Source analysis of global anthropogenic lead emissions: their quantities and species

Lead poisoning of raptors: state of the science and cross-discipline mitigation options for a global problem

Lead poisoning is an important global conservation problem for many species of wildlife, especially raptors. Despite the increasing number of individual studies and regional reviews of lead poisoning of raptors, it has been over a decade since this information has been compiled into a comprehensive global review. Here, we summarize the state of knowledge of lead poisoning of raptors, we review developments in manufacturing of non-lead ammunition, the use of which can reduce the most pervasive source of lead these birds encounter, and we compile data on voluntary and regulatory mitigation options and their associated sociological context. We support our literature review with case studies of mitigation actions, largely provided by the conservation practitioners who study or manage these efforts. Our review illustrates the growing awareness and understanding of lead exposure of raptors, and it shows that the science underpinning this understanding has expanded considerably in recent years. We also show that the political and social appetite for managing lead ammunition appears to vary substantially across administrative regions, countries, and continents. Improved understanding of the drivers of this variation could support more effective mitigation of lead exposure of wildlife. This review also shows that mitigation strategies are likely to be most effective when they are outcome driven, consider behavioural theory, local cultures, and environmental conditions, effectively monitor participation, compliance, and levels of raptor exposure, and support both environmental and human health.

Oxidative potential of metal-polluted urban dust as a potential environmental stressor for chronic diseases

Oxidative stress (OS) associated with metals in urban dust has become a public health concern. Chronic diseases linked to general inflammation are particularly affected by OS. This research analyzes the spatial distribution of metals associated with OS, the urban dust´s oxidative potential (OP), and the occurrence of diseases whose treatments are affected by OS. We collected 70 urban dust samples during pre- and post-monsoon seasons to achieve this. We analyzed particle size distribution and morphology by scanning electron microscopy, as well as metal(loid)s by portable X-ray fluorescence, and OP of dust in artificial lysosomal fluid by using an ascorbic acid depletion assay. Our results show that the mean concentration of Fe, Pb, As, Cr, Cu, and V in pre-monsoon was 83,984.6, 98.4, 23.5, 165.8, 301.3, and 141.9 mg kg^-1, while during post-monsoon was 50,638.8, 73.9, 16.7, 124.3, 178.9, and 133.5 mg kg^-1, respectively. Impoverished areas with the highest presence of cardiovascular, cancer, diabetes, and respiratory diseases coincide with contaminated areas where young adults live. We identified significant differences in the OP between seasons. OP increases during the pre-monsoon (from 7.8 to 237.5 nmol AA min^-1) compared to the post-monsoon season (from 1.6 to 163.2 nmol AA min^-1). OP values are much higher than measured standards corresponding to contaminated soil and urban particulate matter, which means that additional sources beside metals cause the elevated OP. The results show no risk from chronic exposure to metals; however, our results highlight the importance of studying dust as an environmental factor that may potentially increase oxidative stress.

Analysis of iron composite flow in China

Iron is an important metal material that is crucial to social and national economic development. In order to understand iron's material flow, energy flow, and value flow in China, a composite flow framework is here established. Based on this framework, the concept of price is introduced, and China is taken as an example to study the composite flow of iron in 2018. The results showed the following. First, as iron moved down the industrial chain, its material flow decreased gradually, while the price continued to rise. Second, the annual loss of raw materials from iron processing was 150-200 million tons, and scrap iron had great potential for secondary utilization. Third, China had a trade deficit in terms of importing raw materials and exporting products, but it also had a trade surplus in trade volume. Finally, China imported iron-containing goods at high prices but exported iron-containing goods at low prices. This was due to the lack of high-end science and technology, which made China less competitive in the international market.

