United States house dust Pb concentrations are influenced by soil, paint, and house age: insights from a national survey.

BACKGROUND: Lead (Pb) in house dust contributes significantly to blood lead levels (BLLs) in children which may result in dire health consequences. Assessment of house dust Pb in the United States, relationships with Pb in soil and paint, and residential factors influencing Pb concentrations are essential to probing drivers of house dust Pb exposure. OBJECTIVE: Pb concentrations in vacuum-collected house dust are characterized across 346 homes participating in the American Health Homes Survey II (AHHS II), a US survey (2018-2019) evaluating residential Pb hazards. Connections between house dust Pb and soil Pb, paint Pb, and other residential factors are evaluated, and dust Pb concentration data are compared to paired loading data to understand Pb hazard standard implications. RESULTS: Mean and median vacuum dust Pb concentrations were 124 µg Pb g-1 and 34 µg Pb g-1, respectively. Vacuum-collected dust concentrations and dust wipe Pb loading rates were significantly correlated within homes (α < 0.001; r ≥ 0.4). At least one wipe sample exceeded current house dust Pb loading hazard standards (10 µg ft-2 or 100 µg Pb ft-2 for floors and windowsills, respectively) in 75 of 346 homes (22%). House dust Pb concentrations were correlated with soil Pb (r = 0.64) and Pb paint (r = 0.57). Soil Pb and paint Pb were also correlated (r = 0.6). IMPACT: The AHHS II provides a window into the current state of Pb in and around residences. We evaluated the relationship between house dust Pb concentrations and two common residential Pb sources: soil and Pb-based paint. Here, we identify relationships between Pb concentrations from vacuum-collected dust and paired Pb wipe loading data, enabling dust Pb concentrations to be evaluated in the context of hazard standards. This relationship, along with direct ties to Pb in soil and interior/exterior paint, provides a comprehensive assessment of dust Pb for US homes, crucial for formulating effective strategies to mitigate Pb exposure risks in households.

Reduced prevalence of childhood asthma after housing renovations in an underresourced community.

Background: Despite improvements in asthma symptom management and asthma morbidity, the prevalence of asthma in the United States remains high, especially in underresourced communities. Objective: Our goal was to determine whether housing renovations affect the prevalence of asthma in an underresourced community. Methods: The Fay Apartments (~800 units) in Cincinnati, Ohio, were renovated to "green building" standards between 2010 and 2012 and renamed the Villages at Roll Hill. The prevalence of asthma among 7-year-olds in the Villages at Roll Hill was determined by accessing Ohio Medicaid data for the years 2013 to 2021. Results: In the first 6 years after the renovations (2013-2018), the prevalence of asthma among 7-year-olds in the community averaged 12.7%. In contrast, in postrenovation years 7 through 9 (2019-2021), the average prevalence of asthma was 5.9%. Logistic regression modeling for the log odds of asthma diagnosis in this age group was used to test the statistical significance of asthma prevalence for 2013-2018 versus for 2019-2021. The model resulted in demonstration of a significant (P < .001) reduction in asthma prevalence between 2013-2018 and 2019-2021. Conclusions: The renovation of an underresourced community's housing resulted in a lower prevalence of asthma for 7-year-olds who were born after the renovations had been completed.

A national survey of lead and other metal(loids) in residential drinking water in the United States.

BACKGROUND: Exposure to lead (Pb), arsenic (As) and copper (Cu) may cause significant health issues including harmful neurological effects, cancer or organ damage. Determination of human exposure-relevant concentrations of these metal(loids) in drinking water, therefore, is critical. OBJECTIVE: We sought to characterize exposure-relevant Pb, As, and Cu concentrations in drinking water collected from homes participating in the American Healthy Homes Survey II, a national survey that monitors the prevalence of Pb and related hazards in United States homes. METHODS: Drinking water samples were collected from a national survey of 678 U.S. homes where children may live using an exposure-based composite sampling protocol. Relationships between metal(loid) concentration, water source and house age were evaluated. RESULTS: 18 of 678 (2.6%) of samples analyzed exceeded 5 µg Pb L-1 (Mean = 1.0 µg L-1). 1.5% of samples exceeded 10 µg As L-1 (Mean = 1.7 µg L-1) and 1,300 µg Cu L-1 (Mean = 125 µg L-1). Private well samples were more likely to exceed metal(loid) concentration thresholds than public water samples. Pb concentrations were correlated with Cu and Zn, indicative of brass as a common Pb source is samples analyzed. SIGNIFICANCE: Results represent the largest national-scale effort to date to inform exposure risks to Pb, As, and Cu in drinking water in U.S. homes using an exposure-based composite sampling approach. IMPACT STATEMENT: To date, there are no national-level estimates of Pb, As and Cu in US drinking water collected from household taps using an exposure-based sampling protocol. Therefore, assessing public health impacts from metal(loids) in drinking water remains challenging. Results presented in this study represent the largest effort to date to test for exposure-relevant concentrations of Pb, As and Cu in US household drinking water, providing a critical step toward improved understanding of metal(loid) exposure risk.

