Interior Dust Research Articles

The Influence of Exterior Dust and Soil Lead on Interior Dust Lead Levels in Housing That Had Undergone Lead-Based Paint Hazard Control

To aid in understanding the contribution of exterior dust/soil lead to postintervention interior dust lead, a subset of housing from the HUD Lead-Based Paint Hazard Control Grant Program Evaluation was selected for study. Housing from 12 state and local governments was included. Exterior entry and street dust samples were obtained by a vacuum method, and soil samples were building perimeter core composites. Interior dust wipe lead data (μg/ft2) and paint lead data (mg/cm2) were also available for each of the dwelling units and included in the modeling. Results from 541 dwelling units revealed a wide range of exterior dust and soil lead levels, within and between grantees. Minimum and maximum geometric mean lead levels, by grantee, were 126 and 14,400 μg/ft2 for exterior entry dust; 325 and 4,610 μg/ft2 for street dust; and, for soil concentration, 383 and 2640 ppm. Geometric mean exterior entry dust lead concentration (1641 ppm) was almost four times as high as street dust lead concentration (431 ppm), suggesting that lead dust near housing was often a source of street dust lead. Geometric mean exterior entry dust lead loading was more than four times as high as window trough dust lead loading and more than an order of magnitude higher than interior entry dust lead loading. Statistical modeling revealed pathways from exterior entry dust lead loading to loadings on interior entryway floors, other interior floors, and windowsills. Paint lead was found to influence exterior entry dust lead. Results of this study show that housing where soil lead hazard control activities had been performed had lower postintervention exterior entry, interior entry floor, windowsills, and other floor dust loading levels. Soil was not present for almost half the buildings. Statistical analysis revealed that exterior strategy influenced soil lead concentration, and soil lead concentration influenced street dust lead loading. This study represents one of the few where an impact of soil treatments on dust lead levels within the housing has been documented and may represent the first where an impact on exterior entry dust lead has been found. The inclusion of measures to mitigate the role of exterior sources in lead hazard control programs needs consideration.

The effect of soil abatement on blood lead levels in children living near a former smelting and milling operation.

To evaluate the effect of soil abatement on children's blood lead concentrations and on environmental levels of lead and arsenic. Two cross-sectional surveys were conducted. The first (1989) was of a random sample of 6- to 72-month-old children (n=112). The second (1998) included all 6- to 72-month-old children whose parents agreed to participate in the survey (n=215). From 1993 to 1996, soil abatement was conducted around homes with average soil lead concentration >500 parts per million (ppm). Venipuncture blood samples were taken, interviews were conducted, and samples of house dust, soil, water, and paint were tested for lead and arsenic, using identical protocols in both surveys. The expected decline in blood lead concentrations were calculated for children who lived in houses that were abated, compared with children who lived in houses that were not abated. Lead and arsenic in soil and interior dust in homes that underwent soil abatement declined significantly compared to unabated homes (p<.05). After adjustment for potential confounders, the blood lead concentration in children ages 6 to 72 months who lived in soil-abated housing declined 42.8% faster than children who lived in unabated housing (p=0.14). In children ages 6 to 36 months, the decline was 45.4% faster (p=0.03). The estimated reduction in blood lead for children ages 6 to 36 months was 3.5 micro g/dL for every 1,000 ppm reduction in soil lead concentration (95% confidence interval [CI]=2.4 micro g/dL, 4.6 micro g/dL). Soil abatement was associated with a significant decline in children's blood lead and indoor environmental levels of lead and arsenic.

The prevalence of lead-based paint hazards in U.S. housing.

