The relationship between atmospheric lead emissions and aggressive crime: an ecological study

Potential Health Risks of Lead Exposure from Early Life through Later Life: Implications for Public Health Education

Lead (Pb) exposure has been a serious environmental and public health problem throughout the world over the years. The major sources of lead in the past were paint and gasoline before they were phased out due to its toxicity. Meanwhile, people continue to be exposed to lead from time to time through many other sources such as water, food, soil and air. Lead exposure from these sources could have detrimental effects on human health, especially in children. UNICEF reported that approximately 800 million children have blood lead levels (BLLs) at or above 5 micrograms per deciliter (µg/dL) globally. This paper reports on the potential risks of lead exposure from early life through later life. The articles used in this study were searched from databases such as Springer, Science Direct, Hindawi, MDPI, Google Scholar, PubMed and other academic databases. The levels of lead exposure in low income and middle-income countries (LMICs) and high-income countries (HICs) were reported, with the former being more affected. The intake of certain nutrients could play an essential role in reducing (e.g., calcium and iron) or increasing (e.g., high fat foods) lead absorption in children. Elevated blood lead levels may disturb the cells' biological metabolism by replacing beneficial ions in the body such as calcium, magnesium, iron and sodium. Once these ions are replaced by lead, they can lead to brain disorders, resulting in reduced IQ, learning difficulties, reduced attention span and some behavioral problems. Exposure to lead at an early age may lead to the development of more critical problems later in life. This is because exposure to this metal can be harmful even at low exposure levels and may have a lasting and irreversible effect on humans. Precautionary measures should be put in place to prevent future exposure. These will go a long way in safeguarding the health of everyone, most especially the young ones.

Lead exposure and antisocial behavior: A systematic review protocol

BACKGROUND

Lead exposure remains highly prevalent worldwide despite decades of research highlighting its link to numerous adverse health outcomes. In addition to well-documented effects on cognition, there is growing evidence of an association with antisocial behavior, including aggression, conduct problems, and crime. An updated systematic review on this topic, incorporating study evaluation and a developmental perspective on the outcome, can advance the state of the science on lead and inform global policy interventions to reduce exposure.

OBJECTIVES

We aim to evaluate the link between lead exposure and antisocial behavior. This association will be investigated via a systematic review of human epidemiological and experimental nonhuman mammalian studies.

METHODS

The systematic review protocol presented in this publication is informed by recommendations for the conduct of systematic reviews in toxicology and environmental health research (COSTER) and follows the study evaluation approach put forth by the U.S. EPA Integrated Risk Information System (IRIS) program.

DATA SOURCES

We will search the following electronic databases for relevant literature: PubMed, BIOSIS and Web of Science. Search results will be stored in EPA's Health and Environmental Research Online (HERO) database.

STUDY ELIGIBILITY AND CRITERIA

Eligible human epidemiological studies will include those evaluating any population exposed to lead at any lifestage via ingestion or inhalation exposure and considering an outcome of antisocial behavior based on any of the following criteria: psychiatric diagnoses (e.g., oppositional defiant disorder (ODD), conduct disorder (CD), disruptive behavior disorders (DBD)); violation of social norms (e.g., delinquency, criminality); and aggression. Eligible experimental animal studies will include those evaluating nonhuman mammalian studies exposed to lead via ingestion, inhalation, or injection exposure during any lifestage. The following outcomes will be considered relevant: aggression; antisocial behavior; and altered fear, anxiety, and stress response.

STUDY APPRAISAL AND SYNTHESIS METHODS

Screening will be conducted with assistance from an artificial intelligence application. Two independent reviewers for each data stream (human, animal) will screen studies with highest predicted relevance against pre-specified inclusion criteria at the title/abstract and full-text level. Study evaluation will be conducted using methods adapted from the U.S. EPA IRIS program. After data extraction, we will conduct a narrative review and quantitative meta-analysis on the human epidemiological studies as well as a narrative review of the experimental animal studies. We will evaluate the strength of each evidence stream separately and then will develop a summary evidence integration statement based on inference across evidence streams.

