Multiple metal accumulation as a factor in learning achievement within various New Orleans elementary school communities

Contamination of children's sandboxes with potentially toxic elements in historically polluted industrial city

When playing in sandboxes, children are particularly vulnerable to poisoning with potentially toxic elements (PTE) due to their hand-to-mouth behaviour. In Slovenia, the city of Celje is heavily contaminated due to zinc ore smelting and iron industry. In some sandboxes, sand from Mežica Pb-Zn mine waste was used. Granulometric and XRF analysis showed that all samples contain larger percentage of fine-sized particles and some have higher As, Ba, Cd, Pb and Zn contents than allowed. By XRD and SEM/EDS analysis we identified carries of PTE, and confirmed three possible sources of contamination: the waste material from the Pb-Zn mine, the emissions from local industry and from the old Zn-smelting stockpile used as a landfill. The total health risk (ΣHI) exceeds critical value in one sandbox. The bioaccessibility of PTEs is alarming due to presence of highly soluble metal-bearing particles. Study revealed importance of combining results of health risk evaluation with bioaccessibility of elements, which is a function of the carriers of PTE. This knowledge is essential for undertaking remedial measures. Improper use of waste material could result in introducing hazardous material in the environment. We propose frequent replacement of sand and stricter legislation regulating status and usage of waste materials.

Hazardous air pollutants are associated with worse performance in reading, math, and science among US primary schoolchildren

Emerging evidence demonstrates that chronic exposure to air pollution may negatively impact children's cognitive processing and memory. Little is currently known about how air pollution impacts individual children's academic performance through time. Academic performance is practically important, given its linkage to children's future life course trajectories. Individual-level, longitudinal data from 16,000 US primary school students are combined with a tract-level hazardous air pollutant (HAP) measure to assess how kindergarten exposures are associated with competencies in reading, math and science through third grade. We employed linear mixed models with repeated measures within children (e.g., five math tests across four years), clustering within census tracts, and random effects specified at the child- and census tract-levels. Controlling for a comprehensive list of time variant and time invariant covariates, we found statistically significant associations between higher levels of HAPs and lower reading (b = -0.02; p < 0.05), math (b = -0.02; p < 0.001), and science (b = -0.05; p < 0.001) scores. These negative effects of pollution on academic competency in the early primary school years add to the weight of evidence that air pollution harms children's academic potential.

Remediation techniques for removal of heavy metals from the soil contaminated through different sources: a review

Heavy metal pollution is one of the serious problems and contaminates the environment by different means with the blow of industries in several countries. Different techniques like physical, chemical, and biological have been used for removal of heavy metal contaminants from the environment. Some of these have limitations such as cost, time consumption, logistical problems, and mechanical involvedness. Nowadays, in situ immobilization of metals, phytoremediation and biological techniques turned out to be best solution for elimination of metal(loid) s from the soil. Here, we reviewed the different remediation techniques for extraction of heavy metals from soil and especially highlighting in situ immobilization technique. The aim of remediation efforts at the contaminant site is to restrict the heavy metal to enter in the environment, food chain, and exposure to humans beings. The type of method used at a given site depends on the various factors like natural processes take place at the contaminated site, soil type, type of chemicals, and the depth of contaminated site.

The concurrent decline of soil lead and children's blood lead in New Orleans

The inextricable link between topsoil lead (Pb) and children’s blood lead (BPb) has not been widely accepted. Pb is associated with multiple health adversities. Urban residents are at risk from exposure to legacy Pb dust in topsoil resulting from smelting, industrial discharges, leaded gasoline emissions, leaded paint, and incineration. In New Orleans, topsoil median Pb decreased in ∼15 y from 99 mg/kg to 54 mg/kg, or ∼2.4 mg⋅kg⋅y⁻¹. In ∼12 y, children’s median BPb declined from 3.6 μg/dL to 1.3 μg/dL, or ∼0.2 μg⋅dL⋅y⁻¹. We argue that depletion of topsoil Pb is an important factor in the continuous decline of children’s BPb. Similar processes are expected in all US cities. Primary prevention requires curtailing Pb in all sources, including topsoil.

Lead (Pb) is extremely toxic and a major cause of chronic diseases worldwide. Pb is associated with health disparities, particularly within low-income populations. In biological systems, Pb mimics calcium and, among other effects, interrupts cell signaling. Furthermore, Pb exposure results in epigenetic changes that affect multigenerational gene expression. Exposure to Pb has decreased through primary prevention, including removal of Pb solder from canned food, regulating lead-based paint, and especially eliminating Pb additives in gasoline. While researchers observe a continuous decline in children’s blood lead (BPb), reservoirs of exposure persist in topsoil, which stores the legacy dust from leaded gasoline and other sources. Our surveys of metropolitan New Orleans reveal that median topsoil Pb in communities (n = 274) decreased 44% from 99 mg/kg to 54 mg/kg (P value of 2.09 × 10⁻⁰⁸), with a median depletion rate of ∼2.4 mg⋅kg⋅y⁻¹ over 15 y. From 2000 through 2005 to 2011 through 2016, children’s BPb declined from 3.6 μg/dL to 1.2 μg/dL or 64% (P value of 2.02 × 10⁻⁸⁵), a decrease of ∼0.2 μg⋅dL⋅y⁻¹ during a median of 12 y. Here, we explore the decline of children’s BPb by examining a metabolism of cities framework of inputs, transformations, storages, and outputs. Our findings indicate that decreasing Pb in topsoil is an important factor in the continuous decline of children’s BPb. Similar reductions are expected in other major US cities. The most contaminated urban communities, usually inhabited by vulnerable populations, require further reductions of topsoil Pb to fulfill primary prevention for the nation’s children.

