. Six different aerosol dimensional fractions were collected using a multi-stage Andersen impactor to better understand local and global circulation with the aim of disentangling the source of inorganic tracers from specific natural or anthropogenic sources. The wsTE and wsREE content, especially in the finest fractions in remote areas, is primarily related to long-range transport and it gives valuable information on (1) the global circulation, (2) the natural sources and (3) the contribution of human activities to aerosol composition. A Factor Analysis was applied to the dataset, including levoglucosan and methanesulfonic acid (MSA), to assess the possibility of using certain inorganic tracers as indicators of specific transport events or circulation regimes. We also investigate back-trajectories to determine potential source areas.

Concentrations, particle-size distributions, and dry deposition fluxes of aerosol trace elements over the Antarctic Peninsula in austral summer

Abstract. Size-segregated particulate air samples were collected during the austral summer of 2016–2017 at Palmer Station on Anvers Island, western Antarctic Peninsula, to characterize trace elements in aerosols. Trace elements in aerosol samples – including Al, P, Ca, Ti, V, Mn, Ni, Cu, Zn, Ce, and Pb – were determined by total digestion and a sector field inductively coupled plasma mass spectrometer (SF-ICP-MS). The crustal enrichment factors (EFcrust) and k-means clustering results of particle-size distributions show that these elements are derived primarily from three sources: (1) regional crustal emissions, including possible resuspension of soils containing biogenic P, (2) long-range transport, and (3) sea salt. Elements derived from crustal sources (Al, P, Ti, V, Mn, Ce) with EFcrust&lt;10 were dominated by the coarse-mode particles (&gt;1.8 µm) and peaked around 4.4 µm in diameter, reflecting the regional contributions. Non-crustal elements (Ca, Ni, Cu, Zn, Pb) showed EFcrust&gt;10. Aerosol Pb was primarily dominated by fine-mode particles, peaking at 0.14–0.25 µm, and likely was impacted by air masses from southern South America based on air mass back trajectories. However, Ni, Cu, and Zn were not detectable in most size fractions and did not present clear size patterns. Sea-salt elements (Ca, Na+, K+) showed a single-mode distribution and peaked at 2.5–4.4 µm. The estimated dry deposition fluxes of mineral dust for the austral summer, based on the particle-size distributions of Al measured at Palmer Station, ranged from 0.65 to 28 mg m−2 yr−1 with a mean of 5.5±5.0 mg m−2 yr−1. The estimated dry deposition fluxes of the target trace elements in this study were lower than most fluxes reported previously for coastal Antarctica and suggest that atmospheric input of trace elements through dry deposition processes may play a minor role in determining trace element concentrations in surface seawater over the continental shelf of the western Antarctic Peninsula.

Characteristics, emission sources and health risk assessment of trace elements in size-segregated aerosols during haze and non-haze periods at Ningbo, China.

To characterize trace elements from inhalable particles and to estimate human health risks, airborne particles at an urban area of Ningbo city during haze and non-haze periods from November 2013 to May 2014 were collected by a nine-stage sampler. Seventeen trace elements (Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Cd and Pb) were measured by inductively coupled plasma mass spectrometry (ICP-MS). The concentrations of trace elements are in the ranges of 0.51ngm-3 (Co) ~ 1.53µgm-3 (K) for fine particles (Dp < 2.1μm), and 1.07ngm-3 (Co) ~ 4.96µgm-3 (K) for coarse particles (2.1μm < Dp < 9.0μm) during the haze days, which are 1.15 -4.30 and 1.23- 7.83-fold as those of non-haze days, respectively. These elements could be divided into crustal elements (Na, Mg, Al, Ca, Ti, Fe and Co), non-crustal elements (Cu, Zn, Cd and Pb) and mixed elements (K, V, Cr, Mn, Ni and As) according to their enrichment factor values (EFs) and size distribution characteristics. Five emission sources of trace elements were identified by positive matrix factorization (PMF) modeling. The main sources of trace elements in fine particles are traffic emission (21.7%), coal combustion (23.6%) and biomass burning (32.1%); however, soil dust (61.5%), traffic emission (21.9%) and industry emissions (11.8%) are the main contributors for coarse particles. With the help of the multiple-path particle dosimetry (MPPD) model, it was found that deposition fractions of seventeen measured elements in the pulmonary region were in the range of 12.4%-15.1% and 6.66% -12.3% for the fine and coarse particles, respectively. The human health risk assessment (HRA) was employed according to the deposition concentration in the pulmonary region. The non-carcinogenic risk (HI) was below the safety limit (1.00). Nonetheless, the excess lifetime carcinogenic risk (ELCR) for adults increased by 2.42-fold during the haze days (2.06 × 10-5) as compared to that of non-haze days (8.50 × 10-6) in fine particles. Cr (VI) and As together contributed 96.5% and 96.3% of the integrated cancer risks during the haze and non-haze periods, respectively. Moreover, the related ELCR values in coarse particles were 36.7% and 62.8% of those in the fine particles for the non-haze period and haze period, respectively.

