Use Of Leaded Gasoline Research Articles

Lead-sheathed telecom cables and historic leaded gasoline emissions substantially raise environmental lead levels in Portland, Oregon

We conducted a high-resolution study of lead in an urban moss, Orthotrichum lyellii, to better understand lead distributions and sources in Portland, Oregon (United States). The outdoor lead landscape is found to be heterogenous, with lead concentrations varying with age of neighborhood: on average 8.3× and 19× the rural background in newer (≥1948) and older neighborhoods (≤1915), respectively. This study finds leaded gasoline to be a pervasive and persistent lead source, decades after the complete phase out of leaded gasoline use by on-road vehicles. The highest lead levels, up to 590× the rural background, are found in older residential neighborhoods where relic lead-sheathed telecommunication cables were identified. Leaching of lead from these cables is thought to be responsible for elevated lead in older residential neighborhoods in cities across the country. Targeted research is needed to quantify the impact of these cables on lead exposures in affected communities.

Temporal transition trends of cord blood lead levels in various human development index countries and in the Taipei metropolitan area

Since low-level lead exposure is still of concern for neonates, it is worth further characterizing the temporal transition trends of cord blood lead levels (CBLLs) globally and locally in Taipei, Taiwan, after the cessation of leaded gasoline use. A literature review on CBLLs around the world was performed by searching three databanks, i.e., PubMed, Google Scholar and Web of Science, with the search keywords “cord blood” combined with “lead” or “Pb” for studies published from 1975 to May 2021. In total, 66 articles were included. Linear regressions for the reciprocal of sample size weighed CBLLs against calendar year presented a high r2 value (0.722) for the very high Human Development Index (HDI) countries and a moderate r2 value (0.308) for the combined high and medium HDI countries. The predicted CBLLs in 2030 and 2040 were 6.92 (95% CI: 6.02–7.81) μg/L and 5.85 (95% CI: 5.04–6.66) μg/L, respectively, for the very high HDI countries and 13.10 (95% CI: 7.12–19.09) μg/L and 10.63 (95% CI: 5.37–15.89) μg/L, respectively, for the combined high and medium HDI countries. To characterize the CBLL transitions in the Great Taipei metropolitan area, data from five studies conducted from 1985 to 2018 were employed. Although the results of the early four studies indicated that the Great Taipei metropolitan area did not reach the pace in CBLL reduction among the very high HDI countries, the CBLLs of the latest study during 2016–2018 were pretty low (8.1 ± 4.5 μg/L), approximately 3 years in advance of the very high HDI countries as one group to reach this low CBLL. In conclusion, further effective reduction in environmental lead exposure is challenging and must be based on the efforts from the aspects reflected by the HDI index compositions, i.e., economics, education and health, mostly implying health disparity and inequality.

Proteomic analysis of T. qataranse exposed to lead (Pb) stress reveal new proteins with potential roles in Pb tolerance and detoxification mechanism

Soil lead (Pb) contamination is one of the environmental problems facing the modern world. Sources of Pb in soil include industrial activities such as mining and smelting processes, agricultural activities such as application of insecticide and municipal sewage sludges, and urban activities such as use of lead in gasoline, paints, and other materials. Phytoremediation is the direct use of living green plants and is an effective, cheap, non-invasive, and environmentally friendly technique used to transfer or stabilize all the toxic metals and environmental pollutants in polluted soil or groundwater. Current work in this area is invested in elucidating mechanisms that underpin toxic-metal tolerance and detoxification mechanisms. The present study aims to gain insight into the mechanisms of Pb tolerance in T. qataranse by comparative proteomics. MALDI-TOF/MS and in silico proteome analysis showed differential protein expression between treated (50 mg kg⎯1 Pb) and untreated (0 mg kg⎯1 Pb) T. qataranse. A total of eighty-six (86) differentially expressed proteins, most of which function in ion and protein binding, antioxidant activity, transport, and abiotic response stress, were identified. In addition, essential stress-regulating metabolic pathways, including glutathione metabolism, cellular response to stress, and regulation of HSF1-mediated heat shock response, were also enriched. Also, at 52- and 49-kDa MW band areas, up to six hypothetical proteins with unknown functions were identified. Of these, protein AXX17_AT2G26660 is highly rich in glycine amino acid residues (up to 76%), suggesting that it is a probable glycine-rich protein (GRP) member. Although GRPs are known to be involved in plant defense against abiotic stress, including salinity and drought, there is no report on their role on Pb tolerance and or detoxification in plants. Further enrichment analysis in the current study reveals that the hypothetical proteins do not interact with known proteins and are not part of any enriched pathway. However, additional research is needed to functionally validate the role of the identified proteins in Pb detoxification mechanism.