Comparison of ERMI results for dust collected from homes by an electrostatic cloth and by the standard vacuum method.

The Environmental Relative Moldiness Index (ERMI) is a scale used to compare mold contamination levels in U.S. homes. To create the ERMI scale, a nationally representative set of U.S. homes was selected (n = 1,096). From each of these homes, a standard vacuum-dust sample was collected and then 36 common molds, the 26 Group 1 and 10 Group 2 molds, as grouped for forming the ERMI metric, were quantified using quantitative PCR assays. However, in investigations of mold in homes, it is not always practical or even possible to collect dust using the standard vacuum method. Therefore, we performed a comparative study of dust samples collected in the same homes (n = 151) by the standard vacuum method and by an electrostatic cloth (EC) method. First, floor dust was collected by vacuuming a 2 m2 area in the living room and a 2 m2 area in a bedroom, directly adjacent to the sofa or bed, for 5 min each with a Mitest sampler-fitted vacuum. Second, immediately after the collection of the vacuum dust sample, an EC dust sample was collected by wiping above-floor horizontal surfaces in the living room and bedroom. Then, the ERMI analysis of each sample was performed by a commercial laboratory. The results showed the average concentrations of 33 of the 36 ERMI molds were not significantly different in the vacuum and EC samples. Also, the average summed logs of the Group 1 molds, Group 2, or ERMI values were significantly (p < 0.001) correlated between the vacuum and EC samples. Logistic regression indicated that an EC sample could identify homes in the highest ERMI quartile 96% of the time by using the same ERMI value cutoff as vacuum sample ERMI value cutoff and 35% of samples proved to be false positives. When it is not practical to obtain the standard vacuum-dust sample, an EC sample can provide a useful practical alternative for ERMI analyses.

The Environmental Relative Moldiness Index reveals changes in mold contamination in United States homes over time.

The Environmental Relative Moldiness Index (ERMI) is a scale created to compare mold contamination levels in U.S. homes. The ERMI was developed as a result of the Department of Housing and Urban Development's (HUD) first American Healthy Homes Survey (AHHS I), which sampled 1,096 homes selected to be representative of the U.S. housing stock. In AHHS I, a dust sample from each home was analyzed using quantitative PCR assays (qPCR) for 36 common indoor molds: 26 Group 1 molds, which were associated with water damage in homes and 10 Group 2 molds, which primarily enter the home from the outside environment. In 2019, HUD completed AHHS II by sampling 695 homes. Because lead was banned from paint in 1978, a larger proportion of homes selected for AHHS II had been built before 1978 compared to AHHS I. The 36 ERMI molds were analyzed in AHHS II exactly as in AHHS I. For the 36-ERMI molds, the rates of detection, average concentrations, and geometric means were in significant concordance (p < 0.001) between AHHS I and II, indicating that the ERMI methodology was stable over time. However, the average ERMI value in AHHS II homes was greater than in AHHS I. The reason for the difference was investigated by examining the Group 1 and 2 mold populations. The average summed logs of Group 1 molds were significantly greater in homes built before 1978 than the average for homes built later. Conversely, the average summed logs of Group 2 mold populations were the same in homes built before 1978 and homes built later. Since the summed logs of Group 2 mold is subtracted from the summed logs of Group 1 molds in the ERMI calculation, the average ERMI value was higher in AHHS II homes than AHHS I. In conclusion, by using the ERMI metric, we were able to demonstrate that water damage and mold growth were more likely to occur as homes get older.

Identifying Jurisdictions at Risk of Containing Housing Units With Deteriorated Paint: Results and Targeting Implications for the US Department of Housing and Urban Development.

