Childhood Lead Poisoning 1970-2022: Charting Progress and Needed Reforms.

CONTEXT: Childhood lead poisoning prevention in the United States was marked by a largely failed medical approach from 1971 to 1990; an emergent (but small) healthy housing primary prevention strategy from 1991 to 2015; and implementation of large-scale proven interventions since then. PROGRAM: Childhood Lead Poisoning Prevention & Healthy Housing. METHODS: Historic and recent health and housing data from the National Health and Nutrition Examination Survey (NHANES) and the American Healthy Homes Survey (AHHS) were retrieved to analyze trends and associated policy gaps. EVALUATION: Approximately 590 000 US children aged 1 through 5 years had elevated blood lead levels of 3.5 µg/dL and greater in 2016, and 4.3 million children resided in homes with lead paint in 2019. Despite large improvements, racial and other disparities remain stubbornly and statistically significant. The NHANES and the AHHS require larger sample sizes. The Centers for Disease Control and Prevention has not published children's blood lead surveillance and NHANES data in several years; the Department of Housing and Urban Development (HUD) has no analogous housing surveillance system; and the Environmental Protection Agency (EPA) and the Occupational Safety and Health Administration (OSHA) have not updated training, Superfund, and occupational standards in decades. DISCUSSION: The nation has been without a plan and an associated budget for more than 2 decades. Congress has not reformed the nation's main lead poisoning prevention laws in more than 30 years. Such reforms include stopping US companies from producing new residential lead paint in other countries; enabling the disclosure law to identify all residential lead hazards; closing loopholes in federally assisted housing regulations and mortgage insurance standards; harnessing tax policy to help homeowners mitigate lead hazards; streamlining training requirements; increasing the size of health and housing surveys and surveillance systems; and updating housing codes, medical guidance, dust lead standards, training, Superfund, and worker exposure limits. Congress and the president should reauthorize a cabinet-level task force (dormant since 2010) to develop a new strategic plan with an interagency budget to implement it. These reforms will scale and optimize markets, subsidies, enforcement, and other proven interventions to end ineffective, costly, harmful, and irrational cost shifting that threatens children, workers, and affordable housing.

Using Artificial Intelligence to Identify Sources and Pathways of Lead Exposure in Children.

CONTEXT: Sources and pathways of lead exposure in young children have not been analyzed using new artificial intelligence methods. OBJECTIVE: To collect environmental, behavioral, and other data on sources and pathways in 17 rural homes to predict at-risk households and to compare urban and rural indicators of exposure. DESIGN: Cross-sectional pilot study. SETTING: Knox County, Illinois, which has a high rate of childhood lead poisoning. PARTICIPANTS: Rural families. METHODS: Neural network and K-means statistical analysis. MAIN OUTCOME MEASURE: Children's blood lead level. RESULTS: Lead paint on doors, lead dust, residential property assessed tax, and median interior paint lead level were the most important predictors of children's blood lead level. CONCLUSIONS: K-means analysis confirmed that settled house dust lead loadings, age of housing, concentration of lead in door paint, and geometric mean of interior lead paint samples were the most important predictors of lead in children's blood. However, assessed property tax also emerged as a new predictor. A sampling strategy that examines these variables can provide lead poisoning prevention professionals with an efficient and cost-effective means of identifying priority homes for lead remediation. The ability to preemptively target remediation efforts can help health, housing, and other agencies to remove lead hazards before children develop irreversible health effects and incur costs associated with lead in their blood.

Pathways and sources of lead exposure: Michigan Children's Lead Determination (the MI CHILD study).