Air pollution and violent crime

The article discusses the impact of air pollution, the source of which is transport, on the criminal behavior of a person. Major theories have been explored, including those on human exposure to lead during childhood and the impact of that exposure on violent crime rates. It was checked whether the ban on the use of lead in gasoline had an impact on violent crime in some regions of Russia. Among the causes of violent crime, the main ones are the high level of unemployment, the low financial security of the region and the high level of alcoholism. The article examines the impact of air pollution and from stationary sources on the criminal behavior of a person in a particular region. The regions with the highest level of air pollution are considered. In terms of the rate of homicides, the regions in question are in the middle of the all-Russian rating. At the same time, the rate of deliberate infliction of grievous bodily harm in these regions remains quite high. Of course, the environmental factor has an impact on violent crime. But its importance should not be overestimated, it should be studied in a complex and systematic way with other factors.

Novel Policies are Required to Reduce Pediatric Lead Exposure from Legacy Lead (Pb) in Soil and Air

In 1925, a U.S. conference on lead (Pb) additives tacitly approved their use in petrol. Over five-decades an exponential increase of air lead occurred from commercial marketing of leaded petrol and the sale of automobiles. The ability to measure microgram quantities of Pb was unavailable to medical researchers until the late 1960s and early 1970s. The clinical application of advanced analytical technology demonstrated that pediatric lead exposure was excessive. Beginning in the mid-1970s, actions were taken to curtail Pb additive and decreases of pediatric lead poisoning coincided with decreased air Pb from leaded petrol use. Exogenous Pb exhaust particles are absorbed through inhalation and ingestion routes of exposure. Exogenous Pb is metabolically mistaken for calcium and stored endogenously in bones, teeth, and other tissues. Endogenous Pb has intergenerational effects. All organs, most notably the nervous system, are affected. Clinical studies indicate that there is no safe level of Pb exposure. A worldwide ban on leaded petrol was achieved on August 30, 2021. Banning leaded petrol corresponded with marked decreases in lead exposure. However, exogenous Pb dust persists in soil as a legacy from the era of leaded petrol. Soil Pb is remobilized into the air. Because of traffic congestion and Pb dust emissions, population centers are of particular concern. An exceedingly strong association exists between soil Pb and blood Pb indicating that at the community-scale Pb dust mitigation is necessary to decrease pediatric Pb exposure. Urban soil Pb and blood Pb studies indicate the risk of excessive exposure from legacy Pb dust in communities is highest where the median soil Pb is ≥ 50 mg/kg. The objective of this article is to demonstrate the practical application of an advanced hand-held analytical instrument to map Pb in children’s playgrounds adjacent to a major traffic corridor. We illustrate soil Pb mapping and then consider mitigation procedures for primary prevention of legacy Pb. Mapping soil Pb provides an informed basis for advising parents and encouraging community mitigation responses for reducing pediatric Pb exposure from legacy Pb dust. The soil health-plant health-animal/human health signaling nexus is compromised by legacy Pb. For the medical pediatric community, the existence of legacy lead requires new policies to address intervention of the soil-air-blood linkages of the Pb exposure pathway.