In this study we estimated the number of housing units in the United States with lead-based paint and lead-based paint hazards. We included measurements of lead in intact and deteriorated paint, interior dust, and bare soil. A nationally representative, random sample of 831 housing units was evaluated in a survey between 1998 and 2000; the units and their occupants did not differ significantly from nationwide characteristics. Results indicate that 38 million housing units had lead-based paint, down from the 1990 estimate of 64 million. Twenty-four million had significant lead-based paint hazards. Of those with hazards, 1.2 million units housed low-income families (< 30,000 US dollars/year) with children under 6 years of age. Although 17% of government-supported, low-income housing had hazards, 35% of all low-income housing had hazards. For households with incomes greater than or equal to 30,000 US dollars/year, 19% had hazards. Fourteen percent of all houses had significantly deteriorated lead-based paint, and 16% and 7%, respectively, had dust lead and soil lead levels above current standards of the U.S. Department of Housing and Urban Development and the U.S. Environmental Protection Agency. The prevalence of lead-based paint and hazards increases with age of housing, but most painted surfaces, even in older housing, do not have lead-based paint. Between 2% and 25% of painted building components were coated with lead-based paint. Housing in the Northeast and Midwest had about twice the prevalence of hazards compared with housing in the South and West. The greatest risk occurs in older units with lead-based paint hazards that either will be or are currently occupied by families with children under 6 years of age and are low-income and/or are undergoing renovation or maintenance that disturbs lead-based paint. This study also confirms projections made in 2000 by the President's Task Force on Environmental Health Risks and Safety Risks to Children of the number of houses with lead-based paint hazards. Public- and private-sector resources should be directed to units posing the greatest risk if future lead poisoning is to be prevented.

Environmental Lead Contamination in the Rudnaya Pristan – Dalnegorsk Mining and Smelter District, Russian Far East

A preliminary survey of a remote mining and smelting region of the Russian Far East (RFE) indicates significant soil lead contamination and a high probability of childhood lead poisoning. Lead concentrations in residential gardens (476–4310 mg/kg, Gx̄=1626 mg/kg) and in roadside soils (2020–22900 mg/kg, Gx̄=4420 mg/kg) exceed USEPA guidance for remediation. Preliminary biokinetic estimates of mean blood levels suggest that preschool children are at significant risk of lead poisoning from soil/dust ingestion with levels predicted to average 13–27 μg/dl. Samples of other pathways, such as air, water, paint, interior dust, and garden produce, and pediatric and occupational blood lead levels are needed. An assessment of the industry's ability to improve emissions controls and materials handling should also be undertaken. Global lessons in remediating contamination problems and preventing childhood lead poisoning must be applied in innovative ways to meet the logistical, social, and economic challenges in the RFE.

The high cost of improper removal of lead-based paint from housing: a case report.

The costs of lead-based paint hazard control in housing are well documented, but the costs of cleanup after improper, inherently dangerous, methods of removing lead-based paint are not. In this article we report a case of childhood lead poisoning and document the costs of decontamination after uncontained power sanding was used to remove paint down to bare wood from approximately 3,000 ft(2) of exterior siding on a large, well-maintained 75-year-old house in a middle-income neighborhood. After the uncontrolled removal of lead-based paint, interior dust lead levels ranged from 390 to 27,600 micro g Pb/ft(2) (on floors and windowsills) and bare soil lead levels ranged from 360 ppm in the yard to 3,900 ppm along the foundation to 130,000 ppm in the child's play area, well above applicable U.S. Department of Housing and Urban Development/U.S. Environmental Protection Agency standards. The hard costs of decontamination were over $195,000, which greatly exceeds the incremental cost of incorporating lead-safe work practices into repainting. This case report highlights the need to incorporate lead-safe work practices into routine repainting, remodeling, and other renovation and maintenance jobs that may disturb lead-based paint.

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.

The Contribution of Lead-Contaminated House Dust and Residential Soil to Children's Blood Lead Levels: A Pooled Analysis of 12 Epidemiologic Studies

In 1992, the U.S. Congress passed the Residential Lead-Based Paint Hazard Reduction Act, which requires the promulgation of health-based dust lead and soil lead standards for residential dwellings to prevent undue lead exposure in children. Unfortunately, the levels of lead in house dust and soil that are associated with elevated blood lead levels among U.S. children remain poorly defined. This pooled analysis was done to estimate the contributions of lead-contaminated house dust and soil to children's blood lead levels. The results of this pooled analysis, the most comprehensive existing epidemiologic analysis of childhood lead exposure, confirm that lead-contaminated house dust is the major source of lead exposure for children. These analyses further demonstrate that a strong relationship between interior dust lead loading and children's blood lead levels persists at dust lead levels considerably below the U.S. Department of Housing and Urban Development's current postabatement standards and the Environmental Protection Agency's guidance levels. Finally, these analyses demonstrate that a child's age, race, mouthing behaviors, and study-site specific factors influence the predicted blood lead level at a given level of exposure. These data can be used to estimate the potential health impact of alternative health-based lead standards for residential sources of lead exposure.