There has been little research on childhood lead exposure pathways since the 1990s. New data from Michigan in 2017-2021 for 429 children in 345 homes included lead in blood, paint, dust, soil, water, and other housing, demographic, and behavioral metrics. Fifty-three percent of these children had blood lead (BPb) ≥5 µg/dL. A repeated measures pathway model that accounted for multiple children in the same home was constructed using weighted least squares mean estimation and included variance-covariance model multiple imputation. Results showed that children's BPb was directly predicted by lead in settled floor house dust, child's age, season, and mouthing behavior and indirectly predicted by window sill and trough dust lead (DPb), bare soil lead (SPb), proportion of floors with carpets, and exterior building deteriorations. Paint lead (PPb) was also an indirect predictor of BPb through the soil and settled dust pathways. Water lead (WPb), water consumption and other lead sources/pathways were not significant predictors of BPb in this cohort. Although risk factors for individual children are highly variable and worthy of investigation to pinpoint their exposures, this study shows that the main direct and indirect pathways of lead exposure for most children in older housing remain paint and the contaminated dust and soil it generates. Pathway analyses in other jurisdictions using current data should be performed to confirm these results. This study suggests both DPb and BPb in high-risk homes may have declined since the 1990s and that lead in dust, soil, and paint all should be measured to predict risk and target remediation. Because most homes still have not been assessed for lead hazards and remediated, too many children remain at needless risk.

Evaluating and Assessing Radon Testing in Multifamily Housing.

CONTEXT: To determine if radon mitigation is needed to protect occupants of multifamily housing, reliable testing procedures are needed. Yet, protocols on how many ground-contact housing units must be tested vary from 10% to 25% to 100%. OBJECTIVES: To estimate the probability of failing to identify a building containing at least one unit with elevated radon level when all ground-contact units are not tested. DESIGN: Retrospective analysis of previously collected data from licensed (ie, certified) radon measurement professionals using hypergeometric and Monte Carlo statistical methods to estimate the confidence that there are no units with radon levels of 4 picoCuries/liter of air (pCi/L) or more based on various testing percentages. SETTING: Testing data were obtained from 29 US states for 7892 ground-contact units in 687 multifamily buildings, primarily 5 to 20 units per building. MAIN OUTCOME MEASURE: Probability of failing to identify elevated radon levels in untested units. RESULTS: About 15% (n = 1163) of the units had radon levels of more than 4 pCi/L (the EPA action level); 59 units had more than 20 pCi/L (maximum of 96 pCi/L). For building sizes of 5 to 20 ground-contact units, the 2018 federal testing protocols that currently require testing of 10% and 25% of ground-contact units in each building failed to identify 47%-69% and 32%-46% of the units, respectively, depending on building size. CONCLUSIONS: Measurement of 90% of the ground-contact units in buildings with 5 to 20 ground-contact units results in up to 4% of the units with elevated radon levels being missed. To achieve 95% confidence that no units in the building have radon levels of 4 pCi/L or more in buildings up to 20 units, 100% sampling is required. For the vast majority of multifamily buildings, all ground-contact units in multifamily buildings should be tested for radon.

Residential dust lead levels and the risk of childhood lead poisoning in United States children.

BACKGROUND: The United States Environmental Protection Agency (EPA) recently lowered residential floor and windowsill dust lead hazard standards, but maintained previous post-abatement clearance standards. We examined whether the discrepancy in these regulations places children at higher risk of lead poisoning. METHODS: In 250 children from Cincinnati, Ohio (2004-2008) living in homes built before 1978, we measured residential floor and windowsill dust lead loadings and blood lead concentrations at ages 1 and 2 years. Using linear regression with generalized estimating equations, we estimated covariate-adjusted associations of dust lead levels with blood lead concentrations and risk of lead poisoning. RESULTS: An increase in floor dust lead from 10 (revised dust lead hazard standard) to 40 µg/ft2 (post-abatement clearance standard) was associated with 26% higher (95% confidence interval (CI):15, 38) blood lead concentrations and 2.1 times the risk of blood lead concentrations ≥5 µg/dL (95% CI: 1.44, 3.06). Extrapolating our findings to US children age 1-5 years, we estimated that 6.9% (95% CI: 1.5, 17.2) of cases of blood lead concentrations ≥5 µg/dL are attributable to floor dust lead loadings between 10 and ≤40 µg/ft2. CONCLUSIONS: The EPA's residential dust lead regulations place children at increased risk of lead poisoning. We recommend adopting more protective dust lead standards. IMPACT: We determined whether children are at increased risk of lead poisoning with the 2019 EPA residential post-abatement lead clearance standards being higher than dust lead hazard standards. In this observational study, 2019 EPA dust lead clearance standards were associated with increased risk of lead poisoning compared to the revised dust lead hazard standard. Both EPA standards were associated with increased risk of lead poisoning compared to more stringent standards employed in our study. Extrapolating our findings to US children, the 2019 EPA dust lead clearance standards could place up to 36,700 children at risk of lead poisoning.

