Lead Dust Research Articles

The Beat

Vol. 117, No. 10 NewsOpen AccessThe Beat Erin E. Dooley Erin E. Dooley Search for more papers by this author Published:1 October 2009https://doi.org/10.1289/ehp.117-a438bAboutSectionsPDF ToolsDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmail Vehicles Concentrate NicotineA study by Patrick Breysse et al. published online 25 August 2009 ahead of print in Tobacco Control found that vehicle passengers riding with smokers may be exposed to nicotine levels 40–50% higher than those found in restaurants and bars that permit smoking. Nicotine concentrations inside vehicles increased twofold for every cigarette smoked, and while opening the windows reduced smoke somewhat, it did not eliminate exposure within the vehicle. Breysse et al. state the levels are unacceptable for nonsmoking passengers, especially children, who are at increased risk for secondhand smoke–related health problems..USDA Maps Local Food ProductionUntil recently, low fuel prices meant the U.S. food system could rely on food imported from other countries, but rising transport costs and regional food shortages and crop failures are among several factors encouraging a closer look at local food production. Wayne Honeycutt and colleagues at the Agricultural Research Service are now mapping data from Maine to Virginia on weather, soil, land use, and water availability to model potential crop production and determine local food production capacity. They say expanding opportunities for local food production could stimulate rural development and offset the risk of food shortages by diversifying and increasing local production in other areas.Fredon Township School playgroundSchool Averts EMF-Related ClosureThe debate over the safety of electromagnetic fields (EMFs) nearly closed a New Jersey school this fall until the state’s biggest electric utility and the Sussex County Board of Education reached an eleventh-hour settlement. The board had planned to close the K–6 Fredon Township School 1 October 2009 because the existing high-voltage power line crossing the school’s playground had been found to emit EMF levels more than 8 times the WHO-recommended maximum of 3 milligauss. Under the settlement, Public Service Electric & Gas Co. agreed to pay $95,000 to relocate playgrounds located under its lines. There is limited evidence that EMFs from power lines may be a risk factor for childhood leukemia.Colorimetric “Nose” Alerts Chemical HandlersIn a report published online 13 September 2009 in Nature Chemistry, Kenneth Suslick and colleagues present a postage stamp–sized electronic sensor capable of quickly and inexpensively detecting toxic chemicals and their concentrations through color visualization. The pattern created by color changes in the disposable 36-dye sensor array identifies both the toxicant and its concentration. The sensor can detect more chemicals than previous methods and produces most results within 2 minutes. The researchers have developed a handheld version similar to a card-scanning device that uses LED illumination and an ordinary camera.Take-Home Dust Boosts Car Seat Lead LevelsSeveral studies have established that lead-exposed workers can carry lead-contaminated dust off the jobsite on their clothing, shoes, and tools. In the 21 August 2009 MMWR Tina Bernier et al. report the first known cases of childhood lead poisoning attributed to take-home lead dust deposited onto car safety seats. No contamination was found in the six children’s homes, leading the researchers to examine family vehicles and car seats, where high lead levels were found. Although previous studies have recommended monitoring blood lead levels among children of lead-exposed workers, no standards exist for levels of lead dust contamination in vehicles or on child car safety seats.Indoor Greenery Releases VOCsPeace lilies, snake plants, weeping figs (ficus trees), and areca palms are just a few of the houseplants that have been shown to remove volatile organic compounds (VOCs) from indoor air, but a new study by Dong Sik Yang et al. in the August 2009 issue of HortScience finds they can also release these chemicals. The authors found these four types of houseplants released 12–23 VOCs, and although the researchers did not quantify potential exposures, they did note that emissions were higher during the day than at night. The authors attributed the VOCs to pesticides used in nurseries, microorganisms living in the growing medium, and offgassing of plastic planters.FiguresReferencesRelatedDetails Vol. 117, No. 10 October 2009Metrics About Article Metrics Publication History Originally published1 October 2009Published in print1 October 2009 Financial disclosuresPDF download License information EHP is an open-access journal published with support from the National Institute of Environmental Health Sciences, National Institutes of Health. All content is public domain unless otherwise noted. Note to readers with disabilities EHP strives to ensure that all journal content is accessible to all readers. However, some figures and Supplemental Material published in EHP articles may not conform to 508 standards due to the complexity of the information being presented. If you need assistance accessing journal content, please contact ehponline@niehs.nih.gov. Our staff will work with you to assess and meet your accessibility needs within 3 working days.

