Major Source Of Pb Research Articles

Size distributions and sources of elements in particulate matter at curbside, urban and rural sites in Beijing

Abstract Size distributions of 29 elements in aerosols collected at urban, rural and curbside sites in Beijing were studied. High levels of Mn, Ni, As, Cd and Pb indicate the pollution of toxic heavy metals cannot be neglected in Beijing. Principal component analysis (PCA) indicates 4 sources of combustion emission, crust related sources, traffic related sources and volatile species from coal combustion. The elements can be roughly divided into 3 groups by size distribution and enrichment factors method (EFs). Group 1 elements are crust related and mainly found within coarse mode including Al, Mg, Ca, Sc, Ti, Fe, Sr, Zr and Ba; Group 2 elements are fossil fuel related and mostly concentrated in accumulation mode including S, As, Se, Ag, Cd, Tl and Pb; Group 3 elements are multi-source related and show multi-mode distribution including Be, Na, K, Cr, Mn, Co, Ni, Cu, Zn, Ga, Mo, Sn and Sb. The EFs of Be, S, Cr, Co, Ni, Cu, Ga, Se, Mo, Ag, Cd, Sb, Tl and Pb show higher values in winter than in summer indicating sources of coal combustion for heating in winter. The abundance of Cu and Sb in coarse mode is about 2-6 times higher at curbside site than at urban site indicating their traffic sources. Coal burning may be the major source of Pb in Beijing since the phase out of leaded gasoline, as the EFs of Pb are comparable at both urban and curbside sites, and about two times higher in winter than that in summer.

Impact of Land-Use Patterns on Chemical Properties of Trace Elements in Soils of Rural, Semi-Urban, and Urban Zones of the Niger Delta, Nigeria

The study of the concentrations of Cr, Zn, Cd, Pb, Ni, and Cu in soils under different land uses in rural, semi-urban, and urban zones in the Niger Delta was carried out with a view to providing information on the effects of the different land uses on the concentrations of trace elements in soils. Our results indicate significant variability in concentrations of these metals in soils under different land uses in rural, semi-urban, and urban zones. The maximum concentrations of metals in the examined soil samples were 707.5 mg.kg−1, 161.0 mg.kg−1, 2.6 mg.kg−1, 59.6 mg.kg−1, 1061.3 mg.kg−1, and 189.2 mg.kg−1 for Cr, Zn, Cd, Pb, Ni, and Cu, respectively. In the rural zone, the cassava processing mill is a potent source of Ni, Cr, Cu, and Zn while agricultural activities are a source of Cd, and automobile emissions and the use of lead oxide batteries constitute the major sources of Pb. In the urban zone, soils around the wood processing mill showed elevated concentrations of Cu, Cr, Zn, and Ni, while soils around automobile mechanic works and motor parks showed elevated levels of Pb. Elevated Cd concentrations were observed in soils under the following land uses: urban motor park, playground, welding and fabrication sheds, and metallic scrap dump. The contamination/pollution index of metals in the soil follows the order: Ni > Cd > Cr > Zn > Cu > Pb. The multiple pollution index of metals at different sites were greater than 1, indicating that these soils fit into “slight pollution” to “excessive pollution” ranges with significant contributions from Cr, Zn, Cd, Ni, and Cu.

Lead concentrations in fine particulate matter after the phasing out of leaded gasoline in Xi’an, China

Daily concentrations of lead (Pb) were determined for PM 2.5 samples collected from an urban location in Xi’an, China from 2007 to 2009 to assess the effects of the phasing out of leaded gasoline in 2000. The Pb concentrations (annual average: 0.306 μg m −3 , range: below detection limit to 2.631 μg m −3 ) have declined after the phasing out of leaded gasoline, but the concentrations were still higher than those reported in many other cities. Seasonal variations of Pb were significant, with high concentrations in winter, presumably due to the burning of coal, and low concentrations in summer, due to a deep mixed layer and scavenging of aerosols by precipitation. Correlation analyses and enrichment factor calculations both indicated that anthropogenic sources had a large influence on atmospheric Pb. The lead isotope ratios were low in winter (the average 207 Pb/ 206 Pb ratio was 0.843 ± 0.032; 208 Pb/ 206 Pb was 1.908 ± 0.058) and high in summer ( 207 Pb/ 206 Pb was 0.860 ± 0.032; 208 Pb/ 206 Pb was 2.039 ± 0.057), suggesting that coal combustion was the major Pb source in winter and vehicular emission was the major Pb source in summer. Positive Matrix Factorization receptor model indicated that there were five major sources for Pb in PM 2.5 . Coal combustion was the major contributor, accounting for 39.0% PM 2.5 mass, followed by vehicular emissions (30.4%). Other contributors included 17.8% from industrial emissions, 11.6% from biomass burning, and 1.2% from fugitive dust. ► Pb concentrations (average: 0.306 μg m −3 during 2007–2009) have declined after the phasing out of leaded gasoline. ► Pb concentrations in Xi’an are still higher than those reported in many other cities. ► Coal combustion was the strongest source for PM 2.5 Mass (39.0%).

