Lead Hazard Control Research Articles

Friction and Impact Surfaces: Are They Lead-Based Paint Hazards?

Professionals who identify residential lead-based paint hazards and develop lead hazard control plans are instructed to assess painted friction and impact surfaces in homes as potentially active sources of dust lead, a known exposure vector for young children. However, empirical tests of the importance of these surfaces had not been conducted. Using data collected as part of a 1998 three-community study of the Housing and Urban Development Lead Risk Assessment protocols, this article explores how much rubbing or binding on friction and impact surfaces on windows and doors influence dust lead levels on windowsills and floors, while taking into account paint condition on these surfaces and other sources of lead. The analyses included windowsill dust wipe samples from 611 rooms in 182 homes and 782 floor dust wipe samples collected in 209 rooms from 104 homes. The study found that when the paint on windows is intact but the window is rubbing or binding, the dust lead levels on the windowsills are significantly higher than on windows with intact paint without rubbing or binding, after controlling for other lead sources. Windowsill dust lead on a window with intact lead-based paint at 1 mg/cm2 and no rubbing/binding would be 27% lower than on a window with nonintact paint, rubbing/binding surfaces, or both of these conditions. An independent effect of rubbing/binding of doors on floor dust lead loadings was not observed. These findings support federal regulations calling for lead risk assessors to check the friction/impact surfaces at windows when dust lead samples taken below them are elevated, but these analyses did not offer support for taking extra observations of friction/impact surfaces around doors.

Screening for Elevated Blood Lead Levels in Children and Pregnant Women

The US Preventive Services Task Force (USPSTF) is redesigning its recommendation statement in response to feedback from primary care clinicians. The USPSTF plans to release, later in 2006, a new, updated recommendation statement that is easier to read and incorporates advances in USPSTF methods. The recommendation statement below is an interim version that combines existing language and elements with a new format. Although the definitions of grades remain the same, other elements have been revised. ### Children 1. The US Preventive Services Task Force (USPSTF) concludes that evidence is insufficient to recommend for or against routine screening for elevated blood lead levels (BLLs) in asymptomatic children aged 1 to 5 who are at increased risk (I recommendation) (see “Clinical Considerations” for a discussion of risk). 2. The USPSTF recommends against routine screening for elevated BLLs in asymptomatic children aged 1 to 5 years who are at average risk (D recommendation). ### Pregnant Women 1. The USPSTF recommends against routine screening for elevated BLLs in asymptomatic pregnant women (D recommendation). ### Importance BLLs in children have declined dramatically in the United States over the past 2 decades. However, segments of the population remain at increased risk for higher BLLs. Even relatively low BLLs are associated with neurotoxic effects in children. Severely elevated BLLs in symptomatic pregnant women are associated with poor health outcomes; however, BLLs in this range are rare in the US population. ### Detection There is good evidence that venous sampling accurately detects elevated BLLs and fair evidence that validated questionnaires are modestly useful in identifying children at increased risk for elevated BLLs. ### Benefits of Detection and Early Intervention The USPSTF found good-quality evidence that interventions do not result in sustained decreases in BLLs and found insufficient evidence (no studies) evaluating residential lead hazard-control efforts (ie, dust or paint removal, soil abatement, counseling, or education) or nutritional interventions for improving neurodevelopmental outcomes in children with mildly-to-moderately elevated … Address correspondence to Ned Calonge, MD, MPH, Chair, US Preventive Services Task Force, c/o Program Director, USPSTF, Agency for Healthcare Research and Quality, 540 Gaither Rd, Rockville, MD 20850. E-mail: uspstf{at}ahrq.gov

Identifying Housing That Poisons

The purpose of our study was to develop a method to identify and prioritize "high-risk" buildings in Chicago that could be targeted for childhood lead poisoning prevention activities. We defined "high-risk" buildings as those where multiple children younger than 6 years with elevated blood lead levels (BLLs) had lived and where lead hazards were previously identified on environmental inspection. By linking 1997-2003 Chicago elevated blood lead surveillance, environmental inspection, and building footprint data, we found that 49,362 children younger than 6 years with elevated BLLs lived at 30,742 buildings. Of those, 67 were "high-risk" buildings and these were associated with 994 children with elevated BLLs. On average, 15 children with elevated BLLs had lived in each building (range: 10-53, median: 13). Almost two thirds (n = 43) of the high-risk buildings had two or more referrals for inspection to the same apartment or housing unit; of those, 40 percent (n = 17) failed to maintain lead-safe status after compliance. Linking blood lead surveillance, environmental inspection, and building footprint databases allowed us to identify individual high-risk buildings. This approach prioritizes lead hazard control efforts and may help health, housing, and environmental agencies in targeting limited resources to increase lead-safe housing for children.