Mass Lead Poisoning in Dakar: Battery Recycling Exacts a Heavy Toll

In a neighborhood of Dakar, Senegal, 18 children died from an aggressive central nervous system disease between November 2007 and March 2008. Experts from the World Health Organization and local health authorities were called in to investigate the deaths, but cultural prohibitions preempted autopsies of the children. So the researchers examined 32 of the children’s siblings and 23 of the siblings’ mothers along with 18 unrelated local children and 8 unrelated adults. They concluded that the cause of death likely was encephalopathy resulting from severe lead poisoning [EHP 117:1535–1540; Haefliger et al.]. The source of the lead, in turn, was determined to be contamination resulting from the reclamation of used lead‐acid batteries, a lucrative business in developing countries that often is performed in the open with few pollution controls. Since 1995, local people had broken apart batteries from vehicles and appliances and sorted the components in an open sandy area of the neighbhorhood. They sifted through the sand for scraps of valuable lead to sell, even carrying sacks of contaminated sand into their homes. People were probably exposed by inhaling and ingesting lead dust, with children particularly exposed through hand‐to‐mouth activity and eating the contaminated soil. The developing nervous system of children is particularly vulnerable to the toxic effects of lead. Blood lead concentrations as low as 10 μg/dL are known to impair neurologic development, resulting in permanent intellectual impairment. However, recent evidence suggests there may be no safe threshold of exposure. Among the 50 children tested, blood lead levels ranged from 39.8 to 613.9 μg/dL. Seventeen of the 50 children showed neuropsychiatric symptoms including convulsions, irritability, and aggression, and 21 showed gastrointestinal symptoms such as anorexia and vomiting. Adult blood lead levels ranged from 32.5 to 98.9 μg/dL, and their most commonly reported symptom was gastrointestinal upset. Recycling activity reportedly ended by March 2008 following a public awareness campaign, and the neighborhood soil was partially remediated. Nevertheless, lead concentrations measured in the sandy work area after this time still reached 209,000 mg/kg, and levels inside homes reached 14,000 mg/kg. The U. S. Department of Housing and Urban Development sets 400 mg/kg as for the standard for lead in bare soil in children’s play areas (there is no comparable standard in Senegal). The lead poisoning in this study was severe enough to catch the attention of health experts, but the global incidence of lead poisoning from battery recycling is unknown. The authors believe many cases go unaddressed in developing countries because local authorities lack resources to recognize, diagnose, and manage lead toxicity. However, they write, lead poisoning can be prevented through measures such as public education and the implementation and enforcement of lead recycling guidelines.

Determination of lead, naphthalene, phenanthrene, anthracene and pyrene in street dust

Street dust is a potential source of lead exposure to humans, however scarce information about the pollution levels with lead and polyromatic hydrocarbons exists in Venezuela, limiting the appropriate evaluation of the levels of risk of the people. This work was aimed in the determination of the concentrations of lead, naphtalene, anthracene, phenanthrene and pyrene in the street dust of the most transited avenues and streets of Maracay city. Thirty street dust samples were collected at the streets and avenues, troll and bus main station. Lead was determined by atomic absorption spectrometry after acid digestion (Pb-total), also the fractions of lead soluble in 1 M MgCl 2 and 0.5 M ammonium acetate (pH = 7) were quantified. The polyaromatic hydrocarbons concentrations were determined by capillary gas chromatography equipped with a flame ionization detector. The Pb-total ranged between 734 and 11.439 µg/g with the higher values at the most transited streets and avenues. About 60 % of samples exhibited concentrations between 1.000 and 2.500 µg/g, similar to the values reported in the literature for soils of urban areas. The fraction of lead soluble in magnesium accounted for less than 3 % of Pb-Total, while the 0.5 M ammonium acetate solution represented more than the 75 % of the total loads of the pollutant. The most contaminated samples were those taken at the toll with concentrations of 695.5 and 252.1 µg/g phenanthrene and anthracene were the most abundant, while at the bus station all compounds were detected.