A 3500-Year Record of Hg and Pb Contamination in a Mediterranean Sedimentary Archive (The Pierre Blanche Lagoon, France)

A sediment core encompassing 3500 years of continuous sedimentation has been collected from a coastal lagoon located on the southwestern French Mediterranean coast. Lead concentrations and stable isotopes show that the sediments have recorded the three major periods of Pb pollution: the Etruscan-Greek-Roman period (650 BC to AD 50), the medieval period (AD 650 to AD 1450), and the modern period (from around AD 1850 to the present). These periods were separated by low pollution periods during the Dark Ages (between AD 50 and 650) and during the 16th century. From the end of the 19th century to the 1960s, Pb pollution increased exponentially. Coal combustion was the major source of Pb in the lagoon in the second half of the 20th century. Both the decrease in coal consumption and the ban on leaded gasoline resulted in a decrease in Pb pollution by a factor of 1.5 between 1973 and 1995. From 1991, sewage treatment plants and incinerators could be the major source of Pb. The average baseline Hg concentration from 1525 BC to AD 900 was 0.017 ± 0.003 μg g⁻¹ (n = 54). The Hg concentrations profile shows three major peaks: in AD 1150, AD 1660, and AD 1969, with the concentrations being respectively 8, 5, and 34 times higher than the baseline levels. The medieval peak (AD 1150) is attributed the medical use of Hg in the town of Montpellier and/or the burning of soil and vegetation. Noticeable Hg pollution was also detected during the 17th century in relation to gold and silver amalgamation in Europe. From the end of the 19th century, Hg concentrations increased exponentially until 1969. This modern pollution is attributed to the burning of coal.

Deposition and migration of atmospheric Pb in soils from a forested silicate catchment today and in the past (Strengbach case): Evidence from 210Pb activities and Pb isotope ratios

210Pb activities, Pb isotope ratios and elemental abundances of leachates from soils were determined to identify the origin of atmospheric Pb and characterize its migration in mineralogically and chemically different soil systems of a forested silicate catchment. Leaching experiments were performed to separate the leachable, mobile reservoir of the soil system – mainly containing atmosphere derived Pb – from that of the residual bedrock reservoir. Pb isotope data allow recognition of an evolution in the soil leachates with increasing depth pointing to at least two major Pb sources. Surface samples collected in 2001 show a Pb isotopic signature which is comparable with that of particulate matter (PM) collected in 1995 and 2005/2006 in an urban environment close to the catchment and hence corresponds to a very recent isotopic signature of the atmosphere. The more radiogenic Pb isotopic signature in soil leachates from 30 to 40 cm depth corresponds to older airborne Pb probably derived from historical mining and smelting close to the catchment (< 5 km). 210Pb inventories confirm trace element data and indicate that the soils are important sinks of atmospheric Pb in the uppermost part (40 cm) of the soil profile. The migration speeds derived from these inventories for the different depths (0.5 cm y − 1 , 0.2 cm y − 1 , 1.6 cm y − 1 ) suggest that the atmospheric Pb needs less than 150 years to reach the depth of 40 cm. Thus, the Pb enrichments above this depth might be related to a period of local mining activities which ceased in the mid-20th century. The soil solutions are not in isotopic equilibrium with the corresponding soil leachates. Soil solutions from 5 to 60 cm depth have Pb isotopic compositions similar to those of stream and spring waters and soil leachates from 10 to 20 cm depth. They carry a Pb with current atmospheric Pb isotopic compositions. The presence of anthropogenic Pb in spring waters might suggest that some of it migrated rather quickly through the soils.

