Quantifying lead-attributable cardiovascular disease burden in the United States.

Lead exposure has been linked to a myriad of cardiovascular diseases. Utilizing data from the 2019 Global Burden of Disease Study, we quantified age-standardized lead exposure-related mortality and disability-adjusted life years (DALYs) in the United States between 1990 and 2019. Our analysis revealed a substantial reduction in age-standardized cardiovascular disease (CVD) mortality attributable to lead exposure by 60 % (from 7.4 to 2.9 per 100,000), along with a concurrent decrease in age-standardized CVD DALYs by 66 % (from 143.2 to 48.7 per 100,000).

Improving Equitability and Inclusion for Testing and Detection of Lead Poisoning in US Children.

Policy Points Child lead poisoning is associated with socioeconomic inequity and perpetuates health inequality. Methods for testing and detection of child lead poisoning are ill suited to the current demographics and characteristics of the problem. A three-pronged revision of current testing approaches is suggested. Employing the suggested revisions can immediately increase our national capacity for equitable, inclusive testing and detection. ABSTRACT: Child lead poisoning, the longest-standing child public health epidemic in US history, is associated with socioeconomic inequity and perpetuates health inequality. Removing lead from children's environments ("primary prevention") is and must remain the definitive solution for ending child lead poisoning. Until that goal can be realized, protecting children's health necessarily depends on the adequacy of our methods for testing and detection. Current methods for testing and detection, however, are no longer suited to the demographics and magnitude of the problem. We discuss the potential deployment and feasibility of a three-pronged revision of current practices including: 1) acceptance of capillary samples for final determination of lead poisoning, with electronic documentation of "clean" collection methods submitted by workers who complete simple Centers for Disease Control and Prevention-endorsed online training and certification for capillary sample collection; 2) new guidance specifying the analysis of capillary samples by inductively coupled plasma mass spectrometry or graphite furnace atomic absorption spectrometry with documented limit of detection ≤0.2 µg/dL; and 3) adaptive "census tract-specific" universal testing and monitoring guidance for children from birth to 10 years of age. These testing modifications can bring child blood lead level (BLL) testing into homes and communities, immediately increasing our national capacity for inclusive and equitable detection and monitoring of dangerous lower-range BLLs in US children.

Lead Poisoning Prevention Efforts in High-Risk Environments: Follow-up Testing Rates among Preschool Children in Flint, Michigan, 2013-2015.

OBJECTIVES: Despite the importance of screening in efforts to address lead poisoning, many children in the United States have never been tested for lead, even when required to receive blood lead testing by state and federal healthcare policy. Fewer children gain access to follow-up or confirmatory testing when elevated blood lead levels are detected. METHODS: In response to previous research that illustrates the extent to which follow-up treatment services have been underutilized and poorly coordinated, this retrospective cohort study examines follow-up testing trends for lead poisoning among Medicaid-enrolled children 6 years and younger in Flint, Michigan, between 2013 and 2015. RESULTS: These findings illustrate that compliance with follow-up testing procedures was less than adequate during the period of study. CONCLUSION: As illustrated in this bivariate analysis, subpopulations in Flint most likely to have lead poisoning were least likely to receive follow-up testing. Evidence also demonstrates that the likelihood that children with lead poisoning received follow-up testing was overwhelmingly associated with their blood lead concentration level than other indicators including socioeconomic status in this high-risk environment.

Validation of a Machine Learning Model to Predict Childhood Lead Poisoning.