Geochemical characteristics of trace elements in size-resolved coastal urban aerosols associated with distinct air masses over tropical peninsular India: Size distributions and source apportionment

Trace elements in atmospheric particulate matter play a significant role in air quality, health and biogeochemical cycles. The present study reports on geochemical characteristics of size-resolved trace elements in PM10 aerosols collected under different air masses over a coastal urban location in peninsular India. A contrast in elemental distribution was observed for the particle size above 7.0 μm and below 1.1 μm under the influence of northeasterly air masses as characterized by Al > Fe > Zn and Fe > Al > Zn, respectively. The concentrations of the crustal elements (Al, Fe, Ti, P, Ba, Co) were high and illustrated by a unimodal size distribution with a peak in coarse mode (>2.0 μm) during northwesterly air masses. On the other hand, combustion-derived metals (Cu, Zn, Cd, Sb, and Pb) were maximized under northeasterly air masses, characterized by unimodal size distribution with a peak in fine mode (<2.0 μm). The enrichment factor (EF) analysis reveals the contribution of anthropogenic emissions to Cd, Sb, Pb, Zn, Cu, Cr, Ni, As, and Sn metals, particularly to the high enrichment of trace metals in fine mode. These results suggest that crustal emissions are major sources of trace metals in coarse mode aerosols; whereas combustion derived anthropogenic emissions contribute to the fine mode aerosols. The positive matrix factorization (PMF) analysis revealed that crustal sources (52–90%) were most abundant for particles >7.0 μm, whereas combustion related emissions such as vehicular and traffic sources are predominant for particles <1.1 μm. The present study demonstrates that trace metals in coastal urban aerosols are affected by changes in emission sources/strengths and regional transport of air masses originated from the northeasterly and northwesterly parts of the tropical Indian subcontinent.

Daytime concentrations of minor and trace elements in atmospheric aerosols at four sampling sites of Dar es Salaam, Tanzania

Tropospheric aerosols (total suspended particulate, TSP) were sampled at four sampling sites of various anthropogenic impact (industrial, commercial, heavy trafficked, and mixed urban influence), located in Dar es Salaam, the commercial capital of Tanzania. Air concentrations of minor and trace elements (Al, As, Br, Ca, Cd, Cl, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, S, Si, Sb, and Zn) in TSP were determined by means of wavelength-dispersive X-ray fluorescence (WDXRF) spectrometry and inductively coupled plasma atomic emission spectrometry (ICP-AES). From these data, the main ionic composition of particulate matter was inferred by means of a species correlation/ratio-derived approach, based on former studies of the region. Enrichment factors, bivariate correlations, diagnostic ratios, and chemical mass closures were calculated utilizing the concentration data of TSP constituents for each site in order to reveal the emission sources. A couple of diagnostic ratios (Ni/Cd, Zn/Cd, Br/Ni, Ni/Sb) were useful for source identification, e.g., motor vehicle exhaust and non-exhaust emissions. Significant increases in concentrations of As, Br, Cr, Cu, Mn, Ni, Pb, and Zn were observed, as compared to results for the city before 2010. Moreover, first-time air levels are reported for Cd and Sb, which are important markers of non-exhaust emissions. Air quality indices and calculations with the AIRQ+ model have foreseen increases in the negative health effects of the sensitive groups of the local population at the study areas, especially those with heavy traffic, industrial, and/or mixed urban influence.

Determination of Trace Elements in Aerosols at a Rural Mountainous Area and a Local City of Eastern Shikoku Region, Japan.

A simple digestion method for a mixed cellulose membrane filter in order to analyze trace elements in aerosols was examined. The determination of Cu, Fe and Ni in the certified reference materials of China loess (CJ-1) could be conducted using the digestion method. Trace elements in aerosols smaller than 10 μm size collected at Tokushima City and near mountain areas for each season were determined as a water-soluble fraction and all components by the digestion method. Back trajectory analysis implied that the contribution from the Asian continent was larger in the winter and spring than the summer. Systematic changes in the trace element compositions for each season were not observed, except for Fe, Th and U. Water-soluble components in aerosols at Tokushima City showed higher concentrations of all trace elements than those of the mountain areas. For aerosols in Tokushima City and near to the mountain areas, As, Bi, Cd, Cu and Pb were mainly derived from anthropogenic sources, whereas Ba, Co, Cs, Ga, Mn, Rb, Sr, Th, U and V were derived from natural crustal sources. The origin of Pb and Cd was considered based on the Pb/Cd ratio.