Evaluation of HUD-funded lead hazard control treatments at 6 years post-intervention

The Evaluation of the HUD Lead-Based Paint Hazard Control Grant Program (Evaluation) was a HUD-funded study of the effectiveness of lead hazard control (LHC) treatments conducted by 14 grantees in communities across the country. A stratified random sampling scheme was used to select treated units at four grantee sites for continued environmental assessment at 6 years post-intervention. The study compared the relative effectiveness after 6 years of the different classes of interventions used by the grantees, after controlling for such factors as housing conditions and characteristics and resident and neighborhood characteristics. Geometric mean dust-lead levels on floors and window sills were 11% and 23% lower, respectively, at 6 years post-intervention than at any preceding point following the intervention. Although geometric mean window trough dust-lead levels were slightly higher at 6 years post-intervention than at other post-intervention time periods, they were still over 75% lower than before intervention. Treatment at more-intensive levels was associated with lower window sill and window trough dust-lead levels; however, statistical modeling found no significant difference in floor dust-lead loadings over time between the levels of treatment; however, significant differences in window sill and window trough dust-lead levels between treatment levels were evident. Findings from the 6-Year Extension study indicate that across all grantees and treatment strategies the treatments applied were effective at significantly reducing environmental lead levels on floors, window sills, and window troughs at least 6 years following the intervention.

A Coordinated Relocation Strategy for Enhancing Case Management of Lead Poisoned Children: Outcomes and Costs

Controlling residential lead hazards is critical for case management of lead poisoned children. To attain this goal, permanent relocation of the family is sometimes necessary or advisable for many reasons, including poor housing conditions; extensive lead hazards; lack of abatement resources, landlord compliance and local enforcement capacity; and family eviction. During 1996-1998, the Kennedy Krieger Institute implemented a unique capitated program for case management of Baltimore City children with blood lead concentrations (PbB) >19 microg/dL. The Program provided financial, housing, and social work assistance to facilitate relocation as a means of providing safer housing. Nearly half of the Program families relocated with direct assistance, and 28% relocated on their own. The Program evaluation examined the costs and benefits of relocation. Average relocation cost per child was relatively inexpensive (<1,500 dollars). Average relocation time of 5 months (range <2 months to >12 months) was less than the 8-month average time to complete lead hazard control work in 14 city and state programs funded by U.S. HUD. Relocation was associated with (1) a statistically significant decrease in dust lead loadings on floors, windowsills and window troughs that persisted for one year, and (2) statistically significantly greater decreases in children's PbB compared to children who did not relocate from untreated homes. Children relocated to housing that met current Federal residential dust lead standards had statistically significant decreases in blood lead levels. Visual inspection did not consistently identify relocation houses with dust lead levels below current Federal standards, indicating that dust testing should be an essential component of future programs. This will require additional resources for dust testing and possibly cleaning and repairs but is expected to yield additional benefits for children. The findings support recent U.S. CDC case management recommendations suggesting that permanent relocation to safer housing is a viable means to reduce children's lead exposure. The benefits of relocation notwithstanding, 40% of families moved at least twice. Research is needed to better understand how to expedite relocation and encourage families to remain in safe housing. Relocation does not negate owners' and health authorities' responsibilities to address lead hazards in the child's original house in order to protect future occupants.

