Trace Metals In Aerosols Research Articles

A simple approach to analysing trace metals in aerosols produced by e-cigarettes.

Electronic cigarettes are a relatively new alternative to cigarettes, which have been marketed as being safer for users than conventional cigarettes. However, they may still result in inhalation of potentially toxic or carcinogenic substances, including metals produced by the heating element. This study looked at the levels of trace metals being produced by different atomizers used in e-cigarettes using a sample introduction technique based on the collection of aerosols produced by e-cigarettes in nitric acid, using glass midget impingers. Collected metals were then identified using an inductively coupled plasma-mass spectrometer (ICP-MS), which allowed detection in the low ppb range. Results obtained showed considerable variation in the levels of metals between both manufacturers of atomizers and also between different batches of coils. This variation is likely to be even greater if the ability of users to customise some types of e-cigarettes is considered. Although there are limitations in terms of possible interferences from other metallic components in the e-cigarettes, the findings suggest the proposed method could be of use in investigating the risk of inhalation of toxic metals from e-cigarette use.

Assessment of leaching protocols to determine the solubility of trace metals in aerosols

Atmospheric deposition of aerosols to the ocean provides an important pathway for the supply of vital micronutrients, including trace metals. These trace metals are essential for phytoplankton growth, and therefore their delivery to marine ecosystems can strongly influence the ocean carbon cycle. The solubility of trace metals in aerosols is a key parameter to better constrain their potential impact on phytoplankton growth. To date, a wide range of experimental approaches and nomenclature have been used to define aerosol trace metal solubility, making data comparison between studies difficult. Here we investigate and discuss several laboratory leaching protocols to determine the solubility of key trace metals in aerosol samples, namely iron, cobalt, manganese, copper, lead, vanadium, titanium and aluminium. Commonly used techniques and tools are also considered such as enrichment factor calculations and air mass back-trajectory projections and recommendations are given for aerosol field sampling, laboratory processing (including leaching and digestion) and analytical measurements. Finally, a simple 3-step leaching protocol combining commonly used protocols is proposed to operationally define trace metal solubility in aerosols. The need for standard guidelines and protocols to study the biogeochemical impact of atmospheric trace metal deposition to the ocean has been increasingly emphasised by both the atmospheric and oceanographic communities. This lack of standardisation currently limits our understanding and ability to predict ocean and climate interactions under changing environmental conditions.

Impact of surface ocean conditions and aerosol provenance on the dissolution of aerosol manganese, cobalt, nickel and lead in seawater

Abstract Atmospheric deposition is an important pathway by which bioactive trace metals are delivered to the surface ocean. The proportions of total aerosol trace metals that dissolve in seawater, and thus become available to biota, are not well constrained and are therefore a key uncertainty when estimating atmospheric fluxes of these elements to surface waters. The aim of this study was to elucidate the main physico-chemical controls on the dissolution of the bioactive trace metals manganese (Mn), cobalt (Co), nickel (Ni) and lead (Pb). To this end, aerosol and surface seawater samples were collected in the Sargasso Sea and subsequently used in sequential seawater leach dissolution experiments to assess the role of aerosol source, seawater temperature, pH, and concentrations of dissolved oxygen and organic ligands, on aerosol trace metal dissolution. Results reveal that changes in key physico-chemical parameters in seawater leaches had little effect on the proportions of Mn, Co, Ni and Pb released from aerosols, although organic ligand amendments impacted the size distribution of aerosol-derived Mn in solution. Conversely, aerosol source and composition had the most significant effect on the dissolution of aerosol Co and Pb, with the most ‘anthropogenic’ aerosol samples displaying the highest fractional solubilities in seawater (up to 58% for Co and 112% for Pb). Fractional solubilities over the range of samples and conditions tested were in the range of 50–104% for Mn, 29–58% for Co, 40–85% for Ni and 67–112% for Pb. A large proportion (36–100%, median 89%) of the total dMn, dCo, dNi and dPb was mobilised rapidly during the first leaching step (5 min), with less dTM being released in leaches 2 through 4. Furthermore, investigation of the size distribution of the aerosol-derived trace metals in seawater showed that dissolved Pb was mostly colloidal (0.02–0.4 μm), dissolved Mn and Co were mostly soluble (

