Uptake of metals during chelant-assisted phytoextraction with EDDS related to the solubilized metal concentration

The use of chelants to enhance phytoextraction is one method being tested to make phytoextraction efficient enough to be used as a remediation technique for heavy metal pollution in the field. We performed pot experiments with sunflowers in order to investigate the use of the biodegradable chelating agent SS-EDDS for this purpose. We used singly and combined contaminated soils (Cu, Zn) and multimetal contaminated field soils (Cu, Zn, Cd, Pb). EDDS (10 mmol kg(-10 soil) increased soil solution metals greatly for Cu (factor 840-4260) and Pb (factor 100-315), and to a lesser extent for Zn (factor 23-50). It was found that Zn (when present as the sole metal), Cu, and Pb uptake by sunflowers was increased by EDDS, butin multimetal contaminated soil Zn and Cd were not. EDDS was observed in the sunflower roots and shoots at concentrations equal to metal uptake. The different metal uptake in the various soils can be related to a linear relationship between Cu and Zn in soil solution in the presence of EDDS and plant uptake, indicating the great importance of measuring and reporting soil solution metal concentrations in phytoextraction studies.     

Influence of the sea rush Juncus maritimus on metal concentration and speciation in estuarine sediment colonized by the plant

Metal accumulation by Juncus maritimus and the role of this plant on the physical and chemical composition of sediments, from the Douro river estuary (NW Portugal), were investigated. The contents of Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn were determined (by atomic absorption spectrophotometry) in sediments, rhizosediments (those among plant roots and rhizomes), and different plant tissues (roots, rhizomes, leaves, and stems). Metal fractionation in sediments through sequential extraction was carried out and used for interpretation of sediment/J. maritimus interactions. Two estuarine sites with different characteristics were studied: site I displayed sandy sediment with lower organic matter and metals more weakly bound to it than site II sediment, which was muddy. At both sites, higher metal contents were observed in rhizosediments than in the surrounding sediment, but metals were more weakly bound to rhizosediment. Therefore, J. maritimus markedly influenced the sediments among its roots and rhizomes, changing metal distribution and speciation. Different patterns of both metal uptake and metal distribution among J. maritimus tissues were observed at the two sites. Plant bioaccumulation was only observed for Cd, Cu, and Zn, being similar for Cd atthe two sites and significantly higher for Cu and Zn (9 and 4 times higher, respectively) at site I. In conclusion, J. maritimus was shown to have potential for phytoextraction (or phytostabilization) of Cd, Cu, and Zn in estuarine environment. However, an eventual application of J. maritimus for this purpose will require a periodic removal of the plants together with their own rhizosediment.     

Geochemistry of Cd,Cr, and Zn in highly contaminated sediments and its influences on assimilation by marine bivalves

We tested the controls of metal geochemistry in sediments collected from an extremely contaminated Chinese bay on metal assimilation by marine mussels and clams. Metal speciation in the contaminated sediments, quantified by the Tessier operational extraction method, was significantly dependent on metal concentrations in the sediments. The fractions of Cd in the easily exchangeable and carbonate phases increased, while the reducible and residue phases decreased with increasing Cd concentration. The majority (72-91%) of Cr was associated with the residue component with the remainder of Cr in the organic matter and reducible phases. Zn in carbonate phase increased, whereas in the organic matter and residue phases it decreased with increasing Zn concentration. The bioavailability of Cd, Cr, and Zn to marine green mussels (Perna viridis) and clams (Ruditapes philippinarum) was quantified using radiotracer spiked technique with concurrent measurements of speciation of spiked metals. There was a significant correlation between the Cd assimilation efficiency (AE) by both mussels and clams and Cd partitioning in the easily exchangeable and reducible phases. In contrast to previous studies, a negative correlation was found between the Cd AE and its total concentration in sediment, likely caused by the saturation of Cd binding sites in the gut or by its antagonistic interaction with a very high Zn concentration in these collected sediments. In contrast, there was no significant correlation between the AEs of Cr or Zn and any of their geochemical phases or their concentrations. The metal AEs were further quantified by experimentally manipulating different concentrations and ratios of acid volatile sulfide (AVS) and simultaneously extractable metals (SEM). There was no statistically significant relationship between the AEs of the three metals and the concentrations of AVS and SEM or [SEM-AVS]. Geochemical controls on metal assimilation from contaminated sediment are therefore only relatively apparent for Cd. The influences of metal speciation on metal bioavailability can be confounded by the degree to which sediments are contaminated with metals.     