Importance: Childhood lead poisoning causes irreversible neurobehavioral deficits, but current practice is secondary prevention. Objective: To validate a machine learning (random forest) prediction model of elevated blood lead levels (EBLLs) by comparison with a parsimonious logistic regression. Design, Setting, and Participants: This prognostic study for temporal validation of multivariable prediction models used data from the Women, Infants, and Children (WIC) program of the Chicago Department of Public Health. Participants included a development cohort of children born from January 1, 2007, to December 31, 2012, and a validation WIC cohort born from January 1 to December 31, 2013. Blood lead levels were measured until December 31, 2018. Data were analyzed from January 1 to October 31, 2019. Exposures: Blood lead level test results; lead investigation findings; housing characteristics, permits, and violations; and demographic variables. Main Outcomes and Measures: Incident EBLL (≥6 µg/dL). Models were assessed using the area under the receiver operating characteristic curve (AUC) and confusion matrix metrics (positive predictive value, sensitivity, and specificity) at various thresholds. Results: Among 6812 children in the WIC validation cohort, 3451 (50.7%) were female, 3057 (44.9%) were Hispanic, 2804 (41.2%) were non-Hispanic Black, 458 (6.7%) were non-Hispanic White, and 442 (6.5%) were Asian (mean [SD] age, 5.5 [0.3] years). The median year of housing construction was 1919 (interquartile range, 1903-1948). Random forest AUC was 0.69 compared with 0.64 for logistic regression (difference, 0.05; 95% CI, 0.02-0.08). When predicting the 5% of children at highest risk to have EBLLs, random forest and logistic regression models had positive predictive values of 15.5% and 7.8%, respectively (difference, 7.7%; 95% CI, 3.7%-11.3%), sensitivity of 16.2% and 8.1%, respectively (difference, 8.1%; 95% CI, 3.9%-11.7%), and specificity of 95.5% and 95.1% (difference, 0.4%; 95% CI, 0.0%-0.7%). Conclusions and Relevance: The machine learning model outperformed regression in predicting childhood lead poisoning, especially in identifying children at highest risk. Such a model could be used to target the allocation of lead poisoning prevention resources to these children.

Assessment of Bone Turnover Biomarkers in Lead-Battery Workers with Long-Term Exposure to Lead.

BACKGROUND: The major portion of lead in the body resides in skeletal system. The bone turnover affects the release of lead into the circulation from bones. The bone turnover biomarkers (BTM) in lead-battery workers with long-term exposure to lead have not been explored yet. OBJECTIVE: To evaluate the BTM (formation and resorption) in lead-battery workers with long-term exposure to lead in lead-battery manufacturing plant. METHODS: 176 male lead-exposed workers and 80 matched comparison group were studied. All participants were examined for blood lead levels (BLLs), bone formation biomarkers- serum osteocalcin (OC), alkaline phosphatase (ALP), bone-specific alkaline phosphatase (BALP)-and bone resorption biomarkers-serum pyridinoline (PYD), deoxypyridinoline (DPYD), tartarate-resistant acid phosphatase-5b (TRACP-5b), and urinary hydroxyproline (UHYP). RESULTS: We found a significantly higher bone formation biomarkers such as BALP (p=0.007) and bone resorption biomarkers, eg, PYD (p=0.048), TRCAP-5b (p=0.001), and UHYP (p=0.001) in lead-exposed workers. A significant (p=0.041) negative correlation (ρ ­0.128) was noted between BLLs and OC. A significant positive correlation was noted between BLLs and TRACP-5b (ρ 0.176, p=0.005) and UHYP (ρ 0.258, p=0.004). Serum OC (p=0.040) and UHYP (p=0.015) levels changed significantly with BLL level. Bone resorption biomarkers levels- PYD, TRACP-5b, and BALP-were higher among those with higher BLLs levels. The duration of exposure was significantly associated with BALP (p=0.037), DPYD (p=0.016), TRACP-5b (p=0.001), and UHYP (p=0.002) levels. CONCLUSION: Long-term lead exposure affects the bone turnover.

Assessment of Child Lead Exposure in a Philadelphia Community, 2014.