Environmental exposure to low-level lead (Pb) co-occurring with other neurotoxicants in early life and neurodevelopment of children

Lead (Pb) is a worldwide environmental contaminant that even at low levels influences brain development and affects neurobehavior later in life; nevertheless it is only a small fraction of the neurotoxicant (NT) exposome. Exposure to environmental Pb concurrent with other NT substances is often the norm, but their joint effects are challenging to study during early life. The aim of this review is to integrate studies of Pb-containing NT mixtures during the early life and neurodevelopment outcomes of children. The Pb-containing NT mixtures that have been most studied involve other metals (Mn, Al, Hg, Cd), metalloids (As), halogen (F), and organo-halogen pollutants. Co-occurring Pb-associated exposures during pregnancy and lactation depend on the environmental sources and the metabolism and half-life of the specific NT contaminant; but offspring neurobehavioral outcomes are also influenced by social stressors. Nevertheless, Pb-associated effects from prenatal exposure portend a continued burden on measurable neurodevelopment; they thus favor increased neurological health issues, decrements in neurobehavioral tests and reductions in the quality of life. Neurobehavioral test outcomes measured in the first 1000 days showed Pb-associated negative outcomes were frequently noticed in infants (<6 months). In older (preschool and school) children studies showed more variations in NT mixtures, children's age, and sensitivity and/or specificity of neurobehavioral tests; these variations and choice of statistical model (individual NT stressor or collective effect of mixture) may explain inconsistencies. Multiple exposures to NT mixtures in children diagnosed with 'autism spectrum disorders' (ASD) and 'attention deficit and hyperactivity disorders' (ADHD), strongly suggest a Pb-associated effect. Mixture potency (number or associated NT components and respective concentrations) and time (duration and developmental stage) of exposure often showed a measurable impact on neurodevelopment; however, net effects, reversibility and/or predictability of delays are insufficiently studied and need urgent attention. Nevertheless, neurodevelopment delays can be prevented and/or attenuated if public health policies are implemented to protect the unborn and the young child.

Curtailing Lead Aerosols: Effects of Primary Prevention on Declining Soil Lead and Children's Blood Lead in Metropolitan New Orleans

After decades of accumulation of lead aerosols in cities from additives in gasoline, in 1975 catalytic converters (which are ruined by lead) became mandatory on all new cars. By 1 January 1986 the rapid phase-down banned most lead additives. The study objective is to review temporal changes of environmental lead and children's blood lead in communities of metropolitan New Orleans. In 2001, a soil lead survey of 287 census tracts of metropolitan New Orleans was completed. In August-September 2005 Hurricanes Katrina and Rita storm surges flooded parts of the city with sediment-loaded water. In April-June 2006, 46/287 (16%) of the original census tracts were selected for resurvey. A third survey of 44/46 (15%) census tracts was completed in 2017. The census tract median soil lead and children's median blood lead decreased across surveys in both flooded and unflooded areas. By curtailing a major urban source of lead aerosols, children's lead exposure diminished, lead loading of soil decreased, and topsoil lead declined. Curtailing lead aerosols is essential for primary prevention. For the sake of children's and ultimately societal health and welfare, the long-term habitability of cities requires terminating all remaining lead aerosols and cleanup of legacy-lead that persists in older inner-city communities.

The role of soil mineralogy on oral bioaccessibility of lead: Implications for land use and risk assessment

Understanding the oral bioaccessibility of lead (Pb) present in soils in urbanized areas is important for the human exposure risk assessment. In particular, the role of the soil-mineralogy in the oral bioaccessibility has not been extensively studied. To investigate bioaccessibility, five types of periurban soils were collected, samples were spiked with the same amount of lead-chromates from traffic paint, and subjected to the in vitro Physiological Based Extraction Test (PBET). Ten samples of urban topsoils were collected at elementary schools playgrounds, Pb-bioaccessibility was measured, and a prediction equation for bioaccessibility was constructed. Mineralogy, and metal content were identified with a combination of X-ray powder diffraction, scanning electron microscopy, and portable X-ray fluorescence techniques. Traffic paint sample is made of 15% quartz (SiO₂), 13% crocoite (PbCrO₄), 55% calcite (CaCO₃), and 17% kaolinite (Al₂Si₂O₅(OH)₄) and it contains high metal content (Pb, Cr, Zn, and Ca). Studied soils are characterized by variable amounts of acid-neutralizing minerals (carbonates) and low metal content. Spiked soils contained almost equal concentration of Pb, Cr, and Zn, because the contribution of these metals is from the added paint. However, obtained Pb-bioaccessibility at gastric and intestinal conditions are variable (40 to 51% gastric, 24 to 70.5% intestinal). Carbonate content shows significant correlation (p < 0.05) with Cr, Ca, calcite, crocoite, and Pb-bioaccessible at gastric conditions. Correlation of Pb-bioaccessible at intestinal conditions is significant (p < 0.05) with kaolinite. Variability of Pb-bioaccesibility in urban environments is commonly associated to differences in Pb-sources, however, our results show that the bioaccessibility of the same pollutant behaves different for each soil type. This suggests that soil mineralogy may play a role in Pb-releasing at gastrointestinal conditions. Soil information about mineralogical characteristics from this study may help to reduce exposure to lead from urban sources if data are incorporated into urban planning.

School environmental conditions and links to academic performance and absenteeism in urban, mid-Atlantic public schools

School facility conditions, environment, and perceptions of safety and learning have been investigated for their impact on child development. However, it is important to consider how the environment separately influences academic performance and attendance after controlling for school and community factors. Using results from the Maryland School Assessment, we considered outcomes of school-level proficiency in reading and math plus attendance and chronic absences, defined as missing 20 or more days, for grades 3-5 and 6-8 at 158 urban schools. Characteristics of the environment included school facility conditions, density of nearby roads, and an index industrial air pollution. Perceptions of school safety, learning, and institutional environment were acquired from a School Climate Survey. Also considered were neighborhood factors at the community statistical area, including demographics, crime, and poverty based on school location. Poisson regression adjusted for over-dispersion was used to model academic achievement and multiple linear models were used for attendance. Each 10-unit change in facility condition index, denoting worse quality buildings, was associated with a decrease in reading (1.0% (95% CI: 0.1-1.9%) and math scores (0.21% (95% CI: 0.20-0.40), while chronic absences increased by 0.75% (95% CI: 0.30-1.39). Each log increase the EPA's Risk Screening Environmental Indicator (RSEI) value for industrial hazards, resulted in a marginally significant trend of increasing absenteeism (p < 0.06), but no association was observed with academic achievement. All results were robust to school-level measures of racial composition, free and reduced meals eligibility, and community poverty and crime. These findings provide empirical evidence for the importance of the community and school environment, including building conditions and neighborhood toxic substance risk, on academic achievement and attendance.