National-Scale Assessment of Environmental Justice Trends in Public School Proximity to Industrial Lead Sources

BACKGROUND

Lead poisoning can severely affect neurological development in small children. Communities with environmental justice concerns often face higher levels of lead exposure via multiple routes of exposure. School-aged children can be exposed to lead at their schools through the deposition of lead emissions onto soil over time.

METHOD

Public school students' demographics in 'proximate schools;' those within 1.5 km of facilities with lead emissions were compared to other schools in their area. The average proximate emissions per student were calculated for different demographic groups in various geographic areas.

RESULTS

Schools in combined statistical areas within 1.5 km of lead facilities were found to be composed of significantly more Black (22%) and Hispanic (30%) students than other schools in the area (17% and 26% respectively). Meanwhile, schools close to lead sources tended to have smaller proportions of white students (37% in 'proximate schools', but 47% overall. When average emissions around students were calculated for a handful of combined statistical areas, inequality in lead exposure could be seen in almost every geographic area, across income and racial lines.

DISCUSSION

Students of color consistently faced the highest emissions in every area, though amounts, inequities, and at-risk populations differed throughout the different geographic areas.

CONCLUSION

The unique history of each location regarding immigration, discrimination, zoning laws, urban sprawl, and industrial past can contribute to this variety in inequities. These findings are not only consistent with environmental justice trends but also highlight other vulnerabilities for students like age and food security.

Children's exposure to environmental lead: A review of potential sources, blood levels, and methods used to reduce exposure

Lead has been used for thousands of years in different anthropogenic activities thanks to its unique properties that allow for many applications such as the manufacturing of drinking water pipes and its use as additives to gasoline and paint. However, knowledge of the adverse impacts of lead on human health has led to its banning from several of its applications, with the main goal of reducing environmental pollution and protecting human health. Human exposure to lead has been linked to different sources of contamination, resulting in high blood lead levels (BLLs) and adverse health implications, primarily in exposed children. Here, we present a summary of a literature review on potential lead sources affecting blood levels and on the different approaches used to reduce human exposure. The findings show a combination of different research approaches, which include the use of inspectors to identify problematic areas in homes, collection and analysis of environmental samples, different lead detection methods (e.g. smart phone applications to identify the presence of lead and mass spectrometry techniques). Although not always the most effective way to predict BLLs in children, linear and non-linear regression models have been used to link BLLs and environmental lead. However, multiple regressions and complex modelling systems would be ideal, especially when seeking results in support of decision-making processes. Overall, lead remains a pollutant of concern and many children are still exposed to it through environmental and drinking water sources. To reduce exposure to lead through source apportionment methods, recent technological advances using high-precision lead stable isotope ratios measured on multi-collector induced coupled plasma mass spectrometry (MC-ICP-MS) instruments have created a new direction for identifying and then eliminating prevalent lead sources associated with high BLLs.

Gut Escherichia coli expressing Pb2+-adsorption protein reduces lead accumulation in grass carp, Ctenopharyngodon idellus

Lead (Pb²⁺) is easy to accumulate in fish which become a major source of Pb²⁺ exposure to humans. In this study, a recombinant Escherichia coli strain expressing Pb²⁺-specific surface-binding protein anchored by the ice nucleation protein was introduced into grass carp (Ctenopharyngodon idellus) gut to investigate its protective effect against dietary Pb²⁺ exposure. Pb²⁺ mostly precipitated on the surface of the engineered strain through Pb²⁺-specific surface-binding protein, with a maximum adsorption efficiency of 73% and an adsorption capacity of 163 μmol/g dry cells. The Pb²⁺ concentration in engineered bacteria-fed grass carp was reduced significantly, and the residual level of Pb²⁺ in feces was increased by 76%, compared with the control group. Meantime, the engineered bacteria were able to mitigate the oxidative stress and histological alterations of intestines and dysbiosis of gut microbiota induced by Pb²⁺exposure. Thus, the engineered bacterium that can effectively reduce Pb²⁺ residue in grass carp might be a useful tool for decontamintion of lead in aquatic organisms.