Development of a Portable Heavy Metal Ion Analyzer Using Disposable Screen-Printed Electrodes

: Stripping analysis, Heavy metal, Screen-printed electrodeEnvironmental pollution with heavy metal ions is the worst poisoning material. Lead is the most common metal involved in chronic poisoning. Lead poisoning can affect nearly every system in the body. Elevated human blood lead concentrations are associated with damage to the kidney, the liver, and the gastrointestinal trace as well as with neurological damage and decreased hemoglobin production. It is often called silent epidemic because it occurs without obvious symptoms, it frequently goes unrecognized. Lead exposure occurs when lead dust or fumes are inhaled, or when lead is ingested via contaminated hands, food, water, or clothing. Lead entered the respiratory and digestive system is released to the blood and distributed throughout the body. Children are exposed to lead poisoning more easily through toys, soil which are already contaminated with heavy metals. Children begin to exhibit permanent neurological and behavioral dysfunctions at low blood lead levels (BLL), with significant neurological damage occurring over the 5 ~ 10 µg/dL (0.25 ~ 0.5 µM) range.

Is Lead Dust Within Nuclear Medicine Departments a Hazard to Pediatric Patients?

Because of the penetrating ability of the radiation used in nuclear medicine, metallic lead is widely used as radiation shielding. However, this shielding may present an insidious health hazard because of the dust that is readily removed from the surfaces of lead objects. The lead dust may become airborne, contaminate floors and other nearby surfaces, and be inadvertently inhaled or ingested by patients. We determined if the quantity of lead dust encountered within nuclear medicine departments exceeded Environmental Protection Agency (EPA) standards. For lead dust quantification, professional lead test kits were used to sample fifteen 1-ft(2) sections of different surfaces within the department. Four samples were collected once per week from each site. The samples were then submitted to a National Lead Laboratory-accredited program for a total lead measurement. Lead contamination (mug/ft(2)) for each of the 60 samples was compared with the EPA standards for lead dust. Lead contamination was present at 6 of the 15 sites, and of 60 samples, 18 exceeded the EPA standard of 50 mug/ft(2). Lead contamination is present within nuclear medicine departments, and corrective measures should be considered when dealing with pediatric patients. A larger series needs to be conducted to confirm these findings.

Making the Needed Linkages and Economic Case for Continued Lead-Paint Abatement

Making the Needed Linkages and Economic Case for Continued Lead-Paint Abatement

Lead loadings in household dust in Delhi, India

Lead in household dust is dangerous to children who ingest lead from playing close to the ground, and having frequent hand-to-mouth contact. Although there have been several investigations of lead levels in India in air, blood and new paint, the literature is sparse on the levels of lead in household dust. This study analyzed 99 samples of dust taken from bare floors and 49 samples of dust taken from windowsills in a cross-section of Delhi, India houses for lead loadings. The arithmetic mean of lead loading for floor samples and windowsill dust samples was found to be 36.24 microg/ft(2) and 129.5 microg/ft(2), respectively. The geometric mean of dust lead loading for floor and interior windowsill samples was found to be 19.7 microg/ft(2) and 75.5 microg/ft(2), respectively. Comparing the results with US geometric mean dust lead levels from a national cross-section of US housing, which in 2000 were 1.1 microg/ft(2) and 9.4 microg/ft(2) on floors and windowsills, respectively as reported by Jacobs et al. (2002) suggests that the lead content of the dust in Delhi homes is much higher than that in the national data in the US and that the levels pose a hazard to children. Practical Implications The present study is first of its kind in this part of the world. In the context of ongoing efforts to eliminate lead from paints worldwide this research will help the scientists and policy makers in assessing the Children's exposure to lead in developing country as well. Since more than one half of the housing units tested had at least one dust lead sample exceeding US health-based standards, health care providers and public health officials need to give attention to possible lead poisoning in Delhi children. Routine blood lead screening of children should follow recommended public health practice for children at risk. Additional larger-scale studies are needed in Delhi and elsewhere to determine how representative these findings are and to attempt to delineate the sources of the high dust lead which are expected to vary depending on the location. Knowledge of the sources is needed to appropriately allocate resources. From other studies performed in India it is likely that lead-based paint is one of the sources and its continued use should be discontinued.