Welcome to the New L&amp;O: Methods Associate Editors!

Welcome to the New <i>L&amp;O</i>: <i>Methods</i> Associate Editors!

Size-segregated trace elements in continental suburban aerosols: seasonal variation and estimation of local, regional, and remote emission sources.

We have measured trace element contents in suburban aerosols from six size fractions in the range of PM0.27-16 from a background station in Belgrade (Serbia). The distribution and concentration of elements were determined within each of the investigated Dp fractions with emphasis on the fine and coarse modes. Fine/coarse mode ratios of element can provide information regarding their anthropogenic or natural origin. Analysis of seasonal variations of element contents in fine and coarse mode show that Cd, Co, K, and V have higher concentrations in the fine mode during heating season, while Fe contents are lower. In the coarse mode, Cu and V have higher concentrations during the heating season, while Al, Fe, Mg, Mn, and Sb contents are lower. We also apply a distribution probability model (normal, log-normal, and three-parameter Weibull) as new approach to estimate the distances of emission sources that can contribute to pollutant contents in particulate matter of the investigated location.

Concentrations, provenance and flux of aerosol trace elements during US GEOTRACES Western Arctic cruise GN01

The Arctic region is undergoing significant changes in climate, with a notable decrease in summertime sea ice coverage over the past three decades. This trend means an increasing proportion of Arctic Ocean surface waters can receive direct deposition of material from the atmosphere, potentially influencing marine biogeochemical cycles and delivery of pollutants to the Arctic ecosystem. Here, we present aerosol concentrations of selected trace elements (Al, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, Cd, and Pb) measured during the US GEOTRACES Western Arctic cruise (GN01, also known as HLY1502) in August–October 2015. Concentrations of “lithogenic” elements (Al, Ti, V, Mn, Fe, and Co) were similar to those measured in remote and predominantly marine-influenced air masses in previous studies, reflecting the remoteness of the Arctic Ocean from major dust sources. Concentrations of Ni, Cu, Zn, Pb, and Cd showed significant enrichments over crustal values, and were often of similar magnitude to concentrations measured over the North Atlantic in air masses of North American or European provenance. We use 7Be inventory and flux data from GN01 to estimate a bulk atmospheric deposition velocity during the study period, and combine it with our aerosol concentrations to calculate atmospheric deposition fluxes of the trace elements in the Arctic region during late summer. The resulting estimates for mineral dust and Fe deposition fall at the low end of global estimates and confirm the Arctic Ocean as a low-dust environment during the summer months.This article is part of a special issue entitled: Conway GEOTRACES - edited by Tim M. Conway, Tristan Horner, Yves Plancherel, and Aridane G. González.

Regional trends in the fractional solubility of Fe and other metals from North Atlantic aerosols (GEOTRACES cruises GA01 and GA03) following a two-stage leach

Abstract. The fractional solubility of aerosol-derived trace elements deposited to the ocean surface is a key parameter of many marine biogeochemical models. Despite this, it is currently poorly constrained, in part due to the complex interplay between the various processes that govern the solubilisation of aerosol trace elements. In this study, we used a sequential two-stage leach to investigate the regional variability in fractional solubility of a suite of aerosol trace elements (Al, Ti, Fe, Mn, Co, Ni, Cu, Zn, Cd, and Pb) from samples collected during three GEOTRACES cruises to the North Atlantic Ocean (GA01, GA03-2010, and GA03-2011). We present aerosol trace element solubility data from two sequential leaches that provide a solubility window, covering a conservative lower limit to an upper limit, the maximum potentially soluble fraction, and discuss why this upper limit of solubility could be used as a proxy for the bioavailable fraction in some regions. Regardless of the leaching solution used in this study (mild versus strong leach), the most heavily loaded samples generally had the lowest solubility. However, there were exceptions. Manganese fractional solubility was relatively uniform across the full range of atmospheric loading (32 ± 13 and 49 ± 13 % for ultra high-purity water and 25 % acetic acid leaches, respectively). This is consistent with other marine aerosol studies. Zinc and Cd fractional solubility also appeared to be independent of atmospheric loading. Although the average fractional solubilities of Zn and Cd (37 ± 28 and 55 ± 30 % for Zn and 39 ± 23 and 58 ± 26 % for Cd, for ultra high-purity water and 25 % acetic acid leaches, respectively) were similar to Mn, the range was greater, with several samples being 100 % soluble after the second leach. Finally, as the objective of this study was to investigate the regional variability in TE solubility, the samples were grouped according to air mass back trajectories (AMBTs). However, we conclude that AMBTs are not sufficiently discriminating to identify the aerosol sources or the potential effects of atmospheric processing on the physicochemical composition and solubility of the aerosols.