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.

Natural and anthropogenic processes that concentrate Mn in rural and urban environments of the lower Mississippi River delta.

This study evaluated natural processes and projected methylcyclopentadienyl manganese tricarbonyl fuel additives as sources of Mn accumulation in the environment. Data sets include fresh alluvium and sediments from the lower Mississippi River Delta and a soil metal survey of metropolitan New Orleans. The (1) railroad Mn, (2) industrial Mn, and (3) dynamic aquifer-stream transfer of Mn hypotheses were tested with the Mississippi River Delta data. Friction between Mn-rich steel wheels and rails contributes Mn (P = 0.017) to the environment, supporting (1). Sediment loads of Mn were similar (P = 0.77) upstream and downstream from the Louisiana industrial corridor, not supporting (2). The median Mn on the alluvium surface (59 mg/kg), in the aquifer (159 mg/kg), and in the riverbank aquifer discharge zone (513 mg/kg) support (3) as a mechanism for Mn enrichment of clay. The New Orleans soil metal survey data set shows a rural to urban increase of fourfold for Mn and three orders of magnitude for Pb. At 1999 U.S. highway fuel use, 8.3 mg of Mn per L would yield 5000 metric tons of Mn annually. If 13% of Mn were emitted, 650 tons of Mn would become aerosols annually, while 87% or 4350 tons would remain in engines. The 1999 toxic release inventory for Mn shows 370 tons as total emissions compared to the potential of 390 and 260 tons from vehicles, respectively, in urban and rural areas. A precautionary lesson from the use of Pb as a fuel additive is that the use of Mn as a fuel additive would be associated with an increased risk for neonates exceeding the estimated total tolerable daily intake of 2.1-16.5 micrograms Mn (especially in urban inner city environments) because neonates lack fully functional hepatic clearance for Mn.

Multiple metal contamination from house paints: consequences of power sanding and paint scraping in New Orleans.

Power sanding exterior paint is a common practice during repainting of old houses in New Orleans, Louisiana, that triggers lead poisoning and releases more than Pb. In this study we quantified the Pb, zinc, cadmium, manganese, nickel, copper, cobalt, chromium, and vanadium in exterior paint samples collected from New Orleans homes (n = 31). We used interior dust wipes to compare two exterior house-painting projects. House 1 was measured in response to the plight of a family after a paint contractor power sanded all exterior paint from the weatherboards. The Pb content (approximately 130,000 microg Pb/g) was first realized when the family pet died; the children were hospitalized, the family was displaced, and cleanup costs were high. To determine the quantity of dust generated by power sanding and the benefits of reducing Pb-contaminated dust, we tested a case study house (house 2) for Pb (approximately 90,000 microg/g) before the project was started; the house was then dry scraped and the paint chips were collected. Although the hazards of Pb-based paints are well known, there are other problems as well, because other toxic metals exist in old paints. If house 2 had been power sanded to bare wood like house 1, the repainting project would have released as dust about 7.4 kg Pb, 3.5 kg Zn, 9.7 g Cd, 14.8 g Cu, 8.8 g Mn, 1.5 g Ni, 5.4 g Co, 2.4 g Cr, and 0.3 g V. The total tolerable daily intake (TTDI) for a child under 6 years of age is 6 microg Pb from all sources. Converting 7.4 kg Pb to this scale is vexing--more than 1 billion (10(9)) times the TTDI. Also for perspective, the one-time release of 7.4 x 10(9) microg of Pb dust from sanding compares to 50 x 10(9) microg of Pb dust emitted annually per 0.1 mile (0.16 km) from street traffic during the peak use of leaded gasoline. In this paper, we broaden the discussion to include an array of metals in paint and underscore the need and possibilities for curtailing the release of metal dust.

PAH and metal mixtures in New Orleans soils and sediments.