Identifying geogenic and anthropogenic controls on different spatial distribution patterns of aluminium, calcium and lead in urban topsoil of Greater London Authority area

Quantifying variation of metals in urban soils is crucial for efficient environmental and public health management. Prior to the interferences of human activities, regional topsoil geochemical distributions were generally primarily controlled by the underlying parent materials (PMs). With the rapid urbanisation, urban topsoil geochemical distributions have been modified with different levels. Three metals, aluminium (Al), calcium (Ca) and lead (Pb), were chosen to investigate the different levels of geogenic and anthropogenic controls in urban topsoil of Greater London Authority (GLA) area. These three metal elements clearly demonstrated the different spatial distribution affected by human activities using analysis of variance (ANOVA) and GIS-based spatial analysis. The high values of Al were in the clay which is located in the north and south GLA area; Pb accumulated in built-up areas and near traffic roads, which was likely associated with leaded paints and leaded petrol, respectively; the high Ca concentrations were in the Chalk bedrock of the southern GLA area and historical deconstruction and reconstruction sites in the city centre. Based on spatial interpolation and hot spot analysis (local Moran's I), this study reveals the different levels of geogenic and anthropogenic controls on different chemicals in urban soils: while the spatial distribution of Pb, which is more easily affected by human activities, can be significantly changed, the inert element Al may still be able to maintain its natural spatial distribution even in the heavily urbanized GLA area, and Ca demonstrates the mixed spatial distribution affected by both natural factors and human activities.

An Important Personality Trait Varies with Blood and Plumage Metal Concentrations in a Free-Living Songbird

Metal pollution is a global problem, which threatens to seriously disrupt behavioral patterns and health in humans and wildlife. Nonetheless, little is known regarding how exposure to metal pollution affects animal personalities, as defined by repeatable among individual differences in behavior. We used a large dataset to investigate the relationship between individual blood and feather metal concentrations and three personality traits (exploration behavior, territorial aggressiveness, and aggressiveness during nest defense) in great tits (Parus major), a model species for animal personality research. We previously demonstrated slower exploration behavior at highly polluted study sites, where exposure to lead, cadmium, and arsenic is high. Here, we demonstrate the across-year repeatability of exploration behavior and aggressiveness during nest defense, providing strong evidence for the existence of personalities in our populations. Furthermore, we demonstrate that individuals with high blood lead concentrations and high concentrations of multiple metals in the feathers exhibit slower exploration behavior but no differences in territorial aggressiveness or nest defense relative to less exposed birds. The mechanism underlying the relationship between metal exposure and exploration behavior remains to be determined but could involve neurotoxic effects. Our study highlights that metal pollution could have underappreciated effects on animal personalities, with implications for individual fitness and societal function.

A study protocol to determine the association between lifetime lead exposure and violent criminal behaviour in young males in conflict with the law

Background

Low-level lead exposure has harmful and persistent effects on behaviour. Recent studies have linked environmental lead exposure and the development of aggressive, violent and criminal behaviour. This protocol is designed to study an association between lifetime (bone) lead levels and violent criminal behaviour among young males in conflict with the law in Gauteng youth development centres.

Methods

This paper describes a study to determine a link between lifetime lead exposure and violent criminal behaviour. Lifetime lead exposure will be measured using bone lead measurement, while blood lead levels will be observed for current exposure. Thereafter, criminal records of participants will be reviewed whereas violent behaviour and risk factors will be observed using a questionnaire. The study focused on young males in conflict with the law in three centres within Gauteng Provence, South Africa. After stratifying the centres, we randomly selected participants. The researcher shall adhere to ethical requirements throughout the study. Data will be analysed for descriptive and inferential analysis using Statistical Package for Social Science (SPSS).

Discussion

The study will provide a strong foundation for an improved understanding of the relationship between environmental contamination from lead exposure and aggression/violent criminal behaviour. Beyond the health sector, the study findings may be able to inform new approaches to crime prevention through environmental action with an emphasis on the role of non-health sectors.