Spatiotemporal dynamic transformations of soil lead and children's blood lead ten years after Hurricane Katrina: New grounds for primary prevention

BACKGROUND

The contribution of lead contaminated soil to blood lead, especially as it is a large reservoir of lead dust, has been underestimated relative to lead-based paint. On 29 August 2005 Hurricane Katrina flooded and disrupted habitation in New Orleans. Soil and blood lead were mapped prior to Katrina. This unique study addresses soil and blood lead conditions pre- and ten years post-Katrina and considers the effectiveness of low lead soil for lead exposure intervention.

OBJECTIVES

Comparison of soil and blood lead levels pre- and ten years post-Katrina to evaluate and assess the impact of flooding on soil and blood lead at the scale of the city of New Orleans.

METHODS

Post-Katrina soil and blood lead data were stratified by the same census tracts (n=176) as pre-Katrina data. This unique city scale data-set includes soil lead (n=3314 and 3320, pre- vs. post-Katrina), blood lead (n=39,620 and 17,739, pre- vs. post-Katrina), distance, and changes in percent pre-1940 housing. Statistical analysis entailed permutation procedures and Fisher's Exact Tests.

RESULTS

Pre- vs. ten years post-Katrina soil lead median decreased from 280 mg/kg to 132 mg/kg, median blood lead decreased from 5μg/dL to 1.8μg/dL, respectively. Percent pre-1940 housing did not change significantly (P-value=0.674). Soil and blood lead decrease with distance from the center of New Orleans. Except for age-of-housing results, P-values were extremely small (<10(-12)).

CONCLUSIONS

Ten years after Katrina, profound changes in soil lead and children's blood lead occurred in New Orleans. Decreasing the lead on soil surfaces reduces children's interaction with lead dust, thus underscoring soil as a major of source of exposure.

Nature and extent of metal-contaminated soils in urban environments (keynote talk)

Research on the nature and extent of metal-contaminated soil began with an urban garden study in Baltimore, MD (USA). Largest quantities of soil metals were clustered in the inner city with lesser amounts scattered throughout metropolitan Baltimore. The probability values of metal clustering varied from P value 10(-15)-10(-23) depending on element. The inner-city clustering of lead (Pb) could not be explained by Pb-based paint alone. A major Pb source was tetraethyl lead (TEL), developed as an anti-knock agent for use in vehicle fuel, thereby making highway traffic flow a toxic substance delivery system in cities. Further study in Minneapolis and St. Paul confirmed the clustering of inner-city soil metals, especially Pb. Based on the evidence, the Minnesota State Legislature petitioned Congress to curtail Pb additives resulting in the rapid phasedown of TEL on January 1, 1986, 10 years ahead of the EPA scheduled ban. Further research in New Orleans, Louisiana (NOLA), verified the link between soil Pb, blood Pb, morbidity, and societal health. Although Pb is a known cause of clinical impairment, there is no known effective medical intervention for reducing children's blood Pb exposure. Ingestion and inhalation are routes of exposure requiring prevention, and soil is a reservoir of Pb. Children's blood Pb exposure observed in pre-Hurricane Katrina (August 29, 2005) NOLA underwent substantial decreases 10 years post-Katrina due to many factors including input of low Pb sediment residues by the storm surge and the introduction of low Pb landscaping materials from outside of the city. Investigation on the topic is ongoing.

Chemometric analysis of ecological toxicants in petrochemical and industrial environments

The application of chemometrics in the assessment of toxicants, such as heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs) potentially derived from petrochemical activities in the microenvironment, is vital in providing safeguards for human health of children and adults residing around petrochemical industrial regions. Several multivariate statistical methods are used in geosciences and environmental protection studies to classify, identify and group prevalent pollutants with regard to exhibited trends. Chemometrics can be applied for toxicant source identification, estimation of contaminants contributions to the toxicity of sites of interest, the assessment of the integral risk index of an area and provision of mitigating measures that limit or eliminate the contaminants identified. In this study, the principal component analysis (PCA) was used for dimensionality reduction of both organic and inorganic substances data in the environment, which are potentially hazardous. The high molecular weight (HMW) PAHs correlated positively with stronger impact on the model than the lower molecular weight (LMW) PAHs, the total petroleum hydrocarbons (TPHs), PAHs and BTEX correlate positively in the F1 vs F2 plot indicating similar source contributions of these pollutants in the environmental material. Cu, Cr, Cd, Fe, Zn and Pb all show positive correlation in the same space indicating similar source of contamination. Analytical processes involving environmental assessment data obtained in the Niger Delta area of Nigeria, confirmed the usefulness of chemometrics for comprehensive ecological evaluation.

Evolving from reactive to proactive medicine: community lead (Pb) and clinical disparities in pre- and post-Katrina New Orleans

In 2012 the U.S. Centers for Disease Control (CDC) set the blood Pb reference value at ≥5 µg/dL. Clinical analysis of children's blood Pb levels is the common way to diagnose environmental Pb contamination, and intervention ensues with education and household dust cleanup. Recent review indicates that education and household dust cleanup are not effective at reducing children's Pb exposure. Here we review mapping environmental Pb and children's blood Pb response as an alternative approach for proactive Pb dust intervention. New Orleans was divided into a high (≥100 mg/kg) and low (<100 mg/kg) soil Pb communities. The children's blood Pb prevalence ≥5 µg/dL for the high and low Pb domains were 58.5% and 24.8% respectively pre-Katrina vs. 29.6% and 7.5% post-Katrina. Elevated soil Pb (mg/kg) and consequently Pb loading (µg/square area) permeates the high Pb domain and outdoor locations lack Pb dust safe play areas. The U.S. EPA 400 mg/kg soil Pb standard poses an outside Pb dust loading burden >37 times larger than allowed on interior residential floor environments. Environmental Pb dust is decreasing because of the transfer of large quantities of low Pb soil into selected communities. City-scale soil Pb mapping is an alternative diagnostic tool that provides information for planning proactive medicine to prevent clinical Pb exposure in the first place.