The Effect of Leaded Gasoline on Elderly Mortality: Evidence from Regulatory Exemptions

Leaded gasoline is still used globally for aviation and automotive racing. Exploiting regulatory exemptions and a novel quasi-experiment, we find that leaded gasoline use in racing increases ambient lead, elevated blood lead rates, and elderly mortality. The mortality estimates indicate that each gram of lead added to gasoline exceeds $1,100 in damages. Our setting allows us to rule out potential confounders, such as correlated pollutants or socioeconomic status. We provide the first causal estimates linking adult mortality to leaded gasoline, highlight the value of banning on-road leaded gasoline, and present policy-relevant cost estimates at the lowest ambient levels to date. (JEL I12, J14, L71, Q51, Q53)

Risk factors and early renal effects of environmental exposure to the trace elements in Moroccan adolescents.

In Morocco, the use of leaded-gasoline is still common even after its ban in 2011, and other sources of contamination by traces elements are not regulated. We aimed to assess blood and urinary cadmium, blood lead, and total blood mercury levels in Moroccan adolescents and to identify determinants and early renal effects of exposure. The study included 149 school adolescents (12 to 18 years), from urban, industrial, and rural areas in Fez city (north of Morocco). Risk factors were investigated by interviews and questionnaires. Internal doses and early renal effects were evaluated by analyzing blood and urinary samples. The mean of blood lead levels (BLLs) in all adolescents was 47.81μg/l with no difference between boys and girls. Adolescents from the urban area had the highest BLLs mean. The means of blood cadmium levels (BCLs) and urinary cadmium levels (UCLs) were 0.29μg/l and 0.45μg/l respectively, with no differences between living areas or according to sex. The total blood mercury levels (BMLs) mean was 0.52 μg/l. BMLs mean was higher in the industrial area and among boys. This can be associated to the frequency of fish intake, the use of dental amalgams fillings, and the consumption of chewing gum. Rates of early renal effects markers were low, not correlated to the metals, and may indicate that renal effects of this environmental exposure could be limited. There is an urgent need for the limitation of trace elements' sources, particularly the strict application of the laws concerning leaded-petrol prohibition.

Regional and global perspectives of honey as a record of lead in the environment

Honey from Apis mellifera is a useful and inexpensive biomonitor for mapping metal distributions in urban centers. The sampling resolution of a biomonitoring survey (e.g., city versus global scale) determines which geochemical processes are reflected in the results. This study presents Pb isotopic compositions and metal concentrations in honey from around the world, sampled at varying resolutions: honey from Canada (n = 21), the United States (n = 111), Belgium (n = 25), and New Zealand (n = 10), with additional samples from Afghanistan, Brazil, Cuba, Germany, Liberia, Taiwan, and Turkey. Honey was sampled at high resolution in two uniquely different land-use settings (New York Metro Area and the Hawaiian island of Kauaʻi), at regional-scale resolution in eastern North America (including the Great Lakes region), and Pb isotopic compositions of all samples were compared on a global scale. At high sampling resolution, metal concentrations in honey reveal spatially significant concentration gradients: in New York City, metals associated with human activity and city infrastructure (e.g., Pb, Sb, Ti, V) are more concentrated in honey collected within the city compared to honey from upstate New York, and metal concentrations in honey from Kauaʻi suggest polluting effects of nearby agricultural operations. At lower resolution (regional and global scales), lead isotopic compositions of honey are more useful than metal concentrations in revealing large-scale Pb processes (e.g., the enduring legacy of global leaded gasoline use throughout the twentieth century) and the continental origin of the honey. Lead isotopic compositions of honey collected from N. America (especially from the eastern USA) are more radiogenic (206Pb/207Pb: 1.132–1.253, 208Pb/206Pb: 2.001–2.129) compared to European honey, and honey from New Zealand, which has the least radiogenic isotopic compositions measured in this study (206Pb/207Pb: 1.077–1.160, 208Pb/206Pb: 2.090–2.187). Thus, biomonitoring using honey at different resolutions reflects differing processes and, to some extent, a honey terroir defined by the Pb isotopic composition. The data presented here provide important (and current) global context for future studies that utilize Pb isotopes in honey. Moreover, this study exhibits community science in action, as most of the honey was collected by collaborators around the world, working directly with local apiarists and hobby beekeepers.