The Influence of Common Area Lead Hazards and Lead Hazard Control on Dust Lead Loadings in Multiunit Buildings

Owners of multiunit buildings built before 1978 that have interior common areas, and who receive certain forms of federal assistance are generally required to address lead-based paint hazards in those common areas. This study examines the relationships between common area paint and dust lead levels and the floor dust lead loadings in associated dwelling units, as well as the effects of lead hazard control treatments in common areas. This article presents data from common areas in 145 low-income, mostly pre-1940, multiunit buildings with 342 associated dwellings in the U.S. Department of Housing and Urban Development Lead Hazard Control Grant Program at preintervention, clearance, and 1-year postintervention. Interior common areas in these multiunit buildings were not as well maintained as the dwellings in the buildings. At preintervention, a higher percent of the interior common areas had non-intact, lead-based paint on windows, doors and trim, and other interior components than in associated dwellings (95% versus 85%; 78% versus 67%; and 85% versus 62%). Common areas had preintervention entry and interior (i.e., nonentry) floor dust lead loadings more than four times higher than in dwelling units (128 versus 30 μ g/ft2; 130 versus 28 μ g/ft2) while 1-year postintervention common area dust lead loadings are four to six times that of dwelling dust lead loadings (41 versus 11 μ g/ft2; 44 versus 8 μ g/ft2). Windowsill dust lead loadings in common areas were twice the loadings in dwelling units at preintervention and 1-year postintervention (756 versus 383 μ g/ft2; 154 versus 68 μ g/ft2). Interior common area treatments reduced geometric mean common entry dust lead loadings 71% from preintervention to clearance, and maintained those reduced levels from clearance to 1-year postintervention. Higher level interventions were not more effective than low-level interventions in reducing preintervention levels to clearance or 1-year postintervention. This study demonstrates that interior common areas in the multiunit buildings examined contain substantial amounts of deteriorated lead-based paint and dust. Remediation of common areas can effectively reduce those hazards.

Effectiveness of lead-hazard control interventions on dust lead loadings: Findings from the evaluation of the HUD Lead-Based Paint Hazard Control Grant Program

From 1994 to 1999, the Evaluation of the US Department of Housing and Urban Development Lead-Based Paint Hazard Control Grant Program studied the intervention experiences of over 2800 homes in 11 states in the USA. Each interior intervention was categorized as (in order of increasing intensity) (a) cleaning/spot painting; (b) complete repainting; (c) complete repainting plus window treatments; (d) window abatement plus treatments to other components; (e) abatement of all lead-based paint hazards; or (f) abatement of all lead-based paint. Complete dust testing and environmental data were available for 1034 and 278 dwellings through 12 and 36 months postintervention, respectively. Strategies ranging from complete repainting to window abatement plus other treatments reduced geometric mean preintervention windowsill and floor dust lead loadings up to 36 months postintervention (reductions for complete repainting, from 16 to 5 μg/ft 2 on floors and 182 to 88 μg/ft 2 on sills; for window abatement plus other treatments, 27–8 μg/ft 2 on floors and 570–124 μg/ft 2 on sills). Full abatement reduced windowsill and floor loadings from baseline to 12 months postintervention [95–6 μg/ft 2 on floors and 518–30 μg/ft 2 on sills (data were not available for this strategy at 36 months)]. Window lead-hazard abatement was the most effective measure to reduce dust lead loadings on windows, but this treatment would need to be performed in conjunction with treatments to floors as well as exterior and soil treatments for the most effective control of dust lead on floors.

Evaluation of lead hazard control treatments in four Massachusetts communities through analysis of blood-lead surveillance data

This study utilized existing blood-lead surveillance data and records of housing properties treated for lead hazard control (LHC) in order to investigate the effectiveness of LHC treatments performed in four Massachusetts communities (Boston, Cambridge, Malden, and Springfield). This research is part of the US Department of Housing and Urban Development's (HUD) overall program evaluation strategy for assessing the effectiveness of their LHC Grant Program. Childhood blood-lead levels (BLLs) in housing units that were treated through HUD's LHC Grant Program were compared to BLLs in untreated matched control housing units. Data from multiple sources—local housing departments, local tax assessor departments, and the Massachusetts Department of Public Health—were linked to identify similar sets of treated and untreated dwellings. Geometric mean BLLs from before and after treatment were compared for the two sets of housing. Ten years of blood-lead surveillance data for children living in the selected dwellings were analyzed using log-linear mixed models and logistic regression models. Results indicate a 50% decline in BLLs in treated homes, a significantly larger decline than in untreated homes after adjusting for the general downward trend in BLLs observed in the general population for the last several years. Data show that homes that received HUD LHC treatments had children with blood-lead levels that declined twice as fast as in similar untreated homes. These findings show that LHC efforts are successful in reducing children's blood-lead levels.