CONTEXT: The US Department of Housing and Urban Development provides millions in annual funding to make low-income housing lead safe, but funds are limited relative to need. To adequately target efforts, local program administrators must identify neighborhoods that are the most "at risk" of residential lead exposure; however, no federal agency currently provides a public data set for this use. OBJECTIVES: To examine pre-1980 households with large areas of deteriorated paint, a significant and common predictor of lead dust, and identify high-risk jurisdictions. To highlight the potential use of a newly available data set for strategic lead poisoning prevention and targeting. DESIGN: Microdata from the 2011 American Housing Survey and the 2009-2013 American Community Survey were used to develop a household-level predicted risk metric that identifies housing units at risk of containing large areas of deteriorated paint. Predicted risk, defined as the mean predicted percentage of occupied housing units at risk of containing deteriorated paint within a given jurisdiction, was summarized by state, county, and tract. SETTING: National, all occupied housing units. PARTICIPANTS: Occupied housing units summarized by household (n = 9 363 000), census tract (n = 72 235), county (n = 3143), and state (n = 51). MAIN OUTCOME MEASURE: Housing units built prior to 1980 with a large area of deteriorated paint. RESULTS: New York, Rhode Island, New Jersey, Massachusetts, and Pennsylvania had the highest predicted percentage of at-risk households (range: 2.52%-2.90%). County-level and tract-level estimates are the most useful when examining a predefined jurisdiction; New York state was presented as a case study. County-level quartile risk scores revealed Albany as an at-risk jurisdiction. Tract-level quartile risk scores further identified at-risk neighborhoods in northeastern Albany. CONCLUSIONS: Findings can help housing and health policy makers identify and target geographic areas with a high probability of households at risk of potential exposure to deteriorated lead-based paint.

Characteristics and Correlates of Cigarette Smoking Status Among US Adults Receiving Federal Housing Assistance.

This study describes patterns of cigarette smoking (current, former, never) by sociodemographic, household, and chronic disease characteristics and correlates among US adults receiving housing assistance from the US Department of Housing and Urban Development (HUD) during 2007-2012. Estimates were generated from 4,771 adults by using National Health Interview Survey and HUD-linked data. Overall, 48.4% of HUD-assisted adults were never smokers, 33.0% were current smokers, and 18.6% were former smokers; smoking status varied by sex, age, race/ethnicity, whether children were living in the household, and chronic disease status. These estimates could inform tobacco control interventions to improve the health and well-being of HUD-assisted residents.

Cigarette smoking and adverse health outcomes among adults receiving federal housing assistance.

Cigarette smoking is higher among low-income adults and individuals who reside in federally assisted housing are particularly susceptible to the adverse effects of smoking and secondhand smoke exposure. This study assessed smoking-related behaviors and health outcomes among U.S. adults who received federal housing assistance during 2006-2012. National Health Interview Survey data linked with administrative data from the U.S. Department of Housing and Urban Development were analyzed; 5218 HUD-assisted adults were assessed. Demographic characteristics associated with smoking, including frequency and consumption, were assessed among adult cigarette smokers. Fourteen adverse health outcomes were examined among cigarette smoking and nonsmoking adults. One-third (33.6%) of HUD-assisted adults were current cigarette smokers. Smoking prevalence was highest among adults aged 25-44 (42.5%), non-Hispanic whites (39.5%), and adults who resided in households with children (37.5%). Half attempted to quit in the past year; 82.1% were daily smokers; and, 35.8% of daily smokers reported smoking 20+ cigarettes a day. Multivariable analyses revealed that compared to nonsmokers, cigarette smokers had increased likelihood of reporting fair or poor health (95% CI: 1.04-1.52), chronic obstructive pulmonary disease (CI: 1.87-3.06), disability (CI: 1.25-1.83), asthma (CI: 1.02-1.55), serious psychological distress (CI: 1.39-2.52), >1 emergency room visit in the past year (CI: 1.09-1.56), and ≥10 work loss days in the past year (CI: 1.15-3.06). Adults who receive housing assistance represent an at-risk population for adverse health outcomes associated with smoking and secondhand smoke. Housing assistance programs provide a valuable platform for the implementation of evidence-based tobacco prevention and control measures, including smokefree policies.

Antigen unmasking enhances visualization efficacy of the oocyte activation factor, phospholipase C zeta, in mammalian sperm.