Site-specific data confirm arsenic exposure predicted by the U.S. Environmental Protection Agency.

The EPA uses an exposure assessment model to estimate daily intake to chemicals of potential concern. At the Anaconda Superfund site in Montana, the EPA exposure assessment model was used to predict total and speciated urinary arsenic concentrations. Predicted concentrations were then compared to concentrations measured in children living near the site. When site-specific information on concentrations of arsenic in soil, interior dust, and diet, site-specific ingestion rates, and arsenic absorption rates were used, measured and predicted urinary arsenic concentrations were in reasonable agreement. The central tendency exposure assessment model successfully described the measured urinary arsenic concentration for the majority of children at the site. The reasonable maximum exposure assessment model successfully identified the uppermost exposed population. While the agreement between measured and predicted urinary arsenic is good, it is not exact. The variables that were identified which influenced agreement included soil and dust sample collection methodology, daily urinary volume, soil ingestion rate, and the ability to define the exposure unit. The concentration of arsenic in food affected agreement between measured and predicted total urinary arsenic, but was not considered when comparing measured and predicted speciated urinary arsenic. Speciated urinary arsenic is the recommended biomarker for recent inorganic arsenic exposure. By using site-specific data in the exposure assessment model, predicted risks from exposure to arsenic were less than predicted risks would have been if the EPA's default values had been used in the exposure assessment model. This difference resulted in reduced magnitude and cost of remediation while still protecting human health.

Environmental Arsenic Exposure of Children around a Former Copper Smelter Site

Arsenic residues in the communities surrounding former smelters remain a public health concern, especially for infants and children. To evaluate environmental exposure among these children, a population-based cross-sectional study was conducted in the vicinity of a former copper smelter in Anaconda, Montana. A total of 414 children less than 72 months old were recruited. First morning voided urine samples and environmental samples were collected for arsenic measurements. The geometric mean of speciated urinary arsenic was 8.6 μg/liter (GSD = 1.7,N= 289). Average arsenic levels of different types of soil ranged from 121 to 236 μg/g, and were significantly related to proximity and wind direction to the smelter site. The same significant relationship was observed for interior dust arsenic. Speciated urinary arsenic was found to be significantly related to soil arsenic in bare areas in residential yards (P < 0.0005). In general, elevated excretion of arsenic was demonstrable and warranted parents' attention to reduce exposure of their children to environmental arsenic.

The relationship between surface dust lead loadings on carpets and the blood lead of young children

The final clean-up of residential lead abatement projects in federally-supported housing, as well as in other housing in a number of states, must meet surface dust lead clearance levels expressed as μg of lead per square foot. These clearance levels were established because hand-to-mouth ingestion of lead-contaminated dust is recognised as a major pathway through which many children are exposed. A dilemma exists because many floors in housing undergoing abatement are carpeted and the established clearance levels are generally not recommended for use on carpets. These clearance levels are also used as 'action levels' to determine whether exposure reduction activities are needed. The US Environmental Protection Agency is currently in the process of issuing standards for hazardous levels of lead in interior dust and bare soil under Title X of the Housing and Community Development Act of 1992, 'The Residential Lead-Based Paint Hazard Reduction Act of 1992'. An effort to develop a potential surface dust lead clearance level for carpets was made using an existing vacuum dust collection method that has previously been shown to be a reliable indicator of childhood lead exposure. This method was designed for use on carpeted and non-carpeted surfaces. Using data from the Cincinnati Soil Lead Abatement Demonstration Project, the suggested floor-dust lead level where an estimated 95% of the population of children would be expected to have blood lead values below the national goal of 10 μg dL(-1), was more than an order of magnitude lower than the current floor-dust lead clearance level of 1080 μg m(-2) (100 μg ft(-2)). Further comparisons of blood lead and carpet lead levels in other parts of the country should be performed before a risk-based lead loading clearance level is established.