An initial assessment of spatial relationships between respiratory cases, soil metal content, air quality and deprivation indicators in Glasgow, Scotland, UK: relevance to the environmental justice agenda

There is growing interest in links between poor health and socio-environmental inequalities (e.g. inferior housing, crime and industrial emissions) under the environmental justice agenda. The current project assessed associations between soil metal content, air pollution (NO2/PM10) and deprivation and health (respiratory case incidence) across Glasgow. This is the first time that both chemical land quality and air pollution have been assessed citywide in the context of deprivation and health for a major UK conurbation. Based on the dataset 'averages' for intermediate geography areas, generalised linear modelling of respiratory cases showed significant associations with overall soil metal concentration (p = 0.0367) and with deprivation (p < 0.0448). Of the individual soil metals, only nickel showed a significant relationship with respiratory cases (p = 0.0056). Whilst these associations could simply represent concordant lower soil metal concentrations and fewer respiratory cases in the rural versus the urban environment, they are interesting given (1) possible contributions from soil to air particulate loading and (2) known associations between airborne metals like nickel and health. This study also demonstrated a statistically significant correlation (-0.213; p < 0.05) between soil metal concentration and deprivation across Glasgow. This highlights the fact that despite numerous regeneration programmes, the legacy of environmental pollution remains in post-industrial areas of Glasgow many decades after heavy industry has declined. Further epidemiological investigations would be required to determine whether there are any causal links between soil quality and population health/well-being. However, the results of this study suggest that poor soil quality warrants greater consideration in future health and socio-environmental inequality assessments.

Analysis of U.S. soil lead (Pb) studies from 1970 to 2012

Although lead (Pb) emissions to the air have substantially decreased in the United States since the phase-out of leaded gasoline by 1995, amounts of lead in some soils remain elevated. Lead concentrations in residential and recreational soils are of concern because health effects have been associated with Pb exposure. Elevated soil Pb is especially harmful to young children due to their higher likelihood of soil ingestion. The purpose of this study is to create a comprehensive compilation of U.S. soil Pb data published from 1970 through 2012 as well as to analyze the collected data to reveal spatial and/or temporal soil Pb trends in the U.S. over the past 40 years. A total of 84 soil Pb studies across 62 U.S. cities were evaluated. Median soil Pb values from the studies were analyzed with respect to year of sampling, residential location type (e.g., urban, suburban), and population density. In aggregate, there was no statistically significant correlation between year and median soil Pb; however, within single cities, soil Pb generally declined over time. Our analysis shows that soil Pb quantities in city centers were generally highest and declined towards the suburbs and exurbs of the city. In addition, there was a statistically significant, positive relationship between median soil Pb and population density. In general, the trends examined here align with previously reported conclusions that soil Pb levels are higher in larger urban areas and Pb tends to remain in soil for long periods of time.

Distribution of mercury and other trace metals in the sediments of Cochin estuary (a Ramsar site), Kerala, India

Sediment quality data provide essential information for evaluating ambient environmental quality conditions. Sediments are important carriers of trace metals in the environment and reflect the current quality of the system. In the present study, distribution of mercury, lead, cadmium, copper, zinc, chromium and manganese in Cochin estuary were studied. The distribution of oxides of metals and textural quality were also studied in detail. It was found that the concentration of metals in the sediments near the industrial belt was extremely high. Correlation of different metals and metal oxides were analysed. It was found that all the alloys were correlated significantly (α < 0.01) but in case of metals, correlation was only among certain metals.

Environmental and health disparities in residential communities of New Orleans: the need for soil lead intervention to advance primary prevention

Urban environments are the major sites for human habitation and this study evaluates soil lead (Pb) and blood Pb at the community scale of a U.S. city. There is no safe level of Pb exposure for humans and novel primary Pb prevention strategies are requisite to mitigate children's Pb exposure and health disparities observed in major cities. We produced a rich source of environmental and Pb exposure data for metropolitan New Orleans by combining a large soil Pb database (n=5467) with blood Pb databases (n=55,551 pre-Katrina and 7384 post-Katrina) from the Louisiana Childhood Lead Poisoning Prevention Program (LACLPPP). Reanalysis of pre- and post-Hurricane Katrina soil samples indicates relatively unchanged soil Pb. The objective was to evaluate the New Orleans soil Pb and blood Pb database for basic information about conditions that may merit innovative ways to pursue primary Pb exposure prevention. The city was divided into high (median census tract soil≥100 mg/kg) and low Pb areas (median census tract soil<100mg/kg). Soil and blood Pb concentrations within the high and low Pb areas of New Orleans were analyzed by permutation statistical methods. The high Pb areas are toward the interior of the city where median soil Pb was 367, 313, 1228, and 103 mg/kg, respectively for samples collected at busy streets, residential streets, house sides, and open space locations; the low Pb areas are in outlying neighborhoods of the city where median soil Pb was 64, 46, 32, and 28 mg/kg, respectively for busy streets, residential streets, house sides, and open spaces (P-values<10(-16)). Pre-Katrina children's blood Pb prevalence of ≥5 μg/dL was 58.5% and 24.8% for the high and low Pb areas, respectively compared to post-Katrina prevalence of 29.6% and 7.5%, for high and low Pb areas, respectively. Elevated soil Pb permeates interior areas of the city and children living there generally lack Pb safe areas for outdoor play. Soil Pb medians in outlying areas were safer by factors ranging from 3 to 38 depending on specific location. Patterns of Pb deposition from many decades of accumulation have not been transformed by hastily conducted renovations during the seven year interval since Hurricane Katrina. Low Pb soils available outside of cities can remedy soil Pb contamination within city interiors. Mapping soil Pb provides an overview of deposition characteristics and assists with planning and conducting primary Pb exposure prevention.