Sources of lead exposure in various countries

This review evaluates the sources of lead exposure worldwide. Studies from searches relating to sources of lead exposure in various countries within different regional zones were reviewed. Results indicated that in Nigeria, exposure sources include electronic waste, paint and batteries. In Mexico exposure sources include glazed ceramics, lead contaminated utensils and lead contaminated water, for India lead sources include cosmetics and traditional medicines. Sources of lead exposure in China include e-waste, traditional medicines and industrial emissions. In France, exposure sources included lead paint from older homes, imported ceramics and cosmetics and industrial emissions. Australia's exposure sources include paint, dust, imported toys and traditional medicines. Finally, in the United States exposure sources included paint, the industrial legacy of lead exposure and batteries. In high-income countries (HICs) the legacy of lead exposure keeps populations continuously exposed. In lower- and middle-income countries (LMICs), in addition to the legacy of lead exposure, lack of regulations or the inability to enforce regulations keeps populations exposed. In all, evidence suggests that lead exposure remains an issue of public health significance in both HIC and LMIC.

Analysis of blood lead levels of young children in Flint, Michigan before and during the 18-month switch to Flint River water

Background: The toxicity of lead, like any xenobiotic, is directly linked to the duration of exposure and toxin concentration in the body. The elevation in blood lead levels (BLLs) in young Flint, Michigan children noted in time-periods before, and during the 18-month exposure to Flint River water (FRW) from 25 April 2014 to 15 October 2015 is well-known internationally. The length of time BLLs were elevated is unknown, yet key in understanding the potential health impact of the event. The objective of this study was to evaluate whether BLLs in Flint children were increased during the entire 18-month FRW exposure compared to similar earlier time periods. Methods: We conducted a retrospective study analyzing BLLs from Flint children aged 5 years and under. The geometric mean (GM) BLLs and percentages of BLLs ≥5.0 μg/dL in Period I: 25 April 2006 to 15 October 2007 (earliest timeframe available for study) and Period II: 25 April 2012 to 15 October 2013 (timeframe immediately before the water switch), were compared to Period III, 25 April 2014 to 15 October 2015 (FRW exposure). Results: There were 5663 BLLs available for study. GM ± SE BLLs decreased from 2.19 ± 0.03 μg/dL in Period I to 1.47 ± 0.02 μg/dL in Period II [95% CI, 0.64, 0.79]; p<.001 and decreased further to 1.32 ± 0.02 µg/dL during the FRW Period III [95% CI, 0.79, 0.95]; p<.001. The percentage of BLLs ≥5.0 μg/dL decreased from Period I (10.6%) to Period II (3.3%) [95% CI, 5.7, 8.8]; p<.001 and from Period I to Period III (3.9%) [95% CI, 5.0, 8.2]; p=.002. The 0.6% increase from Period II to Period III was not statistically significant [95% CI, -1.9, 0.57]; p=.30. Conclusion: Analyses of GM and percentages ≥5.0 μg/dL of BLLs do not support the occurrence of a global increase in BLLs in young children of Flint during the entire 18-month period of FRW exposure.

Fort J, Taylor MP. Assessment of the Presence of Soil Lead Contamination Near a Former Lead Smelter in Mombasa, Kenya

BACKGROUND

The informal settlement of Owino Uhuru near an abandoned lead smelter attracted international attention due to an apparent lead poisoning event. Despite this attention, the environmental data collected to date do not indicate high levels of residual contamination.

OBJECTIVES

To further confirm previous findings and determine any necessary risk mitigation measures, an assessment of surface soil lead concentrations was conducted in the community.

METHODS

Investigators carried out an assessment of the soil in a ~12,000 m2 section of the Owino Uhuru neighborhood over the course of a single day in June 2017 with the assistance of community leaders. Fifty-nine in situ soil measurements were taken using an Innov-X tube-based (40 kV) alpha X-ray fluorescence instrument (pXRF).

RESULTS

The assessment found that mean surface soil lead concentrations in areas conducive to exposure were 110 mg/kg (95% CI: 54-168); below United States Environmental Protection Agency and the Environment Canada screening levels of 400 mg/kg and 140 mg/kg, respectively.

CONCLUSIONS

There is likely no current need for risk mitigation activities in the community. These results could inform discussions on the allocation of public health spending.