Study of quality control and metal distribution in urban airborne particulates

In this investigation, results of 33 elements in airborne samples collected continuously over nine urban locations are discussed. Inductively coupled plasma-atomic emission spectrometry technique was used for determining concentration of metals. Quality control was established prior to analysis of real air samples. The guidelines followed are based on USEPA Compendium Method IO-3.4. Uncertainty in analysis was also established. Based on the concentration of metals in airborne particulates, we attempted to study the metal distribution characteristics in ambient air at various urban locations. Metals such as Al, Ca, Fe were comparatively at higher concentrations than the other elements under study at most of the locations. The city vehicles operate on lead-free fuels; however, concentration of lead in urban dust was observed in the concentration range of 0.33–6.24 μg/m3. Soil samples were also collected from sites close to the air sampling locations. Soil samples were also analysed for metal content. Enrichment factor was determined for elements measured at nine urban locations. The data supports interpretation of results in terms of contribution of metals in airborne particulates from anthropogenic and noncrustal origin.

The Evolving Paradigm of Laws on Lead-Based Paint: From Code Violation to Environmental Hazard

This article explores the significance of an ongoing paradigm shift for the legal approach to lead-based paint in privately owned residential properties from a housing paradigm to an environmental paradigm. The housing paradigm, still prevalent in most state and local law, has resulted in general silence on the lead-based paint issue in the community and, consequently, to little actual abatement of the hazard. The shift to an environmental paradigm for addressing hazards of lead-based paint in private housing is reflected in some state and federal legislation. Because of its focus on the discovery of health hazards, on the handling of hazardous material, and on long-term planning, an environmental lens offers a paradigm more likely to lead to actual abatement of lead hazards. This article first explores the existing framework of laws on lead hazards. Lead poisoning seriously affects the health of children and pregnant women and disproportionately affects ethnic minorities. Federal legislation separate from the major environmental laws addresses the issue of lead-based paint in federally owned or subsidized housing, but that law has not been extended to privately owned housing. Participants in the housing system - owners, rental property managers, lenders - have resisted accepting responsibility for reduction of the environmental hazard of lead-based paint in part due to the expense of abatement and the uncertainty of safe abatement techniques and standards. State and local health, housing, criminal, and property transfer laws have been generally ineffective in bringing about change in the housing stock and in protecting the health of occupants from poisoning. Examples of stalemates that arise when seeking legal relief from lead hazards are drawn from Maryland law. The article next distinguishes the housing paradigm, under which tenant - landlord disputes have provided the context for the development of the law, from an emerging environmental paradigm, which calls for discovery and response to hazards when occupants, workers, or the community around the dwelling may be affected. The article explores elements of this paradigm in Massachusetts law, in 1992 federal legislation, and in voluntary private market response of requiring an environmental assessment of residential property by the Federal National Mortgage Association (FNMA), a secondary mortgage market entity. By requiring disclosure of this hazard in housing to potential buyers and tenants, the federal government may force the residential real estate market to take the hazard into account in setting the rental amount and sales price. Market aversion to risks of liability and to loss of investment is likely to bring about voluntary compliance with hazard abatement laws. The interdisciplinary approach endorsed in the 1992 legislation is particularly appropriate for an area in which public knowledge and technology are changing. The article concludes with recommendations about how state and federal law on lead hazards might further develop as the paradigm takes hold. At the federal level, the government should set uniform standards for lead dust levels and safe abatement, and should provide a funding mechanism for hazard abatement. At the state level, the law should require both testing and disclosure before the sale of real property, testing and hazard abatement before rental, and provisions for relocation of tenants at landlord expense during hazard abatement. Local registration laws for rental property could trigger the testing process. In addition, states should establish and enforce sanctions for knowing endangerment of persons by lead hazards.