Predictors of Water Lead Levels in Drinking Water of Homes With Domestic Wells in 3 Illinois Counties.

CONTEXT: Millions of US homes receive water from private wells, which are not required to be tested for lead (Pb). An approach to prioritizing high-risk homes for water lead level (WLL) testing may help focus outreach and screening efforts, while reducing the testing of homes at low risk. OBJECTIVE: To (1) characterize distribution of WLLs and corrosivity in tap water of homes with private residential wells, and (2) develop and evaluate a screening strategy for predicting Pb detection within a home. DESIGN: Cross-sectional. SETTING: Three Illinois counties: Kane (northern), Peoria (central), and Jackson (southern). PARTICIPANTS: 151 private well users from 3 Illinois counties. INTERVENTION: Water samples were analyzed for WLL and corrosivity. MAIN OUTCOME MEASURES: (1) WLL and corrosivity, and (2) the sensitivity, specificity, and predictive value of a strategy for prioritizing homes for WLL testing. RESULTS: Pb was detected (>0.76 ppb) in tap water of 48.3% homes, and 3.3% exceeded 15 ppb, the US Environmental Protection Agency action level for community water systems. Compared with homes built in/after 1987 with relatively low corrosivity, older homes with more corrosive water were far more likely to contain measurable Pb (odds ratio = 11.07; 95% confidence interval, 3.47-35.31). The strategy for screening homes with private wells for WLL had a sensitivity of 88%, specificity of 42%, positive predictive value of 58%, and negative predictive value of 80%. CONCLUSIONS: Pb in residential well water is widespread. The screening strategy for prioritizing homes with private wells for WLL testing is greater than 85% sensitive.

Radon and moisture impacts from interventions integrated with housing energy retrofits.

Energy retrofits can reduce air exchange, raising the concern of whether indoor radon and moisture levels could increase. This pre/post-intervention study explored whether simple radon interventions implemented in conjunction with energy retrofits can prevent increases in radon and moisture levels. Treatment homes (n = 98) were matched with control (no energy retrofits or radon intervention) homes (n = 12). Control homes were matched by geographic location and foundation type. t-tests were used to determine whether post-energy retrofit radon and moisture level changes in treatment homes significantly differed from those in control homes. The radon interventions succeeded in preventing statistically significant increases in first floor radon using arithmetic (p = 0.749) and geometric means (p = 0.120). In basements, arithmetic (p = 0.060) and geometric (p = 0.092) mean radon levels statistically significantly increased, consistent with previous studies which found that basement radon levels may increase even if first floor levels remain unchanged. Changes in infiltration were related to changes in radon (p = 0.057 in basements; p = 0.066 on first floors). Only 58% of the change in infiltration was due to air sealing, with the rest due to weather changes. There was no statistically significant association between air sealing itself and radon levels on the first floor (p = 0.664). Moisture levels also did not significantly increase.

Ten questions concerning the implications of carpet on indoor chemistry and microbiology.