National evaluation of the US Department of Housing and Urban Development Lead-Based Paint Hazard Control Grant Program: Study methods

The US Department of Housing and Urban Development (HUD) undertook an evaluation of its Lead Hazard Control Grant Program between 1994 and 1999. The Evaluation is the largest study ever done on the effectiveness of lead hazard controls implemented in residential dwellings. The Evaluation had several major objectives: determining the effectiveness of various lead hazard controls in reducing residential dust lead levels and children's blood lead levels, establishing the costs of doing lead hazard control work and factors that influence those costs, determining the rate of clearance testing failures and their causes, and identifying possible negative effects of lead hazard control work on children's blood lead levels. This paper reports the overall research design and data collection methods of the Evaluation. The large number of dwelling units enrolled in the Evaluation was possible only by the innovative partnership among HUD, the Evaluators, and the grantees. HUD and the Evaluators relied on the grantees for essentially all of the data collection. The 14 participating HUD Lead Hazard Control Grantees were responsible for implementing the lead hazard control programs in their communities and collecting the study data. This paper describes the methods for recruiting and enrolling dwellings and families, collecting environmental and housing data, interviewing participating families, and collecting data on lead hazard control work performed and its costs. The paper also describes the basic quality control and quality assurance procedures used. The principal outcome measures were lead in dust collected using wipes from floors, window sills, and window troughs and lead in blood collected from children who were 6 years old or younger at enrollment. Data collection was conducted before intervention, immediately postintervention, and 6 and 12 months postintervention. For a subset of dwellings undergoing an extended follow-up data were also collected at 24 and 36 months postintervention. This paper provides the context for subsequent reports that will describe such findings as the influence of lead hazard control work on serial dust lead levels, the influence of lead hazard control work on serial blood lead levels in children, the nature and costs of the lead hazard control work done at the dwellings, and the experience of the grantees in meeting clearance testing requirements.

Residential Dust Lead Loading Immediately After Intervention in the HUD Lead Hazard Control Grant Program

At the conclusion of most lead hazard control interventions in federally assisted housing built before 1978, a certified clearance examiner must verify that the lead hazard control work was completed as specified and that the area is safe for residents, a process referred to as clearance. This study explores the experience of 14 grantees participating in the Evaluation of the HUD Lead-Based Paint Hazard Control Grant Program in passing clearance. The study also considers how preintervention lead levels (interior dust and paint), building condition/characteristics, and the scope of work influenced initial clearance dust lead loadings and clearance rates. At the initial clearance inspection, 80% of the 2682 dwellings achieved grantee-specific clearance standards on windowsills, window troughs (500 μ g/ft 2 and 800 μ g/ft 2 , respectively), and floors (80, 100, or 200 μ g/ft 2 depending on state/local regulations at the dates of clearance in the mid-1990s), with individual grantee success rates ranging from 63 to 100%. Dwellings that failed initial clearance required an average of 1.13 retests to clear. The high level of success at clearance demonstrates that following methods for work site containment, lead hazard control, and cleaning similar to those recommended in the HUD Guidelines for the Evaluation and Control of Lead-Based Paint in Housing is effective. The most common lead hazard control intervention was window abatement accompanied by the repair or abatement of all other deteriorated lead-based paint (56% of dwellings). An additional 5% of dwellings were fully abated, 29% had lower intensity interventions. Interventions including window replacement are recommended to reduce dust lead loading on windowsills and troughs at clearance, but lower level interventions such as full paint stabilization are just as good at reducing floor dust lead loadings. Whatever lead hazard control activities are selected, the condition of the surfaces of interest should be in good condition at clearance.