Seasonal changes of metals in willow (Salix sp.) stands for phytoremediation on dredged sediment

Fast growing biomass plants such as Salix species are promising for use in phytoremediation of contaminated land. This study assessed the seasonal variations and changes with stand age in metal concentrations of S. fragilis L. and S. triandra L. grown in field conditions on contaminated dredged sediment substrates with comparable properties. A lesser proportion of total soil Cd was extractable by ammonium-acetate in the 6-year-old stand (6%) compared to the 1-year-old stand (17%). This suggests that the potential to remove metals from the site declines with tree age. Metal concentrations in willow biomass compartments decreased with stand age. Concentrations of Cd and Zn in leaves, wood, and bark increased toward the end of the growing season, irrespective of the species. Only Cd behavior offered limited prospects for targeting effective removal of the metal from the sediment through repeated harvest. The most efficient removal of Cd would require the combined harvest of stems and leaves; at the same time the risk of spreading Cd and Zn to the surroundings with leaf fall would be avoided.     

Adsorption of several metal ions onto a low-cost biosorbent: kinetic and equilibrium studies

Sugar beet pulp generated by sugar-refining factories has been shown to be an effective adsorbent for the removal of heavy metals from aqueous solutions. The structural components related to the metallic adsorption being determined, batch adsorption studies were performed for several metal ions, namely, Pb2+, Cu2+, Zn2+, Cd2+, and Ni2+ cations. Two simple kinetic models, that is, pseudo-first- and pseudo-second-order, were tested to investigate the adsorption mechanisms. The kinetic parameters of the models were calculated and discussed. For an 8 x 10(-4) M initial metal concentration, the initial sorption rates (v0) ranged from 0.063 mmol x g(-1) x min(-1) for Pb2+ to 0.275 mmol x g(-1) x min(-1) for Ni2+ ions, in the order Ni2+ > Cd2+ > Zn2+ > Cu2+ > Pb2+. The equilibrium data fitted well with the Langmuir and Freundlich models and showed the following affinity order of the material: Pb2+ > Cu2+ > Zn2+ > Cd2+ > Ni2+. The metal removal was strongly dependent on pH and, to a lesser extent, ionic strength. Ion exchange with Ca2+ ions neutralizing the carboxyl groups of the polysaccharide was found to be the predominant mechanism, added with complexation for Pb2+, Cu2+, and Zn2+ metals.     

Determination of heavy metals (Cd,Pb) and trace elements (Cu,Zn) in sediments and fish of the Southeastern Aegean Sea (Turkey) by atomic absorption spectrometry

The Bay of Güllük in Southeastern Aegean Sea (Turkey) is very important by the potential of marine product in the Aegean Sea. There are various polluting elements in Güllük Bay. The current situation of the bay and impact of pollutants have became necessity. Dicentrarchus labrax are frequently used for human consumption. In this study, heavy metals (Pb, Cd) and trace elements (Cu, Zn) were analyzed in fish (D. labrax) and sediments in the Bay of Güllük by atomic absorption spectrometry. The average metal concentrations in the fish varied in the following ranges: Pb; <0.02–0.4, Cd; <0.01–0.04, Cu; <0.1, Zn; <0.5–7.2 mg kg⁻¹. In addition, seven sediment samples were analyzed and avarage concentrations of them were found as Zn; 80.8 ± 0.45, Cu; 25.2 ± 0.14, Pb; 20.0 ± 2, Cd; 0.560.08 mg kg⁻¹. The accuracy and precision of our results were checked by using International Certified Reference samples (fish: DORM-2, sediment: HISS-1).     