Isotopic evidence for the source of lead in the North Pacific abyssal water

The absence of accurate measurements of lead (Pb) isotopic composition in the North Pacific abyssal water has made it difficult to assess the relative importance of what are believed to be the two major Pb sources: the natural Pb introduced during preindustrial time and recent anthropogenic Pb resulting from leaded gasoline combustion and high temperature industrial activities. Here we report a vertical profile of seawater 206Pb/ 207Pb ratio and a meridional section of Pb concentration in the North Pacific Ocean. We observe 2–3-fold increases in Pb concentration along the deep-water flow path and a deep-water 206Pb/ 207Pb ratio (∼1.188) substantially lower than the pre-industrial value (∼1.210). These data suggest that anthropogenic Pb has invaded the North Pacific abyssal water and become the predominant Pb source there. A simple model calculation based on these data indicates that the anthropogenic Pb is transported to the deep ocean by sinking particles and that this Pb vertical flux has a 206Pb/ 207Pb ratio that decreased during the past two centuries.

Heavy Metal Distribution in Soils near the Almalyk Mining and Smelting Industrial Area, Uzbekistan

Abstract:The present study demonstrates distribution and chemical forms of heavy metals in soils of the Almalyk mining and smelting industrial area along five transects. The study area is located in Almalyk, Uzbekistan, where the intensification of industrial enterprises negatively impacts the environment. The distribution of 17 heavy metals (Cu, Zn, Pb, Sc, V, Cr, Co, Ni, Ga, Rb, Sr, Y, Zr, Nb, Ba, Th, and U) were studied in 21 sampling locations (21×3=63 soil samples) along five radial transects with a total length of 60 km downwind deposition gradient. Soil samples were collected from the upper layer (0–10 cm) at 4–6 km intervals. As a result of X‐ray fluorescence spectrometry analyses by using X‐ray fluorescence spectroscopy (XRF, Philips Analytical Ink, USA), a significant decrease in heavy metal (Cu, Zn, Pb) deposition was found going from the source in a downwind direction. Soil samples taken from the first location (near the pollution sources) showed higher concentrations of Cu, Zn and Pb, and lower concentrations with increasing distance from the source. Obtained data showed different impact of pollution sources to heavy metal deposition and distribution in soils. The Almalyk mining and smelting complex is the major source of Pb, Zn and Cu enrichment in soils. Distribution of other trace elements does not exceed background content and suggests lithogenic background. This allowed us to divide these elements into two groups: (1) technogenic (Cu, Zn and Pb); and (2) lithogenic (Sc, V, Cr, Co, Ni, Ga, Rb, Sr, Y, Zr, Nb, Ba, Th and U) origins.

Characterization of Aerosols Containing Zn, Pb, and Cl from an Industrial Region of Mexico City

Recent ice core measurements show lead concentrations increasing since 1970, suggesting new nonautomobile-related sources of Pb are becoming important worldwide (1). Developing a full understanding of the major sources of Pb and other metals is critical to controlling these emissions. During the March, 2006 MILAGRO campaign, single particle measurements in Mexico City revealed the frequent appearance of particles internally mixed with Zn, Pb, Cl, and P. Pb concentrations were as high as 1.14 microg/m3 in PM10 and 0.76 microg/m3 in PM2.5. Real time measurements were used to select time periods of interest to perform offline analysis to obtain detailed aerosol speciation. Many Zn-rich particles had needle-like structures and were found to be composed of ZnO and/or Zn(NO3)2 x 6H2O. The internally mixed Pb-Zn-Cl particles represented as much as 73% of the fine mode particles (by number) in the morning hours between 2-5 am. The Pb-Zn-Cl particles were primarily in the submicrometer size range and typically mixed with elemental carbon suggesting a combustion source. The unique single particle chemical associations measured in this study closely match signatures indicative of waste incineration. Our findings also show these industrial emissions play an important role in heterogeneous processing of NO(y) species. Primary emissions of metal and sodium chloride particles emitted by the same source underwent heterogeneous transformations into nitrate particles as soon as photochemical production of nitric acid began each day at approximately 7 am.