Transboundary and Local Air Pollutants in Western Japan Distinguished on the Basis of Ratios of Metallic Elements in Size-Segregated Aerosols

Trace metals in aerosols were observed at an urban site (Kumamoto, Kyushu, Japan) and a rural site (Cape Hedo, Okinawa, Japan) to investigate the relative contributions of transboundary air pollutants from mainland Asia and local air pollutants in western Japan. We used a cascade impactor to collect aerosols in five size classes. We apportioned the sources of the air masses on the basis of elemental components. Transboundary and local air pollutants were distinguished by use of the Pb/Cu and V/As ratios in selected size fractions of aerosols. The contribution of Pb (primarily from coal combustion in China) to total anthropogenic elements was greatest in spring, autumn, and winter in the 0.5–1 µm size fraction at both collection sites. The atmospheric environment at both sites was affected by this transboundary air pollutant. The contribution of Cu (primarily from local vehicle traffic) to total anthropogenic elements was greatest in all seasons in the 2.5–10 µm fraction at Kumamoto. Local air pollutants such as road dust, automobile brake abrasion, and waste incineration affected ambient air quality in Kumamoto. Because these pollutants resided mainly in the coarse aerosol fraction (> 2.5 µm), most of them were not transported to Cape Hedo in air bodies that we were able to trace to Kumamoto by backward projection. Based on our data the ambient air quality at Cape Hedo was little affected by local air pollutants emitted in the Kumamoto area.

Soluble trace metals in aerosols over the tropical south-east Pacific offshore of Peru

Abstract. Bulk aerosol samples collected during cruise M91 of FS Meteor off the coast of Peru in December 2012 were analysed for their soluble trace metal (Fe, Al, Mn, Ti, Zn, V, Ni, Cu, Co, Cd, Pb, Th) and major ion (including NO3− and NH4+) content. These data are among the first recorded for trace metals in this relatively poorly studied region of the global marine atmosphere. To the north of ∼ 13° S, the concentrations of several elements (Fe, Ti, Zn, V, Ni, Pb) appear to be related to distance from the coast. At the south of the transect ( ∼ 15–16° S), elevated concentrations of Fe, Cu, Co, and Ni were observed, and we calculated dry deposition fluxes of soluble Cu approximately an order of magnitude higher than a recent model-based estimate of total Cu deposition to the region. The model did not take account of emissions from the large smelting facilities in the south of Peru and northern Chile, and our results may indicate that these facilities constitute an important source of trace metals to the region. Calculated dry deposition fluxes (3370–17800 and 16–107 nmol m−2 d−1 for inorganic nitrogen and soluble Fe respectively) indicated that atmospheric input to the waters of the Peru upwelling system contains an excess of Fe over N, with respect to phytoplankton requirements. This may be significant as primary production in these waters has been reported to be limited by Fe availability, but atmospheric deposition is unlikely to be the dominant source of Fe to the system.

Estimation of the Atmospheric Flux of Nutrients and Trace Metals to the Eastern Tropical North Atlantic Ocean*