STUDY QUESTION: Is it possible to improve clinical visualization of phospholipase C zeta (PLCζ) as a diagnostic marker of sperm oocyte activation capacity and male fertility? SUMMARY ANSWER: Poor PLCζ visualization efficacy using current protocols may be due to steric or conformational occlusion of native PLCζ, hindering antibody access, and is significantly enhanced using antigen unmasking/retrieval (AUM) protocols. WHAT IS KNOWN ALREADY: Mammalian oocyte activation is mediated via a series of intracellular calcium (Ca2+) oscillations induced by sperm-specific PLCζ. PLCζ represents not only a potential clinical therapeutic in cases of oocyte activation deficiency but also a diagnostic marker of sperm fertility. However, there are significant concerns surrounding PLCζ antibody specificity and detection protocols. STUDY DESIGN, SIZE DURATION: Two PLCζ polyclonal antibodies, with confirmed PLCζ specificity, were employed in mouse, porcine and human sperm. Experiments evaluated PLCζ visualization efficacy, and whether AUM improved this. Antibodies against two sperm-specific proteins [post-acrosomal WW-binding protein (PAWP) and acrosin] were used as controls. PARTICIPANTS/MATERIALS, SETTING, METHODS: Aldehyde- and methanol-fixed sperm were subject to immunofluorescence analysis following HCl exposure (pH = 0.1-0.5), acid Tyrode's solution exposure (pH = 2.5) or heating in 10 mM sodium citrate solution (pH = 6.0). Fluorescence intensity of at least 300 cells was recorded for each treatment, with three independent repeats. MAIN RESULTS AND THE ROLE OF CHANCE: Despite high specificity for native PLCζ following immunoblotting using epitope-specific polyclonal PLCζ antibodies in mouse, porcine and human sperm, immunofluorescent visualization efficacy was poor. In contrast, sperm markers PAWP and acrosin exhibited relatively impressive results. All methods of AUM on aldehyde-fixed sperm enhanced visualization efficacy for PLCζ compared to visualization efficacy before AUM (P < 0.05 for all AUM interventions), but exerted no significant change upon PAWP or acrosin immunofluorescence following AUM. All methods of AUM enhanced PLCζ visualization efficacy in mouse and human methanol-fixed sperm compared to without AUM (P < 0.05 for all AUM interventions), while no significant change was observed in methanol-fixed porcine sperm before and after. In the absence of aldehyde-induced cross-linkages, such results suggest that poor PLCζ visualization efficacy may be due to steric or conformational occlusion of native PLCζ, hindering antibody access. Importantly, examination of sperm from individual donors revealed that AUM differentially affects observable PLCζ fluorescence, and the proportion of sperm exhibiting detectable PLCζ fluorescence in sperm from different males. LIMITATIONS, REASONS FOR CAUTION: Direct correlation of fertility outcomes with the level of PLCζ in the sperm samples studied was not available. Such analyses would be required in future to determine whether the improved methodology for PLCζ visualization we propose would indeed reflect fertility status. WIDER IMPLICATIONS OF THE FINDINGS: We propose that AUM alters conformational interactions to enhance PLCζ epitope availability and visualization efficacy, supporting prospective application of AUM to reduce misinterpretation in clinical diagnosis of PLCζ-linked male infertility. Our current results suggest that it is perhaps prudent that previous studies investigating links between PLCζ and fertility parameters are re-examined in the context of AUM, and may pave the way for future work to answer significant questions such as how PLCζ appears to be kept in an inactive form in the sperm. LARGE SCALE DATA: Not applicable. STUDY FUNDING/COMPETING INTERESTS: J.K. is supported by a Health Fellowship award from the National Institute for Social Care and Health Research (NISCHR). M.N. is supported by a Marie Curie Intra-European Research Fellowship award. This work was also partly funded by a research grant from Cook Medical Technologies LLC. There are no competing financial interests to declare.

Functional disparity between human PAWP and PLCζ in the generation of Ca2+ oscillations for oocyte activation.

Mammalian oocyte activation is mediated by cytosolic calcium (Ca(2+)) oscillations initiated upon delivery of a putative 'sperm factor' by the fertilizing sperm. Previous studies suggest the identity of this sperm factor as the testis-specific phospholipase C-zeta (PLCζ). Recently, a post-acrosomal sheath WW domain-binding protein (PAWP) has been proposed as an alternative sperm factor candidate, following a report that human PAWP protein and cRNA elicited Ca(2+) oscillations in mouse and human oocytes. Those Ca(2+) oscillations were inhibited by a PAWP-derived peptide corresponding to a functional PPGY binding motif. Herein, using a series of human PAWP expression constructs, we demonstrate that both human PAWP protein and cRNA are, in our experiments, unable to elicit Ca(2+) release following microinjection into mouse oocytes. Parallel experiments performed with human PLCζ elicited the characteristic Ca(2+) oscillations present at mammalian fertilization, which produced oocyte activation and embryo development. Furthermore, sperm-induced Ca(2+) oscillations were not inhibited by the PAWP-derived PPGY peptide following in vitro fertilization or intracytoplasmic sperm injection. Thus, the functional disparity with PLCζ leads us to conclude that human PAWP is neither sufficient nor necessary for the Ca(2+) oscillations that initiate mammalian oocyte activation at fertilization.