COMPETING INTERESTS

The authors declare no competing financial interests. BE, VOO, CN and JSF are employees of Pure Earth. MPT sits on the Editorial Board of the Journal of Health and Pollution.

A meta-analysis of blood lead levels in India and the attributable burden of disease

Multiple studies in India have found elevated blood lead levels (BLLs) in target populations. However the data have not yet been evaluated to understand population-wide exposure levels. We used arithmetic mean blood lead data published from 2010 to 2018 on Indian populations to calculate the average BLLs for multiple subgroups. We then calculated the attributable disease burden in IQ decrement and Disability Adjusted Life Years (DALYs). Our Pubmed search yielded 1066 articles. Of these, 31 studies representing the BLLs of 5472 people in 9 states met our study criteria. Evaluating these, we found a mean BLL of 6.86 μg/dL (95% CI: 4.38-9.35) in children and 7.52 μg/dL (95% CI: 5.28-9.76) in non-occupationally exposed adults. We calculated that these exposures resulted in 4.9 million DALYs (95% CI: 3.9-5.6) in the states we evaluated. Population-wide BLLs in India remain elevated despite regulatory action to eliminate leaded petrol, the most significant historical source. The estimated attributable disease burden is larger than previously calculated, particularly with regard to associated intellectual disability outcomes in children. Larger population-wide BLL studies are required to inform future calculations. Policy responses need to be developed to mitigate the worst exposures.

Cost-benefit analysis for a lead wheel weight phase-out in Canada

Lead wheel weights (LWWs) have been banned in Europe, and some US States, but they continue to dominate the market in Canada. Exposure to lead is associated with numerous health impacts and can result in multiple and irreversible health problems which include cognitive impairment when exposure occurs during early development. Such impacts incur high individual and social costs. The purpose of this study was to assess the costs and public health benefits of a Risk Management Strategy (RMS) that would result from a LWW phase-out in Canada and compare this to a Business-As-Usual (BAU) scenario. The contribution of LWWs to lead concentrations in media including roadway soil/dust, ambient and indoor air, and indoor dust were estimated. The Integrated Exposure Uptake Biokinetic Model for Lead in Children (IEUBK) was used to develop estimates for the blood lead levels (BLLs) in children (μg/dL) associated with the BAU and the RMS. The BLLs estimated via the IEUBK model were then used to assess the IQ decrements associated with the BAU that would be avoided under the RMS. The subsequent overall societal benefits in terms of increased lifetime earning potential and reduced crime rate, were then estimated and compared to industry and government costs. LWWs form 72% of the Canadian wheel weight market and >1500 tonnes of lead as new LWWs attached to vehicles enters Canadian society annually. We estimate that 110-131 tonnes of lead in detached WWs are abraded on roadways in Canada each year. A LWW phase-out was predicted to result in a drop in pre-school BLLs of up to 0.4 μg/dL. The estimated net benefits associated with the RMS based on cognitive decrements avoided and hence increased lifetime earning potential (increased productivity) and reduced crime are expected to be: C$248 million (8% discount rate) to C$1.2 billion (3% discount rate) per year.

Blood Lead Levels of Children in Flint, Michigan: 2006-2016

OBJECTIVE

We evaluated the increases in blood lead levels (BLLs) observed in young children in Flint, Michigan, during their exposure to corrosive Flint River water during the years 2014 and 2015 and compared their BLLs to those of Flint children measured during the years 2006-2013 and 2016.

STUDY DESIGN

This was a retrospective study design using BLLs extracted from databases from 2006 to 2016. We analyzed a population sample of 15 817 BLLs from children aged ≤5 years with potential exposure to contaminated Flint River water. Percentages of BLLs ≥5.0 µg/dL and geometric mean (GM) BLLs were analyzed over time.

RESULTS

A significant decline in the percentages of BLLs ≥5.0 µg/dL from 11.8% in 2006 to 3.2% in 2016 was observed (P < .001). GM ± SE BLLs decreased from 2.33 ± 0.04 µg/dL in 2006 to 1.15 ± 0.02 µg/dL in 2016 (P < .001). GM BLLs increased twice: from 1.75 ± 0.03 µg/dL to 1.87 ± 0.03 µg/dL (2010-2011) and from 1.19 ± 0.02 µg/dL to 1.30 ± 0.02 µg/dL (2014-2015). Overall, from 2006 to 2016, there was a 72.9% decrease in the percentage of children with BLLs ≥5.0 µg/dL and a 50.6% decrease in GM BLLs.