Abstract Atmospheric deposition contributes potentially significant amounts of the nutrients iron, nitrogen, and phosphorus (via mineral dust and anthropogenic aerosols) to the oligotrophic tropical North Atlantic Ocean. Transport pathways, deposition processes, and source strengths contributing to this atmospheric flux are all highly variable in space and time. Atmospheric sampling was conducted during 28 research cruises through the eastern tropical North Atlantic (ETNA) over a 12-yr period, and a substantial dataset of measured concentrations of nutrients and trace metals in aerosol and rainfall over the region was acquired. This database was used to quantify (on a spatial and seasonal basis) the atmospheric input of ammonium, nitrate, soluble phosphorus, and soluble and total iron, aluminum, and manganese to the ETNA. The magnitude of atmospheric input varies strongly across the region, with high rainfall rates associated with the intertropical convergence zone contributing to high wet deposition fluxes in the south, particularly for soluble species. Dry deposition fluxes of species associated with mineral dust exhibited strong seasonality, with the highest fluxes associated with wintertime low-level transport of Saharan dust. Overall (wet plus dry) atmospheric inputs of soluble and total trace metals were used to estimate their soluble fractions. These also varied with season and were generally lower in the dry north than in the wet south. The ratio of ammonium plus nitrate to soluble iron in deposition to the ETNA was lower than the N:Fe requirement for algal growth in all cases, indicating the importance of the atmosphere as a source of excess iron.

Atmospheric trace metal concentrations, solubility and deposition fluxes in remote marine air over the south-east Atlantic

Total and soluble trace metal concentrations were determined in atmospheric aerosol and rainwater samples collected during seven cruises in the south-east Atlantic. Back trajectories indicated that the samples all represented remote marine air masses, consistent with climatological expectations. Aerosol trace metal loadings were similar to previous measurements in clean, marine air masses. Median total Fe, Al, Mn, V, Co and Zn concentrations were 206, 346, 5, 3, 0.7 and 11pmolm−3 respectively. Solubility was operationally defined as the fraction extractable using a pH4.7 ammonium acetate leach. Median soluble Fe, Al, Mn, V, Co, Zn, Cu, Ni, Cd and Pb concentrations were 6, 55, 1, 0.7, 0.06, 24, 2, 1, 0.05 and 0.3pmolm−3 respectively. Large ranges in fractional solubility were observed for all elements except Co; median solubility values for Fe, Al and Mn were below 20% while the median for Zn was 74%. Volume weighted mean rainwater concentrations were 704, 792, 32, 10, 3, 686, 25, 0.02, 0.3 and 10nmolL−1 for Fe, Al, Mn, V, Co, Zn, Cu, Ni, Cd and Pb respectively (n=6). Wet deposition fluxes calculated from these values suggest that rain makes a significant contribution to total deposition in the study area for all elements except perhaps Ni.

Rapid and gradual modes of aerosol trace metal dissolution in seawater.

Atmospheric deposition is a major source of trace metals in marine surface waters and supplies vital micronutrients to phytoplankton, yet measured aerosol trace metal solubility values are operationally defined, and there are relatively few multi-element studies on aerosol-metal solubility in seawater. Here we measure the solubility of aluminum (Al), cadmium (Cd), cobalt (Co), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn) from natural aerosol samples in seawater over a 7 days period to (1) evaluate the role of extraction time in trace metal dissolution behavior and (2) explore how the individual dissolution patterns could influence biota. Dissolution behavior occurs over a continuum ranging from rapid dissolution, in which the majority of soluble metal dissolved immediately upon seawater exposure (Cd and Co in our samples), to gradual dissolution, where metals dissolved slowly over time (Zn, Mn, Cu, and Al in our samples). Additionally, dissolution affected by interactions with particles was observed in which a decline in soluble metal concentration over time occurred (Fe and Pb in our samples). Natural variability in aerosol chemistry between samples can cause metals to display different dissolution kinetics in different samples, and this was particularly evident for Ni, for which samples showed a broad range of dissolution rates. The elemental molar ratio of metals in the bulk aerosols was 23,189Fe: 22,651Al: 445Mn: 348Zn: 71Cu: 48Ni: 23Pb: 9Co: 1Cd, whereas the seawater soluble molar ratio after 7 days of leaching was 11Fe: 620Al: 205Mn: 240Zn: 20Cu: 14Ni: 9Pb: 2Co: 1Cd. The different kinetics and ratios of aerosol metal dissolution have implications for phytoplankton nutrition, and highlight the need for unified extraction protocols that simulate aerosol metal dissolution in the surface ocean.