Stone-built heritage as a proxy archive for long-term historical air quality: A study of weathering crusts on three generations of stone sculptures on Broad Street, Oxford

Black crusts on historic buildings are mainly known for their aesthetic and deteriorative impacts, yet they also can advance air pollution research. Past air pollutants accumulate in distinct layers of weathering crusts. Recent studies have used these crusts to reconstruct pollution to improve our understanding of its effects on stone-built heritage. However, the majority of the studies provide only coarse resolution reconstruction of pollution, able to distinguish between ‘inner = old’ and ‘outer = modern’ crust layers. In contrast, very few studies have linked distinct periods of exposure to pollution variations in the composition of these crusts. Here we address this research gap by developing a finer-scale resolution pollution record. Our study explored the unique configuration of limestone sculptures in central Oxford, which have been exposed over the last 350 years to three different periods of atmospheric pollution; the early Industrial Revolution, the Victorian period and the 20th century. When the first two generations of sculptures were moved to less polluted areas, their ‘pollution clocks’ were stopped. Here we discuss the potential of investigating the ‘pollution clock’ recorded in the geochemical makeup of each sculpture generation's weathering crust layers. We found the analysed crusts record clear changes related to the evolution of modes of transport and industrial and technological development in Oxford. Higher levels of Arsenic (As), Selenium (Se) are linked to pollution from coal burning during Victorian times and Lead (Pb) indicated leaded petrol use in modern times. Our work shows that stone-built heritage with a known history of air pollution exposure allows improving the pollution reconstruction resolution of these weathering crusts. The results provide the basis for calibrating long-term geochemical archives. This approach may be used to reconstruct past air quality and has the potential to inform stone weathering research and conservation, in addition to improving the reconstruction of historical pollution.

A bat guano deposit in Jamaica recorded agricultural changes and metal exposure over the last >4300 years

Bats are excellent ecological indicators because they are long-lived, globally distributed, and show predictable responses to environmental stressors. Unaltered bat guano deposits, although rare, can serve as environmental archives to reveal changes in dietary patterns over millennial time scales. We inferred changes in agricultural and industrial practices using a continuous 4300-year-old bat guano deposit from Jamaica. Cadmium, mercury, lead, and zinc increased during the Industrial Revolution, (which began in ca. 1760), a period characterized by elevated emissions of metals to the atmosphere. Beginning in the early 20th century, decreases in 206Pb/207Pb isotopes tracked the history of leaded gasoline use. Metal concentrations in the bat guano deposit exceeded those recorded in two nearby lake sediment cores from Jamaica. Carbon, nitrogen, and sulfur stable isotope profiles in bat guano tracked the agricultural history of Jamaica, specifically the introduction of nitrogen fertilizers, sugarcane, and possibly fungicides. Bat populations are under stress globally, and such intact guano deposits provide potentially critical information on long-term changes in their food source and exposure to metals.

Distinct basin-scale-distributions of aluminum, manganese, cobalt, and lead in the North Pacific Ocean