The purpose of this study is to determine the degree of PAH contamination and the association of PAHs with inorganic substances in soils and sediments of New Orleans. Bonnet Carré Spillway (BCS) (n = 5) provides modern baseline data, while urban soil samples (CTY) (n = 27) and sediment samples from Bayou St. John (BSJ) (n = 11) provide experimental data for New Orleans. Soil samples were collected from the top 2.5 cm of the surface, air-dried, and sieved (2 mm). Sediments samples were collected with a Wildco-Ekman bottom dredge, air-dried and finely ground. Accelerated solvent extraction (ASE) was used to release PAHs from the samples and analysis was conducted with gas chromatography-mass spectrometry (GC-MS). Metals were extracted using a 5:1 ratio of 1 mol/L nitric acid (room temperature) for soil and sediment samples, shaken for 2 h, centrifuged (1000 x g for 15 min) and filtered. Metal analysis was done by inductively coupled plasma-atomic emission spectrometry (ICP-AES). Mann-Whitney tests show PAH differences (P < 0.001). Ranking of total PAHs is, BSJ sediments (10.3 mg/kg) > CTY soils (3.7 mg/kg) > BCS alluvium (0.28 mg/kg). The sum of the metals are similar for BSJ sediments (698 mg/kg) and CTY soils (679 mg/kg) and significantly lower for BCS (189 mg/kg). Manganese of these samples is similar for each site. For paired samples, Pearson Product Moment Correlation tests reveal that many PAHs are strongly associated with each other at all locations. For BCS alluvium and BSJ sediments, total PAHs are not significantly associated with total metals. For CTY, most pairs of metals are significantly associated, and total soil PAHs are strongly associated with total soil metals (correlation 0.78, P = 4.9 x 10(-4)). The linear model, total soil PAH = 136.3 + 6.25 (total soil metals) forms the basis for a predicted PAH map of New Orleans. Previous empirical research demonstrates an association between soil lead and children's lead exposure. This study indicates that PAHs are part of the soil mixture of accumulated substances and by-products of industrial society that presents exposure potential in cities.

Quantities and associations of lead, zinc, cadmium, manganese, chromium, nickel, vanadium, and copper in fresh Mississippi delta alluvium and New Orleans alluvial soils.

The topic of this study is the effect of anthropogenic metals on the geochemical quality of urban soils. This is accomplished by comparing the metal contents and associations between two alluvial soils of the lower Mississippi River Delta, freshly deposited alluvial parent materials and alluvial soils collected from a nearby urban environment. Fresh alluvium samples (n = 97) were collected from the Bonnet Carré Spillway. The urban alluvial soil samples (n = 4026) were collected from New Orleans and stratified by census tracts (n = 286). The Spillway samples tend to have less Pb and Zn than generally noted for the baseline of natural soils. Except for Mn and V, Spillway alluvium contains significantly less metal than urban soils. For Spillway samples, the median metal content (in microg g(-1)) is 4.7 Pb, 11.1 Zn, 0.7 Cd, 164 Mn, 0.8 Cr, 3.9 Ni, 3.2 V, and 3.9 Cu. For urban soils, the median metal content (in microg g(-1)) is 120 Pb, 130 Zn, 3.2 Cd, 138 Mn, 2.1 Cr, 9.8 Ni, 3.8 V, and 12.7 Cu. Metal associations also differ between Spillway alluvium and urban alluvial soils. Fresh alluvium correlation coefficients between individual metals vary from 0.87 to 0.99 (P < 10(-13)) except for Cr which ranges from 0.57 to 0.68 (P < 10(-7)). The urban soil correlation coefficients for metals and the index value are 0.40-0.98. In urban soils, Pb, Zn, Cr, and Cu are dominant metals and highly associated, with a correlation coefficient ranging from 0.83 to 0.98 (P < 10(-25)). Their strong association justifies the use of GIS to map the integrated soil metal index (sum of the medians of metals by census tract) of New Orleans. Although also positively correlated (0.40-0.68, P < 10(-10)), Cd, Mn, Ni and V differ in their distribution in the city compared to Pb, Zn, Cr and Cu. Overall, significantly higher metal values occur in the inner city and lower values occur in outlying areas. The human health impact of the mixture of metals is not well understood. This study provides empirical data about the mixture and distribution of metals in New Orleans alluvial soils. Given common technical development, especially of traffic flows in cities, similar patterns of soil metals are expected for all US cities and probably international cities as well. Primary prevention of urban metal accumulations is necessary to enhance and sustain the development of urban culture.

The urban environment and children's health: soils as an integrator of lead, zinc, and cadmium in New Orleans, louisiana, U.S.A.

Soils are evaluated as a diagnostic tool of environmental conditions that influence health. The samples for this study are urban topsoil (0-2.5 cm depth) samples (n=4026) analyzed for Pb, Zn, and Cd by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The parent materials for New Orleans soils are derived from the Mississippi River, and alluvium from the Bonnet Carré Spillway (n=31) serve as control samples for this study. The urban samples were stratified by census tract (n=286). Blood Pb (BL) levels of children /=310 microgram g(-1) and <310 microgram g(-1)) for higher metal census tracts (HMCTs) and lower metal census tracts (LMCTs), respectively, represents median BL exposures above and below 9 microgram dL(-1). HMCTs and LMCTs were characterized by demographic and socioeconomic data. HMCTs are more likely (P=4. 5x10(-6)) inhabited by Blacks than by Whites. Of 13,803 children

Soil is an important pathway of human lead exposure.