Tracing Source Pollution in Soils Using Cadmium and Lead Isotopes

Tracing the source of heavy metals in the environment is of key importance for our understanding of their pollution and natural cycles in the surface Earth reservoirs. Up to now, most exclusively Pb isotopes were used to effectively trace metal pollution sources in the environment. Here we report systematic variations of Cd isotope ratios measured in polluted topsoils surrounding a Pb-Zn refinery plant in northern France. Fractionated Cd was measured in soil samples surrounding the refinery, and this fractionation can be attributed to the refining processes. Despite the Cd isotopic ratios being precisely measured, the obtained uncertainties are still large compared to the total isotopic variation. Nevertheless, for the first time, Cd isotopically fractionated by industrial processes may be traced in the environment. On the same samples, Pb isotope systematics suggested that materials actually used by the refinery were not the major source of Pb in soils, probably because refined ore origins changed over the 100 years of operation. On the other hand, Cd isotopes and concentrations measured in topsoils allowed identification of three main origins (industrial dust and slag and agriculture), assuming that all Cd ores are not fractionated, as suggested by terrestrial rocks so far analyzed, and calculation of their relative contributions for each sampling point. Understanding that this refinery context was an ideal situation for such a study, our results lead to the possibility of tracing sources of anthropogenic Cd and better constrain mixing processes, fluxes, transport, and phasing out of industrial input in nature.

Lead isotopes in tap water: implications for Pb sources within a municipal water supply system

Residential tap waters were investigated to examine the feasibility of using isotopic ratios to identify dominant sources of water Pb in the Columbus (Ohio, USA) municipal supply system. Overall, both the concentrations, which are generally low (0.1–28 μg/L), and isotopic compositions of tap water Pb show wide variations. This contrasts with the situation for a limited number of available service lines, which exhibit only a limited Pb-isotope variation but contain Pb of two very different types with one significantly more radiogenic than the other. Most tap water samples in contact with Pb service lines have Pb-isotope ratios that are different from the pipe Pb. Furthermore, the Pb isotope compositions of sequentially drawn samples in the same residence generally are similar, but those from separate residences are different, implying dominant Pb sources from domestic plumbing. A separate pilot study at two residences without Pb service lines shows isotopic similarity between water and solders in each house, further suggesting that the major Pb sources are domestic in these cases and dominated by Pb from solder joints. Although complicated by the broad range of overall Pb-isotope variations observed and limited by sample availability, the results suggest that Pb isotopes can be used effectively to constrain the sources of Pb in tap waters, especially for individual houses where multiple source candidates can be identified.

Atmospheric lead deposition to Okefenokee Swamp, Georgia, USA

Contamination of the environment from atmospheric deposition during the twentieth century is pervasive even in areas ostensibly considered pristine or remote from point sources. In this study, Pb concentrations in a 210Pb-dated peat core collected from the Okefenokee Swamp, GA were used to assess historical contaminant input via atmospheric deposition. Lead isotope ratios were determined by dynamic reaction cell ICP-MS (DRC-ICP-MS). Increases in Pb concentration occurred in the late nineteenth century and a marked rise in Pb concentrations pre-dated the widespread use of leaded gasoline within the US. The 206Pb/207Pb ratios of 1.19 during this period were consistent with coal combustion emissions. A later increase in Pb concentration, concurrent with a trend toward more radiogenic 206Pb/207Pb ratios in gasoline is consistent with an increased input of Pb from leaded gasoline emissions. However, it appears that coal combustion emissions remain a major source of Pb to the Okefenokee.

Suspended particulates in the Jamaican atmosphere

The results of a survey of air particulates at 23 sites across Jamaica for total suspended particulates (TSP), Al, Br, Cl, Na, Pb, and V, by instrumental neutron activation analysis (INAA) and X-ray fluorescence analysis (XRF) are reported. The geometric mean of TSP values, 35 g m-3, is well within the World Health Organisation's standard of 60 g m-3 for TSP, but in areas of high vehicular traffic density the TSP values exceeded this limit. The correlation coefficient between Br and Pb concentrations in the particulates was 0.92 and the Br/Pb ratio of 0.38 compares well with a ratio of 0.39 found in commercial petrol indicating that the exhaust from vehicular traffic is the major source of Pb in atmospheric particulate matter in Jamaica.