Aerosol Trace Metal Concentrations over the Mediterranean Basin: observations through six cruise campaigns on board the CNR Research Vessel URANIA

The Mediterranean basin, due to its semi-enclosed configuration, is one of the areas heavily affected by aerosols. Despite implications on both human health and radiative budget involve an increasing interest, aerosol data are yet relatively scarce. In this work we show a dataset resulting from five ship-borne measurements performed, from 2003 to 2007, across the Mediterranean basin. Results involve daily fine (PM2.5) and coarse (PM2.5-10) particle size fraction concentrations as well as trace metal chemical analysis. According to aerosol optical properties and to chemical composition, continental aerosols, Saharan dust and maritime aerosols have been identified during the cruise campaigns. Shipping emissions, representing both local harbours and maritime traffic across the basin, were also tested using the marker ratio of V and Ni, showing a quite large contribution to the total aerosol load. Spatial variability of the aerosol concentrations resulted in a larger fine concentration over the eastern Mediterranean sector compared with that resulted in the western one mainly due to the background contribution of anthropogenic compounds.

Atmospheric trace metals over the south-west Indian Ocean: Total gaseous mercury, aerosol trace metal concentrations and lead isotope ratios

Atmospheric concentrations of trace metals (Al, Fe, Ba, Mn, Co, V, Cr, Mo, Sr, Pb, Cd, As, Zn, Cu and Ni) and major ions (Na +, Mg 2+, Ca 2+, K +, NH 4 +, Cl −, NO 3 −, SO 4 2− and oxalate) were analysed in aerosol and rain samples collected during an Indian Ocean cruise from Seychelles to Mauritius. Semi-continuous total gaseous mercury (TGM) measurements were also made during the cruise. Data for trace metals in the marine atmosphere is sparse for the southern hemisphere, particularly for Hg, and these are the first reported TGM concentrations for this part of the Indian Ocean. TGM was 1.05–1.51 ng m − 3 during the cruise (average 1.2 ng Hg m − 3 ), towards the lower end of mercury levels observed over oceans in the northern hemisphere. The TGM data appears to show a concentration gradient over the cruise with increasing concentrations at more northern locations closer to the inter-tropical convergence zone. This trend was also observed in some of the trace metals in aerosols. Air mass back trajectories suggest the air encountered had spent at least five days over the ocean prior to collection. Enrichment factors were calculated for the metals in the aerosols which suggested As, Pb, Ni, Cu, Cd, Zn and to some extent Cr were enriched above both crustal and oceanic sources. The total metal concentrations were measured in the aerosol samples along with the fraction soluble in pH 4.7 buffer and pH 1 nitric acid. For Fe these fractions were < 5% and ∼ 13% respectively. The solubility of Al and Fe was significantly higher in pH 1 nitric acid than pH 4.7 buffer, but for the other metals studied there was no significant difference. Most of the Cd, Zn and As in the aerosols was readily soluble in both pH 1 nitric and pH 4.7 buffer. Nickel, Cu and Pb solubility in these solutions was more limited (in pH 4.7 buffer 63, 72 and 69%; in pH 1 nitric acid 60, 72 and 57% respectively). Stable lead isotope ratios were also measured in the aerosol samples to investigate their origin. For most of the aerosol samples, the Pb isotopes clustered within a small range of fairly radiogenic values ( 207Pb/ 206Pb 0.84–0.85, 208Pb/ 206Pb 2.03–2.07). No significant trend was found for Pb isotopes with aerosol size fractions. The isotope ratios are consistent with an increased importance of coal combustion as a source of Pb over the Indian Ocean.