Abstract Aluminum (Al), manganese (Mn), cobalt (Co), and lead (Pb) are key trace elements in seawater and thus significant in chemical oceanography research. However, although all of these elements are highly scavenged in the ocean, only a few studies focus on the intercomparison of their distributions. Here, we report the basin-scale and full-depth sectional distributions of these elements observed during three GEOTRACES Japan cruises in the North Pacific. We confirmed that a surface maximum of the dissolved (d) species is not a common feature for the four elements and that the d species have the lowest concentrations in the Pacific Deep Water (PDW) as compared to other oceans. The elements showed different speciations and distributions. The fraction of labile particulate (lp) species was calculated as the difference between the total dissolvable (td) species and d species. The lpM/tdM ratio, where M refers to an element, is highest for Al, at 0.66 ± 0.31 (average ± sd, n = 489), and lowest for Pb, at 0.02 ± 0.08 (n = 575). Further, the distribution of each element is uniquely related to ocean circulation. The tdAl concentration is high in the Equatorial Under Current (EUC), the North Equatorial Current (NEC), and the Lower Circumpolar Deep Water (LCDW). Manganese is supplied from reductive sources such as sediments on the continental shelves around the northern boundary. Cobalt is concentrated in the North Pacific Intermediate Water (NPIW) and in the Equatorial Pacific Intermediate Water (EqPIW) owing to the combined effects of supply from the continental shelves, biogeochemical cycling, and scavenging. Lead shows a subsurface maximum centered at ∼35°N and ∼200 m depth, implying an association with the formation of the Subtropical Mode Water (SMW) and the Central Mode Water (CMW). Although the subsurface Pb maximum in the Atlantic has diminished over the last three decades owing to the ban on leaded gasoline use, it has been sustained in the North Pacific through the growth of other anthropogenic sources in Asia and Russia. We propose that the enrichment factor of dM, defined as EF(dM) = (dM/dAl)seawater/(M/Al)upper crust, where (M/Al)upper crust is the molar ratio in upper crustal abundance, can be a good parameter for the sources. The median is 1.3 × 102 (n = 436) for EF(dMn), 3.2 × 102 (n = 430) for EF(dCo), and 1.2 × 103 (n = 413) for EF(dPb). The EF(dPb) found in this study is on the same order of magnitude as the EF values for aerosols found in the literature, suggesting that the deposition of aerosols is a major source for dPb. Because EF(dMn) and EF(dCo) are ten to hundred times higher than the EF for aerosols, sources other than the aerosol deposition are more significant contributors to the concentrations of Mn and Co.

Tracing natural and industrial contamination and lead isotopic compositions in an Australian native bee species

This study investigates trace element concentrations (arsenic (As), manganese (Mn), lead (Pb) and zinc (Zn)) and Pb isotopic compositions in an Australian native bee species, Tetragonula carbonaria, and its products of honey and wax. Co-located soil and dust samples were simultaneously analysed with the objective of determining if the bees or their products had potential application as a proxy for monitoring environmental contamination. The most significant relationships were found between Pb concentrations in honey (r = 0.814, p = 0.014) and wax (r = 0.883, p = 0.004) and those in co-located dust samples. In addition, Zn concentrations in honey and soil were significantly associated (r = 0.709, p = 0.049). Lead isotopic compositions of native bee products collected from background sites adjacent to Sydney national parks (206Pb/207Pb = 1.144, 208Pb/207Pb = 2.437) corresponded to local geogenic rock and soil values (206Pb/207Pb = 1.123–1.176, 208Pb/207Pb = 2.413–2.500). By contrast, inner Sydney metropolitan samples, including native bees and wax (206Pb/207Pb = 1.072–1.121, 208Pb/207Pb = 2.348–2.409), co-located soil and dust (206Pb/207Pb = 1.090–1.122, 208Pb/207Pb = 2.368–2.403), corresponded most closely to aerosols collected during the period of leaded petrol use (206Pb/207Pb = 1.067–1.148, 208Pb/207Pb = 2.341–2.410). A large range of Pb isotopic compositions in beehive samples suggests that other legacy sources, such as Pb-based paints and industrials, may have also contributed to Pb contamination in beehive samples. Native bee data were compared to corresponding samples from the more common European honey bee (Apis mellifera). Although Pb isotopic compositions were similar in both species, significant differences in trace element concentrations were evident across the trace element suite, the bees and their products. The statistical association between T. carbonaria and co-located environmental contaminant concentrations were stronger than those in European honey bees, which may be attributable to its smaller foraging distance (0.3–0.7 km versus 5–9 km, respectively). This implies that T. carbonaria may be more suitable for assessing small spatial scale variations of trace element concentrations than European honey bees.