Influence of Environmental Factors on Heavy Metal Concentration in Lake Sediments in Southern Norway Indicated by Path Analysis

We studied relationships between environmental factors and accumulation of Hg, Cd, Pb, and Ni in sediments in 132 lakes in southern Norway. Generally, the concentrations of Hg, Cd, and Pb in surface sediments were considerably elevated as compared with sediments deposited in preindustrial times whereas Ni concentrations showed only minor increases. By path analysis, we modelled how different environmental factors may influence the metal concentrations in surface sediments. The models indicated that both Hg and Pb were associated with sedimenting organic matter, and sediment concentrations were strongly influenced by atmospheric deposition (indirectly measured as metal concentration in mosses) and the amount of organic carrier particles in lake water. Cd behaved similarly, except for a weaker association with organic matter and a positive effect from pH, indicating that Cd is mobilized during acidification. Ni was associated with the inorganic fractions in lake sediments and seemed also to be mobilized during acidification. Geochemical contributions of Ni were larger in sediments than atmospheric deposition whereas atmospheric deposition was the major source of Pb. For the other two elements, estimates of geochemical contributions were lacking.

Lead and barium sources in Cambrian siliciclastics and sediment provenance of a sector of the Taconic Orogen, Quebec: a mixing scenario based on Pb-isotopic evidence

To test the hypothesis that siliciclastic rocks constituted the major source of Pb and Ba in barite-galena deposits of the Taconic Orogen, we determined Pb-isotope ratios in galena, barren rocks and contained minerals, as well as concentrations of Pb, U, Th and Ba in the latter (detrital feldspars, sandstones, mudstones, rock clasts and carbonate cements and clasts). Ranges in 206Pb/ 204Pb, 207Pb/ 204Pb and 208Pb/ 204Pb of 28 galena samples are 17.96–18.05, 15.56–15.59 and 37.75–37.93, respectively; ranges for 41 barren rocks and minerals are 16.17–23.31, 15.26–15.86 and 35.98–42.51, respectively. The lowest ratios are in feldspar, and the highest in carbonate and mudstone. Values of the mudstones samples overlap those of galena when corrected for in situ decay of U and Th since galena precipitation (∼450Ma). We thus propose that mudstones constituted a source of lead. Corrected ratios for anomalously Pb-rich mudstones are virtually identical to galena-Pb ratios and may be due to contamination by lead-bearing brines. Assuming that burial diagenesis did not disturb the Pb-isotope values of sandstones, these rocks contributed only a minor fraction of lead to the galena, estimated at∼20% for one deposit. The source of barite-Ba was probably perthite. Low Ba and Pb concentrations of sandstone adjacent to this deposit, compared to high concentrations remote from it, support leaching of barium (and minor lead) from feldspar penecontemporaneous with feldspar dissolution. Geological data indicate that the provenance of the siliciclastic rocks was mainly from Grenville terrane. A comparison of our Pb-isotopic data for Taconic perthite with those of Grenville K-feldspar, as well as ratios of trace elements, support this provenance for both sandstones and mudstones. The presence of carbonate platforms peripheral to the orogen, and the Middle Ordovician-Middle Devonian depositional range of the studied and Mississippi Valley type deposits north (Newfoundland) and south (U.S.A. Appalachians) of our study area suggest targets for exploration in these platforms.

Pb–Zn occurrences and their Pb-isotopic signatures bearing on metallogeny and mineral exploration—Paleozoic sedimentary rocks, northern Appalachians, Quebec

Galena Pb-isotope ratios of epithermal vein and disseminated sulfide occurrences in the Taconian Orogen and Siluro-Devonian basin cluster around 17.90–18.05 for 206Pb/204Pb and 37.70–38.00 for 208Pb/204Pb. The major source of Pb in most, if not all, occurrences is a fairly common continental crust, a characteristic found in published analyses of Grenville feldspar Pb. A southwest to northeast increase in galena 206Pb/204Pb ratios is ascribed to the supply of several types of detritus from Grenville basement during the Cambro-Ordovician: coarse-grained, K-feldspar-bearing in the southwest, grading into fine-grained phyllitic, and relatively more highly radiogenic in the northeast.Emplacement (i) of Pb–Zn–barite veins and disseminations, commonly of homogeneous crustal Pb-isotopic signature, was late Taconian; (ii) of Pb–Zn–quartz veins, of less homogeneous signature, was post-Taconian; and (iii) of Pb–Zn–carbonate veins, relatively highly radiogenic and commonly homogeneous, was late or post-Acadian. Signatures of the first-mentioned group seem to be most useful in exploration.