A Noninvasive Isotopic Approach to Estimate the Bone Lead Contribution to Blood in Children: Implications for Assessing the Efficacy of Lead Abatement

Lead hazard control measures to reduce children’s exposure to household lead sources often result in only limited reductions in blood lead levels. This may be due to incomplete remediation of lead sources and/or to the remobilization of lead stores from bone, which may act as an endogenous lead source that buffers reductions in blood lead levels. Here we present a noninvasive isotopic approach to estimate the magnitude of the bone lead contribution to blood in children following household lead remediation. In this approach, lead isotopic ratios of a child’s blood and 5-day fecal samples are determined before and after a household intervention aimed at reducing the child’s lead intake. The bone lead contribution to blood is estimated from a system of mass balance equations of lead concentrations and isotopic compositions in blood at the different times of sample collection. The utility of this method is illustrated with three cases of children with blood lead levels in the range of 18–29 μg/dL. In all three cases, the release of lead from bone supported a substantial fraction of the measured blood lead level postintervention, up to 96% in one case. In general, the lead isotopic compositions of feces matched or were within the range of the lead isotopic compositions of the household dusts with lead loadings exceeding U.S. Environmental Protection Agency action levels. This isotopic agreement underscores the utility of lead isotopic measurements of feces to identify household sources of lead exposure. Results from this limited number of cases support the hypothesis that the release of bone lead into blood may substantially buffer the decrease in blood lead levels expected from the reduction in lead intake.

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.

Occurrence and determinants of increases in blood lead levels in children shortly after lead hazard control activities

This study is an examination of the effect of lead hazard control strategies on children's blood lead levels immediately after an intervention was conducted as part of the US Department of Housing and Urban Development's Lead-Based Paint Hazard Control Grant Program. Fourteen state and local government grantees participated in the evaluation. The findings indicated an overall average reduction in the blood lead levels of 869 children soon after the implementation of lead hazard controls. However, 9.3% of these children ( n=81) had blood lead increases of 5 μg/dL or more. Data routinely collected as part of the evaluation, as well as additional information supplied by the individual programs, were used to determine potential reasons for these observed increases in blood lead. A logistic regression analysis indicated that three principal factors were associated with the blood lead increases: the number of exterior deteriorations present in the child's home (prior to intervention), the educational level of the female parent or guardian of the child, and the child's age. The statistical analysis did not find evidence that children living in households that either did not relocate or relocated for less than the full work period were significantly more likely to have a blood lead increase equal to or greater than 5 μg/dL than children living in households that fully relocated. Statistical analyses also did not reveal any single interior strategy to be more or less likely than others to be associated with a blood lead increase of 5 μg/dL or more.

The effect of lead-based paint hazard remediation on blood lead levels of lead poisoned children in New York City

Despite the widespread use of lead paint hazard control for children with lead poisoning, few controlled studies that estimate the effect of such control on children's blood lead levels have been published. This retrospective follow-up study examined the effects of lead hazard remediation and its timing on the blood lead levels of lead-poisoned children. From the New York City child blood lead registry, 221 children were selected who had an initial blood lead level of 20–44μg/dL between 1 July 1994 and 31 December 1996; were 6 months to 6 years of age; had a report of a follow-up blood lead test between 10 and 14 months after the initial test; had a lead-based paint hazard identified in the primary dwelling unit prior to the 10- to 14-month follow-up blood lead test; had resided or spent time at only one address with an identified lead-based paint hazard; and were not chelated. The decline in geometric mean blood lead levels from baseline to 10–14 months later was compared for children whose homes were remediated and whose homes were not remediated during the follow-up period. Regardless of remediation, geometric mean blood lead levels declined significantly from 24.3μg/dL at the initial diagnosis to 12.3μg/dL at the 10- to 14-month follow-up blood lead test (P<0.01). Among the 146 children whose homes were remediated the geometric mean blood lead levels declined 53% compared to 41% among the 75 children whose homes were not remediated by the follow-up blood lead test, a remediation effect of approximately 20% (P<0.01). After adjusting for potential confounders, the remediation effect was 11%, although it was no longer significant. Race was the only factor that appeared to confound the relationship: Black children had higher follow-up blood lead levels even after controlling for other factors, including the natural logarithm of the initial blood lead level. The effect of remediation appeared to be stronger for younger (10 to <36 months old) than for older (36 to 72 months old) children (P=0.06). While children in homes with earlier remediation (within less than 3 months) appeared to have greater declines in blood lead levels at the follow-up test than children in homes with later remediation (after 3 or more months), this trend was not significant when controlling for confounding factors. The findings of this study suggest that early identification of lead-poisoned children and timely investigation and abatement of hazards contribute to reducing blood lead levels. However, the apparent effect is modest and further research is needed to systematically test and improve the effectiveness of lead hazard controls.