Carpet and rugs currently represent about half of the United States flooring market and offer many benefits as a flooring type. How carpets influence our exposure to both microorganisms and chemicals in indoor environments has important health implications but is not well understood. The goal of this manuscript is to consolidate what is known about how carpet impacts indoor chemistry and microbiology, as well as to identify the important research gaps that remain. After describing the current use of carpet indoors, questions focus on five specific areas: 1) indoor chemistry, 2) indoor microbiology, 3) resuspension and exposure, 4) current practices and future needs, and 5) sustainability. Overall, it is clear that carpet can influence our exposures to particles and volatile compounds in the indoor environment by acting as a direct source, as a reservoir of environmental contaminants, and as a surface supporting chemical and biological transformations. However, the health implications of these processes are not well known, nor how cleaning practices could be optimized to minimize potential negative impacts. Current standards and recommendations focus largely on carpets as a primary source of chemicals and on limiting moisture that would support microbial growth. Future research should consider enhancing knowledge related to the impact of carpet in the indoor environment and how we might improve the design and maintenance of this common material to reduce our exposure to harmful contaminants while retaining the benefits to consumers.

Occupational Safety and Health and Healthy Housing: A Review of Opportunities and Challenges.

PURPOSE: Occupational safety and health (OSH) risks in construction of healthy housing (HH) have not been examined and collaboration between HH and OSH professionals is inadequate. The World Health Organization is developing international HH guidelines and the International Labour Organization is working to improve OSH in construction globally. METHODS: We searched for exemplary reports (including gray literature) on construction hazards; preventive measures for occupants and workers; OSH frameworks, laws, and regulations; definitions; and HH. RESULTS: Healthy housing construction typically improves ventilation, moisture and mold, pest control, injury hazards, cleanability, maintenance, accessibility, thermal conditioning, and avoidance of toxic building materials. To date, this work is done without explicit requirements for worker health. Construction is among the most hazardous sectors around the globe, although protective measures are well known, including engineering and administrative controls and provision of personal protective equipment. Residential construction, renovation, repair, and maintenance are fragmented, consisting mostly of small companies without proper OSH training, equipment, and knowledge of HH principles. Residential construction is often undertaken by informal or unauthorized workers, putting them at high risk. Reduced exposure to toxic building materials is an example of a benefit for both workers and occupants if OSH and HH collaboration can be improved. By recognizing that homes under new construction or renovation are both a workplace and a residence, HH and OSH initiatives can apply public health principles to occupants and workers simultaneously. This article publishes key definitions, hazards and interventions common to both fields. CONCLUSIONS: A global increase in residential construction and renewed global interest in HH poses both risks and opportunities for primary prevention. Policy and practice interventions can benefit the health of occupants and those who work on their homes. Improvements in legislation, regulation, and international frameworks are needed to maximize OSH and HH collaboration and realize significant cobenefits. Occupational safety and health and HH standards should include requirements to protect both workers and occupants. Because homes can also be workplaces, both workers and housing occupants will receive important cobenefits when OSH and HH standards use proven interventions to protect workers and occupants.

A Cost-Benefit Analysis of a State-Funded Healthy Homes Program for Residents With Asthma: Findings From the New York State Healthy Neighborhoods Program.

CONTEXT: Despite considerable evidence that the economic and other benefits of asthma home visits far exceed their cost, few health care payers reimburse or provide coverage for these services. OBJECTIVE: To evaluate the cost and savings of the asthma intervention of a state-funded healthy homes program. DESIGN: Pre- versus postintervention comparisons of asthma outcomes for visits conducted during 2008-2012. SETTING: The New York State Healthy Neighborhoods Program operates in select communities with a higher burden of housing-related illness and associated risk factors. PARTICIPANTS: One thousand households with 550 children and 731 adults with active asthma; 791 households with 448 children and 551 adults with asthma events in the previous year. INTERVENTION: The program provides home environmental assessments and low-cost interventions to address asthma trigger-promoting conditions and asthma self-management. Conditions are reassessed 3 to 6 months after the initial visit. MAIN OUTCOME MEASURES: Program costs and estimated benefits from changes in asthma medication use, visits to the doctor for asthma, emergency department visits, and hospitalizations over a 12-month follow-up period. RESULTS: For the asthma event group, the per person savings for all medical encounters and medications filled was $1083 per in-home asthma visit, and the average cost of the visit was $302, for a benefit to program cost ratio of 3.58 and net benefit of $781 per asthma visit. For the active asthma group, per person savings was $613 per asthma visit, with a benefit to program cost ratio of 2.03 and net benefit of $311. CONCLUSION: Low-intensity, home-based, environmental interventions for people with asthma decrease the cost of health care utilization. Greater reductions are realized when services are targeted toward people with more poorly controlled asthma. While low-intensity approaches may produce more modest benefits, they may also be more feasible to implement on a large scale. Health care payers, and public payers in particular, should consider expanding coverage, at least for patients with poorly controlled asthma or who may be at risk for poor asthma control, to include services that address triggers in the home environment.