Preliminary comparison of trace metals in coastal aerosols between Qingdao and Liverpool

Aerosol samples were collected at two coastal suburban stations, Qingdao (China) in 1995–1996 and Liverpool (U.K.) in 1995, respectively. The samples were analyzed to determine the concentrations of trace metals (Cr, Zn, Cu, Co, Ni, Pb, V, and Cd) as well as Al, Fe and Mn. Data were examined to understand the difference of trace metals in aerosols between coastal zones downwind the developing area (near the Yellow Sea) and developed region (near the Irish Sea). The results show that most elements at Qingdao have levels 4–5 times higher than those at Liverpool, particularly for the crust-dominated elements (e.g. Al, Fe and Mn). Moreover, the aerosol composition at Qingdao is higher in spring than in summer, underlying the influence of westerlies and local emissions in combination, whereas seasonal change of aerosol composition is not significant at Liverpool. The enrichment factors for the crustal source elements (EFcrust) at Liverpool are much higher than those at Qingdao. The contributions from the pollutant source (Rp) for some trace metals like Cu, Pb, Zn and Cd are >90% at Qingdao and Liverpool, suggesting overwhelming anthropogenic contributions to these metals. The contributions from crustal source (Rc) for trace metals tend to increase with higher aerosol levels and Al concentration at Qingdao, indicating a good correlation between the crust-dominated component and the air mass. At Liverpool, the Rc values for trace metals are positively correlated with Al concentrations instead of with aerosol mass, suggesting that Al in aerosols represents the crustal component even though the aerosols come from different sources.

An assessment of air quality in Belgrade urban area: PM10, PM2.5and trace metals

An extensive study on urban aerosols with the aim to determine the sources and provide a physico-chemical description of PM, present in the urban air of Belgrade, was performed. Air aerosol samples for PM10and PM2.5and trace metals were collected during June 2002 to July 2005 at representative locations in urban Belgrade area. Mass concentrations of PM10and PM2.5were determined gravimetrically, concentrations of 10 elements (Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb, V and Zn) were determined with graphite furnace atomic absorption spectrometry and source identification was carried out by Principal Factor Analysis. The mean PM10mass concentration of 68.4 μg m−3exceeded the EC annual limit value of 40 μg m−3; 68 % exceedance of the proposed PM10daily limit value (50 μg m−3) was obtained and the mean PM2.5mass concentration of 61.4 μg m−3was more than 3 times the EC annual mean value of 20 μg m−3. The limit values of toxic trace elements from WHO and EC Air quality guidelines were not exceeded except for Ni. SEM/EDS analysis has been employed to individually characterize particles collected. The results of this study shows that the majority of trace metals in aerosols come from traffic emissions and traffic-induced road-dust resuspension along with industrial activities.

Trace metals in aerosol at Terra Nova Bay, Antarctica

Atmospheric particulate with an aerodynamic diameter <10 microm (PM10) was sampled continuously during the austral summers of 2000-2001 and 2001-2002 at a coastal site near to the Italian base of Terra Nova, Antarctica. Li, Pb, Cd, U, Ba, Bi, Cs, Rb, Tl, Sr, Al, V, Fe, Cu, Mn, Zn, Co, Ag were determined by inductively coupled sector field mass spectroscopy (ICP-SFMS) after sample digestion by a combination of HF, HNO3, and H2O2 in ultraclean conditions. Quality control of the analytical procedure was carried out by blank control, by evaluating the limits of detection, recoveries and repeatability. Concentrations found are extremely low for most metals, confirming the high purity of Antarctic aerosol. Principal Component Analysis (PCA) highlights high correlations among Pb, Cr, Bi, Cu and Zn concentration values and among Li, U, Ba, Cs, Rb, Al, V, Fe, Mn, Co concentration values permitting the identification of two principal source groups, namely crustal dust and human emission activities. Elements of anthropogenic origins (Pb, Cr, Cu, Zn) were highly enriched with respect to their crustal composition.