Life near the Fast Lane

ArticleOpen AccessLife near the Fast Lane E Hood E Hood Search for more papers by this author Published:1 February 2003https://doi.org/10.1289/ehp.111-a111Cited by:1AboutSectionsPDF ToolsDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InReddit "Life near the Fast Lane." Environmental Health Perspectives, 111(2), pp. A111–A112FiguresReferencesRelatedDetailsCited byGould E (2009) Childhood Lead Poisoning: Conservative Estimates of the Social and Economic Benefits of Lead Hazard Control, Environmental Health Perspectives, 117:7, (1162-1167), Online publication date: 1-Jul-2009. Vol. 111, No. 2 February 2003Metrics About Article Metrics Publication History Originally published1 February 2003Published in print1 February 2003 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 [email protected]. Our staff will work with you to assess and meet your accessibility needs within 3 working days.

The effect of interior lead hazard controls on children's blood lead concentrations: a systematic evaluation.

Dust control is often recommended to prevent children's exposure to residential lead hazards, but the effect of these controls on children's blood lead concentrations is uncertain. We conducted a systematic review of randomized, controlled trials of low-cost, lead hazard control interventions to determine the effect of lead hazard control on children's blood lead concentration. Four trials met the inclusion criteria. We examined mean blood lead concentration and elevated blood lead concentrations (> or = 10 microg/dL, > or = 15 microg/dL, and > or = 20 microg/dL) and found no significant differences in mean change in blood lead concentration for children by random group assignment (children assigned to the intervention group compared with those assigned to the control group). We found no significant difference between the intervention and control groups in the percentage of children with blood lead > or = 10 microg/dL, 29% versus 32% [odds ratio (OR), 0.85; 95% confidence interval (CI), 0.56-1.3], but there was a significant difference in the percentage of children with blood lead > or = 15 microg/dL between the intervention and control groups, 6% versus 14% (OR, 0.40; 95% CI, 0.21-0.80) and in the percentage of children with blood lead > or = 20 microg/dL between the intervention and control groups, 2% versus 6% (OR, 0.29; 95% CI, 0.10-0.85). We conclude that although low-cost, interior lead hazard control was associated with 50% or greater reduction in the proportion of children who had blood lead concentrations exceeding 15 microg/dL and > or = 20 microg/dL, there was no substantial effect on mean blood lead concentration.

Characterization of the New Jersey Lead Hazard Control Workforce

Individuals performing lead evaluation and abatement activities in New Jersey must complete certified training, an examination, and have a state permit card. Key demographic information was collected and summarized to describe this newly emerging lead workforce, to enhance lead training, to identify education and outreach needs, and to promote environmental justice. Summarizing these data also will assist other states implementing similar lead training and certification programs. As of June 30, 1998, the New Jersey Department of Health and Senior Services (NJDHSS) issued 2,370 permits to individuals in six disciplines. The lead workforce s average age was 38 years and 88 percent male. Most females were in the Inspector/Risk Assessor and Worker-Housing and Public Buildings (HPB) disciplines. Eighty percent of the workforce resided in New Jersey. Whites and Asians/Pacific Islanders were more educated than Hispanics or Blacks and a greater proportion of them were employed in the more skilled disciplines. Inadequate work experience may have prevented Blacks from qualifying for the more skilled disciplines; for Hispanics, there was also a language barrier. Twenty-nine percent of Workers and Supervisors had children less than six years of age residing in their household, which was higher than comparable state rates. The proportion of households with children under six years of age were similar for Black (32 percent), Hispanic (30 percent), and White (27 percent) households. The number of children less than six years of age per Black and Hispanic permittee was significantly higher than for Whites. Take-home lead issues and possible initiatives to promote minorities in the more skilled disciplines are discussed.