A field experiment to determine the relative importance of prey and water as sources of As, Cd, Co, Cu, Pb, and Zn for the aquatic invertebrate Sialis velata

We measured the relative importance of water and food as sources of the trace elements As, Cd, Co, Cu, Pb, and Zn for larvae of the benthic insect Sialis velata. To achieve this end, we first exposed its prey, the midge Chironomus riparius, to trace elements in a contaminated lake located near a nonferrous metal smelter in northwestern Quebec. Concentrations of five of the six trace elements reached a steady state in prey within one week. When predators were exposed to these contaminated prey, their trace element concentrations increased markedly for all of the trace elements studied. In contrast, exposure of S. velata to contaminated lake water led to no significant increase in their concentrations of five of the six trace elements ([Pb] increased only slightly). Additional treatments in which the predator was exposed to these trace elements in both food and water or in a combination of food and water and sediment did not lead to further increases in its contaminant concentrations beyond those measured in the food-only treatment. We conclude that food (prey) is the almost exclusive source of As, Cd, Co, Cu, and Zn for S. velata and that it is the source of 94% of its Pb. Model curves for trace element accumulation over time by the predator fit our measured data well, and trace element concentrations in food alone are sufficient to model the exchange of these contaminants in this insect.     

Critical evaluation of desorption phenomena of heavy metals from natural sediments

In natural sediments, the majority of heavy metal ions are generally associated with the solid phase. To become bioavailable, the metal ions must desorb from the solid. Numerous studies of heavy metals in sediments have suggested that sorption and desorption exhibit hysteresis (i.e., the two processes are not reversible), while other studies have suggested that desorption hysteresis does not exist. In this study, sorption/desorption hysteresis of lead (Pb) and cadmium (Cd) was evaluated over the following range of conditions: (i) desorption induced by replacing the supernatant liquid with contaminant-free electrolyte solution; (ii) desorption induced by lowering the solution pH with mineral acid; and (iii) desorption induced by sequestration with EDTA. Given the importance of dissolved organic and inorganic ligands in regulating heavy metal behavior in nature sediments, sorption/desorption experiments were conducted on both untreated and prewashed sediments. Prewashing treatment increases the sorption potential of Cd but not Pb. Desorption hysteresis is observed in both the untreated and the prewashed sediments using the replaced supernatant method, and the desorption hysteresis appears to increase with aging time. Hysteresis is not observed when desorption is initiated by lowering the solution pH. A large fraction of the sorbed heavy metal ions can be easily desorbed by EDTA; between 0.04 and 1.2 mmol/kg Cd and Pb ions are resistant to desorption.     

北京地区池塘底泥中重金属分布及其污染评价

目的针对北京地区17家养殖池塘底泥中重金属污染状况进行调查及评价重金属生态风险,为水产养殖环境提供理论依据并指导生产。方法使用原子吸收分光光度法测定底泥中Cu、Zn、Cr、Pb、Cd含量,用原子荧光分光光度法测定底泥中Hg、As含量;采用单项污染指数、综合污染指数法及Hakanson潜在生态风险评价方法对养殖池塘底泥中重金属的污染状况分别进行评价。结果 17家池塘底泥中重金属Cu、Zn、Cr、Pb、Cd、As的平均含量分别为17.85、50.27、33.09、14.50、0.06和1.98mg/kg(均以湿基计),Hg未检出;Zn、Pb、Cd、Hg和As处于安全等级,Cu污染处于警戒线,Cr污染处于轻度污染;底泥中重金属的潜在生态风险顺序依次CdCuPbAsCrZn,潜在生态风险危害程度轻微。结论北京地区17家养殖场池塘底泥中重金属含量的蓄积对养殖水产品质量影响较小,适宜水产养殖。     