This review shows the equal or greater importance of leaded gasoline-contaminated dust compared to lead-based paint to the child lead problem, and that soil lead, resulting from leaded gasoline and pulverized lead-based paint, is at least or more important than lead-based paint (intact and not pulverized) as a pathway of human lead exposure. Because lead-based paint is a high-dose source, the biologically relevant dosage is similar to lead in soil. Both lead-based paint and soil lead are associated with severe lead poisoning. Leaded gasoline and lead in food, but not lead-based paint, are strongly associated with population blood lead levels in both young children and adults. Soil lead and house dust, but not lead-based paint, are associated with population blood lead levels in children. Most soil lead and house dust are associated with leaded gasoline. Lead-based paint dust is associated with cases of renovation of either exterior or interior environments in which the paint was pulverized. Based upon the limited data to date, abatement of soil lead is more effective than abatement of lead-based paint in reducing blood lead levels of young children. About equal numbers of children under 7 years of age are exposed to soil lead and lead-based paint. Seasonality studies point to soil lead as the main source of population blood lead levels. Soil lead is a greater risk factor than lead-based paint to children engaged in hand-to-mouth and pica behavior. In summary, soil lead is important for addressing the population of children at risk of lead poisoning. When soil lead is acknowledged by regulators and the public health community as an important pathway of human lead exposure, then more effective opportunities for improving primary lead prevention can become a reality.

Associations between soil lead and childhood blood lead in urban New Orleans and rural Lafourche Parish of Louisiana.

This study evaluates associations between soil lead concentrations (SPb), age of housing, and blood lead levels (BPb) of children in metropolitan New Orleans and Lafourche Parish, Louisiana. The database includes over 2,600 SPb and 6,000 BPb samples paired by their median values and pre-1940 housing percentages for 172 census tracts. Associations were evaluated with Fisher's exact test and Spearman's rho test and modeled with the least sum of absolute deviations regression. Census tracts with low SPb are associated with new housing, but census tracts with high SPb are evenly split between old and new housing [Fisher's exact test, p = 8.60 X 10(-13) for the percentage of housing built before 1940 (percent pre-1940 housing) versus SPb]. The p-value for SPb versus BPb is 12 orders of magnitude stronger than the p-value for percent pre-1940 housing versus BPb. Census tracts with low BPb are associated with new housing, but census tracts with high BPb are split evenly between old and new housing (Fisher's exact test, p = 1. 67 X 10(-12) for percent pre-1940 housing versus BPb). Census tracts with high SPb are associated with high BPb and census tracts with low SPb are associated with low BPb (Fisher's exact test, p = 3.18 X 10(-24) for BPb versus SPb). The Spearman's rho test of the association of SPb and BPb in Orleans and Lafourche Parishes yielded a p-value of 6.12 X 10(-24). The least sum of absolute deviations regression model of the data is BPb = 1. 845 + 0.7215 (SPb)0.4. A comparison of the modeled BPb versus observed BPb has an r(2) of 0.552 and a p-value of 2.83 X 10(-23) that this relation was due to chance. If blood lead in children is more closely associated to soil lead than to the age of housing, then primary lead prevention should also include soil lead.

Environmental health in minority and other underserved populations: Benign methods for identifying lead hazards at day care centres of New Orleans.

This study tests the hypothesis that exterior sources of lead dust are more important than interior sources in the route of exposure of children. Benign field methods were used to distinguish between potential and actual lead exposure problems. Utilising hand wipe and surface wipe techniques, hand and environmental samples were obtained from selected day care centres at different locations within New Orleans. Previous research has shown that soil lead is determined by location within the city. Private and public day care centres were selected from inner and outer city areas to estimate the extent of hand lead exposure. To measure and identify the extent of environmental lead exposure, hand wipes were taken before and after playing outdoors. Results of preliminary findings show that outdoor lead dust is a more potent contaminant of hands than indoor lead dust. An association was found between the amount of lead on children's hands after playing outdoors and the lead content in the exterior dust and soil. Although two girls out of forty children had exceptionally high hand lead quantities after playing outdoors, in general, boys have higher hand lead levels than girls. The private inner-city day care centre had a severe contamination problem in its outdoor play area. By contrast, the outdoor play area of the public inner city day care centre is of such a high quality that the quantity of lead dust is independent of location in the city.

Influence of fertilizer and sewage sludge compost on yield and heavy metal accumulation by lettuce grown in urban soils.

