The use of stable lead isotope ratios and elemental composition to discriminate the origins of lead in aerosols at a rural site in eastern Canada (original) (raw)
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Stable lead isotope ratios in arctic aerosols: evidence for the origin of arctic air pollution
Atmospheric Environment (1967)
The isotopic composition of aerosol lead in the polar region potentially contains information on the origin of Arctic pollution which will complement that from meteorological and trace elemental composition studies. Weekly samples of atmospheric aerosols were collected at three locations in the Canadian Arctic from mid-1983 to mid-1984. They were analyzed for elemental composition and stable lead isotope ratios (Pb 206/207). High crustal enrichment factors confirmed that the majority of samples contained lead of anthropogenic origin. Pb 206/207 ratios were very uniform over time and between sites, suggesting a common origin of lead pollution in the Canadian Arctic. The mean isotope ratios at the Alert and Mould Bay stations were 1.160~0.010 and 1.161+0.006, respectively (samples from a third site at Igloolik were eiidently contaminated by local sources). A small nun&r of samples from Spitsbergen, taken durine flow medominantlv out of the northern U.S.S.R.. were found to have a similar mean Pb 206/207 ratio .d 1 of 1.154~0.006. From published lead isotope analyses of Soviet lead-bearing ores, we would ex&t a mean isotope ratio in industrial and vehicular emissions in the U.S.S.R. of around 1.158. Contributions to Arctic lead pollution from the U.S. and western Canadian sources can probably be ruled out, as they have significantly higher Pb 206/207 ratios. Similarly, emissions from northern Canadian and Kola Peninsula smelters can be disregarded, as they appear to have low isotope ratios. Eastern Canadian automotive lead aerosol contained only marginally lower Pb 206/207 ratios than in the Arctic, but meteorological studies argue against this region being a major source area for Arctic pollution. Scant European data suggest that European Pb emissions generally have lower isotope ratios than the Arctic samples. However, more data in Eurasia are needed before apportionments of Arctic Pb between sources within the region can be made.
Environment International, 2014
Background: Blood lead levels (BLLs) were measured in the adult Inuit population of Nunavut, Northern Canada, during the Inuit Health Survey (IHS) in [2007][2008]. Approximately 10% of the adult participants had BLL over the Health Canada's guidance of 100 μg/L. Objectives: 1) To repeat the measurement of BLL among the IHS participants with high BLL and household members including pregnant women and children under 10 years of age; 2) to measure lead (Pb) concentrations in environmental samples to identify potential sources and 3) to explore how Pb from environmental samples contributes to BLL using Pb stable isotopic analyses. Methods: Blood samples were collected from 100 adults and 56 children in 2012. A total of 169 environmental samples (tap water, house dust, paint, country food, soil, and ammunition) were collected from 14 houses from three communities where the IHS participants had the highest BLL. Total Pb concentrations and Pb isotope mass balance were determined by inductively coupled plasma-mass spectrometry (ICP-MS). Results: The geometric mean of BLL was 43.1 μg/L; BLL increased with age and was higher in adults than children (71.1 vs. 17.5 μg/L). Median Pb concentrations in water (1.9 μg/L) and dust (27.1 μg/m 2 for wiped dust, 32.6 mg/kg for vacuum dust coarse fraction, and 141.9 mg/kg for vacuum dust fine fraction) were generally higher than in other parts of Canada. Median Pb concentrations of food and soil coarse and fine fractions were low (36.6 μg/kg, 5.4 mg/kg and 11.8 mg/kg respectively); paint chips exceeded the Canadian guidelines in two houses (median: 3.8 mg/kg). Discriminant analyses and isotope ratio analyses showed that ammunition and house dust are major sources of Pb in this study population. Conclusion: Analyses of Pb stable isotopes are useful to identify the routes of exposure to Pb. This approach can contribute to develop targeted public health programmes to prevent Pb exposure.