Source identification, size distribution and indicator screening of airborne trace metals in Kanazawa, Japan

The concentrations of trace metals in aerosols of different sizes in the suburban area of Kanazawa, Japan were determined with inductively coupled plasma mass spectrometry (ICP-MS). The results indicated that, among the anthropogenic elements, the ambient concentration of Zn in the total suspended particles (TSP) was the highest ( 1386 ng / m 3 ) and Cd concentration was the lowest ( 0.45 ng / m 3 ) . For the contribution of each particle size fraction to the total metal concentration in aerosols, except for V (33.6%), the “very coarse” aerosol size range ( > 11 μ m ) contributed a small mass fraction (only 4.05–11.7%). While the “coarse fraction” (11– 3.3 μ m ) had the largest mass percentage for most elements. However, the mass percentage of individual metals to the total sum of all investigated metals in each particle size range (from very coarse to very fine) was quite similar, which implied that the coagulation of airborne particles occurred in the study area due to the high humidity over the sampling period. High enrichment factor (EF) values (18.87–1139) were obtained for Zn, Cd, Pb and Cu reflecting the importance of anthropogenic inputs. In contrast, the EF values calculated for V, Ca, Mg, Mn, Sr and Co were low (1.05–15.81) suggesting that they were primarily of natural sources. The concentration ratios of natural sources derived elements (V, Ca, Mg, Mn and Sr) to Fe, and anthropogenic elements (Cd, Pb and Cu) to Zn are quite close in each particle size range, revealing that Fe can be a fine indicator for the prediction of ambient concentrations along with their size distributions of other elements mainly from natural processes, and Zn can be a favorable surrogate for assessment of air pollution resulting from volatile trace elements in this area.

Daily concentrations of trace metals in aerosols in Beijing, China, determined by using inductively coupled plasma mass spectrometry equipped with laser ablation analysis, and source identification of aerosols

This paper describes the daily concentrations of trace metals and ionic constituents in the aerosol of Beijing, China from March 2001 to August 2003. Daily PM 10 concentrations were also measured from September 2001 to August 2003. The daily average PM 10 concentration at Beijing, China from September 2001 to August 2003 was 171±117 μg m −3 ( n=673), which is 5-fold higher than at Yokohama, Japan. Trace metal concentrations were analyzed by using inductively coupled plasma mass spectrometry equipped with a laser ablation sample introduction (LA/ICP-MS), which is a rapid and simultaneous method for multi-element analysis. The daily average metal concentrations in TSP in Beijing from March 2001 to August 2003 were: Al: 3.5±2.4 ( n=727), Ti: 0.47±0.35 ( n=720), V: 0.013±0.010 ( n=716), Cr: 0.019±0.015 ( n=618), Mn: 0.24±0.16 ( n=730), Fe: 5.5±3.9 ( n=728), Co: 0.0046±0.0055 ( n=629), Ni: 0.022±0.024 ( n=680), Cu: 0.11±0.11 ( n=660), Zn: 0.77±0.60 ( n=726), As: 0.048±0.047 ( n=731), Se: 0.010±0.010 ( n=550), Cd: 0.0068±0.0082 ( n=709), Sb: 0.033±0.036 ( n=687), and Pb: 0.43±0.50 ( n=728) (unit, μg m −3). All the metal concentrations in TSP in Beijing, China were 1.7–21.8 times higher than those in TSP in the center of Tokyo, Japan. Notably, As concentrations in TSP in Beijing were 20-fold higher than those in Tokyo. Source identification of aerosols in Beijing was carried out by using the chemical mass balance (CMB) receptor model, with the daily concentration of metals in the aerosol. The major primary sources of the aerosol of Beijing were considered to be soil dust and coal combustion. Vehicle exhaust contribution tended to increase.