Previous research has demonstrated that many urban soils are enriched in Pb, Cd and Zn. Culture of vegetable crops in these soils could allow transfer of potentially toxic metals to foods. 'Tanya' lettuce (Lactuca sativa L.) was grown in pots of five urban garden soils and one control agricultural soil to assess the effect of urban-soil metal enrichment, and the effect of soil amendments, on heavy metal uptake by garden vegetables. The amendments included NPK fertilizer, limestone, Ca(H2PO4)2, and two rates of limed sewage sludge compost. Soil Cd ranged from 0.08 to 9.6 mg kg(-1); soil Zn from 38 to 3490 mg kg(-1); and soil Pb from 12 to 5210 mg kg(-1). Lettuce yield on the urban garden soils was as great as or greater than that on the control soil. Lettuce Cd, Zn and Pb concentrations increased from 0.65, 23, and 2.2 mg kg(-1) dry matter in the control soil to as high as 3.53, 422 and 37.0 mg kg(-1) on the metal-rich urban garden soils. Adding limestone or limed sewage sludge compost raised soil pH and significantly reduced lettuce Cd and Zn, while phosphate fertilizer lowered soil pH and had little effect on Zn but increased Cd concentration in lettuce. Urban garden soils caused a significant increase in lettuce leaf Pb concentration, especially on the highest Pb soil. Adding NPK fertilizer, phosphate, or sludge compost to two high Pb soils lowered lettuce Pb concentration, but adding limestone generally did not. On normally fertilized soils, Pb uptake by lettuce was not exceptionally high until soil Pb substantially exceeded 500 mg kg(-1). Comparing garden vegetables and soil as potential sources of Pb risk to children, it is clear that the risk is greater through ingestion of soil or dust than through ingestion of garden vegetables grown on the soil. Urban dwellers should obtain soil metal analyses before selecting garden locations to reduce Pb risk to their children.

Heavy metal concentrations in two populations of crayfish.

To monitor the environmental contamination of heavy metals in Tuskegee Lake (TL) and National Forest Creek (NFC), Tuskegee, Alabama, adult crayfish muscle and exoskeleton and sediment samples were collected and analyzed for Hg, Pb, Cd, Cu, Co, Ni and Zn. In both TL and NFC crayfish Cu and Zn were not different in muscle and exoskeleton; however, Pb and Cd were significantly different. The Pb in exoskeleton and the Cu and Zn in muscle and exoskeleton of TL crayfish were significantly higher than that of NFC crayfish; however, Cd and Ni were not different between tissues or crayfish sources. Levels of Hg and Co were not detectable.

Trace element concentrations in tissues of goats from Alabama.

Liver, kidney and muscle tissues of goats slaughtered in Alabama were analyzed for Cu, Fe, Mn and Zn. The Cu, Fe and Mn concentrations were significantly higher in livers than in kidneys and muscles. The Zn was significantly higher in livers and muscles than in kidneys. The concentrations of Cu, Fe, Mn and Zn in muscle were not significantly different between male and female goats. However, the Cu, Fe and Mn in livers and Fe in kidneys were significantly different between males and females. The concentrations of Fe, Mn and Zn in livers, Fe and Zn in muscles, and Fe in kidneys were significantly different between young and old goats. The Cu, Mn and Zn in kidneys were not significantly different between the young and old.

Lead in New Orleans soils: New images of an urban environment.

This paper describes a survey of lead in soil and computer generated maps that have been derived for New Orleans, Louisiana. The soil survey included streetside, houseside and open space samples. Because the survey covered every census tract in the metropolitan area it was possible to construct a computer-generated map of the distribution of lead dust in the soils of the urban environment. The data base consists of coordinates, site characteristics and lead analytical results of 3,704 soil samples. The resulting graphics show peaks of lead ranging from 600-1,200 µg per g in the streetside soil of the inner-city and a steeply declining slope to the suburban areas of the city where the lead content of streetside soils is less than 75 µg/g. In the inner-city, the amount of lead in soils found near building foundations is 10 to 20 times higher than the soils adjacent to streets where the median lead content of soils is over 300 µg g(-1). In areas surrounding the city core ("mid-city"), the amount of lead next to the foundation and adjacent to the street are equivalent with medians of 110 µg g(-1). In suburban locations, the median lead content of soil along streetsides is 86 µg g(-1). Soils adjacent to surburban foundations has a median Pb content of 50 µg g(-1). The lowest median lead content in soil is found in open spaces, ranging from 212 to 40 to 28 µg g(-1), respectively, for the inner-city, mid-city, and suburbs. These observations are consistent with the production and consumer use of lead-based paint and leaded-fuels within the modern city.