Replacing Windows Reduces Childhood Lead Exposure: Results From a State-Funded Program.

CONTEXT: Despite considerable evidence that window replacement reduces childhood lead exposure and improves energy conservation and market value, federal policies in childhood lead poisoning, home improvement, and weatherization programs all tend to discourage it. OBJECTIVE AND INTERVENTION: To evaluate a state bond-financed pilot program that replaced old lead-contaminated windows with new lead-free energy efficient ones. DESIGN AND SETTING: Pre-/post evaluation in 1 urban and 1 rural jurisdiction. PARTICIPANTS: Low-income households (n = 96). MAIN OUTCOME MEASURES: Dust wipe sampling, visual assessment, and physical and mental self-reported health at baseline and 1 year. RESULTS: Geometric mean lead dust (PbD) from baseline to 1 year for interior floors, interior sills, and exterior troughs declined by 44%, 88%, and 98%, respectively (P < .001); 1 year later, levels remained well below baseline but rose slightly compared with clearance sampling just after intervention. PbD declined significantly on both sills and troughs in both the urban and rural jurisdictions from baseline to 1 year. On interior floors, PbD significantly declined by 58% (P = .003) in the rural area and 25% (P = .38) in the urban area, where the decline did not reach statistical significance. Households reported improvements in uncomfortable indoor temperatures (P < .001) and certain health outcomes. Economic benefits were estimated at $5 912 219 compared with a cost of $3 451 841, resulting in a net monetary benefit of $2 460 378. Residents reported that they were "very satisfied" with the window replacement work (87%). CONCLUSION: Local and state governments should fund and operate window replacement programs to eliminate a major source of childhood lead exposure, improve energy bills, increase home market value, and create local construction and industrial jobs. Federal agencies should encourage (not discourage) replacement of old windows contaminated with lead. In budget climates such as Illinois with reduced public expenditures, making wise investments such as lead-safe window replacement is more important than ever.

An investigation into porch dust lead levels.

Lead in porch dust can expose children through direct contact or track-in to the home, but has not been adequately evaluated. At homes undergoing lead hazard control in Rochester, NY, we sampled settled dust lead on exterior porch floors at baseline, immediately post-lead hazard control and one-year post-work (n=79 homes with complete data) via wipe sampling and collected housing, neighborhood and soil data. Baseline GM porch floor dust lead loading (PbPD) was 68 µg/ft(2), almost four times more than baseline GM interior floor dust lead (18 µg/ft(2)). Immediate post-work PbPD declined 55% after porch floor replacement and 53% after porch floor paint stabilization (p=0.009 and p=0.041, respectively). When no porch floor work was conducted but lead hazard control was conducted elsewhere, immediate post-work PbPD increased 97% (p=0.008). At one-year, GM PbPD continued to decline for porch replacement (77% below baseline) and paint stabilization (72% below baseline), but where no porch floor work was done, GM PbPD was not significantly different than baseline (p<0.001, p=0.028 and p=0.504, respectively). Modeling determined that porch floor replacement had significantly lower one-year PbPD than stabilization when baseline PbPD levels were higher than 148 µg/ft(2) (the 77th percentile) but not at lower levels. Treatment of porches with lead paint results in substantial declines in PbPD levels. It is of concern that PbPD levels increased significantly at immediate post-work when lead hazard control was not conducted on the porch but was conducted elsewhere. Standards for porch lead dust should be adopted to protect children from inadequate clean-up after lead hazard control.