Development and field trial of a household surface lead loading rate sampling device in a lead-contaminated community of southern Thailand

A new dust-collecting device was developed to assess surface lead loading rates in houses in communities contaminated with lead oxide dust used for caulking in nearby boat-repair yards. The device consists of two small glass sheets with total area of 1,200 cm(2) placed in two plastic trays suspended from the ceiling in the house for 3 months before wiping and sending the dust specimen for determination of lead content using flame atomic absorption spectrophotometry. After a pilot trial in four households, further data were collected from 43 matched pairs of boat-caulkers' and neighboring control households. All devices were retained in the house for 3 months without any complaint. Static measurements of lead dust levels were also assessed in all households. The values significantly discriminated high from low lead exposure households (p = 0.015) and provided good correlations with floor lead loading (Spearman rank correlation coefficient, r = 0.39 to 0.62) and dust lead content (r = 0.53 to 0.64). This sampling method is an alternative to others which consume more household space or require a longer collection period.

Air pollution assessment in urban areas and its impact on human health in the city of Quetta, Pakistan

Nowadays, air over major cities throughout the world has become overburdened with gases produced by automobiles. The death rate due to automobile pollution is increasing rapidly in the metropolitan areas. With passage of time, people realized that polluted air has serious effects on their health, climate and economics. Weather and climate have integrated impact on human activities resulting in worldwide concentration of the particulates of environmental pollution, viz., chlorofluorocarbons, carbon dioxide, methane, nitrogen oxide, lead and several other dust and gaseous particles. Like many other mega cities in the world the ambient air quality of Quetta, Pakistan is also deteriorating nowadays. Automobile exhausts and certain industrial pollutants produce O3 by photochemical reactions. The particulate matter, particularly less than 10 μm in size, can pass through the natural protective mechanism of human respiratory system and plays an important role in genesis and augmentation of allergic disorders. Sources of air pollution in the area and the unique problem arising out of the emission from the vehicles, industries, etc. have been described. Ambient air quality was monitored along with micrometeorological data and the results are discussed. The status of air pollution in the area has been evaluated and a questionnaire survey was conducted to estimate the allergic symptoms and exposure to assess the respiratory disorders. The data are analyzed to evaluate the critical situation arising out of the emission of air pollutants and the impact on human health due to respirable diseases (RDs) in middle class sub-population (activity-wise) in the area assessed. A strategic air quality management plan has been proposed. For the mitigation of air pollution problems in the city, different measures to be adopted to maintain the balance between sustainable development and environmental management have been discussed. Air pollution has significant effects on exacerbation of asthma, allergy and other respiratory diseases.

Influence of vehicular density on the distribution pattern of lead and cadmium in road dust of Port Harcourt city, Nigeria

No Abstract. International Journal of Natural and Applied Sciences Vol. 4 (1) 2008: pp. 29-32

Isotopic composition of lead in soils and street dust in the Southeastern administrative district of Moscow

The content and isotope ratios of lead were studied in soils, street dust, and snow sampled in the Southeastern administrative district of Moscow. The relationships between the lead isotope ratios and the content of different lead compounds in soils were revealed. It was shown that isotope ratios for the total lead have low information values upon low levels of lead contamination. The contribution of technogenic lead compounds to the isotopic composition of lead increases in the following sequence: total lead < acid-soluble lead < mobile lead. The effect of emissions from thermal power stations and vehicles’ exhaust on the isotopic composition of lead in the street dust and soils was estimated.