Diversity, abundances and distribution of antibiotic resistance genes and virulence factors in the South China Sea revealed by metagenomic sequencing

Antibiotic resistance genes (ARGs) and virulence factors (VFs) pose considerable health risks to humans. The occurrence and abundance of several typical ARGs in the sea have been widely investigated. However, the full profiles and abundances of the antibiotic resistome and VFs in the South China Sea remain unexplored. Therefore, in this study, we investigated the full profiles of the ARGs and VFs, as well as their abundances and distribution, in the South China Sea using metagenomic approaches. In total, 140 ARG subtypes and 155 VFs were detected. The most abundant ARG was multidrug resistance gene, followed by bacitracin resistance gene. Flagella was the most abundant VF. Pearson correlation analysis revealed a strong and positive correlation between the abundances of ARGs and VFs. Redundancy analysis and co-occurrence network analysis showed that the predominant VFs were positively correlated with the predominant ARGs in the South China Sea. Nonmetric multidimensional scaling and Procrustes analyses demonstrated that the sampling sites were clustered into three compartments according to the geographical location, i.e., offshore, open sea, and reef zones. The abundances of ARGs and VFs in the offshore zone were much higher than those in the open sea and reef zones (p < 0.05). Several physico-chemical factors most closely associated with anthropogenic activities, i.e., nitrate, lead, copper, and zinc, were positively correlated with the predominant ARGs and VFs in the South China Sea. Our results suggest that the ocean is a large reservoir of diverse and abundant ARGs and VFs, which may threaten human health and seafood safety. These findings improve the understanding of the relationship between ARG dissemination and intensive anthropogenic activities and can aid in improving ocean management and seafood product safety.

Catchment Soil Properties Affect Metal(loid) Enrichment in Reservoir Sediments of German Low Mountain Regions

Sediment management is a fundamental part of reservoir operation, but it is often complicated by metal(loid) enrichment in sediments. Knowledge concerning the sources of potential contaminants is therefore of important significance. To address this issue, the concentrations and the mobile fractions of metal(loid)s were determined in the sediments and the respective catchment areas of six reservoirs. The results indicate that reservoirs generally have a high potential for contaminated sediment accumulation due to preferential deposition of fine particles. The median values of the element-specific enrichment factor (EF) demonstrates slight enrichments of arsenic (EF: 3.4), chromium (EF: 2.8), and vanadium (EF: 2.9) for reservoir sediments. The enrichments of cadmium (EF: 8.2), manganese (EF: 3.9), nickel (EF: 4.8), and zinc (EF: 5.0) are significantly higher. This is enabled by a diffuse element release from the soils into the impounded streams, which is particularly favored by soil acidity. Leaching from the catchment soils partially enriches elements in stream sediments before their fine-grained portions in particular are deposited as reservoir sediment. We assume that this effect is of high relevance especially for reservoirs impounding small streams with forested catchments and weakly acid buffering parent material of soil formation.

Demographic implications of lead poisoning for eagles across North America

Lead poisoning occurs worldwide in populations of predatory birds, but exposure rates and population impacts are known only from regional studies. We evaluated the lead exposure of 1210 bald and golden eagles from 38 US states across North America, including 620 live eagles. We detected unexpectedly high frequencies of lead poisoning of eagles, both chronic (46 to 47% of bald and golden eagles, as measured in bone) and acute (27 to 33% of bald eagles and 7 to 35% of golden eagles, as measured in liver, blood, and feathers). Frequency of lead poisoning was influenced by age and, for bald eagles, by region and season. Continent-wide demographic modeling suggests that poisoning at this level suppresses population growth rates for bald eagles by 3.8% (95% confidence interval: 2.5%, 5.4%) and for golden eagles by 0.8% (0.7%, 0.9%). Lead poisoning is an underappreciated but important constraint on continent-wide populations of these iconic protected species.