Chemical speciation of Zn,Cd, Cu,and Pb in pore waters of agricultural and contaminated soils using Donnan dialysis

Knowledge of trace metal speciation in soil pore waters is important in addressing metal bioavailability and risk assessment of contaminated soils. Numerous analytical methods have been utilized for determining trace metal speciation in aqueous environmental matrixes; however, most of these methods suffer from significant interferences. The Donnan dialysis membrane technique minimizes these interferences and has been used in this study to determine free Zn2+, Cd2+, Cu2+, and Pb2+ activities in pore waters from 15 agricultural and 12 long-term contaminated soils. The soils vary widely in their origin, pH, organic carbon content, and total metal concentrations. Pore water pM2+ activities also covered a wide range and were controlled by soil pH and total metal concentrations. For the agricultural soils, most of the free metal activities were below detection limit, apart from Zn2+ for which the fraction of free Zn2+ in soluble Zn ranged from 2.3 to 87% (mean 43%). Five of the agricultural soils had detectable free Cd2+ with fractions of free metal ranging from 59 to 102% (mean 75%). For the contaminated soils with detectable free metal concentrations, the fraction of free metal as a percentage of soluble metal varied from 9.9 to 97% (mean 50%) for Zn2+, from 22 to 86% (mean 49%) for Cd2+, from 0.4 to 32.1% (mean 5%) for Cu2+, and from 2.9 to 48.8% (mean 20.1%) for Pb2+. For the contaminated soils, the equilibrium speciation programs GEOCHEM and WHAM Model VI provided reasonable estimates of free Zn2+ fractions in comparison to the measured fractions (R2 approximately 0.7), while estimates of free Cd2+ fractions were less agreeable (R2 approximately 0.5). The models generally predicted stronger binding of Cu2+ to DOC and hence lower fractions of free Cu2+ as compared with the observed fractions. The binding of Cu2+ and Pb2+ to DOC predicted by WHAM Model VI was much strongerthan that predicted by GEOCHEM.     

冀东典型蔬菜种植区设施土壤重金属特征

目的探究冀东典型蔬菜种植区(唐山市和承德市)设施土壤重金属特征。方法对设施大棚进行调查并采集表层土壤样品,检测其重金属,即镉(Cd)、汞(Hg)、砷(As)、铅(Pb)、铬(Cr)、铜(Cu)、锌(Zn)含量,并依据HJ/T 333—2006《温室蔬菜产地环境质量评价标准》进行了土壤质量评价。结果除As外,其他重金属均超过河北省土壤背景值(国家环境保护局),最高为Hg,为背景值的3.46倍。Cd与棚龄呈显著负相关关系(P<0.05)。从地理分布来看,Hg呈现西高东低的分布特征,而As、Pb则呈现南高北低的分布特征。从重金属单项质量指数来看,Cd、Hg、As、Cr、Zn均未超标;Cu、Pb超标率分别为7.37%和22.11%,属轻度污染。从重金属综合质量指数看,3.16%的土壤为超标土壤,属轻度污染,超标率较高的区县为隆化县、乐亭县、滦平县、宽城县和滦南县,重金属综合质量指数与土壤pH呈极显著负相关关系(P<0.01)。结论冀东典型蔬菜种植区设施土壤存在Cu、Pb的轻度污染现象,后续需要对蔬菜中的Cu、Pb进行调查以评估蔬菜产品的安全性。     

Voltammetric determination of heavy metals in meat and the internal organs of slaughter cattle