Pilot study of sources of lead exposure in Moscow, Russia

This preliminary investigation of sources of lead exposure in Moscow, Russia, by Russian and US collaborators measured lead in paint, interior dust, and drinking water in seven day-care centres, and in petrol, soil and canned food. Some paint samples exceeded US regulatory standards for lead in paint on surfaces (0.5%). Dust lead loadings were < 1.7 μg cm(-2) and below the guidance levels of the US EPA. Drinking water lead concentrations were at or below the US drinking water standard of 15 μg L(-1). Lead concentrations in petrol from Moscow vehicles and petrol stations were consistent with a regulation banning the sale of leaded petrol within the Moscow City limits. Except for baby food, lead levels were higher in the Russian canned foods (range 6 to 1240 μg kg(-1), dry weight) compared to corresponding US canned foods, with ratios of Russian to US levels of up to 120:1 for evaporated milk. Lead concentrations in soil generally ranged from 500 to 2000 μg g(-1), levels that would trigger hazard reduction measures according to US EPA guidance. These findings, together with the use of lead in petrol outside Moscow, indicate multiple sources of lead exposure in Russia. Priorities for future research are discussed including the establishment of interlaboratory quality control programmes.

Comparison of IEUBK model predictions and actual blood lead values at a former battery recycling site

This paper presents an evaluation of US EPA's integrated exposureuptake biokinetic model for lead (IEUBK model) using data obtained during emergency removal operations at a former lead-acid battery recycling plant and the surrounding community. Data employed in the study include soil lead and interior dust lead, air lead levels collected at the site perimeter, drinking water lead levels at the community water main and blood lead data collected from an annual blood lead monitoring programme conducted over a four year period during the remediation activities.Geometric mean soil and dust concentrations were found to be a better predictor of blood lead than arithmetic mean data. However, weight based dust lead data were believed to be an inappropriate measure of dust lead levels. Estimates of household dust lead concentrations based upon surface loading data (μg m(-2)) yielded blood lead predictions which were more consistent with data collected in the blood lead monitoring programme.

Mm/submm-Bolometer observations of star-forming regions

Methods are described to estimate hydrogen column densities and masses using molecular lines and mm/submm dust emission as probes (Section I). Possible errors and uncertainties in the latter method are discussed (Section II). NGC2024 is shown as an example where molecular lines cease to be reliable tracers of hydrogen column densities (Section III). Sgr B2 is shown as an example where FIR dust emission observed by IRAS misses a dense and cool GMC because its interior dust is too cool (Section IV).

Expanding Shell around a Void and Universe Model

Under the thin-shell approximation, we study the expansion of the shell formed around a single spherical void in the dust universe. We find that the peculiar velocity of the shell is determined mostly by the density parameter Ω 0 . It also depends on the interior dust energy density, but is not so sensitive to a cosmological constant. This feature may open a possibility of determining the universe model from the surface motion of voids

Expanding Shell around a Void and Universe Model

Under the thin-shell approximation, we study the expansion of the shell formed around a single spherical void in the dust universe. We find that the peculiar velocity of the shell is determined mostly by the density parameter Ω 0 . It also depends on the interior dust energy density, but is not so sensitive to a cosmological constant. This feature may open a possibility of determining the universe model from the surface motion of voids

Lead-Contaminated Soil Abatement and Urban Children's Blood Lead Levels

To test the hypothesis that a reduction of 1000 ppm or more of lead in soil accessible to children would result in a decrease of at least 0.14 mumol/L (3 micrograms/dL) in blood lead levels. Urban neighborhoods with a high incidence of childhood lead poisoning and high soil lead levels. Randomized controlled trial of the effects of lead-contaminated soil abatement on blood lead levels of children followed up for approximately 1 year after the intervention. A total of 152 children less than 4 years of age with venous blood lead levels of 0.34 to 1.16 mumol/L (7 to 24 micrograms/dL). Children were largely poor and had a mean age at baseline of 32 months, a mean blood lead level of 0.60 mumol/L (12.5 micrograms/dL), and a median surface soil lead level of 2075 ppm. Children were randomized to one of three groups: the study group, whose homes received soil and interior dust abatement and loose paint removal; comparison group A, whose homes received interior dust abatement and loose paint removal; and comparison group B, whose homes received only interior loose paint removal. Change in children's blood lead levels from preabatement levels to levels approximately 6 and 11 months after abatement. The mean decline in blood lead level between preabatement and 11 months after abatement was 0.12 mumol/L (2.44 micrograms/dL) in the study group (P = .001), 0.04 mumol/L (0.91 microgram/dL) in group A (P = .04), and 0.02 mumol/L (0.52 microgram/mL) in group B (P = .31). The mean blood lead level of the study group declined 0.07 mumol/L (1.53 micrograms/dL) more than that of group A (95% confidence interval [CI], -0.14 to -0.01 mumol/L [-2.87 to -0.19 micrograms/dL]) and 0.09 mumol/L (1.92 micrograms/dL) more than group B (95% CI, -0.16 to -0.03 mumol/L [-3.28 to -0.56 micrograms/dL]). When adjusted for preabatement lead level, the 11-month mean blood lead level was 0.06 mumol/L (1.28 micrograms/dL) lower in the study group as compared with group A (P = .02) and 0.07 mumol/L (1.49 micrograms/dL) lower than in group B (P = .01). The magnitude of the decline independently associated with soil abatement ranged from 0.04 to 0.08 mumol/L (0.8 to 1.6 micrograms/dL) when the impact of potential confounders, such as water, dust, and paint lead levels, children's mouthing behaviors, and other characteristics, was controlled for. These results demonstrate that lead-contaminated soil contributes to the lead burden of urban children and that abatement of lead-contaminated soil around homes results in a modest decline in blood lead levels. The magnitude of reduction in blood lead level observed, however, suggests that lead-contaminated soil abatement is not likely to be a useful clinical intervention for the majority of urban children in the United States with low-level lead exposure.

