Household interventions for preventing domestic lead exposure in children

A study protocol to evaluate the impact of a personal and domestic hygiene intervention on lead exposure in a community next to a mine dump

Background

Lead has been associated with adverse health effects, especially neurocognitive and behavioural effects, in children. Communities living close to mining land are at risk of elevated exposure to lead.

Methods

This paper outlines a before and after intervention study protocol to evaluate the impact of a personal and domestic hygiene intervention on lead exposure in a community located adjacent to a mine dump. In each participating household, parents or guardians will be interviewed using a structured questionnaire to obtain information on socio-demographic characteristics, living conditions, domestic hygiene practices and potential alternative sources of exposure to lead. A registered nurse will collect hand wipe samples from children aged one to five years, for whom parental consent and where possible child assent has been obtained. Environmental dust samples will be collected from the floors and/or windowsills of children’s dwellings for lead content analysis. Soil samples will be collected from yards to determine lead content. An educational intervention will then be applied to the intervention group, including the engagement of households or guardians in an educational discussion on the sources, pathways of exposure, health effects of lead exposure and protective measures, with the aid of a specially designed educational brochure. Data will be analysed for descriptive and inferential statistics using Stata version 16.

Discussion

The study will determine whether the intervention led to a reduction in indoor dust lead levels, and if shown to be effective, will inform the development of an awareness campaign to reduce lead exposure in communities located in close proximity to mine dumps.

Trial registration

The study is retrospectively registered on ClinicalTrials.gov Protocol Registration and Results System with registration number NCT05265572 and first release date of 18th February 2022.

Legacy Lead in Urban Garden Soils: Communicating Risk and Limiting Exposure

Lead (Pb) exposure has long been recognized as a hazard to human health. Urban garden soils often contain elevated levels of Pb, mainly from legacy sources, which is a main barrier for urban gardening. The capacity of gardeners to access, understand, and act on scientific data related to soil contamination is also variable. This synthesis paper briefly summarizes the current scientific knowledge on soil Pb in urban gardens. Our objective is to produce clear recommendations about assessing actual risks and limiting exposure. First, we synthesize the nature and extent of soil contamination with Pb, and then describe how the bioavailability and risk of this contamination to humans is assessed. We then go on to potential exposure pathway through plants and remediation methods to improve soil health and reduce human exposure. We have developed best management practices for practitioners that include: (1) urban soil testing should be prioritized because of the high probability of Pb contamination, and urban gardening should not begin until thorough testing or remediation has been done; (2) documentation of land-use history should be required in all property transactions so that the potential for soil (and other) contamination can be clearly identified; (3) amendments cannot be relied upon as a treatment for contaminated soils to reduce risk to gardeners because they do not always make contaminants less harmful; (4) certain crops (such as fruiting vegetables) are much less susceptible to contamination than others and thus should be prioritized in urban gardens; (5) wherever feasible, raised beds filled with upcycled local mineral and organic materials are the preferred substrate for urban gardening. Further monitoring of potentially contaminated and remediated soils as well as effective communication with the public are necessary to ensure human safety.

Receipt of Early Intervention Services Before Age 3 Years and Performance on Third-Grade Standardized Tests Among Children Exposed to Lead

IMPORTANCE

Research has shown that early intervention programs can improve academic outcomes of children with developmental delays. It has been suggested that similar programs may combat the deleterious effects of lead on children's neurodevelopment. However, to our knowledge, there are no published studies examining this possibility.

OBJECTIVE

The objective of this study was to estimate the association between receipt of early intervention services and third-grade standardized test scores among children exposed to lead before age 3 years.

DESIGN, SETTING, AND PARTICIPANTS

Cohort study including children born in New York City, New York, from 1994 to 1998 within an administrative data linkage of birth, lead monitoring, early intervention, and education data systems. Participants had a blood lead level of 4 μg/dL or greater at any point before age 3 years and later attended public school in New York City.

EXPOSURES

Any use of early intervention services from birth through age 3 years.

MAIN OUTCOMES AND MEASURES

Children who did or did not receive early intervention services were matched using propensity scores. Linear and log-binomial regression were used to estimate the association between receipt of early intervention services before age 3 years and standardized test scores in math and English-language arts in third grade.