Multiple links towards integrating teams for understanding of disease and environment (MULTITUDE)

Geochemists have made important contributions in understanding the cause of environmentally related diseases such as the iodine-deficiency disorders (Fuge and Johnson 1986), fluorine toxicity (Ozsvath 2008), and natural arsenic poisoning (Smedley and Kinniburgh 2005). Similarly, the Society for Environmental Geochemistry and Health (SEGH) has developed a model to describe the relationship between lead in dust and soil and lead in blood (Wixson and Davies 1994), which has played an important part in the development of soil-guideline values in the UK and elsewhere. Nevertheless, with the continuing and rapid increase in the volume of knowledge relevant to this field, academic disciplines and areas of interests have necessarily become increasingly specialized. The resulting compartmentation has led, too often, to some disciplines inhabiting different ‘universes’ from others with whom meaningful dialogue and collaboration would be of mutual benefit, even in the environmental health field (Stewart and Pharoah 1996). Concepts, mechanisms, processes, and analytical approaches often cross disciplinary boundaries. The integration of disparate disciplines to examine subject matter from several distinct angles can be frustrating, with different vocabulary and assumptions. However, this integration is an ongoing necessity in order to develop a deeper understanding of the relevant science and to identify fresh multidisciplinary approaches to these complex issues. This special issue, which contributes towards this integration, contains six papers derived from a workshop held in June 2007 in Liverpool, UK. The general theme was the environment and human health, with a particular focus on building research capacity by forging Multiple Links Towards Integrating Teams for Understanding of Disease and Environment (MULTITUDE). The papers should be read as a whole, since the discussions within the targeted workshops crossed not only disciplinary boundaries but also fertilized each other. As a result, it became clear to both the participants and the authors that in environmental geochemistry and health, the understanding of uncertainty, both from sampling and measurement (Ramsey 2008) and conceptual (Briggs et al. 2008), is essential for the development of realistic toxicological and exposure data (Hursthouse and Kowalczyk 2008; Ramsey 2008). This in turn will enable the development of successful strategies for the reduction in the effects of contaminants on human health (Farmer and Jarvis 2008). A. G. Stewart (&) Cheshire and Merseyside Health Protection Unit, Microbiology Laboratory, Countess of Chester Health Park, London Road, Chester CH2 1UL, UK e-mail: alex.stewart@hpa.org.uk

Exposure of U.S. Children to Residential Dust Lead, 1999–2004: I. Housing and Demographic Factors

BackgroundLead-contaminated house dust is a major source of lead exposure for children in the United States. In 1999–2004, the National Health and Nutrition Examination Survey (NHANES) collected dust lead (PbD) loading samples from the homes of children 12–60 months of age.ObjectivesIn this study we aimed to compare national PbD levels with existing health-based standards and to identify housing and demographic factors associated with floor and windowsill PbD.MethodsWe used NHANES PbD data (n = 2,065 from floors and n = 1,618 from windowsills) and covariates to construct linear and logistic regression models.ResultsThe population-weighted geometric mean floor and windowsill PbD were 0.5 μg/ft2 [geometric standard error (GSE) = 1.0] and 7.6 μg/ft2 (GSE = 1.0), respectively. Only 0.16% of the floors and 4.0% of the sills had PbD at or above current federal standards of 40 and 250 μg/ft2, respectively. Income, race/ethnicity, floor surface/condition, windowsill PbD, year of construction, recent renovation, smoking, and survey year were significant predictors of floor PbD [the proportion of variability in the dependent variable accounted for by the model (R2) = 35%]. A similar set of predictors plus the presence of large areas of exterior deteriorated paint in pre-1950 homes and the presence of interior deteriorated paint explained 20% of the variability in sill PbD. A companion article [Dixon et al. Environ Health Perspect 117:468–474 (2009)] describes the relationship between children’s blood lead and PbD.ConclusionMost houses with children have PbD levels that comply with federal standards but may put children at risk. Factors associated with PbD in our population-based models are primarily the same as factors identified in smaller at-risk cohorts. PbD on floors and windowsills should be kept as low as possible to protect children.