The Science of the Total …, 2002
To investigate the capability of the lead isotope signature technique to support a source apportionment study at a Continental scale, atmospheric particulate matter was collected at Cap Gris-Nez (Eastern Channel, northern France), over one year (1995–1996). Four days retrospective trajectories of air masses were available during each sampling experiment. Twenty-eight samples, for which the origin of aerosols was unambiguously determined, were selected for isotopic measurements. Considering the Enrichment Factors, EFCrust of lead and its size distribution, we show that lead is mostly from anthropogenic origin and mainly associated with [0.4<diameter<0.9 μm] particles. The extent to which various Continental sources influence the lead abundance in aerosols is exhibited by considering both the lead concentration and the origin of air masses. Lead concentration is higher by a factor of approximately seven, when air masses are derived from Continental Europe, by comparison with marine air masses. Taking into account these concentrations and the vertical movements of air masses, we compare the different isotopic compositions using a statistical non-parametric test (Kolmogorov–Smirnov). We produce evidence that, for most of the cases, air masses originating from Continental Europe exhibit a more radiogenic composition (1.134<206Pb/207Pb<1.172) than air masses coming from the United Kingdom (1.106<206Pb/207Pb<1.124). Generally, lead isotopic compositions in aerosols are clearly distinct from the gasoline signatures in European countries, strongly suggesting that automotive lead is no longer the major component of this metal in the air. Gasoline and industrial isotopic signatures could explain the origin of lead in our aerosol samples. A source apportionment based upon 206Pb/207Pb ratios, suggests that the difference between British (206Pb/207Pb=1.122±0.038) and Continental (206Pb/207Pb=1.155±0.022) signatures may be largely explained by differences in the petrol lead content of aerosols (23–62% in Great Britain vs. 10–36% in Continental Europe).
Stable lead isotope ratios in Alaskan arctic aerosols
Atmospheric Environment. Part A. General Topics
Aerosol samples collected at Barrow, Alaska, during February and March 1990 were found to have uniform stable lead isotope compositions. The mean 2°Spb/2°Tpb ratio was 2.423 + 0.009 and the mean 2°rpb/2°~Pb ratio was 1.161 + 0.014. The latter ratio is essentially the same as that obtained from an earlier study of aerosols at two Canadian stations in the High Arctic and is typical of, but not unique to, Eurasian sources of atmospheric lead. Further discriminating power was available in this study through the inclusion of 2oa pb/2OTpb ratios, which provided additional evidence that the former Soviet Union and eastern Europe are major contributors to atmospheric particulate lead in the Alaskan Arctic, accounting for around twothirds of the particulate lead measured at Barrow. The remaining third of the lead is attributed to west European sources. There was no evidence for a substantial North American component, other than local contamination.
Historical changes in anthropogenic lead fallout in southern Ontario, Canada
Hydrobiologia, 1982
A quantitative historical record of anthropogenic lead deposition has been determined for the Haliburton region of southern Ontario from a) the relative change in lead concentration in undisturbed sediment cores, and b) the total anthropogenic lead deposition measured in the region. The first parameter was measured on two sediment cores from a meromictic lake. Total lead deposition was assumed to be the average of that measured for eight other lakes in the study area. The validity of this historical record was tested on sediment cores from nearby dimictic lakes. Predicted lead concentration profiles closely resembled observed profiles.
The Science of the total environment, 1997
X-ray fluorescence and stable lead (Pb) isotopic analyses have been undertaken on dusts, known from microscopic investigation to contain significant quantities of industrially- and urban-derived particulate matter, present in the roof cavities of houses in the Illawarra region (N.S.W., Australia), with the objective of examining the historic record of Pb pollution. All investigated houses contained in excess of 250 micrograms g-1 Pb, with dwellings close to a copper smelter, in a large industrial complex including a major steelworks, containing higher (> 2500 micrograms g-1) Pb concentrations. The isotopic composition in the dusts, expressed here as 206Pb/204Pb, is relatively constant at 17.0, irrespective of dwelling age or distance from the industrial complex. Contamination of the dusts by Pb sourced from paint cannot explain the isotopic uniformity of the dust samples. Isotopic modelling indicates that the dusts contain Pb derived from the copper smelter, gasoline-air Pb and a...