INTRODUCTION: Several urban neighborhoods in Philadelphia, Pennsylvania, have a history of soil, household lead paint, and potential lead-emitting industry contamination. OBJECTIVES: To (1) describe blood lead levels (BLLs) in target neighborhoods, (2) identify risk factors and sources of lead exposure, (3) describe household environmental lead levels, and (4) compare results with existing data. METHODS: A simple, random, cross-sectional sampling strategy was used to enroll children 8 years or younger living in selected Philadelphia neighborhoods with a history of lead-emitting industry during July 2014. Geometric mean of child BLLs and prevalence of BLLs of 5 µg/dL or more were calculated. Linear and logistic regression analyses were used to ascertain risk factors for elevated BLLs. RESULTS: Among 104 children tested for blood lead, 13 (12.4%; 95% confidence interval [CI], 7.5-20.2) had BLLs of 5 µg/dL or more. The geometric mean BLL was 2.0 µg/dL (95% CI, 1.7-2.3 µg/dL). Higher geometric mean BLLs were significantly associated with front door entryway dust lead content, residence built prior to 1900, and a child currently or ever receiving Medicaid. Seventy-one percent of households exceeded the screening level for soil, 25% had an elevated front door floor dust lead level, 28% had an elevated child play area floor dust lead level, and 14% had an elevated interior window dust lead level. Children in households with 2 to 3 elevated environmental lead samples were more likely to have BLLs of 5 µg/dL or more. A spatial relationship between household proximity to historic lead-emitting facilities and child BLL was not identified. CONCLUSION: Entryway floor dust lead levels were strongly associated with blood lead levels in participants. Results underscore the importance to make housing lead safe by addressing all lead hazards in and around the home. Reduction of child lead exposure is crucial, and continued blood lead surveillance, testing, and inspection of homes of children with BLLs of 5 µg/dL or more to identify and control lead sources are recommended. Pediatric health care providers can be especially vigilant screening Medicaid-eligible/enrolled children and children living in very old housing.

Using Medicaid Data to Improve Childhood Lead Poisoning Prevention Program Outcomes and Blood Lead Surveillance.

CONTEXT: Wisconsin-specific data revealed that not all Medicaid providers were testing children appropriately for blood lead levels and not all blood lead tests were reported to the Department of Health Services, Childhood Lead Poisoning Prevention Program. The Medicaid program requires blood lead screening for all Medicaid-enrolled children at specific ages. Wisconsin state law requires reporting of all blood lead test results. Projects were implemented to encourage appropriate testing for Medicaid-enrolled children and improve blood lead surveillance. METHODS: Medicaid billing data were linked to blood lead data to identify Medicaid-enrolled children who had not received the required tests. Medicaid provider report cards were distributed annually from 2006 to 2011 to inform providers of their compliance with federal testing requirements and of the names of children within their practice who had not been tested. Blood lead tests billed to Medicaid but not in the blood lead database were identified and billing providers were contacted to obtain the test report. RESULTS: The number of children tested increased from 81 834 children per year in 2006 to 106 003 children per year in 2010. Testing of Medicaid-enrolled children increased by 31% from 2006 to 2010. The percentage of Medicaid-enrolled children receiving an age-appropriate test increased from 46% in 2004 to a high of 55% in 2010. There were 9035 blood lead tests identified in the Medicaid billing data that had not been reported from 2007 to 2015. There were 468 billing providers who had unreported tests. All sites with unreported tests were contacted, 84% of test results were obtained, and 14% of test records could not be retrieved. Outpatient clinics accounted for the majority of all unreported tests (72%) and irretrievable test records (74%). DISCUSSION: Childhood lead poisoning prevention programs can effectively utilize Medicaid data to increase testing and improve blood lead surveillance. Primary health care providers should ensure that Medicaid-enrolled children in their care receive the age-appropriate tests. Many Wisconsin health care providers lack awareness of blood lead test reporting requirements. Outpatient clinics account for the largest proportion of unreported tests and highest priority should be given working with these sites to improve reporting practices.

Childhood Lead Poisoning: A Perpetual Environmental Justice Issue?

As the amount of lead in the environment has significantly decreased with the removal of lead in gasoline and paint, the United States has made great strides in preventing lead poisoning or reducing levels of lead in young children's blood. Even so, lead exposure is not equal for all children-low-income and minority children continue to bear a disproportionate burden of exposure primarily through contact with deteriorating lead-based paint from older housing and potentially through drinking contaminated water resulting from failing leaded pipes, as evidenced by the recent events in Flint, Michigan. These facts suggest that childhood lead poisoning is an environmental justice issue worthy of public health consideration and action; "environmental justice" is focused on identifying and addressing disproportionately high and adverse effects of environmental hazards on low-income and minority communities. The question remains, however, as to whether addressing the quality-of-life "risk" factors associated with lead poisoning might eventually lead to reduction in exposure, as well as potentially resulting in adverse health effects. Utilizing an environmental justice framework and examining this issue through a multidimensional environmental justice lens, we contemplated the quality-of-life factors that may essentially predispose minority children and their families to lead poisoning. Specifically, we examined American Community Survey data (2012-2016) focused on comparing race/ethnicity with other sociodemographic variables known to be associated with risks for childhood lead poisoning. The results provide thought-provoking context for making progress toward eliminating lead poisoning as a major environmental justice concern.