Evaluation of the HUD Lead Hazard Control Grant Program: Early Overall Findings

This study evaluates the effectiveness of lead hazard control methods used in the Lead Hazard Control (LHC) grant program of U.S. Department of Housing and Urban Development. The LHC Program awards funds to local jurisdictions to address lead hazards in privately owned, low-income dwellings. Grantees in 14 cities, states, or counties collected environmental data in over 2600-treated dwellings making this the largest study of residential lead hazard control ever undertaken. Grantees employed a range of treatments, the most common being replacement of windows and repair of deteriorated lead-based paint. In this paper, dust lead loading levels and blood lead levels of children (6 months-6 years, if present) were observed at four periods of time (preintervention, immediate, and 6- and 12-months postintervention) in 1212 dwellings. Dust lead loading levels were also observed in a subset of these dwellings at 24- and 36-months postintervention. The geometric mean floor and window dust lead loadings declined at least 50 and 88% (P<0.0001), respectively, immediately postintervention. Three years later, floor dust lead loadings remained at or below the immediate postintervention levels. Window dust lead loadings had moderate increases, but remained substantially reduced from preintervention levels and below clearance standards. At 1 year after intervention, geometric mean age-adjusted blood lead levels had declined from 11.0 to 8.2 μg/dL, a 26% decline (P<0.0001). The LHC Program interventions produced blood lead declines similar to or greater than the percentage changes reported in earlier 1-year lead intervention studies.

Long-Term Effect of Dust Control on Blood Lead Concentrations

Dust control is recommended to prevent children's exposure to residential lead hazards, but the long-term effect of dust control on children's exposure to environmental lead is unknown. To determine the effect of dust control on children's exposure to lead, as measured by blood lead concentration at 48 months of age. A randomized, controlled trial. Setting. Rochester, New York. A total of 275 urban children were randomized at 6 months of age; 189 (69%) were available for the 48-month follow-up blood test. Intervention. Children and their families were randomly assigned to an intervention group that received cleaning equipment and up to 8 visits by a trained lead hazard control advisor or to a control group. The intervention was terminated when the children were 24 months of age. Geometric mean blood lead concentration and prevalence of elevated blood lead concentration (ie, >/=10 microg/dL, >/=15 microg/dL, and >/=20 microg/dL), by group assignment. For children with 48-month blood tests, baseline geometric mean blood lead concentrations were 2.8 microg/dL (95% confidence interval [CI]: 2.6, 3.0); there were no significant differences in baseline characteristics or lead exposure by group assignment. At 48 months of age, the geometric mean blood lead was 5.9 microg/dL (95% CI: 5.3, 6.7) for the intervention group and 6.1 microg/dL (95% CI: 5.5,6.9) for the control group. The percentage of children with a 48-month blood lead >/=10 microg/dL, >/=15 microg/dL, and >/=20 microg/dL was 19% versus 19%, 2% versus 9%, and 1% versus 2% in the intervention and control groups, respectively. We conclude that dust control, as performed by families and in the absence of lead hazard controls to reduce ongoing contamination from lead-based paint, was not effective in preventing children's exposure to residential lead hazards.

Release of lead-containing particles from a wall enclosure.

The 1995 Department of Housing and Urban Development (HUD) Guidelines for the Evaluation and Control of Lead-Based Paint Hazards in Housing discusses using interior and exterior wall enclosures for lead hazard control. Leaded dust may be aerosolized inside enclosures and released through gaps and cracks into a room. The effects of airflow and mechanical disturbances on dust release were studied using a laboratory wall enclosure model with dust collected from homes with lead-based paint hazards. Airflows relevant to residences were blown down the enclosure and out a 4-, 6-, or 8-mm horizontal gap at its bottom, simulating potential enclosure failure. Then, low-frequency mechanical vibrations also were applied to the enclosure. No significant dust release was found when blowing air down the enclosure even at 37 cm/sec (representing extremely high flow); release occurred only with this high flow and 3 Hz mechanical disturbances. Dust was released primarily from the floor area immediately adjacent to the enclosure gap; the release rate fluctuated over time. Most dust initially settled near the enclosure. Dust release for 1 hour at extreme conditions (high airflow with vibration) yields lead loading above the 1995 HUD clearance level of 100 microg/ft2 only within 3-4 cm of the wall; for the HUD standard (1 ft2) sampling area, the lead loading does not exceed 30 microg/ ft2. Redistributing dust over the room's 16 m2 floor space yields average extreme-condition loading rate of 2 microg/ft2/hour. At less-than-extreme conditions, dust would have to be released for years without cleaning to yield a hazard.