Using isotopic tracers in lake sediments to assess atmospheric transport of lead in Eastern Canada
Water, Air, and Soil Pollution
The isotopm composition of lead pollution in the environment provides information as to the source of emission. The 2°6pb/2°7pb ratio for Canadian industrial emissions (1.1534-0.005) is significantly less than U.S. industrial emissions (1.2134-0.008) making it possible to determine the relative contributions of emissions from both countries within Eastern North America by means of a simple isotopic mixing model. Profundal sediments in lakes chronicle contaminant inputs and are therefore useful monitors of environmental pollution. Surface sediment from 32 sediment cores across Quebec and Ontario, Canada were analyzed for 2°6pb/2°Tpb to ascertain the relative proportions of Pb emission from Canada and the U.S.A. Data show that U.S. contributions to the total lead burden in surficial sediments across much of southern Quebec and Ontario are often in excess of 50%. Local sources were particularly important in the Eastern Township region of Quebec which lies 200 km south east of the city of Montreal. The results are discussed in relation to the major sources of industrial lead emissions in North America.
An isotopic study of atmospheric lead in a megacity after phasing out of leaded gasoline
Atmospheric Environment, 2017
Atmospheric lead (Pb) concentrations in São Paulo city, Brazil, remain significant, despite the fact that leaded gasoline has been phased out. The use of its isotope signature allows tracing emissions from increasing car numbers, urban construction, and industrial emissions in this extremely populated area. High-precision and accurate stable isotope ratio determinations using isotope dilution thermal ionization mass spectrometry (ID-TIMS) combined with particle induced X-ray emission (PIXE) and multivariate analysis were used to identify the main sources of lead present in São Paulo atmospheric particulates. Throughout a period of sixty days, aerosol samples were collected every 12 hours during the summer of 2005 at the University of São Paulo (USP) and simultaneously during one week in an industrial area (Cubatão) and in two more remote areas (São Lourenço da Serra and Juquitiba). The data suggests that aerosols from São Paulo are mainly derived from vehicular exhaust (mostly gasoline) and traffic dust resuspension, with admixing of industrial emissions, including cement. Lead isotopic compositions (expressed as 206 Pb/ 207 Pb ratios) measured in São Paulo aerosols range from 1.1491 to 1.2527 and are similar to those determined from tunnel dust, fuels, and vehicular exhaust; therefore, those are likely to be the main lead sources in the atmosphere of São Paulo. Vehicular traffic (fuel combustion, dust from vehicular components, and road dust) remains an important source of lead in the 2 atmosphere. The maximum concentration occurring during the summer was 0.055 g.m-3 in fine particles, which is detrimental for human health and may lead to exceedances of the Air Quality Standard for lead of 0.15 μg.m-3 (3-month average) during other seasons that are less favourable to pollutant dispersion.
Lead isotope composition and host phases in airborne particulate matter from Budapest, Hungary
Central European Geology, 2013
Lead is a frequent, potentially toxic pollutant of the urban environment. Its risk assessment in airborne particulate matter requires data both on its speciation and potential sources. In this paper we present results of a detailed mineralogical (XRD and TEM) and geochemical (selective chemical extractions and lead isotope ratio analyses) study of total suspended particulate (TSP) matter samples from Budapest, Hungary, to fulfill these requirements. Total lead concentrations showed significant enrichment in the studied TSP samples as compared to its geochemical background value. It could be associated with several host phases. The potentially mobile fraction of lead, which could also be harmful to humans, can be as high as 16% of the total lead. This is represented by Pb sorbed on the surface of clay minerals and in the form of carbonates (and sulfates). On the other hand, between 20 and 30% of total lead of TSP material is hosted by magnetite, a highly resistant mineral. However, its rapid oxidation during combustion processes to hematite and/or weathering in the acidifying urban environment to ferrihydrite, may result in the enhanced mobilization of lead. The lead isotope composition of the TSP samples suggests the mixing of several sources for this metal, with slight variation among the sampling sites. Despite the phasing out of leaded gasoline, its contribution to the Pb content of the TSP was observed. Our data also supported that the presence of lead of gasoline origin decreases in the airborne TSP during the last decade in Budapest. Another important source for lead is found to be coal combustion linked to domestic and industrial heating. Lead isotope ratio data suggest additional source(s) for this metal, at least in certain localities, but further investigations are necessary to specify them.