Comprehensive Electrocardiographic Analysis of Lead Exposed Workers: An Arrhythmic Risk Assessment Study.

BACKGROUND: To evaluate electrocardiographic parameters which are related with atrial and ventricular arrhythmias measured from 12-lead surface electrocardiogram (ECG) in workers occupationally exposed to lead. METHODS: Sixty lead-exposed workers and 60 healthy controls were enrolled. Twelve-lead surface ECG was recorded and measurements of P wave durations (Pmax, Pmin) and P wave dispersion (PWD), QT durations and dispersion (QTd), corrected QT (QTc), Tp-e interval, and Tp-e/QT ratio were analyzed. RESULTS: The lead-exposed and control groups were similar with respect to baseline demographic, laboratory, and transthoracic echocardiographic indices. PWD (26.3 ± 9.7 vs 22.0 ± 9.0 ms, P = 0.014), Pmin (89.9 ± 13.8 vs 79.2 ± 10.1 ms, P < 0.001), and Pmax (116.2 ± 15.0 vs 101.2 ± 14.2 ms, P < 0.001), QT maximum (377.0 ± 27.6 vs 364.9 ± 28.5 ms, P = 0.02), QTd (38.4 ± 16.5 vs 30.5 ± 12.4 ms, P = 0.004), Tp-e interval (78.9 ± 16.5 vs 70.3 ± 14.5 ms, P = 0.003), and Tp-e/QT ratio (0.22 ± 0.04 vs 0.20 ± 0.04, P = 0.013) were significantly higher in lead-exposed workers. QT minimum and QTc values did not differ significantly. QT maximum, QTd, and Tp-e/QT ratio were correlated with urine lead level and Tp-e interval was correlated with both blood and urine lead levels. CONCLUSIONS: Lead-exposed workers have a higher risk for atrial and ventricular arrhythmias even without overt cardiac diseases compared with healthy subjects. These workers should be followed closely for adverse cardiovascular outcomes especially arrhythmias.

Reliability of a decision-tree model in predicting occupational lead poisoning in a group of highly exposed workers.

OBJECTIVE: This study aimed to provide the toxicological profile of some lead-exposed workers and obtain a predictive model for lead poisoning. METHODS: Data regarding external and absorbed exposure were collected from 585 subjects employed in ten metallurgical production departments. Airborne lead concentration, blood lead level (BLL), cumulative blood lead index (CBLI), urine delta-aminolevulinic acid (DALA), age, workplace/section, exposure period, and whether reported lead poisoning as occupational disease were examined using ANOVA, and, post-ANOVA, Pearson correlation matrix, PCA (principal component analysis), decision-tree modeling, and logistic modeling. RESULTS: BLL was less sensitive than CBLI in predicting poisoning. Decision-tree modeling highlighted the importance of CBLI ≥1,041 µg.years/dl and air lead concentration ≥0.3 mg/m(3) in the occurrence of occupational poisoning. Age ≥48 years and DALA ≥19.3 mg/L were also factors. CONCLUSIONS: Workers were at risk of poisoning as a result of their long term unacceptable exposure. Decision-tree modeling is potentially useful for risk management. Am. J. Ind. Med. 59:575-582, 2016. © 2016 Wiley Periodicals, Inc.

Validation and Assessment of Pediatric Lead Screener Questions for Primary Prevention of Lead Exposure.