A review on mechanism of biomineralization using microbial-induced precipitation for immobilizing lead ions

Lead (Pb) is a toxic metal originating from natural processes and anthropogenic activities such as coal power plants, mining, waste gas fuel, leather whipping, paint, and battery factories, which has adverse effects on the ecosystem and the health of human beings. Hence, the studies about investigating the remediation of Pb pollution have aroused extensive attention. Microbial remediation has the advantages of lower cost, higher efficiency, and less impact on the environment. This paper represented a review on the mechanism of biomineralization using microbial-induced precipitation for immobilizing Pb(II), including microbial-induced carbonate precipitation (MICP), microbial-induced phosphate precipitation (MIPP), and direct mineralization. The main mechanisms including biosorption, bioaccumulation, complexation, and biomineralization could decrease Pb(II) concentrations and convert exchangeable state into less toxic residual state. We also discuss the factors that govern methods for the bioremediation of Pb such as microbe characteristics, pH, temperature, and humic substances. Based on the above reviews, we provide a scientific basis for the remediation performance of microbial-induced precipitation technique and theoretical guidance for the application of Pb(II) remediation in soils and wastewater.

Insights into leaded gasoline registered in mud depocenters derived from multivariate statistical tool: southeastern Brazilian coast

Lead has been widely used since antiquity, but its uses drastically increased during the Industrial Revolution. The global emission of Pb into the environment was mainly due to tetraethyl lead added to gasoline as an antiknock additive. Because of its toxicity and neurological effects, the compound was phased out in the 1980s. Isotopic signatures are widely applied to differentiate sources of Pb; however, this is an expensive and sophisticated analysis compared to elemental analysis. Thus, this study aims to gain insight into leaded gasoline registered in mud depocenters from the southeastern Brazilian coast using multivariate statistical tools on elemental analysis data of trace elements. Seven multiple cores were collected on board the Research Vessel Alpha Crucis. Al, As, Ba, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Ni, P, Pb, Sc, Sr, V and Zn were analyzed by acid digestion and quantified by ICP-OES. Levels and enrichment factors of Pb resulted in homogeneous columns, indicating that small variations in concentrations can be attributed to grain size differences, not presenting contaminated levels. From statistical results, the highest contribution on the first component was represented by a lithogenic source with the leaching of continental rocks. Lead content was notable in its high loadings in other components, which suggests atmospheric deposition. An increase in these components in subsurface samples from vertical profiles between 1935 and 1996 could represent a fingerprint of the consumption of leaded gasoline in Brazil between 1923 and 1989. Thus, statistical analysis of elemental data enabled to infer possible sources and pathways of Pb to the environment, without isotopic analysis.

Environmental Pollution Effect Analysis of Lead Compounds in China Based on Life Cycle

Environmental pollution caused by lead toxicity causes harm to human health. Lead pollution in the environment mainly comes from the processes of mining, processing, production, use, and recovery of lead. China is the world’s largest producer and consumer of refined lead. In this paper, the material flow analysis method is used to analyze the flow and direction of lead loss in four stages of lead production, manufacturing, use, and waste management in China from 1949 to 2017. The proportion coefficient of lead compounds in each stage of lead loss was determined. The categories and quantities of lead compounds discharged in each stage were calculated. The results show that in 2017, China emitted 2.1519 million tons of lead compounds. In the four stages of production, manufacturing, use, and waste management, 137.9 kilo tons, 209 kilo tons, 275 kilo tons, and 1.53 million tons were respectively discharged. The emissions in the production stage are PbS, PbO, PbSO₄, PbO₂, Pb₂O₃, and more. The emissions during the manufacturing phase are Pb, PbO, PbSO₄, Pb₂O₃, Pb₃O₄, and more. The main emissions are Pb, PbO, Pb₂O₃, Pb₃O₄, and more. The main emissions in the waste management stage are PbS, Pb, PbO, PbSO₄, PbO₂, PbCO₃, Pb₂O₃, Pb₃O₄, and more. Among them, the emissions of PbSO₄, PbO, Pb, and PbO₂ account for about 90%, which are the main environmental pollution emissions. The waste management stage is an important control source of lead compound emission and pollution. In view of these characteristics of the environmental pollution risk of lead compounds in China, the government should issue more targeted policies to control lead pollution.