Prevalence of Lead Hazards and Soil Arsenic in U.S. Housing.

The American Healthy Homes Survey, June 2005-March 2006, measured levels of lead and arsenic in homes nationwide. Based on a three-stage cluster sample of 1,131 housing units, key statistically weighted estimates of the prevalence of lead-based paint (LBP) and LBP hazards associated with paint, dust, and soil, and arsenic in dust and soil, were as follows: 37.1 million homes (35%) had some LBP; 23.2 million (22%) had one or more LBP hazards; 93% of the homes with LBP were built before 1978. The highest prevalence of LBP and LBP hazards was in the Northeast and Midwest. Over three million homes with children under six years of age had LBP hazards, including 1.1 million low-income households (< $30,000/yr.). Less than 5% of homes had detectable levels of arsenic in dust (≥ 5 µg/ft2). Arsenic in soil (for homes with yard soil) averaged 6.6 parts per million (ppm). Many homes had soil arsenic levels of 20 ppm or greater, including 16% of homes with wooden structures in the yard and 8% of homes without such structures.

Higher Environmental Relative Moldiness Index (ERMI) values measured in homes of asthmatic children in Boston, Kansas City, and San Diego.

OBJECTIVE: Mold in water-damaged homes has been linked to asthma. Our objective was to test a new metric to quantify mold exposures in asthmatic children's homes in three widely dispersed cities in the United States. METHODS: The Environmental Relative Moldiness Index (ERMI) metric was created by the US Environmental Protection Agency, with assistance by the Department of Housing and Urban Development (HUD), to quantify mold contamination in US homes. The ERMI values in homes of asthmatic children were determined for the three widely dispersed cities of Boston, Kansas City, and San Diego. RESULTS: Asthmatic children in Boston (n = 76), Kansas City (n = 60), and San Diego (n = 93) were found to be living in homes with significantly higher ERMI values than were found in homes randomly selected during the 2006 HUD American Healthy Homes Survey (AHHS) from the same geographic areas (n = 34, 22, and 28, respectively). Taken together, the average ERMI value in the homes with an asthmatic child was 8.73 compared to 3.87 for the AHHS homes. In addition, Kansas City homes of children with "Mild, Moderate, or Severe Persistent Asthma" had average ERMI value of 12.4 compared to 7.9 for homes of children with only "Mild Intermittent Asthma." Aspergillus niger was the only mold of the 36 tested which was measured in significantly greater concentration in the homes of asthmatic children in all three cities. CONCLUSION: High ERMI values were associated with homes of asthmatic children in three widely dispersed cities in the United States.

Geographic distribution of Environmental Relative Moldiness Index molds in USA homes.

OBJECTIVE: The objective of this study was to quantify and describe the distribution of the 36 molds that make up the Environmental Relative Moldiness Index (ERMI). MATERIALS AND METHODS: As part of the 2006 American Healthy Homes Survey, settled dust samples were analyzed by mold-specific quantitative PCR (MSQPCR) for the 36 ERMI molds. Each species' geographical distribution pattern was examined individually, followed by partitioning analysis in order to identify spatially meaningful patterns. For mapping, the 36 mold populations were divided into disjoint clusters on the basis of their standardized concentrations, and First Principal Component (FPC) scores were computed. RESULTS AND CONCLUSIONS: The partitioning analyses failed to uncover a valid partitioning that yielded compact, well-separated partitions with systematic spatial distributions, either on global or local criteria. Disjoint variable clustering resulted in seven mold clusters. The 36 molds and ERMI values themselves were found to be heterogeneously distributed across the United States of America (USA).

Housing interventions and control of asthma-related indoor biologic agents: a review of the evidence.