The most important uptake of heavy metal by man occurs through ingestion. Therefore heavy metal analysis of food becomes of great importance. The whole analytical procedure including sampling, transport, drying, homogenisation, digestion and measurement for the determination of Zn, Cd, Pb, Cu, Ni, and Co in meat is described with due consideration given to the requirements for trace and ultratrace analysis. The particular advantages of the voltammetric approach for heavy metal determinations in meat and meat products are generally featured by this study. A standard deviation of 3-5% RSD in the microgram/g-range and 5-10%-RSD in the ng/g-range was obtained. In order to check the accuracy of the results, mixtures of sample and standard reference material were analysed. While the Cd-content in meat is in the range of 1 ng/g (wet weight) it increases in organs, such as liver (100-500 ng/g wet weight) and kidney (600-2000 ng/g wet weight). Pb shows a similar behaviour. The levels of these elements were found to be below the maximum allowable limits set by the "Bundesgesundheitsamt", with the exception of Cd in the kidneys. There is a statistical significant correlation between the Cd and Pb contents in liver and kidney. In liver the Cu content was especially high, because there are Cu-containing enzymes in this organ. Vitamin B12 is a Co containing complex in the liver. Therefore the Co values in liver are clearly higher than those in muscle meat.     

夏枯草中7种重金属元素的测定及污染等级分析

目的 检测夏枯草中铅、镉、汞、砷、铜、锌、铬的含有量,并进行污染等级分析。方法 夏枯草中的7种重金属元素经电感耦合等离子体质谱测定,采用单项指数法和综合指数法对其进行污染等级分析。结果 7种重金属元素在各自浓度范围内呈良好线性,样品加标回收率为84.5%～109.5%,RSD为2.3%～5.1%。将测得的重金属元素结果与《中华人民共和国药典》2020年版等标准规定的限量值进行比较,19批样品中铬元素超标、7批样品中锌元素超标,超标率分别为100.0%、36.8%,其余重金属元素含量均未超标,单项指数从大到小排序为铬、锌、镉、汞、铜、砷、铅,综合污染等级均值为轻度污染及以上。结论 夏枯草主要受铬元素污染,其次是锌元素;该实验可为夏枯草中重金属元素限量标准的起草提供基础数据。     

The effects of season and sex in the metal levels of mature common cuttlefish (Sepia officinalis) in Mersin Bay, Northeastern Mediterranean

The effects of sex and season on metal levels of the mantle of the common cuttlefish that was caught from Mersin Bay were evaluated. The annual range of mantle length (ML), total length (TL), and weight of common cuttlefish specimens were 110 to 183 mm, 380 to 581 mm, and 150.24 to 477.13 g, respectively. The annual range of metal levels in the mantle tissue of common cuttlefish were: 2.34 to 3.89 μg Cd g(-1), 0.30 to 0.63 μg Cr g(-1), 0.15 to 0.54 μg Pb g(-1), 2.35 to 14.90 μg Cu g(-1), 23.22 to 51.88 μg Zn g(-1), and 5.12 to 10.65 μg Fe g(-1). Cu levels of females were significantly higher (P < 0.05) than those found in male throughout all the seasons while Pb levels were lower (P < 0.05) in males than females. Cr levels in the mantle tissue of cuttlefish did not change throughout the seasons. On the contrary, Cd, Pb, Cu, Zn, and Fe levels in the mantle tissue of cuttlefish changed throughout all the seasons. The highest Cd, Zn, and Fe levels were obtained in spring while the highest Cu levels were obtained in autumn. It was also found out that this species was rich in terms of metal levels, particularly, Cd, Cu, Zn, and Fe. It was found out that the mantle tissue of the common cuttlefish, Sepia officinalis, which was caught from Mersin Bay, was contaminated with Cd in all the seasons.     