Self-reported health outcomes associated with green-renovated public housing among primarily elderly residents.

OBJECTIVES: Assess the benefits of green renovation on self-reported health of primarily elderly residents of a low-income public housing apartment building. DESIGN AND SETTING: Using questions from the Medicare Health Outcomes Survey, we interviewed residents at baseline and 1 year after green renovation of their 101-unit building in Mankato, Minnesota, comparing self-reported mental and physical health outcomes of 2 sets of residents (all-ages: median, 66 years, n = 40; elder: median, 72 years, n = 22) with outcomes for 2 same-aged low-income Minnesota comparison groups taken from Medicare Health Outcomes Survey participants (n = 40 and 572, respectively). STUDY GROUP: Mankato apartment building residents. INTERVENTIONS: Green renovation including building envelope restoration; new heating, electrical, and ventilation systems; air sealing; new insulation and exterior cladding; window replacement; Energy-Star fixtures and appliances; asbestos and mold abatement; apartment gut retrofits; low volatile organic chemical and moisture-resistant materials; exercise enhancements; and indoor no-smoking policy. MAIN OUTCOME MEASURES: Self-reported health status including Activities of Daily Living and Veteran's Rand 12 (VR-12) survey results; housing condition visual assessment; indoor environmental sampling; and building performance testing. RESULTS: The all-ages study group's mental health improved significantly more than the comparison group's mental health on the basis of mean number of good mental health days in the past month (P = .026) and mean VR-12 mental component score (P = .023). Sixteen percent fewer all-ages study group people versus 8% more comparison group people reported falls (P = .055). The elder study group's 9% improvement in general physical health was not statistically significantly better than the elder comparison group's decline (6%) (P = 0.094). Significantly fewer people in the all-ages group reported smoke in their apartments because of tobacco products (20% vs 0%, P = .005), likely reflecting the new no-smoking policy. CONCLUSIONS: Green healthy housing renovation may result in improved mental and general physical health, prevented falls, and reduced exposure to tobacco smoke.

Moving into green healthy housing.

BACKGROUND: Green building systems have proliferated but health outcomes and associated costs and benefits remain poorly understood. OBJECTIVE: To compare health before and after families moved into new green healthy housing with a control group in traditionally repaired housing. DESIGN AND SETTING: Mixed methods study in 3 Chicago housing developments. PARTICIPANTS: Public housing and low-income subsidized households (n = 325 apartments with 803 individuals). MAIN OUTCOME MEASURES: Self-reported health status, visual assessment of housing condition, indoor air sampling, and Medicaid expenditure and diagnostic data. Medicaid expenditures and International Classification of Diseases, Ninth Revision codes were modeled using a generalized linear model with γ distribution and log-link. RESULTS: Housing conditions and self-reported physical and mental health improved significantly in the green healthy housing study group compared with both the control group and the dilapidated public housing from which the residents moved, as did hay fever, headaches, sinusitis, angina, and respiratory allergy. Asthma severity measured by self-reported lost school/work days, disturbed sleep, and symptoms improved significantly, as did sadness, nervousness, restlessness, and child behavior. Medicaid data in this exploratory study were inconclusive and inconsistent with self-reported health outcomes and visual assessment data on housing quality but hold promise for future investigation. Possible sources of bias in the Medicaid data include older age in the study group, changes in Medicaid eligibility over time, controlling for Medicaid costs in an urban area, and the increased stress associated with moving, even if the move is into better housing. CONCLUSION: The mixed method approach employed here describes the complex relationships among self-reported health, housing conditions, environmental measures, and clinical data. Housing conditions and self-reported physical and mental health improved in green healthy housing. Health care cost savings in Medicaid due to improved housing could not be quantified here but hold promise for future investigations with larger cohorts over a longer follow-up period.

Effect of weatherization combined with community health worker in-home education on asthma control.