Concentration and isotopic composition of dissolved Pb in surface waters of the modern global ocean

Several years have passed since the global phase-out of leaded petrol use. Nonetheless, emissions from anthropogenic activities remain the principal source of Pb to the oceans. The distribution of elemental Pb and its stable isotopes throughout the surface ocean provide information on the source and transport of these anthropogenic inputs. This study presents dissolved Pb concentrations and isotopic distributions from 110 surface water samples collected during the Malaspina 2010 Circumnavigation Expedition. Dissolved Pb concentrations ranged from 10 pM to 49 pM across the sampling stations covering all major ocean basins. The highest concentrations were found in the northeast Atlantic Ocean and the lowest in both the south Pacific and south Atlantic Oceans. Lead concentrations measured in the north Pacific Ocean, near Hawaii, were compared to previously published data from the same region. That comparison showed that Pb concentration has decreased ∼40% since 1975, although the rate of decrease has slowed in the past two decades. The overall decline in concentration probably has been induced by the cessation of leaded gasoline use in North America. The temporal evolution of stable Pb isotopes in this region shows a shift from dominant North American-like composition in 1979 towards a more Asian-like composition in later years. More widely, the distribution of Pb and Pb isotopes measured in the Malaspina sample set of global surface waters were compared with previously published ratios of aerosols and other atmosphere-derived Pb sources from the countries surrounding the different ocean basins. This comparison identified the potential Pb sources to each ocean basin, providing new insights into the transport and fate of Pb in the oceans.

Identifying Sources of Environmental Contamination in European Honey Bees (Apis mellifera) Using Trace Elements and Lead Isotopic Compositions.

Trace element concentrations (As, Mn, Pb, and Zn) and Pb isotopic compositions were analyzed in honey bees, wax, and honey along with co-located soil and dust samples from Sydney metropolitan and Broken Hill, Australia. Compared with the other trace elements, Pearson correlations show that Pb concentrations in soil and dust had the strongest relationship to corresponding values in honey bees and their products. Dust Pb was not only highly correlated to corresponding soil values (r = 0.806, p = 0.005), it was the strongest predictor of Pb concentrations in honey bees, wax, and honey (p = 0.001, 0.007, 0.017, respectively). Lead isotopic compositions (206Pb/207Pb and 208Pb/207Pb) showed that honey bees and their products from Broken Hill were nearly identical (95-98%) to the composition of the local ore body. Samples of honey bees and their products collected from background sites adjacent to national parks in Sydney had Pb isotopic compositions (206Pb/207Pb = 1.138-1.159, 208Pb/207Pb = 2.417-2.435) corresponding to local geogenic values (206Pb/207Pb = 1.123-1.176, 208Pb/207Pb = 2.413-2.500). By contrast, honey bees and their products from Sydney metropolitan (206Pb/207Pb = 1.081-1.126, 208Pb/207Pb = 2.352-2.408) were similar to aerosols measured during the period of leaded petrol use (206Pb/207Pb = 1.067-1.148, 208Pb/207Pb = 2.341-2.410). These measurements show Pb concentrations and its isotopic compositions of honey bees, and their products can be used to trace both legacy and contemporary environmental contamination, particularly where sources are well documented. Moreover, this study demonstrates that legacy Pb emissions continue to be remobilized in dust, contaminating both food and ecological systems.