Associations between standardized school performance tests and mixtures of Pb, Zn, Cd, Ni, Mn, Cu, Cr, Co, and V in community soils of New Orleans

In New Orleans a strong inverse association was previously identified between community soil lead and 4th grade school performance. This study extends the association to zinc, cadmium, nickel, manganese, copper, chromium, cobalt, and vanadium in community soil and their comparative effects on 4th grade school performance. Adjusting for poverty, food security, racial composition, and teacher-student ratios, regression results show that soil metals variously reduce and compress student scores. Soil metals account for 22%-24% while food insecurity accounts for 29%-37% of variation in school performance. The impact on grade point averages were Ni > Co > Mn > Cu ~ Cr ~ Cd > Zn > Pb, but metals are mixtures in soils. The quantities of soil metal mixtures vary widely across the city with the largest totals in the inner city and smallest totals in the outer city. School grade point averages are lowest where the soil metal mixtures and food insecurity are highest.

Estimation of leaded (Pb) gasoline's continuing material and health impacts on 90 US urbanized areas

The subject of this paper is lead (Pb) additives in gasoline and their material and health impact from Pb dust inputs into 90 US urbanized areas (UAs). The mass of Pb additives for 90 UAs as a total of the US Pb additives in 1982 were estimated from vehicle travel, vehicle fuel economy (miles/gallon), ratio of leaded to unleaded fuel, and Pb/gallon. About 500 billion (10⁹) miles of travel in 90 UA's during 1982 account for ~18,000 metric tons (MT), or nearly 30% of the US Pb additives in 1982. Applying the 1982 proportions to the 90 UAs for 1950 through 1982 fuel sales by state accounts for ~1.4 million MT Pb of the US national total of 4.6 million MT during the same years. Fates of Pb additives in engine systems were used to calculate Pb aerosol inputs into the 90 UAs. The inputs range from 100's to more than 100,000 MT of Pb depending on a given UA's traffic flow patterns. Soils are the reservoir of urban Pb dust. The median background soil Pb for the US is 16.5mg/kg (range 10.3 to 30.1mg/kg), and less by an order of magnitude or more than soil Pb within larger UAs. Recognizing the US input of massive gasoline Pb additives into UAs assists with comprehending soil Pb differences between large and small UAs, inner and outer areas of UAs, health disparities, and school achievement issues within UAs. The findings underscore the need for controlling accumulated exterior urban Pb dust from gasoline additives along with paint sources that have accumulated in soil to meet the goal of primary childhood Pb exposure prevention.

Chemical speciation and bioaccessibility of lead in surface soil and house dust, Lavrion urban area, Attiki, Hellas

In the Lavrion urban area study, Hellas, a five-step sequential extraction method was applied on samples of 'soil' (n = 224), affected by long-term mining and metallurgical activities, and house dust (n = 127), for the purpose of studying the potential bioaccessibility of lead and other metals to humans. In this paper, the Pb concentrations in soil and house dust samples are discussed, together with those in rocks and children's blood. Lead is mainly associated with the carbonate, Fe-Mn oxides and residual fractions in soil and house dust. Considering the very low pH of gastric fluids (1-3), a high amount of metals, present in soil (810-152,000 mg/kg Pb) and house dust (418-18,600 mg/kg Pb), could be potentially bioaccessible. Consequently, children in the neighbourhoods with a large amount of metallurgical processing wastes have high blood-Pb concentrations (5.98-60.49 μg/100 ml; median 17.83 μg/100 ml; n = 235). It is concluded that the Lavrion urban and sub-urban environment is extremely hazardous to human health, and the Hellenic State authorities should urgently tackle this health-related hazard in order to improve the living conditions of local residents.

In situ monitoring (field screening) and assessment of lead and arsenic contaminants in the greater New Orleans area using a portable X-ray fluorescence analyser

This paper reports environmental assessment and identification of environmental contaminants caused by exposure to toxic metals such as Pb and As after Hurricane Katrina using an onsite analysis method. Concentrations of lead (Pb) and arsenic (As) detected in many soil samples after Hurricane Katrina were reported to exceed EPA allowable value. Toxic metals mentioned above were measured by a portable X-ray fluorescence analyzer (XRF) in the greater New Orleans area. The portable XRF analyzer provides rapid data collection in the field. Distribution of Pb in New Orleans is displayed in a regional map using geographic information system (GIS). The map provides an updated image of environmental exposure to Pb contamination in the greater New Orleans area after Hurricane Katrina and also shows Pb contaminated areas where Pb concentrations exceed the EPA allowable level. The portable XRF provides a rapid analysis method for toxic metals and can be used for the field screening of soils at any place and for identifying contamination areas rapidly.

New Orleans before and after Hurricanes Katrina/Rita: a quasi-experiment of the association between soil lead and children's blood lead

Prior to Hurricanes Katrina and Rita (HKR), significant associations were noted between soil lead (SL) and blood lead (BL) in New Orleans. Engineering failure of New Orleans levees and canal walls after HKR set the stage for a quasi-experiment to evaluate BL responses by 13 306 children to reductions in SL. High density soil surveying conducted in 46 census tracts before HKR was repeated after the flood. Paired t test results show that SL decreased from 328.54 to 203.33 mg/kg post-HKR (t = 3.296, p < or = 0.01). Decreases in SL are associated with declines in children's BL response (r = 0.308, p < or = 0.05). When SL decreased at least 1%, median children's BL declined 1.55 microg/dL. Declines in median BL are largest in census tracts with > or =50% decrease in SL. Also individual BL in children was predicted as a function of SL, adjusting for age, year of observation, and depth of flood waters. At the individual scale, BL decreased significantly in post-HKR as a function of SL, with BL decreases ranging from b = -1.20 to -1.65 microg/dL, depending on the decline of SL and whether children were born in the post-HKR period. Our results support policy to improve soil conditions for children.