OBJECTIVE: Pediatric lead screener questions have previously been evaluated for their ability to identify children whose blood lead levels (BLLs) are greater than 10 µg/dL. Based on recent policy changes stressing that there is no safe BLL for children, the current study reevaluates the screener questions for their ability to identify children with BLLs less than 2 µg/dL and the validity of the questions in positively identifying those at greater risk for exposure. METHOD: A total of 202 parents of children enrolled in Head Start programs were administered the pediatric lead screener, questions to validate the screener questions, and children's BLLs were collected in Summer 2013. Pediatric screener questions were validated against children's BLL and the more comprehensive questions on lead risk. RESULTS: In predicting BLL greater than 2 µg/dL, the pediatrician screener tool had a sensitivity of 26.3% and specificity of 72.2%. Each of the screener questions had low sensitivities for identifying children with BLLs above 2 µg/dL. The screener questions did not demonstrate adequate validity when compared against a more comprehensive battery of lead exposure risk indicators. The validation questions improved sensitivity to detect children with BLL >2 µg/dL and reduced the number of false positives. CONCLUSION: The pediatrician screener questions in their current format are not a useful primary prevention tool in identifying children at greater risk for lead exposure and in need of secondary prevention through the receipt of a blood lead test. A revision to the protocol for identifying children at risk could result in better primary and secondary prevention efforts.

Interlaboratory comparison study on lead in blood, in external quality assessment schemes since 1996: a progress report.

In 1992, at the request of the French labor ministry, an External Quality Control for lead in whole blood (F-EQCPbB) came into being. After 15 years (1996-2011), the ministry wished to exploit the database collected with a sufficient number of laboratories. Indeed, the number of participating laboratories had decreased from 73 to 41. However, the key finding pertained to the highly improved performance of the laboratories, which was associated with a spread of the results over the entire range of tested PbB (9 and 700 µg/l). So, it was that in laboratories having participated for >10 years, the good scores rose between 1996 and 2011 from 49% to 93%. To sum up, analysis has shown progressive and highly pronounced diminution of CVs (%) for all the ranges having undergone testing. We have observed increasing use of inductively coupled plasma with mass spectrometry (from 9% in 2005 to 29% in 2011) and decreasing use of electrothermal atomic absorption spectrometry. That said, and provided that they are based on the same degree of expertise in metrology, on all tested concentrations the two analytical techniques yield results that are not statistically different. Thanks to the F-EQCPbB, laboratories have enhanced their proficiency and registered demonstrably improved performance.

[The external quality assessment schemes for lead in blood organized by the French national agency for medicine and health product safety: a synthesis of 15 years of activity]. / L'évaluation externe de la qualité des analyses de plombémie organisée par l'Agence nationale de sécurité du médicament et des produits de santé : bilan de 15 années de contrôle.

In 1992, at the request of the French labor ministry following questions on the ability of medical biology laboratories to satisfactorily measure blood lead level (PbB), a national PbB quality control came into being. Only in 1996 did this external quality control include a number of laboratories sufficient to allow for a significant retrospective evaluation. After fifteen years (1996-2011), The French National Agency for Medicines and Health Products Safety wished to exploit the database collected. The number of participating laboratories went down from 73 to 41. On the other hand, the key finding pertained to the highly improved performance of the laboratories, which was associated with a spread decrease of the results over the entire range of tested PbBs (9 to 700 µg/L). Since 2006, we have observed increasing use of the inductively coupled plasma with mass spectrometry and decreasing use of electrothermal atomic absorption spectrometry. Provided that they rely on identical metrology expertise, the two analytical techniques lead to results on all the tested concentrations that are not statistically different.

Yield and cost of performing screening tests for constipation in children.