Remobilisation of industrial lead depositions in ash during Australian wildfires

This study examined the recycling of lead (Pb) in ash from wildfires, its source and potential contribution to environmental contamination. Ash from wildfires was collected from four Australian sites following uncontrolled fires during 2012 to 2013 close to major urban populations in Sydney (New South Wales), Hobart (Tasmania) and Adelaide (South Australia). The samples were analysed for their total Pb concentration and Pb isotopic composition to determine the sources of Pb and the extent, if any, of industrial contamination and its recycling into the ecosystem. Median ash concentrations (23mg/kg) released from a wildfire close to Australia's largest city, Sydney, exceeded the median ash Pb concentrations from wildfires from the less populated locations of Hobart, Adelaide and NSW Central Coast. Lead isotopic compositions of Duffys Forest wildfire ash demonstrate that anthropogenic inputs from legacy leaded petrol depositions were the predominant source of contamination. Despite the cessation of leaded petrol use in Australia in 2002, historic petrol Pb deposits continue to be a substantial source of contamination in ash: petrol Pb contributed 35% of the Pb in the Woy Woy ash, 73% in Duffys Forest ash, 39% in Forcett ash and 5% in Cherryville ash. The remobilisation of legacy industrial Pb depositions by wildfires in ash results in it being a persistent and problematic contaminant in contemporary environmental systems because of its known toxicity.

Return of naturally sourced Pb to Atlantic surface waters.

Anthropogenic emissions completely overwhelmed natural marine lead (Pb) sources during the past century, predominantly due to leaded petrol usage. Here, based on Pb isotope measurements, we reassess the importance of natural and anthropogenic Pb sources to the tropical North Atlantic following the nearly complete global cessation of leaded petrol use. Significant proportions of up to 30–50% of natural Pb, derived from mineral dust, are observed in Atlantic surface waters, reflecting the success of the global effort to reduce anthropogenic Pb emissions. The observation of mineral dust derived Pb in surface waters is governed by the elevated atmospheric mineral dust concentration of the North African dust plume and the dominance of dry deposition for the atmospheric aerosol flux to surface waters. Given these specific regional conditions, emissions from anthropogenic activities will remain the dominant global marine Pb source, even in the absence of leaded petrol combustion.

Insights into past atmospheric lead emissions using lead concentrations and isotopic compositions in historic lichens and fungi (1852–2008) from central and southern Victoria, Australia

Lead concentrations and lead isotopic compositions were determined in historic central and southern Victoria, Australia lichen (Cladonia and Usnea) and fungi (Trametes) samples collected between 1852 and 2008 to evaluate long-term atmospheric lead contamination sources. The data are grouped into four time intervals of 1850–1931, 1932–1984, 1985–2001 and 2002–2008 corresponding to the history of leaded petrol use in Australia. Elevated lichen and fungi lead concentrations and relatively high isotopic compositions from the period 1850–1931 are attributed to lithogenic sources, gold mining activities and early industrialisation. Significant increases in lichen and fungi lead concentrations and concomitant lower lead isotopic compositions correspond to the marked increase in lead emissions from leaded petrol use after 1932. Following the end of leaded petrol use in 2002 lead isotopic composition values ‘recover’ toward more lithogenic values. However, the lead isotopic composition data indicate that the environmental impact from leaded petrol emissions persists in contemporary samples dated to 2002–2008. Overall, the data reveal that herbarium lichens and fungi from central and southern Victoria can be used as proxies for environmental lead emissions over the past 150 years.

Australian atmospheric lead deposition reconstructed using lead concentrations and isotopic compositions of archival lichen and fungi

Lead concentrations and their isotopic compositions were measured in lichen genera Cladonia and Usnea and fungi genus Trametes from the Greater Sydney region (New South Wales, Australia) that had been collected and archived over the past 120 years. The median lead concentrations were elevated in lichens and fungi prior to the introduction of leaded petrol (Cladonia 12.5 mg/kg; Usnea 15.6 mg/kg; Trametes 1.85 mg/kg) corresponding to early industrial development. During the period of leaded petrol use in Australian automobiles from 1932 to 2002, total median lead concentrations rose: Cladonia 18.8 mg/kg; Usnea 21.5 mg/kg; Trametes 4.3 mg/kg. Following the cessation of leaded petrol use, median total lead concentrations decreased sharply in the 2000s: Cladonia 4.8 mg/kg; Usnea 1.7 mg/kg. The lichen and fungi isotopic compositions reveal a significant decrease in 206Pb/207Pb ratios from the end of 19th century to the 1970s. The following decades were characterised by lower allowable levels of lead additive in fuel and the introduction of unleaded petrol in 1985. The environmental response to these regulatory changes was that lichen and fungi 206Pb/207Pb ratios increased, particularly from 1995 onwards. Although the lead isotope ratios of lichens continued to increase in the 2000s they do not return to pre-leaded petrol values. This demonstrates that historic leaded petrol emissions, inter alia other sources, remain a persistent source of anthropogenic contamination in the Greater Sydney region.