Soil lead concentrations in residential Minnesota as measured by ICP-AES

A total of 2454 samples were collected to evaluate the degree, extent, and distribution of Pb contaminated soil in Minnesota. Samples were collected primarily at locations where susceptible populations were concentrated. Soil Pb concentrations in chilldren's play areas, urban gardens, and at open sites were generally below 100 μg g −1 when Pb painted structures were absent. Street side and yard soils typically had Pb concentrations between 10 to 300 μg g−1, with samples collected near major highways or Pb painted structures exhibiting greater values. The most severely contaminated soils were found in localized areas around the foundations of private residences, where concentrations up to 20 136 μg g−1 were detected. Exterior Pb based house paint is the major Pb source in these soils, and its presence greatly influences the distribution of contaminated soil in individual yards. Contamination attributable to autoemissions is less concentrated but more widespread than contamination from paint. A higher proportion of soils exceeding 1000 wg g−1 Pb was found in large cities than elsewhere. However, a sufficient number were detected in small cities and rural areas to confirm that high soil Pb levels are not exclusively an urban phenomenon. By examining the degree, extent, and distribution of Pb contaminated soils in Minnesota, this study provides information useful in guiding response actions to reduce children's exposure to Pb by this pathway.

Lead (pb) concentrations associated with 1000 mb geostrophic back trajectories At Quillayute, Washington

Daily averaged Pb concentrations in the air at Quillayute, Washington, are related by an objective method to 1000 mb geostrophic backward one-day air trajectories. Although the trajectories ignore topography, the results confirm the expectation that land areas are source regions for Pb. High Pb values in land-trajectory air indicate the influence of anthropogenic sources within the region of the air-monitoring station. Low oceanic trajectory Pb concentrations are indicative of levels to be expected in air over the ocean and away from major Pb sources.

Phase relationships in the system zirconia-thoria

In China, sediment-hosted Pb―Zn deposits represent a significant type of base-metal deposits are major sources of Pb and Zn and significant sources of Ag and Ge. In this paper, we focus discussion on MVT (Mississippi Valley type), SEDEX (sedimentary exhalative) and Jinding-type deposits because they constitute the major subtypes of sediment-hosted Pb―Zn deposits in China. For these deposits, which occur in a wide variety of carbonate and siliciclastic rocks having no obvious genetic association with igneous activity, we present an overview and re-evaluation with regard to: (1) nature, diversity, and geological settings, (2) spatio-temporal distributions, (3) structural controls on mineralization, (4) metallogenic process, and (5) C, O, S and Pb isotope geochemistry. Several of these deposits with known reserves are concentrated in eight main metallogenic belts. Available data from these deposits in China show the highest combined Zn and Pb reserves exist in the Qinling Mountains metallogenic belt, followed by the northern margin of the North China Craton (NCC), the Sanjiang fold belt, the Upper Yangtze River belt, the South China fold system, the Tianshan–Beishan Mountains belt, the Lower Yangtze River belt, and the Qilian Mountains belt. In these belts, the sediment-hosted Pb―Zn deposits have formed in a variety of tectonic settings representing a range of processes that have occurred within two billion years of earth history, but large-scale mineralizations have occurred notably in the Proterozoic, Late Paleozoic and Cenozoic. The Proterozoic era was important for the formation of SEDEX Pb―Zn deposits such as those in the interior and along the edges of the NCC and Yangtze Craton. The Guanmenshan is the only known MVT deposit formed within an intra-continental basin in the Proterozoic era. The Late Paleozoic was a productive period for MVT Pb―Zn deposits in China; in particular, there were significant MVT mineralizations during Devonian to Permian as a result of the amalgamation of the NCC and the South China Craton. The Cenozoic was a significant metallogenic era in China. For example, in the Sanjiang area during the Cenozoic, the Lanping Basin has evolved from a passive margin to open ocean basin and then has experienced ocean basin closure followed by the India–Asia collision and related tectonic activities including thrusting, and formation of strike–slip extensional basins, in which the Jinding-type deposits developed.