Children's blood lead and standardized test performance response as indicators of neurotoxicity in metropolitan New Orleans elementary schools

This study analyzes pre-Katrina variation in aggregate student performance and children's blood lead (BPb) in 117 elementary school districts in metropolitan New Orleans. Fourth grade student achievement on Louisiana Educational Assessment Program (LEAP) tests were analyzed as a function of BPb for children 1-6 years old within school districts, controlling for student-teacher ratios, percent of students eligible for a free or discounted lunch, and school racial demography. Measures of performance across subject areas (English Language Arts, Science, Mathematics, and Social Studies) include school Achievement Test Scores (ATS) and indices of agreement and variation in student achievement. ATS are measured on a 5-point scale, corresponding to achievement categories of advanced=5 to unsatisfactory=1. Regression results show that median BPb (microg/dL) and percent of children with BPb > or =10 microg/dL are significantly associated with reductions in test scores across all subjects and depress variation in student performance across achievement categories. These data suggest that assisting children with improved school performance requires alleviation of pre-school Pb exposure and its associated neurotoxic damage. Cost-benefit calculations suggest that it is more cost effective to pay for onetime primary prevention instead of paying continuous expenses focused on reversing neurotoxic damage.

Multiple risk factors for lead poisoning in Hispanic sub-populations: a review

As a result of recent media attention to lead (Pb) in consumer products, Pb exposure and toxicity to children has been placed back on the national agenda. This review presents the current literature on sources of Pb in Hispanic sub-populations in the broader context of national lead poisoning trends, sources, and exposure pathways. Pb poisoning among Hispanics is a multi-dimensional issue that is far more complex than for the general population in terms of environmental, cultural, and social dimensions. As a result, a higher percentage of Hispanic children have elevated blood lead levels compared to the general population. Given the additional risks that Hispanics face, all Hispanic children should be defined as "at risk" for lead exposure and included in targeted screening programs. This review concludes with specific public policy recommendations that directly address the increased risk of Pb poisoning to Hispanic children so that Pb will poison fewer children in the future.

Human geography of New Orleans' high-lead geochemical setting

Previous soil lead studies in New Orleans focused on the geochemical footprint and its health impacts. This study examines the human geography of race, income, and age in pre-Katrina metropolitan New Orleans within the context of lead accumulation in soils. Sample points of soil lead data (n = 5,467) collected in 1998-2000 were mapped in a geographic information system (GIS), binned into 9 ranges, and queried by (1) 2000 Census racial demographic data, (2) 1999 median household income, and (3) 2000 age data. The absolute population generally declines as lead levels increase except at lead levels from 200-400 to 400-1,000 mg/kg when population increases; the African-American population comprises a disproportionate share of this cohort. The high-lead areas occur in the inner city, home to the largest populations of African-Americans in New Orleans. The mean household income curve indicates that lower economic groups are at risk to higher levels of lead. A total of 44,701 children under the age of 5 years, plus 123,579 children aged 5-17, lived in census block groups containing at least one sample point with over 100 mg/kg lead, and these include 23,124 and 64,064 young people, respectively, who live near at least one point over 400 mg/kg. Lead exposure affects a panoply of outcomes that influence the health and welfare of the community. Unless corrected, children are likely to return to the same or, because of lack of lead-safe practices during renovation, even higher exposure risks than before the flooding of New Orleans.

Soil pollution in day-care centers and playgrounds in Norway: national action plan for mapping and remediation

Systematic geochemical mapping based on sampling and analysis of surface soils (0-2 cm) has been carried out in several Norwegian cities. The soils in the oldest parts of the cities are contaminated with metals (especially Pb) and polycyclic aromatic hydrocarbons (PAH). Due to the fact that children are often in contact with surface soil, it was realized that special focus had to be directed towards soils in day-care centers and playgrounds. The first mapping and remedy program was initiated in Trondheim in 1996. Here, the importance of copper-chromium-arsenic (CCA)-pressure-impregnated wood in playing equipment as a pollution source for soils was documented, and a process was started with the aim to ban this product. Soils from day-care centers in the inner city of Bergen were polluted to a degree that required remediation in 45% out of 87 centers, mainly due to high concentrations of Pb and benzo(a)pyrene. In Oslo, 38% of 700 day-care centers needed remediation due to soil pollution by Pb, BaP, Cd, Hg, Ni and PCB. Removal of CCA-impregnated wood was necessary in more than half of the day-care centers The Norwegian parliament has decided to investigate all outdoor playing areas in day-care centers, playgrounds and schoolyards in Norway, starting in 2007 with day-care centers in the ten largest cities and five most important industrial areas. The Norwegian Institute of Public Health has developed quality criteria for soils in day-care centers and playgrounds for As, Cd, Cr(6+), Hg, Ni, Pb, zinc, PAH(sum16), benzo(a)pyrene, and PCB(sum7). The Geological Survey of Norway has developed guidance for mapping of soil pollution (sampling, chemical analysis and reporting) in day-care centers. Especially the sampling strategy has been developed in the period 1996-2007, and the preferred sampling strategy is to collect at least 10 samples of surface soil (0-2 cm) from (1) "original soil" on the site, (2) artificial man-made "hills", and (3) soils used for growing vegetables. A total number of 2,000 day-care-centres are to be investigated, and necessary remediation should be completed before the end of 2010.

Urban soil-lead (Pb) footprint: retrospective comparison of public and private properties in New Orleans

Lead (Pb) is a toxin that after childhood exposure poses a lifetime of health risks. One route of exposure is soil-Pb as a result of 12 million metric tons of Pb residue in paint and gasoline sold in the US during the 20th Century. Pb accumulated in soil of the community is a good predictor for blood Pb of children living there. This retrospective study compares the soil-Pb on Housing Authority of New Orleans (HANO) properties with adjacent private residential (RES) properties within a 0.8 km (0.5 mile) radius. The sample subset (n = 951) is from two soil-Pb surveys (total n = 9,493) conducted between 1989 and 2000. The properties were in both the inner city (CORE) and outlying (OUTER) communities. The data were analyzed using multiresponse permutation procedures (MRPP). The soil-Pb results differ significantly (P-value < 0.001) on same-aged HANO properties at different locations; thus, year of construction does not give adequate explanation for the soil-Pb differences. HANO and RES soils are significantly more Pb contaminated in the CORE than in OUTER communities (P-value < 0.001). The CORE has many more years of traffic congestion than OUTER communities; therefore, the lead additives to gasoline, and not lead-based paint, best elucidate the differences of the soil-Pb footprint at HANO and RES properties in the CORE and OUTER communites. Currently HANO properties are being redeveloped with cleaner soil, but soil on RES properties in the CORE of New Orleans remains a large source of Pb (median = 707 mg/kg in this study) for human exposure, especially children.