Does atmospheric processing produce toxic Pb-containing compounds? A case study in suburban Beijing by single particle mass spectrometry

A single particle aerosol mass spectrometry (SPAMS) was deployed to investigate the mixing state and chemical processing of Pb-rich particles in suburban Beijing. Based on a large dataset of mass spectra, Pb-rich particles were classified into Pb-O-Cl-N-S (55%), Pb-N (17%), Pb-N-S (15%), and Pb-EC (7%). Residual coal combustion, industrial activities, and meteorological conditions were identified as main factors regulating the variations of Pb-rich particles in the atmosphere. The highest abundance of the Pb-rich particles was observed during heating period (HP) primarily due to the increase in coal usage. Pb in Pb-O-Cl-N-S type was identified in forms of PbO, PbCl_2, and Pb(NO₃)₂. Dominantly presented in the form of Pb(NO₃)₂, Pb-N type represented the completely transformed Pb-rich particles from PbO/PbCl₂ by atmospheric processes. It is found that PbCl₂ and PbO could be transformed to Pb(NO₃)₂, highly dependent on the amount of NO₂ and RH. Significant enhancement of nitrate in Pb-O-Cl-N-S particles was observed when the RH was greater than 60%, emphasizing the importance of heterogeneous hydrolysis of N₂O₅ on the formation of Pb(NO₃)_2. Compared with non-carcinogenic PbCl₂/PbO and insoluble PbO, soluble and carcinogenic Pb(NO₃)₂ produced by atmospheric processes may significantly enhance negative effects of Pb-rich particles on human health and the ecosystem.

Sources, bioaccumulation, health risks and remediation of potentially toxic metal(loid)s (As, Cd, Cr, Pb and Hg): an epitomised review

The release of potentially toxic metal(loid)s (PTMs) such as As, Cd, Cr, Pb and Hg has become a serious threat to the environment. The anthropogenic contribution of these PTMs, especially Hg, is increasing continuously, and coal combustion in thermal power plants (TPPs) is considered to be the highest contributor of PTMs. Once entered into the environment, PTMs get deposited on the soil, which is the most important sink of these PTMs. This review centred on the sources of PTMs from coal and flyash and their enrichment in soil, chemical behaviour in soil and plant, bioaccumulation in trees and vegetables, health risk and remediation. Several remediation techniques (physical and chemical) have been used to minimise the PTMs level in soil and water, but the phytoremediation technique is the most commonly used technique for the effective removal of PTMs from contaminated soil and water. Several plant species like Brassica juncea, Pteris vittata and Helianthus annuus are proved to be the most potential candidate for the PTMs removal. Among all the PTMs, the occurrence of Hg in coal is a global concern due to the significant release of Hg into the atmosphere from coal-fired thermal power plants. Therefore, the Hg removal from pre-combustion (coal washing and demercuration techniques) coal is very essential to reduce the possibility of Hg release to the atmosphere.

Anthropogenic antimony flow analysis and evaluation in China

China is facing a shortage of antimony (Sb) resources, and Sb emissions are worsening. In exploring solutions to these issues, this paper attempts to apply substance flow analysis (SFA) to track Sb flow among the lithosphere, anthroposphere, and biosphere in China. The results are as follows: (1) China's Sb ore faces the risk of depletion. Although China has the largest Sb reserves in the world, the import of Sb concentrate accounted for a large proportion of the total material input during the production stage, which has increased from 9.78% in 2006 to 30.22% in 2016. Moreover, since 2013, the net export rate of Sb products during the manufacture and fabrication (M&F) stage has been growing, reaching 21.32% in 2016. (2) The Sb industry is highly dependent on ores. Moreover, the resource efficiency and cycling ratio of Sb are quite low. (3) Sb emissions cannot be ignored in industrial processes, particularly Sb emissions from the M&F and usage stages. Sb emissions discharged into the biosphere reached 1915.58 Gg in the period from 2006 to 2016.