CONCLUSION

These findings suggest that the 11 year trend of annual decreases in BLLs in children in Flint, Michigan, reversed to a degree consistent with random variation from 2010 to 2011, and again during the exposure to Flint River water in 2014-2015. Historically, public health efforts to reduce BLLs of young children in Flint have been effective over the 11-year period studied.

The application of system dynamics modelling to environmental health decision-making and policy - a scoping review

BACKGROUND

Policy and decision-making processes are routinely challenged by the complex and dynamic nature of environmental health problems. System dynamics modelling has demonstrated considerable value across a number of different fields to help decision-makers understand and predict the dynamic behaviour of complex systems in support the development of effective policy actions. In this scoping review we investigate if, and in what contexts, system dynamics modelling is being used to inform policy or decision-making processes related to environmental health.

METHODS

Four electronic databases and the grey literature were systematically searched to identify studies that intersect the areas environmental health, system dynamics modelling, and decision-making. Studies identified in the initial screening were further screened for their contextual, methodological and application-related relevancy. Studies deemed 'relevant' or 'highly relevant' according to all three criteria were included in this review. Key themes related to the rationale, impact and limitation of using system dynamics in the context of environmental health decision-making and policy were analysed.

RESULTS

We identified a limited number of relevant studies (n = 15), two-thirds of which were conducted between 2011 and 2016. The majority of applications occurred in non-health related sectors (n = 9) including transportation, public utilities, water, housing, food, agriculture, and urban and regional planning. Applications were primarily targeted at micro-level (local, community or grassroots) decision-making processes (n = 9), with macro-level (national or international) decision-making to a lesser degree. There was significant heterogeneity in the stated rationales for using system dynamics and the intended impact of the system dynamics model on decision-making processes. A series of user-related, technical and application-related limitations and challenges were identified. None of the reported limitations or challenges appeared unique to the application of system dynamics within the context of environmental health problems, but rather to the use of system dynamics in general.

CONCLUSIONS

This review reveals that while system dynamics modelling is increasingly being used to inform decision-making related to environmental health, applications are currently limited. Greater application of system dynamics within this context is needed before its benefits and limitations can be fully understood.

Low-level Gestational Lead Exposure Alters Dendritic Spine Plasticity in the Hippocampus and Reduces Learning and Memory in Rats

Lead (Pb) is known to impair children's cognitive function. It has been previously shown that developmental Pb exposure alters dendritic spine formation in hippocampal pyramidal neurons. However, the underlying mechanism has not yet been defined. In this study, a low-level gestational Pb exposure (GLE) rat model was employed to investigate the impact of Pb on the spine density of the hippocampal pyramidal neurons and its regulatory mechanism. Pb exposure resulted in impaired performance of the rats in the Morris water maze tasks, and in decreased EPSC amplitudes in hippocampal CA3-CA1 regions. With a 3D reconstruction by the Imaris software, the results from Golgi staining showed that the spine density in the CA1 region was reduced in the Pb-exposed rats in a dose-dependent manner. Decreased spine density was also observed in cultured hippocampal neurons following the Pb treatment. Furthermore, the expression level of NLGN1, a postsynaptic protein that mediates synaptogenesis, was significantly decreased following the Pb exposure both in vivo and in vitro. Up-regulation of NLGN1 in cultured primary neurons partially attenuated the impact of Pb on the spine density. Taken together, our resultssuggest that Pb exposure alters spine plasticity in the developing hippocampus by down-regulating NLGN1 protein levels.