Atmospheric Deposition History of Trace Metals and Metalloids for the Last 200 Years Recorded by Three Peat Cores in Great Hinggan Mountain, Northeast China

A large number of studies on trace metals and metalloids (TMs) accumulations in peatlands have been reported in Europe and North America. Comparatively little information is available on peat chronological records of atmospheric TMs flux in China. Therefore, the objective of our study was to determine the concentrations and accumulation rates (ARs) of TMs in Motianling peatland from Great Hinggan Mountain, northeast China, and to assess these in relation to establish a historical profile of atmospheric metal emissions from anthropogenic sources. To meet these aims we analyzed 14 TMs (As, Ba, Cd, Co, Cr, Cu, Mo, Ni, Pb, Sr, Sb, Tl, and Zn) and Pb isotopes (206Pb, 207Pb, 208Pb) using ICP-AES and ICP-MS, respectively, in three peat sections dated by 210Pb and 137Cs techniques (approximately spanning the last 200 years). There is a general agreement in the elemental concentration profiles which suggests that all investigated elements were conserved in the Motianling bog. Three principal components were discriminated by principal component analysis (PCA) based on Eigen-values >1 and explaining 85% of the total variance of element concentrations: the first component representing Ba, Co, Cr, Mo, Ni, Sr and Tl reflected the lithogenic source; the second component covering As, Cu and Sb, and Cd is associated with an anthropogenic source from ore mining and processing; the third component (Pb isotope, Pb and Zn) is affected by anthropogenic Pb pollution from industrial manufacturing and fossil-fuel combustion. The pre-industrial background of typical pollution elements was estimated as the average concentrations of TMs in peat samples prior to 1830 AD and with a 207Pb/206Pb ratio close to 1.9. ARs and enrichment factors (EFs) of TMs suggested enhanced metal concentrations near the surface of the peatland (in peat layers dated from the 1980s) linked to an increasing trend since the 2000s. This pollution pattern is also fingerprinted by the Pb isotopic composition, even after the ban of leaded gasoline use in China. Emissions from coal and leaded gasoline combustions in northern China are regarded as one of the major sources of anthropogenic Pb input in this region; meanwhile, the long-distance transportation of Pb-bearing aerosols from Mongolia should be also taken into consideration. The reconstructed history of TMs’ pollution over the past ca. 200 years is in agreement with the industrial development in China and clearly illustrates the influence of human activities on local rural environments. This study shows the utility of taking multi-cores to show the heterogeneity in peat accumulation and applying PCA, EF and Pb isotope methods in multi-proxies analyses for establishing a high resolution geochemical metal record from peatland.

Ball and chain: The global burden of lead poisoning

Lead, the 82nd element in our periodic table, has accompanied humankind throughout the millennia of our history and development. As a ubiquitous heavy metal, lead is used in multiple applications and nine billion tons continue to be extracted globally every year. Although the United States has succeeded in limiting lead exposure among its own citizens by banning the use of lead in gasoline and household paint, while instituting improved working conditions for those who are exposed to lead in the workplace, the battle against lead is not won. In addition, it continues to plague the rest of the world today; the United States has played an increasing role in the world's exposure to lead and plans to stop are currently stalled. The year 2011 marked the centennial celebration of the life's work of Dr. Alice Hamilton in exposing lead poisoning among industrial workers in Chicago, Illinois. Her legacy provides us with the opportunity to look back and reevaluate our leaded history in the US. It also reminds us that there is more to be done to mitigate lead poisoning both domestically and in the developing world.