Hazardous wastes, hazardous materials and environmental health inequity.

This paper reviews issues associated with the equity of locating hazardous waste sites and hazardous materials. Reports and case studies indicate that hazardous waste sites and the locations of hazardous materials are disproportionately situated near minority communities, especially African-American communities. This inequitable placement of hazardous waste sites is of concern, since exposure to toxic waste can adversely affect human health. Proximity to these sites may place these minority communities at higher risk of developing cancers and respiratory, cardiovascular, and neurological diseases, and of incurring increased levels of individual and family stress. The health of persons in minority communities near hazardous waste sites is further compromised by their lack of access to adequate health care. The potential health risks borne by racial and ethnic minorities and by low income communities as a consequence of exposure to toxic waste constitutes environmental inequity. In order to decrease the burden of these risks, we recommend developing environmental policies that address environmental inequity; conducting detailed demographic and health studies that assess the impact of exposure to toxic waste on minority populations; and devising educational programs to sensitize professional service providers and prevent exposure by community residents. This paper identifies research needs and opportunities.

The pattern of cadmium in the environment of five Minnesota cities.

This paper reports on the cadmium results of a soil survey conducted by the State of Minnesota during the summer of 1986. The survey collected soil-dust trom the oldest census tracts of Minneapolis, St. Paul, Duluth, St. Cloud and Rochester. The results reveal fundamental differences in soil cadmium among cities. Soil cadmium exceeds 2 µg g(-1) in 8.4% of the samples in Minneapolis, and 7.0, 4.0, 3.3 and 1.5% respectively of the samples collected in St. Paul, Duluth, St. Cloud and Rochester. Minneapolis and St. Paul residential houseside soil samples had cadmium levels that exceeded 2 µg g(-1) in 24.5 and 21.2% respectively of the samples collected. By comparison, the Minneapolis and St. Paul residential streetside soil samples had cadmium levels that exceeded 2 µg g(-1) in 1.2 and 0.6%, respectively, of the samples collected. Also the Minneapolis and St. Paul residential midyard soil samples had cadmium levels that exceeded 2 µg g(-1) in 1.9 and 5.5%, respectively, of the samples collected. Cadmium levels for the combined data for all cities and communities in Minneapolis appears to be directly related to traffic flow. However, cadmium levels around housesides and in midyards do not follow patterns of traffic flow in the same manner as cadmium content of soils along streetsides. St. Paul has an anomalously high cadmium content toward the east of the city compared with the west side of the city. The Pigs Eye sewage sludge incinerator located east of the city is the most likely source of cadmium to cause this pattern. This study provides essential urban background information about both the fundamental environmental patterns of cadmium as well as processes which appear to operate to cause those patterns.

Urban lead levels in Minneapolis: the case of the Hmong children.

This study uses soil lead as a means of describing the urban lead levels in the metropolitan area of the Twin Cities, and assesses the soil lead levels next to homes of neighborhoods of the metropolitan area. Lead levels of rural soils are around 5 micrograms/g. Near the city limits they increase to 25-50 micrograms/g, and in the central business district they are around 500 to 1000 micrograms/g, or over 100 times greater than in the rural areas. Many Hmong children are suffering from undue lead absorption. The homes of the Hmong children were all located in inner-city neighborhoods. Soil around these homes was compared to soils around homes of a neighborhood away from the inner city. Fifty percent of the Hmong children with lead poisoning inhabit homes which have soil lead levels of 500-999 micrograms/g and 40% live in homes with lead levels of 1000 micrograms/g or more. One home of ten in the outer city has soil lead levels above 500 micrograms/g. The lead sources of the inner city include house paint and leaded gasoline from vehicle traffic. Raising children in high lead environments as found in the Minneapolis inner city has long-term implications because of mental and behavioral deficits that are known to result from chronic exposure to lead.

Lead concentrations in inner-city soils as a factor in the child lead problem.

Soil samples were randomly collected from 422 vegetable gardens in a study area centered in downtown Baltimore, Maryland, and having a radius of 48.28 km (30 miles). The levels of lead, four other metals (cadmium, copper, nickel, and zinc), and pH were measured for each location. The application of multi-response permutation procedures, which are compatible with mapping techniques, reveals that lead (as well as cadmium, copper, nickel, and zinc) is concentrated and ubiquitous within the soils of the inner-city area of Metropolitan Baltimore. The probability values that the concentration of metals occurred by chance alone vary from about 10(-15) to 10(-23) depending on the metal considered. Our findings pose environmental and public health issues, especially to children living within the inner-city.