Geochemical sources, forms and phases of soil contamination in an industrial city

This study examines current soil contamination in an Australian industrial city, Newcastle. Public (roadside verges and parks) and private (homes) surface soils (n=170) contained metal(loid)s elevated above their respective Australian Health Investigation Levels (HIL). Lead (Pb), the most common contaminant in the city, exceeds the HIL for residential soils (HIL-A, 300mg/kg) in 88% of private soils (median: 1140mg/kg). In-vitro Pb bio-accessibility analysis of selected soils (n=11) using simulated gastric fluid showed a high affinity for Pb solubilisation (maximum Pb concentration: 5190mg/kg, equating to 45% Pb bio-accessibility). Highly soluble Pb-laden Fe- and Mn-oxides likely contribute to the bio-accessibility of the Pb. Public and private space surface soils contain substantially less radiogenic Pb (range: ²⁰⁸Pb/²⁰⁷Pb: 2.345-2.411, ²⁰⁶Pb/²⁰⁷Pb: 1.068-1.312) than local background soil (²⁰⁸Pb/²⁰⁷Pb: 2.489, ²⁰⁶Pb/²⁰⁷Pb: 1.198), indicating anthropogenic contamination from the less radiogenic Broken Hill type Pb ores (²⁰⁸Pb/²⁰⁷Pb: 2.319, ²⁰⁶Pb/²⁰⁷Pb: 1.044). Source apportionment using Pb isotopic ratio quantification and soil mineralogy indicate the city's historic copper and steel industries contributed the majority of the soil contaminants through atmospheric deposition and use of slag waste as fill material. High-temperature silicates and oxides combined with rounded particles in the soil are characteristic of smelter dust emissions. Additionally, a preliminary investigation of polycyclic aromatic hydrocarbons in soils, sometimes associated with ferrous metal smelting, coal processing or burning of fossil fuels, shows that these too pose a health exposure risk (calculated in comparison to benzo(a)pyrene: n=12, max: 13.5mg/kg, HIL: 3mg/kg).

Heavy metal burdens of public primary school children related to playground soils and classroom dusts in Ibadan North-West local government area, Nigeria

Information about heavy metal burden of children in Nigeria related to playground soils and classroom dusts is lacking. Playground soil, classroom dust, blood and spot urine samples (n=253) were collected from 6 urban and 2 semi-rural public schools in Ibadan North-West, Nigeria. Samples were analysed for Pb, Cu, Zn, Fe and Mn. Mean blood Pb levels in urban area (male, 41.66±8.78μg/dl vs. female, 40.64±5.46μg/dl) were twice as high as those in semi-rural area (male, 19.71±3.73μg/dl vs. female, 20.65±2.26μg/dl). Concentrations of Pb, Cu, Zn, and Fe in soil and dust samples in the urban schools were between 2- to 4-fold greater than that of semi-rural schools. No correlation was observed between blood and dust metals. A positive correlation (r=0.168, p=0.008) was observed between blood Pb and playground soil Pb. Pb burden in the children might be from their schools' playgrounds and other yet unidentified sources.

Tracing changes in atmospheric sources of lead contamination using lead isotopic compositions in Australian red wine

Air quality data detailing changes to atmospheric composition from Australia's leaded petrol consumption is spatially and temporally limited. In order to address this data gap, wine was investigated as a potential proxy for atmospheric lead conditions. Wine spanning sixty years was collected from two wine regions proximal to the South Australian capital city, Adelaide, and analysed for lead concentration and lead and strontium isotopic composition for source apportionment. Maximum wine lead concentrations (328 μg/L) occur prior to the lead-in-air monitoring in South Australia in the later 1970s. Wine lead concentrations mirror available lead-in-air measurements and show a declining trend reflecting parallel reductions in leaded petrol emissions. Lead from petrol dominated the lead in wine ((206)Pb/(207)Pb: 1.086; (208)Pb/(207)Pb: 2.360) until the introduction of unleaded petrol, which resulted in a shift in the wine lead isotopic composition closer to vineyard soil ((206)Pb/(207)Pb: 1.137; (208)Pb/(207)Pb: 2.421). Current mining activities or vinification processes appear to have no impact with recent wine samples containing less than 4 μg/L of lead. This study demonstrates wine can be used to chronicle changes in environmental lead emissions and is an effective proxy for atmospherically sourced depositions of lead in the absence of air quality data.