Development and Implementation of a Safety and Health Program for Employees Involved with Residential Soil and Dust Lead Abatement and Monitoring

Abstract The safety and health plan that was developed for the Cincinnati Soil Lead Abatement Demonstration Project is described from its development through its initial implementation, review, and revisions. This demonstration project, funded under the Superfund Amendments and Reauthorization Act, was developed to demonstrate the effectiveness of soil and dust lead abatement in inner-city neighborhoods in reducing the blood lead of young children. The project involved extensive sampling of soil, exterior and interior dust, water, paint lead, and blood lead. Abatement activities included soil excavation and replacement, debris removal, pavement cleaning, and housedust abatement by cleaning and furniture/carpet removal. Air lead concentrations were minimal and no significant blood leads were observed. Experiences described should prove to be useful to others engaged in similar lead abatement activities; the overall approach used may also prove useful in the development of safety and health plans for lead paint abatement projects.

Plasma potential and grain charges in a dust cloud embedded in a plasma

We have calculated the plasma potential and dust potential throughout the border region of semiinfinite dust clouds embedded in a plasma. A relevant ordering parameter is P = (N d0/N0)aμ (interior dust density/exterior plasma density) × dust radius (in microns). For comparatively high dust densities (P &gt; 10−3) the cloud potential is high, screening out electrons, with low interior dust charges as a result. For decreasing P the cloud potential becomes less, with a corresponding increase in the dust charges. At P &lt; 10−5 the cloud potential is practically zero and the dust particles have their maximum charge which is identical to that of a single dust particle in a plasma. For diffuse dust border regions with density scale length H ≫ λD (Debye length), the deviations from charge neutrality are small. When H ≲ λD, large deviations from charge neutrality occur in the border region and also some penetration of electric fields inside the border region.

Cotton Gin Occupational Dust Levels and Accuracy of Determination by the Vertical Elutriator

ABSTRACT DUST levels were measured by vertical elutriators in 12 cotton gins in the San Joaquin Valley of Califor-nia during the 1978 ginning season. Effects of cotton processing rate, gin location in the Valley, and harvest date on gin interior dust levels were tested. Processing rate increased interior dust levels by 0.03 mg/m3/bale/h. Valley location or harvest date had no effect on gin inter-ior dust levels. Interior dust level concentrations ranged from 0.38 to 1.41 mg/m3 and averaged 0.74 mg/m3. It was shown that data from vertical elutriators had a 50-percent chance of varying by 0.03 mg/m3 when repeated samples were taken at the same location.

Methodology for cotton gin dust sampling

A methodology for sampling dust levels in cotton gins with vertical elutriators was developed and used successfully in 12 cotton gins located in the San Joaquin Valley of California during the 1978 ginning season in coordination with an independent medical survey of respiratory functions in cotton gin workers to determine the response of cotton-gin workers to cotton dust. The USDA had complete control over dust-survey sites and schedules. The effects of variables such as weather, cotton fires, processing interruptions, and the structural variations of the cotton gins, themselves, on the sampling program are discussed. Average interior dust concentration was 0.74 mg/m3, with a range of 0.38 to 1.41 mg/m3.