Quantitative analysis of the spatio-temporal evolution of the anthropogenic transfer of lead in China

The redistribution of lead to meet human needs reflects the relationship between humans and land, and the redistribution process will influence the future evolution of the land surface. An analysis of the spatial transfer of lead was undertaken to determine the regional distribution of lead in each phase of its life cycle during 1990-2014 using the administrative unit of each province in Mainland China as the spatial unit. A quantitative analysis of the spatio-temporal evolution of the anthropogenic transfer of lead in China was conducted through a comparison of the differences in the spatio-temporal distribution of lead at different stages of its life cycle. The results showed that during 1990 to 2014, the mining of lead ore was gradually transferred from southern China to the northwest inland area and northern China, and lead within products was finally transferred to the eastern coastal area of China to complete its life cycle. The distribution of natural and social resources, supply and demand of markets, and foreign trade affect the lead anthropogenic transfer.

Quantitative analysis of the coupling coefficients between energy flow, value flow, and material flow in a Chinese lead-acid battery system

To reveal the historic characteristics of the material flow, energy flow and value flow in a lead-acid battery (LAB) system, a framework for the coupling relationship among the three flows was established based on material flow analysis and the characteristics of the energy and value flows. The coupling coefficients between energy and material (CCEM) and value and material (CCVM) were also defined. The investigation used by China as a case to study changes in stages and the historic evolution. The results show that the CCEM for lead in LABs was highest in the usage stage, approximately 5-16 times greater than in the other stages. The CCEM for production was almost twice as high for primary lead as for secondary lead, and the CCEM was lowest for the fabrication and product manufacture stage. The CCVM for lead in LABs was 2.5-6 times higher than for other types of lead. The CCVM was lower for scrap lead than for lead ore, and the CCVM was approximately 1.7 times higher for refined lead than for scrap and refined lead. For lead trade, CCVM was correlated with domestic and overseas markets. From 1990 to 2014, the CCEM for each stage was in decline, whereas the opposite was the case for CCVM. The influencing factors were analyzed in terms of resources, the environment, and markets. Increasing the circulation rate of scrap lead is an effective way to rapidly save resources, reduce lead pollution, and promote a circular economy. The limitations and potential value of the study are also highlighted, and future research is outlined.

Effect of hydroxyapatite particle size on the formation of chloropyromorphite in anglesite–hydroxyapatite suspensions

As the HAP particle size was decreased, the surfaces of the undissolved HAPs were coated by newly formed chloropyromorphite at a higher pH value, and particularly at a high P : Pb ratio, indicating that HAP particle size was a rate-limiting factor.

Age-Dependent Changes in Pb Concentration in Human Teeth

The result of exposure to Pb is its accumulation in mineralized tissues. In human body, they constitute a reservoir of approx. 90 % of the Pb reserve. The conducted research aimed at determining the accumulation of Pb in calcified tissues of permanent teeth. The concentration of Pb in 390 samples of teeth taken from a selected group of Polish people was determined using the AAS method. Average concentration of Pb in teeth amounted to 14.3 ± 8.18 μg/g, range of changes: 2.21-54.8 μgPb/g. Accumulation of Pb in human body was determined based on changes in Pb concentration in teeth of subjects aged 13-84 years. It was found that in calcified tissues of teeth, the increase in concentration of Pb that occurs with age is a statistically significant process (p = 0.02, the ANOVA Kruskal-Wallis test). It was determined that the annual increase in concentration of Pb in tissues of teeth is approx. 0.1 μg/g. Moreover, a different course of changes in Pb concentration in tissues of teeth in people born in different years was observed. The level of Pb concentration in teeth of the oldest subjects (>60 years) decreased for those born in the 1930s compared to those in the 1950s. Teeth from younger persons (<60 years) were characterized by an increasing level of Pb concentration. The analysis of changes of Pb indicates that for low exposure, a relatively greater accumulation of Pb concentration in calcified tissues of teeth can occur.