Nonlinear association between soil lead and blood lead of children in metropolitan New Orleans, Louisiana: 2000-2005

Metropolitan New Orleans is unique because it has a universal blood lead (BL) screening dataset (n=55,551) from 2000-2005 spatially coupled with a soil lead (SL) dataset (n=5467) completed in 2000. We evaluated empirical associations between measurements of SL and BL exposure responses of children in New Orleans by stratifying the databases by Census Tracts and statistically analyzing them with permutation methods. A consistent curvilinear association occurred annually between SL and BL with robust significance (P-values<10(-23)). The mathematical model of the pooled BL datasets for 2000-2005 is: BL=2.038+0.172 x (SL)(0.5) (agreement (R) of 0.534, an r(2) of 0.528, and a P-value of 1.0 x 10(-211)) indicating that chance alone cannot explain the association. Below 100 mg/kg SL children's BL exposure response is steep (1.4 microg/dL per 100 mg/kg), while above 300 mg/kg SL the BL exposure response is gradual (0.32 microg/dL per 100 mg/kg). In 1995, the BL prevalence was 37%>or=10 microg/dL for the most vulnerable poor and predominantly African-American children. In the era of universal screening the prevalence of elevated BL is 11.8%>or=10 microg/dL for the general population of children. The SL map describes community variations of potential BL exposure. If health effects occur at BL>or=2 microg/dL, then 93.5% of the children in New Orleans are at risk. These results reinforce the proposal that prevention of childhood Pb exposure must include SL remediation as demonstrated by a New Orleans pilot project and a proactive Norwegian government program.

Potential lead on play surfaces: evaluation of the "PLOPS" sampler as a new tool for primary lead prevention

This New Orleans study tested the "potential lead on play surfaces" (PLOPS) sampler, as a tool for measuring the potential lead (Pb) surface loading per area (e.g., microg/ft2) of the soil. The PLOPS is a cylindrical vinyl envelope filled with 1 kg (2.2 lbs) water. A wet wipe, the same type as used for floor wipes, is clipped to the bottom of the cylindrical vinyl envelope and placed on the soil and turned one quarter of a turn and back to obtain a sample. PLOPS samples paired with one conventional soil lead (SL) sample (amount of Pb per mass) up to 2.5 cm (1 in) deep were collected from 25 properties and 67-69 field sites before and after covering them with clean Mississippi River alluvial soil from the Bonnet Carré Spillway (BCS). Permutation methods were used to evaluate results. The correlation was 0.85 between Plops 1 and 2 and the agreement was 0.79 (P-values0.0000001, i.e., extreme). The averages of PLOPS duplicates were used to correlate PLOPS and SL. The simplest mathematical expressions are in the forms y=a+bxc and x=d+eyf, where x is PLOPS and y is SL. The results were:y=-7.42+0.408x0.97 and x=-43.74+24.85y0.69. The agreements were 0.61 and 0.62, respectively (P-value0.0000001). According to the relationship, when the PLOPS measure 40 microg/ft2, the predicted SL is 7.2 mg/kg. Also, when SL measures 400 mg/kg, 1508 microg/ft2 is predicted for PLOPS; therefore, SL concentration underestimates the potential for Pb exposure from the soil surface. The PLOPS tool provides a measurement that is comparable with interior floor wipes because it measures the amount of Pb per area a child is likely to encounter while at play on the soil surface.

Hurricane Katrina's impact on New Orleans soils treated with low Lead Mississippi River alluvium

Before Hurricane Katrina flooded 80% of New Orleans, 25 heavily Pb contaminated properties were treated with 15 cm of low Pb Mississippi River alluvium from the Bonnet Carré Spillway (BCS). Four phases of soil collection on the properties included pretreatment (phase 1) median surface soil Pb was 1051 mg/kg (range 5-19 627); after BCS cover (phase 2) the median soil Pb decreased to 6.3 mg/ kg (range 3-18); just before Katrina, a soil collection was partially completed (phase 3); and finally, a post-Katrina collection (phase 4) on all 25 properties. Twenty-three properties were flooded. The objective was to compare Pb changes of phases 2 and 3 pre-Katrina with the post-Katrina (phase 4) soil collection. The post-Katrina soil Pb (phase 4) (median of 16.3, range 5.5-1,155) increased significantly (P-value = 3.7 x 10(-10)) from the clean soil, phase 2 results. Matched soil samples collected in phase 3 before flooding and phase 4 after flooding showed that on initially vacant lots the amounts of Pb were not significantly different (P-value = 0.97); but, on properties with homes, the changes were significant (P-value = 0.03). After catastrophic flooding, the clean soil remained relatively undisturbed; the soil Pb changes were small with increases of median Pb of 12 and 6 mg/kg for vacant lots and properties with homes, respectively. Processes accounting for Pb increases include Pb-based paint abatement on one property, home construction on the vacant lots, and resuspension and deposition of Pb dust. As part of the post-Katrina recovery, the combined benefits of Pb-safe paint abatement or renovation and clean soil cover should outweigh the estimated annual cost of Pb poisoning of children returning to New Orleans.

Atmospheric lead fallout over the last century recorded in Gulf of Lions sediments (Mediterranean Sea)

Six marine sediment cores from the Gulf of Lions continental slope (700-1700 m water depth) were analyzed for stable lead isotopes and (210)Pb geochronology in order to reconstruct lead atmospheric fallout pattern during the last century. The detrital lead contribution is 25 microg g(-1) and the mean sediment anthropogenic inventory is 110+/-7 microg cm(-2), a little bit higher than atmospheric deposition estimate. Anthropogenic lead accumulation in sediments peaked in early 1970s (1973+/-2) in agreement with lead emissions features. For the period 1986-1997, the sediment signal also reflect the decrease of atmospheric lead described by independent atmospheric fallout investigations. The anthropogenic Pb deposition in the late 1990s was similar to the 1950s deposition, attesting thus of the output of European environmental policies.