Subject matter experts systematically reviewed evidence on the effectiveness of housing interventions that affect health outcomes, primarily asthma, associated with exposure to moisture, mold, and allergens. Three of the 11 interventions reviewed had sufficient evidence for implementation: multifaceted, in-home, tailored interventions for reducing asthma morbidity; integrated pest management to reduce cockroach allergen; and combined elimination of moisture intrusion and leaks and removal of moldy items to reduce mold and respiratory symptoms. Four interventions needed more field evaluation, 1 needed formative research, and 3 either had no evidence of effectiveness or were ineffective. The 3 interventions with sufficient evidence all applied multiple, integrated strategies. This evidence review shows that selected interventions that improve housing conditions will reduce morbidity from asthma and respiratory allergies.

Primary care and dementia: 2. Long-term care at home: psychosocial interventions, information provision, carer support and case management.

OBJECTIVE: To write a narrative review of the role of primary care physicians in the long-term care of people with dementia living at home, with a focus on psychosocial interventions, the provision of information and carer support, behavioural and psychological symptoms and case management. METHODS: The systematic review carried out for the NICE/SCIE Guidelines was updated from January 2006, Cochrane Reviews were identified and other publications found by consultations with experts. RESULTS: In primary care, the long-term care of people with dementia living at home can be structured around several key themes: reframing dementia with a focus on a social model of disability; active use of information sources; supporting carers (caregivers); the management of behavioural and psychological symptoms and a structured case management approach. CONCLUSIONS: Caring for people with dementia in primary care demands the same systematic approach as the management of other long-term conditions. The systematic follow-up of both people with dementia and their carers should be integrated into primary care. Reframing dementia, with an emphasis on abilities retained may allow people with dementia and their families to develop more effective coping strategies; an increase in skill mix within primary care is required to deliver this and may also improve the management of behavioural problems. The potential benefits of person-centred interventions, like advance care planning, and alternative models of service delivery, such as a structured, collaborative care approach which promotes integrated case management within primary care, require further evaluation.

American Healthy Homes Survey: a national study of residential pesticides measured from floor wipes.

The U.S. Department of Housing and Urban Development in collaboration with the United States Environmental Protection Agency conducted a survey measuring lead, allergens, and insecticides in a randomly selected nationally representative sample of residential homes. Multistage sampling with clustering was used to select the 1131 homes of which a subset of 500 randomly selected homes included the collection of hard surface floor wipes. Samples were collected by trained field technicians between June 2005 and March 2006 using isopropanol wetted wipes. Samples were analyzed for a suite of 24 compounds which included insecticides in the organochlorine, organophosphate, pyrethroid and phenylpyrazole classes, and the insecticide synergist piperonyl butoxide. The most commonly detected were permethrin (89%), chlorpyrifos (78%), chlordane (64%), piperonyl butoxide (52%), cypermethrin (46%), and fipronil (40%). Mean and geometric mean (GM) concentrations varied widely among compounds, but were highest for trans-permethrin (mean 2.22 ng/cm2 and GM 0.14 ng/ cm2) and cypermethrin (mean 2.9 ng/cm2 and GM 0.03 ng/ cm2). Results show that most floors in occupied homes in the U.S. have measurable levels of insecticides that may serve as sources of exposure to occupants.

Exposure of U.S. children to residential dust lead, 1999-2004: I. Housing and demographic factors.

BACKGROUND: Lead-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. OBJECTIVES: In 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. METHODS: We used NHANES PbD data (n=2,065 from floors and n=1,618 from windowsills) and covariates to construct linear and logistic regression models. RESULTS: The population-weighted geometric mean floor and windowsill PbD were 0.5 microg/ft2 [geometric standard error (GSE)=1.0] and 7.6 microg/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 microg/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. CONCLUSION: Most 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.

BACKGROUND: The 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. OBJECTIVES: We aimed to determine how floor dust lead (PbD) loadings and other housing factors influence childhood blood lead (PbB) levels and lead poisoning. METHODS: We 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 >or=5 and >or=10 microg/dL at a range of floor PbD. RESULTS: The population-weighted geometric mean (GM) PbB was 2.0 microg/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 microg/dL (R2=5%). At floor PbD=12 microg/ft2, the models predict that 4.6% of children living in homes constructed before 1978 have PbB>or=10 microg/dL, 27% have PbB>or=5 microg/dL, and the GM PbB is 3.9 microg/dL. CONCLUSIONS: Lowering the floor PbD standard below the current standard of 40 microg/ft2 would protect more children from elevated PbB.