Exposure of U.S. Children to Residential Dust Lead, 1999–2004: II. The Contribution of Lead-Contaminated Dust to Children’s Blood Lead Levels

BackgroundThe U.S. Centers for Disease Control and Prevention collected health, housing, and environmental data in a single integrated national survey for the first time in the United States in 1999–2004.ObjectivesWe aimed to determine how floor dust lead (PbD) loadings and other housing factors influence childhood blood lead (PbB) levels and lead poisoning.MethodsWe analyzed data from the 1999–2004 National Health and Nutrition Examination Survey (NHANES), including 2,155 children 12–60 months of age with PbB and PbD measurements. We used linear and logistic regression models to predict log-transformed PbB and the odds that PbB was ≥ 5 and ≥ 10 μg/dL at a range of floor PbD.ResultsThe population-weighted geometric mean (GM) PbB was 2.0 μg/dL (geometric standard error = 1.0). Age of child, race/ethnicity, serum cotinine concentration, poverty-to-income ratio, country of birth, year of building construction, floor PbD by floor surface and condition, windowsill PbD, presence of deteriorated paint, home-apartment type, smoking in the home, and recent renovation were significant predictors in either the linear model [the proportion of variability in the dependent variable accounted for by the model (R2) = 40%] or logistic model for 10 μg/dL (R2 = 5%). At floor PbD = 12 μg/ft2, the models predict that 4.6% of children living in homes constructed before 1978 have PbB ≥ 10 μg/dL, 27% have PbB ≥ 5 μg/dL, and the GM PbB is 3.9 μg/dL.ConclusionsLowering the floor PbD standard below the current standard of 40 μg/ft2 would protect more children from elevated PbB.

Preparation of basic lead carbonate from lead dust by hydrometallurgical processes

Recycling of lead dust generated from waste lead battery smelter has been attempted to minimize the environmental pollution. For this aim, preparation of basic lead carbonate from lead dust has been tested with hydrometallurgical processes. The major component of lead dust used in the work was found to be PbS and the fraction less than 325 mesh size was about 64%. As a result of leaching with nitric acid, leaching efficiency of lead was more than 95% at the condition of 4 N nitric acid, 40 °C, and slurry density of 50 g/l. In the leaching of lead dust with sulfuric acid, the addition of nitric acid was essentially required because only 4% of lead dust was dissolved by sulfuric acid without nitric acid. In the carbonation test, carbonation of lead sulfate could be successfully accomplished at the reaction temperature of 30 °C while direct carbonation of lead dust was found to give the negligible conversion.

Selecting a Lead Hazard Control Strategy Based on Dust Lead Loading and Housing Condition: II. Application of Housing Assessment Tool (HAT) Modeling Results

In Part I in this issue, modeling was used to identify a Housing Assessment Tool (HAT) that can be used to predict relative intervention effectiveness for a range of intervention intensities and baseline dust lead loadings in occupied dwellings. The HAT predicts one year post-intervention floor and windowsill loadings and the probability that these loadings will exceed current federal lead hazard standards. This article illustrates the field application of the HAT, helping practitioners determine the minimum intervention intensity needed to reach “acceptable” one year post-intervention levels, with acceptability defined based on specific project needs, local needs, regulations, and resource constraints. The HAT is used to classify a dwelling's baseline condition as good or poor. If the average number of interior non-intact painted surfaces per room is ≥2, then the dwelling is rated as poor. If exterior windows/doors are deteriorated and the average number of exterior non-intact painted surfaces per building side is ≥5, then the dwelling is rated as poor. If neither of these conditions is true, then the dwelling's HAT rating is good. The HAT rating is then combined with baseline average floor loading to help select the treatment intensity. For example, if the baseline floor loading is 100 μg/ft2 (1,075 μg/m2 and the HAT rating is poor, the probability that the one-year floor loading exceeds the federal standard of 40 μg/ft2 (430 μg/m2 is 27% for a high-intensity strategy (i.e., window lead abatement with other treatments) but is 54% for a lower-intensity strategy (i.e., cleaning and spot painting). If the HAT rating is good, the probability that the one-year floor loading exceeds 40 μg/ft2 is approximately the same for low-and high-intensity strategies (18% for window lead abatement with other treatments compared with 16% for cleaning and spot painting). Lead hazard control practitioners can use this information to make empirically based judgments about the treatment intensity needed to ensure that one year post-intervention loadings remain below federal standards.