江西抚州烟区土壤及烟叶重金属污染状况评价

为了弄清江西抚州烟区土壤和烟叶中As、Cd、Cr、Cu、Ni、Pb、Zn和Hg等重金属含量和污染状况,运用内梅罗指数和相关分析法,对这些重金属元素在土壤和烟叶中的含量进行了测定。结果表明,该烟区土壤中重金属含量总体上低于我国土壤二级标准（GB15618-1995）,但其污染程度已处于警戒线水平,Cd和Hg为烟区土壤主要风险因子。土壤和烟叶中重金属含量顺序分别为Zn> Pb> Cr> Cu> Ni> As> Cd> Hg和Zn> Cu> Pb> Cd> Cr> Ni> As> Hg,土壤中Hg、Cd、As和烟叶中Ni、Cr变异系数均较大。烟叶中重金属富集系数顺序为Cd> Zn> Cu> Hg> Ni> Cr> Pb> As,烟叶Cd富集系数高达11.67,表明烟草属于Cd强烈富集作物。     

Cu and Zn concentration gradients created by dilution of pH neutral metal-spiked marine sediment: a comparison of sediment geochemistry with direct methods of metal addition

The geochemistry of artificially metal contaminated sediments prepared using three methods of metal-spiking was compared in this study. Marine sediments with a gradient of Cu and Zn concentrations were prepared by direct-spiking without and with pH-adjustment to pH 7, and also by serial dilution of direct-spiked sediment (4000 microg g(-1), pH 7 adjusted) with uncontaminated sediment. Porewater concentrations of Cu, Zn, Fe, and Mn in direct-spiked sediments without pH adjustment were orders of magnitude higher than the equivalent sediments adjusted to pH 7 or those prepared by the serial dilution method. Despite pH-adjustment, porewater Cu and Zn concentrations of direct-spiked sediment remained higher than concentrations observed within metal-contaminated natural sediment. The serial dilution of metal-spiked, pH-adjusted sediment substantially decreased Cu and Zn partitioning to the dissolved phase, and minimized the variation of potential competitive ions (H+, Fe2+, Mn2+) over the entire gradient of spiked Cu and Zn concentrations. Metal concentration gradients created using serial dilution of Cu- and Zn-spiked, pH-adjusted sediments produced porewater Cu or Zn, Fe, and Mn concentrations that resemble sediment-porewater partitioning (Cu, Zn, Fe, Mn) typical of metal-contaminated natural sediments. This method is recommended for whole-sediment toxicology studies.     

Are accumulated sulfide-bound metals metabolically available in the benthic oligochaete Tubifex tubifex?

The present study evaluates the relationship between metal-binding sediment characteristics like acid volatile sulfides (AVS), metal accumulation, and internal metal distribution in the benthic oligochaete Tubifex tubifex and relates this accumulation to the induction of metallothionein-like proteins (MTLPs). In total, 15 Flemish lowland rivers were sampled. Cd, Cu, Zn, Pb, Ni, As, Cr, Co, and Ag concentrations were measured in environmental fractions (water and sediment) and worm tissue (both total and subcellular fractions). Furthermore, total cytosolic MTLP concentrations were measured in the worm tissue. Our results showed that Cd, Pb, Ni, and Cr were mainly stored as biological detoxified metal (BDM) while Cu, Zn, As, and Ag were mostly available in the metal sensitive fraction (MSF). A remarkable difference in the subcellular distribution of accumulated Cd, Ni, and Co between anoxic (SEMMe-AVS<0; mostly stored as BDM) and oxic (SEMMe-AVS>0; mostly stored in the MSF) sediments was noticed. Moreover, a rapid increase in MTLP induction was found when SEMTot-AVS>0. Our results indicate that the accumulated sulfide-bound metals were detoxified and little available to the metabolism of T. tubifex under anoxic conditions.     