Seasonal variations of sulfate, carbonaceous species (black carbon and polycyclic aromatic hydrocarbons), and trace elements in fine atmospheric aerosols collected at subtropical islands in the East China Sea

In order to characterize the outflow of pollution derived aerosols from the Asian Pacific rim to the North Pacific Ocean, seasonal variations of fine aerosol components (aerodynamic diameter &lt;2 μm) were collected at two islands (Amami Island and Miyako Island) that surround the East China Sea. Monthly averaged concentrations of non‐sea‐salt SO42− (nss.SO42−) and black carbon (BC) at Amami and Miyako showed relatively high values in winter to spring and low values in summer. The observed seasonal variation is basically determined by the northwesterly monsoon in winter to spring and southeasterly wind from the stationary North Pacific anticyclone in summer. The minimum concentration levels of nss.SO42− and BC in summer were almost 2–3 times that of the North Pacific background level. Trace metals in aerosols showed similar seasonal variations observed for nss.SO42− and BC. The concentrations of nss.SO42− and Sb were highly correlated; this is in contradiction with the results at stations established in Pacific Exploratory Mission‐West ground monitoring sites. Polycyclic aromatic hydrocarbons (PAHs) also showed a pronounced maximum in winter and/or spring, with maximum concentrations comparable in magnitude to those in spring at Barrow, Alaska. Many of the low molecular weight species of PAHs had high correlation with BC, suggesting that they were either transported independently in a similar way or were transported attached to BC. Furthermore, the relative abundance of some PAH species in the present study and those found in deep‐ocean surface sediments sampled in the middle Pacific Ocean are compared and discussed.

Spatio-temporal aerosol trace metal concentrations and sources in the Levantine Basin of the Eastern Mediterranean

Abstract The current study considers the spatial and temporal variability in aerosol trace metal concentrations (Al, Fe, Mn, Cr, Cu, Pb, Cd, Zn) in the Levantine Basin of the Eastern Mediterranean, utilising an extensive sample library (n=621) collected between 1999 and 2001, at two coastal sites located at the northern, Erdemli (Turkey) and southeastern, Tel Shikmona (TS, Israel), region of the Basin. A critical evaluation of the datasets from the two locations was presented. Enhanced concentrations of Al (1.7×), Fe (1.8×), Mn (2.1×) were detected at the more southerly sampling station, during common dust events, owing to the greater proximity of desert dust sources (NE Africa and Saudi Peninsula); leading to a gradual decline in crustal inputs northwards across the basin. An insignificant Pb gradient was noticed across the Levantine Basin, which has exhibited a decadal decrease (40%). Cr was enriched in the north by a factor of three accounted by local sources. Cu was also enriched, to a lower extent, by about a factor of two. Seasonal variations of the crustal elements (Al, Fe, Mn) at Erdemli were detected (transitional>summer>winter) owing to both, a greater frequency and intensity of dust events during the transitional period and a greater washout effect during winter. It is likely that similar variations occur at TS as both sites experienced similar dust and rainfall events. It was observed at Erdemli that all elements (except Pb and Cd) exhibit their lowest concentrations in the winter period due to a greater washout effect. The lack of seasonal difference between winter and summer for Pb and Cd may have been due to the relatively high emission intensities of regional sources rapidly regenerating aerosol concentrations and their association with fine particles which are less efficiently scavenged during rain events. During the summer, Zn derived from local transportation and agricultural activities, was more pronounced, leading to an enhancement of around 10% in its concentration.

Spatial and temporal variability of trace metals in aerosol from the desert region of China and the Yellow Sea