BACKGROUND: Chronic constipation is one of the most common reasons for pediatric outpatient visits. Clinical guidelines recommend that the work-up for chronic refractory constipation include thyroid function tests, celiac serology, and measurement of calcium and lead levels. Data to justify routine screening of constipated children using these laboratory tests are lacking. OBJECTIVES: To study the prevalence of celiac disease, hypothyroidism, hypercalcemia and lead poisoning in children with chronic constipation; and to estimate the health care costs of applying the guideline recommendations. METHOD: Charts of constipated children from 2007 to 2011 were reviewed for the present retrospective cohort study. Results and costs of thyroid function tests, celiac panel, total immunoglobulin (Ig) A, and determination of lead and calcium levels were analyzed. RESULTS: A total of 7472 children (mean age 7.9 years; 3908 female) were evaluated: 1731 patients were screened for celiac antibodies; 55 had elevated tissue transglutaminase IgA levels and 29 had biopsy-positive celiac disease. Only three celiac patients had constipation as the sole presenting symptom; 1703 patients were screened for total IgA levels; 55 had IgA deficiency and two had biopsy-positive celiac disease; 2332 had free T4 and/or thyroid-stimulating hormone levels; and 14 had hypothyroidism. Only two patients had constipation as the sole presenting symptom; 4651 patients had calcium levels measured, 10 of whom had high levels but normal repeat values. Three patients had normal lead levels. The mean cost per patient was USD$1,014. Total screening cost for all patients was USD$4.7 million. CONCLUSION: Constipation alone did not increase the likelihood of celiac disease or hypothyroidism above the population prevalence. No benefit of screening for hypercalcemia was found. High health care costs were associated with the use of screening tests for organic constipation.

Implications of the new lead screening recommendations in North Carolina.

In June of 2012, the Centers for Disease Control and Prevention updated their recommendations regarding the prevention of childhood lead poisoning. This commentary provides an overview of the new recommendations for blood lead screening and follow up.

The predictive value of self-report questions in a clinical decision rule for pediatric lead poisoning screening.

OBJECTIVE: We derived a clinical decision rule for determining which young children need testing for lead poisoning. We developed an equation that combines lead exposure self-report questions with the child's census-block housing and socioeconomic characteristics, personal demographic characteristics, and Medicaid status. This equation better predicts elevated blood lead level (EBLL) than one using ZIP code and Medicaid status. METHODS: A survey regarding potential lead exposure was administered from October 2001 to January 2003 to Michigan parents at pediatric clinics (n=3,396). These self-report survey data were linked to a statewide clinical registry of blood lead level (BLL) tests. Sensitivity and specificity were calculated and then used to estimate the cost-effectiveness of the equation. RESULTS: The census-block group prediction equation explained 18.1% of the variance in BLLs. Replacing block group characteristics with the self-report questions and dichotomized ZIP code risk explained only 12.6% of the variance. Adding three self-report questions to the census-block group model increased the variance explained to 19.9% and increased specificity with no loss in sensitivity in detecting EBLLs of ≥ 10 micrograms per deciliter. CONCLUSIONS: Relying solely on self-reports of lead exposure predicted BLL less effectively than the block group model. However, adding three of 13 self-report questions to our clinical decision rule significantly improved prediction of which children require a BLL test. Using the equation as the clinical decision rule would annually eliminate more than 7,200 unnecessary tests in Michigan and save more than $220,000.

The important health impact of where a child lives: neighborhood characteristics and the burden of lead poisoning.

Toxins and other health threats can cause health problems, whether they are present in the child's own home, other neighborhood homes where the child spends time, or common areas such as playgrounds. We assess the impact of where a child lives on the burden of lead poisoning. Statewide lead screening data was obtained from the Rhode Island Department of Health. Block group level indicators of old housing and poverty were obtained from the US Census. Of the 204,746 study children, 35,416 (17.3%) had a blood lead level≥10 µg/dL. The proportion of study children who were lead poisoned in each block group ranged from 0.0 to 48.6%. The proportion of study children with an elevated blood lead level increased from 8% among children living in block groups in the lowest quintile of poverty to 31% for those in the highest quintile for poverty. Old housing also had an important impact on the risk of lead poisoning. The proportion of children with an elevated blood lead level increased from 7% among children living in block groups in the lowest quintile for pre-1950 housing to 27% for those in the highest quintile for pre-1950 housing. The adjusted odds ratio was 1.64 for the highest quintile of poverty and 1.77 for the highest quintile of pre-1950 housing. The findings of this large, statewide study demonstrate the powerful impact of where children live on the risk of lead poisoning. The findings have important implications for understanding the problem of lead poisoning and for planning primary prevention programs.