长期沼液灌溉对槟榔芋根区土壤理化性质及重金属含量的影响

目的 探究施用沼液对槟榔芋根区土壤理化性质及重金属含量的影响。方法 采集连续施用沼液6年和未施用沼液的槟榔芋种植地块土壤, 测定土壤中Cu、Zn、Pb、Cd、Cr、Hg、As共7种重金属的含量并进行污染风险评价, 同时测定土壤的基本理化指标, 分析土壤中重金属含量与土壤理化性质间的相关性。结果 长期沼液灌溉会显著增加槟榔芋根区土壤中有机质、碱解氮和速效钾含量, 但也会导致土壤中Cu、Zn、Pb、Cd、Cr显著累积, 尤其Cu和Zn含量均超出了GB 15618—2018中规定的风险筛选值。连续施用沼液增加了土壤重金属的综合污染水平和潜在生态风险, 总体呈现轻度污染等级, 具有中等水平的潜在生态风险, 其中Cu对综合污染水平的贡献率最大, Cd和Hg对综合潜在生态风险的贡献率最大。土壤中Cu、Zn、Pb、Cd、Cr之间可能存在污染同源性, 其含量基本与土壤有机质、碱解氮和速效钾呈极显著正相关, 与速效磷呈显著负相关。结论 沼液还田虽然会提高槟榔芋根区土壤整体养分状况, 但长期沼液灌溉也增加了土壤重金属的污染风险, 尤其是Cu、Cd、Hg可能引起的污染问题要引起重视。     

Experimental measurement of proton, Cd, Pb, Sr, and Zn adsorption onto the fungal species Saccharomyces cerevisiae

Proton, Cd, Pb, Sr, and Zn adsorption onto the fungal species Saccharomyces cerevisiae were measured in bulk adsorption experiments as a function of time, pH, surface: metal ratio, and ionic strength, and we measured the electrophoretic mobility of the cells as a function of pH. We modeled the acid/base properties of the fungal cell wall by invoking a nonelectrostatic surface complexation model with four discrete surface organic acid functional group types, with average pKa values (with 1 sigma uncertainties) of 3.4 +/- 0.4, 5.0 +/- 0.2, 6.8 +/- 0.4, and 8.9 +/- 0.6. The affinity of the fungal cells for the metal ions follows the following trend: Pb > Zn > Cd > Sr. We used the metal adsorption data to determine site-specific stability constants for the important metal fungal surface complexes. Our results suggest that S. cerevisiae may represent a novel biosorbent for the removal of heavy metal cations from aqueous waste streams.     

Concentration and distribution of heavy metals in urban airborne particulate matter in Frankfurt am Main, Germany

Heavy metal concentrations were measured in airborne dust collected at three sites with different traffic densities from August 2001 to July 2002 in the Frankfurt am Main area. Bulk samples of particulate matter (PM) with an aerodynamic equivalent diameter of <22 microm were collected on cellulose nitrate filters using air filtration devices. Fractionated samples of PM with an aerodynamic equivalent diameter of <10 microm were collected using an eight-stage Andersen impactor. Pb, Cd, Mn, Ni, Zn, V, As, Sb, Cu, Cr, Co, and Ce were determined by inductively coupled plasma sector field mass spectrometry, Pt and Rh were determined by adsorptive voltammetry, and Pd was determined by total reflection X-ray fluorescence analysis. The results show that the highest airborne heavy metal concentrations occurred at the main street with a large volume of traffic. With the exception of Co, V, Ce, and Mn, the heavy metals had an elevated enrichment factor compared to their concentrations in the continental crust. The main street site was especially contaminated with Sb, Zn, Cu, V, and Ni. Motor vehicles are the likely source of emissions. With the exception of Cr, Cu, and Zn, most of the airborne heavy metal concentrations determined for impactor samples deviate slightly from the results for total airborne dust. Heavy metal particle size distributions can be divided into three groups. For metals such as As, Cd, Pb, and V, the main fraction can be found in fine particles with a diameter of <2.1 microm, whereas Ce, Cr, Co, and Ni occur mainly in coarse particles with a diameter of >2.1 microm. Cu, Mn, Sb, Zn, Pt, Pd, and Rh occur in high concentrations in the medium range of the impactor stages (particle diameters of 1.1-4.7 microm). Metal concentrations in fine dust particles are needed to assess the human health risks of their inhalation.