OBJECTIVES: We assessed the benefits of adding weatherization-plus-health interventions to an in-home, community health worker (CHW) education program on asthma control. METHODS: We used a quasi-experimental design to compare study group homes (n = 34) receiving CHW education and weatherization-plus-health structural interventions with historical comparison group homes (n = 68) receiving only education. Data were collected in King County, Washington, from October 2009 to September 2010. RESULTS: Over the 1-year study period, the percentage of study group children with not-well-controlled or very poorly controlled asthma decreased more than the comparison group percentage (100% to 28.8% vs 100% to 51.6%; P = .04). Study group caregiver quality-of-life improvements exceeded comparison group improvements (P = .002) by 0.7 units, a clinically important difference. The decrease in study home asthma triggers (evidence of mold, water damage, pests, smoking) was marginally greater than the comparison group decrease (P = .089). Except for mouse allergen, the percentage of study group allergen floor dust samples at or above the detection limit decreased, although most reductions were not statistically significant. CONCLUSIONS: Combining weatherization and healthy home interventions (e.g., improved ventilation, moisture and mold reduction, carpet replacement, and plumbing repairs) with CHW asthma education significantly improves childhood asthma control.

Health and housing outcomes from green renovation of low-income housing in Washington, DC.

Green building systems have proliferated recently, but studies are limited of associated health and housing outcomes. The authors measured self-reported resident physical and mental health, allergens, and building conditions at baseline and one-year follow-up in a low-income housing development being renovated in accordance with green healthy housing improvements (Enterprise Green Communities standards and Leadership in Energy & Environmental Design [LEED] gold certification). Self-reported general health in adults significantly improved from 59% to 67% (p = .026), with large statistically significant improvements in water/ dampness problems, cockroaches and rodents, and reduced pesticide use. Median cockroach (Bla g1) and mouse (Mus m1) allergen dust loadings showed large and statistically significant reductions from baseline to three months postintervention and were sustained at one year (both p < .05). Energy and water cost savings were 16% and 54%, respectively. Incorporating Enterprise Green Communities and LEED standards in low-income housing renovation improves health and housing conditions and can help to reduce disparities. All green housing standards should include health-related requirements.

Repeated home drinking water sampling to improve detection of particulate lead spikes: a simulation study.

BACKGROUND: Lead can be present in drinking water in soluble and particulate forms. The intermittent release of lead particulates in drinking water can produce highly variable water lead levels (WLLs) in individual homes, a health concern because both particulate and soluble lead are bioavailable. More frequent water sampling would increase the likelihood of identifying sporadic lead "spikes," though little information is available to aid in estimating how many samples are needed to achieve a given degree of sensitivity to spike detection. OBJECTIVE: To estimate the number of rounds of tap water sampling needed to determine with a given level of confidence that an individual household is at low risk for the intermittent release of lead particulates. METHODS: We simulated WLLs for 100,000 homes on 15 rounds of sampling under a variety of assumptions about lead spike release. A Markovian structure was used to describe WLLs for individual homes on subsequent rounds of sampling given a set of transitional probabilities, in which homes with higher WLLs at baseline were more likely to exhibit a spike on repeated sampling. RESULTS: Assuming 2% of homes had a spike on the first round of sampling and a mid-range estimate of transitional probabilities, the initial round of sampling had a 6.4% sensitivity to detect a spike. Seven rounds of sampling would be needed to increase the sensitivity to 50%, which would leave unrecognized the more than 15,000 homes that intermittently exhibit spikes. SIGNIFICANCE: For assessing household risk for lead exposure through drinking water, multiple rounds of water sampling are needed to detect the infrequent but high spikes in WLLs due to particulate release. Water sampling procedures for assessment of lead exposure in individual homes should be modified to account for the infrequent but high spikes in WLL. IMPACT: It has been known for decades that intermittent "spikes" in water lead occur due to the sporadic release of lead particulates. However, conventional water sampling strategies do not account for these infrequent but hazardous events. This research suggests that current approaches to sampling tap water for lead testing identify only a small fraction of homes in which particulate spikes occur, and that sampling procedures should be changed substantially to increase the probability of identifying the hazard of particulate lead release into drinking water.