From spring to early summer of 1995 and 1996, about 180–190 aerosol samples were collected from three observatories at Northwest China desert region (i.e., Minqin), coastal suburb area (i.e., Qingdao), and an island in the Yellow Sea (i.e., Qianliyan), respectively. The samples were analyzed to determine the concentrations of trace metals (Al, Fe, Mn, Na, Cr, Zn, Cu, Co, Ni, Pb, V, Sr, and Cd). Data are examined to understand the distribution of trace metals in aerosols at an upwind desert region and downwind marine recipient under westerly flow. The result shows that trace metal composition of aerosols vary considerably in time and space. Trace metal levels display a drastic seasonal change at both Qingdao and Qianliyan, with concentrations generally 2–3 times higher in spring than summer. Daily variation of trace metal concentrations at Minqin is more significant than Qingdao and Qianliyan, however. The enrichment factors for the crustal source (EFcrust) at Minqin are relatively low and unimportant compared with those at Qingdao and Qianliyan. Some of the trace species like Pb, Zn, and Cd have relatively high contributions from the anthropogenic source (Rp), and &gt;98% are found at Qingdao and Qianliyan, with EFcrust values 1–2 orders of magnitude higher than Minqin. Manganese is mainly from low‐temperature weathering products and the contribution from crustal source (Rc) is &gt;70% at Qingdao and Qianliyan. The coastal atmosphere responds to the episodic dust storms in the desert region (i.e., Minqin) by an increase in aerosol level and a higher concentration of crust‐dominated materials. The percentage contributions from the crustal source (Rc) of trace metals, such as Pb, Cd, and Zn, could be increased considerably by 5–10 folds higher during the passage of cold fronts than during calm weather period over the Yellow Sea.

Dry atmospheric inputs of trace metals at the Mediterranean coast of Israel (SE Mediterranean): sources and fluxes

This study presents the first detailed data on aerosol concentrations of trace metals (Cd, Pb, Cu, Zn, Cr, Mn, Fe and Al) at the SE Mediterranean coast of Israel, and assesses their sources and fluxes. Aerosol samples were collected at two sampling stations (Tel-Shikmona and Maagan Michael) along the coast between 1994 and 1997. Two broad categories of aerosol trace metal sources were defined; anthropogenic (Cd, Cu, Pb and Zn) and naturally derived elements (Al, Fe, Mn and Cr). The extent of the anthropogenic contribution was estimated by the degree of enrichment of these elements compared to the average crustal composition (EF crust). High values (median >100) were calculated for Cd, Pb and Zn, minor values for Cu and relatively low values (<10) for Fe, Mn and Cr. The crustal-derived elements exhibited a statistically significant seasonal pattern of higher concentrations during spring and autumn (e.g. Al concentrations in some cases during these periods were observed to be in excess of 1500 ng m −3). In the eastern Mediterranean basin crustal-dominated elements are enriched by 2–3 times while others (Cd and Pb) are comparable to the northwestern Mediterranean. The Pb : Cd ratios of ∼150 are higher than in coastal European sites (60–116) or emission materials (∼50). It is speculated that these differences are attributed mainly to the mixing of crustal material with local and European emissions. At present, it is impossible to quantify the latter two fractions. Back trajectory analysis and the subsequent categorization of two main aerosol populations, ‘European’ and ‘North Africa–Arabian’, exhibited a significantly different geochemical imprint on the aerosol chemical composition. ‘European’-derived air masses indicated significantly higher EF crust values for Cd and Pb due to the greater anthropogenic character of the aerosol population, with a dilution by crustal material of this population leading to comparatively lower EF crust values associated with the North African–Arabian air masses.

Source-Receptor Modeling Using Trace Metals in Aerosols Collected at Three Rural Canadian Great Lakes Sampling Stations

ABSTRACT High-volume air samplers were used to collect aerosol samples on Whatman 41 air filters at the Canadian air sampling stations Burnt Island, Egbert, and Point Petre. The samples were analyzed for trace elements by neutron activation analysis. Air concentrations of over 30 trace elements were determined. Factor analysis, elemental ratios, and enrichment factor analysis were used to determine source-receptor relationships at the three different sites. Factor analysis exhibited trends that indicate oil and coal combustion, road salt, mining, incineration, and smelting as anthropogenic sources to aerosols of the rural Great Lakes. Elemental ratios showed that the Na to Cl ratio in the Great Lakes aerosol is similar to that found in sea water. Enrichment factor analysis revealed elements with non-crustal sources including the elements Ag, As, Br, Cl, Cu, I, In, Sb, Se, Sn, W, and Zn.