Metals in soils of children's urban environments in the small northern European city of Uppsala

Metals occur naturally in soil, but contents are generally increased in the urban environment due to anthropogenic activities. The presence of elevated metals in soils of the urban environment has been recognized as an important source of metal intake in children and is linked to elevated metal levels in children's blood. Several metals have undesirable health effects, especially on children due to their still developing nervous system and small body volumes. Playgrounds are where urban children spend most of their time outdoors and are also where children most frequently come in contact with soil. Elevated contents of metals in playgrounds are therefore of great concern for children's wellbeing. This study investigates the soil metal content of 25 playgrounds located in different land use areas in urban Uppsala, Sweden's fourth largest city. Uppsala covers an area of approximately 100 km2 and has a population of 136,000. The soil samples were analysed for 12 metals (Al, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, W, Zn) using aqua regia. Median metal contents were found to be 1.8, 3.4, 0.21, 32, 25, 2.5, 0.14, 494, 19, 26, 0.35 and 84 mg kg(-1) soil for each of the above metals, respectively. The median clay content was around 20% while the organic matter content was measured by loss on ignition at a median of 8%. The land use areas included industrial land, the city center, road verges, natural land and former industrial land. The results showed that land use did not have the expected large influence on the total metal contents of the soils tested. The clay content together with the age of the site proved to be a more important factor. Sites with elevated clay contents had in general elevated metal contents, which were explained by the relatively high adsorption capacity of clay particles. The soils at sites where land use had not been altered since the 1800s had increased metal contents compared to playgrounds constructed in the late 1900s. The immobility of metals once they had entered the soil system was the reason for increased metal content in soils of old playgrounds. It was concluded that in cities with few internal pollution sources, the soil characteristics of the site and the time the soil has been on-site to accumulate metal residues become important factors in determining the soil metal content.

New Orleans soil lead (Pb) cleanup using Mississippi River alluvium: need, feasibility, and cost

In New Orleans, LA prior to hurricane Katrina 20-30% of inner-city children had elevated blood Pb levels > or =10 microg/ dL and 10 census tracts had a median surface soil level of Pb >1000 mg/kg (2.5 times the U.S. standard). This project tests the feasibility of transporting and grading contaminated properties (n = 25) with 15 cm (6 in.) of clean Mississippi River alluvium from the Bonnet Carré Spillway (BCS) (median soil Pb content 4.7 mg/kg; range 1.7-22.8). The initial median surface soil Pb was 1051 mg/kg (maximum 19 627). After 680 metric tons (750 tons) of clean soil cover was emplaced on 6424 m2 (69 153 ft2), the median surface soil Pb decreased to 6 mg/kg (range 3-18). Interior entrance wipe samples were collected at 10 homes before and after soil treatment and showed a decreasing trend of Pb (p value = 0.048) from a median of 52 microg/ft2 to a median of 36 microg/ft2 (25th and 75th percentiles are 22 and 142 microg/ft2 and 12 and 61 microg/ft2, respectively). Average direct costs for properties with homes were $3,377 ($1.95 per square foot), with a range of $1,910-7,020, vs $2,622 ($0.61 per square foot), with a range of $2,400-3,040 for vacant lots. Approximately 40% (86,000) of properties in New Orleans are in areas of >400 mg Pb/kg soil and estimated direct costs for treatment are between $225.5 and $290.4 million. Annual costs of Pb poisoning in New Orleans are estimated at approximately $76 million in health, education, and societal harm. Urban accumulation of Pb is an international problem; for example, the new Government of Norway established a policy precedence for an isolated soil cleanup program at daycare centers, school playgrounds, and parks to protect children. New Orleans requires a community-wide soil cleanup program because of the extent and quantity of accumulated soil Pb. The post-Katrina benefits of reducing soil Pb are expected to outweigh the foreseeable costs of Pb poisoning to children returning to New Orleans.

Changes of multiple metal accumulation (MMA) in New Orleans soil: preliminary evaluation of differences between survey I (1992) and survey II (2000)

Soil metal surveys were conducted in Baltimore, MD (1976-1979), Minnesota (1981-1988) and most recently, New Orleans, LA (1989-present). The unique characteristic of New Orleans is that it has two surveys; Survey I was completed in 1992 and Survey II was completed in 2000. This paper seeks to determine if there is a perceptible change in the amount of metals during less than a decade that separated these surveys. The Survey I collection was 4,026 samples stratified by 283 census tracts. All samples were collected in residential neighborhoods at least one block from a busy street. The Survey II collection was 5,467 samples stratified by 286 census tracts (plus City Park). The Survey II collection included busy streets as a category of samples. For comparison, the busy street category of 1,078 samples was excluded from Survey II for a total of 4,388 samples. The extraction methods of the two surveys used the same protocol for strength of acid (1 M HNO3), shaker-time (2 hours), and room temperature (approximately 22 degrees C). However, Survey II differed in amount of sample used in extraction. For Surveys I and II, 4.0g and 0.4g were used respectively. The same ICP-AES was used to measure 8 metals in both surveys. To evaluate the analytical results of the two methods, reference soi 1 samples (n=36) from the Wageningen Evaluating Programs for Analytical Laboratories, International Soil-analytical Exchange (WEPAL; ISE) were used. The relationship between the 4.0 and 0.4 g results were linear and the Survey I results were adjusted for sample:acid ratio. Further evaluation was done by creating interpolated Multiple Metal Accumulation (MMA) maps based on the median MMA for each census tract. A new map was created by dividing Survey II MMA by Survey I MMA. The ratio indicates increases of soil metals in the inner city and decreases of soil metals in the outlying areas of Metropolitan New Orleans. Comparing fresh parent alluvium from the Mississippi River with urban soil metal quantities demonstrates that the soils of New Orleans have undergone a massive accumulation of metals. The preliminary results provide ideas about methods needed to further evaluate the changes between these surveys.