Selecting a Lead Hazard Control Strategy Based on Dust Lead Loading and Housing Condition: I. Methods and Results

A methodology was developed to classify housing conditions and interior dust lead loadings, using them to predict the relative effectiveness of different lead-based paint hazard control interventions. A companion article in this issue describes how the methodology can be applied. Data from the National Evaluation of the HUD Lead Hazard Control Grant Program, which covered more than 2800 homes in 11 U.S. states, were used. Half these homes (1417) met the study's inclusion criteria. Interior interventions ranged from professional cleaning with spot painting to lead abatement on windows, and enclosure, encapsulation, or removal of other leaded building components. Modeling was used to develop a visual Housing Assessment Tool (HAT), which was then used to predict relative intervention effectiveness for a range of intervention intensities and baseline floor and windowsill dust lead loadings in occupied dwellings. More than 117,000 potential HATs were considered. To be deemed successful, potential HATs were required to meet these criteria: (1) the effect of interior strategy had to differ for HAT ratings of good vs. poor building condition and/or baseline dust lead loadings; (2) the HAT rating had to be a predictor of one year post-intervention loadings; (3) interior intervention strategy had to be a predictor of one-year loadings; (4) higher baseline loadings could not be associated with lower one-year loadings; and (5) neither exterior work nor site/soil work could result in higher predicted one-year loadings for either HAT rating. Of the 1299 HATs that met these criteria, one was selected because it had the most significant differences between strategy intensities when floors and sills were considered together. For the selected HAT, site/soil work was a predictor of one-year loadings for floors (p = 0.009) but not for sills (p = 0.424). Hazard control work on the building exterior was a predictor of both sill and floor one-year loadings (p = 0.004 and p < 0.001, respectively). Regardless of the type of interior intervention strategy, interior work was a predictor of both floor and sill one-year loadings (each p ≤ 0.001).

Lead exposures in U.S. Children, 2008: implications for prevention.

ObjectiveWe reviewed the sources of lead in the environments of U.S. children, contributions to children’s blood lead levels, source elimination and control efforts, and existing federal authorities. Our context is the U.S. public health goal to eliminate pediatric elevated blood lead levels (EBLs) by 2010.Data sourcesNational, state, and local exposure assessments over the past half century have identified risk factors for EBLs among U.S. children, including age, race, income, age and location of housing, parental occupation, and season.Data extraction and synthesisRecent national policies have greatly reduced lead exposure among U.S. children, but even very low exposure levels compromise children’s later intellectual development and lifetime achievement. No threshold for these effects has been demonstrated. Although lead paint and dust may still account for up to 70% of EBLs in U.S. children, the U.S. Centers for Disease Control and Prevention estimates that ≥30% of current EBLs do not have an immediate lead paint source, and numerous studies indicate that lead exposures result from multiple sources. EBLs and even deaths have been associated with inadequately controlled sources including ethnic remedies and goods, consumer products, and food-related items such as ceramics. Lead in public drinking water and in older urban centers remain exposure sources in many areas.ConclusionsAchieving the 2010 goal requires maintaining current efforts, especially programs addressing lead paint, while developing interventions that prevent exposure before children are poisoned. It also requires active collaboration across all levels of government to identify and control all potential sources of lead exposure, as well as primary prevention.