RESULTS

There were 2986 children exposed to lead who received early intervention services before age 36 months. Of these children, 2757 were propensity score-matched to 8160 children who did not receive services. Children who received early intervention services did 7% (95% CI, 3%-12%) of an SD better on math and 10% (95% CI, 5%-14%) of an SD better on English-language arts tests than children who did not receive services. In addition, children who received services were 14% (95% CI, 9%-19%) and 16% (95% CI, 9%-23%) more likely to meet test-based standards in math and English-language arts, respectively, than children who did not receive services. These associations became larger in magnitude when analyses were restricted to children with higher blood lead levels.

CONCLUSIONS AND RELEVANCE

By leveraging existing public health data, this study found evidence that receipt of early intervention services may benefit the academic performance of children exposed to lead early in life.

Estimating the Effects of Soil Remediation on Children's Blood Lead near a Former Lead Smelter in Omaha, Nebraska, USA

BACKGROUND

Lead exposures from legacy sources threaten children's health. Soil in Omaha, Nebraska, was contaminated by emissions from a lead smelter and refinery. The U.S. Environmental Protection Agency excavated and replaced contaminated soil at the Omaha Lead Superfund Site between 1999 and 2016.

OBJECTIVES

The goal of this study was to assess the association of soil lead level (SLL) and soil remediation status with blood lead levels (BLLs) in children living near or on the site.

METHODS

We linked information on SLL at residential properties with children's BLLs and assigned remediation status to children's BLL measurements based on whether their measurements occurred during residence at remediated or unremediated properties. We examined the association of SLL and remediation status with elevated BLL (EBLL). We distinguished the roles of temporal trend and the intervention with time-by-intervention-status interaction contrasts. All analyses estimated odds ratios (ORs) with a generalized estimating equations approach to ensure robustness under the complex correlations among BLL measurements. All analyses controlled for relevant covariates including children's characteristics.

RESULTS

EBLL (>5μg/dL) was associated with both residential SLL [e.g., OR=2.00; 95% confidence interval (CI): 1.83, 2.19; >400-800 vs. ≤200 ppm] and neighborhood SLL [e.g., OR=1.85 (95% CI: 1.62, 2.11; >400-800 vs. ≤200 ppm)] before remediation but only with neighborhood SLL after remediation. The odds of EBLL were higher before remediation [OR 1.52 (95% CI: 1.34, 1.72)]. Similarly, EBLL was positively associated with preremediation status in our interaction analysis [interaction OR=1.18 (95%CI: 1.02, 1.37)].

DISCUSSION

Residential and neighborhood SLLs were important predictors of EBLLs in children residing near or on this Superfund site. Neighborhood SLL remained a strong predictor following remediation. Our data analyses showed the benefit of soil remediation. Results from the interaction analyses should be interpreted cautiously due to imperfect correspondence of remediation times between remediation and comparison groups. https://doi.org/10.1289/EHP8657.

Reduction in Blood Lead Concentration in Children across the Republic of Georgia following Interventions to Address Widespread Exceedance of Reference Value in 2019

In recent years, reports of lead contamination have dramatically increased in Georgia. Given concerns about the exposure of children to lead (Pb), the National Multiple Indicator Cluster Survey (MICS-2018) included a blood sampling component. The results showed that 41% of the children that participated had blood Pb levels (BLL) ≥ 5 µg/dL and that BLL in children living in Western Georgia were higher than those in Eastern regions. In response to these findings, NCDC implemented written and verbal advice to the families of children who participated in the MICS-2018 on how to reduce Pb exposure. From August 2019 onwards, the state program of clinical follow-up was implemented. The design of this study was a longitudinal study. The intervention of interest was the public health advice and medical follow-up, and the outcome was defined as the difference in BLL between the MICS-2018 survey and the state program follow-up. We observed a significant overall reduction in median BLL between MICS-2018 and state program follow-up in both August 2019 and the latest results (until December 2019). However, we did not observe any significant further reduction between August and the most recent BLL results. In the Georgian setting, written and verbal communication targeting individual households, alongside home visits to the most exposed, effectively reduced BLL in children.

Making the invisible visible: Developing and evaluating an intervention to raise awareness and reduce lead exposure among children and their caregivers in rural Bangladesh

Lead exposure is harmful at any time in life, but pre-natal and early childhood exposures are particularly detrimental to cognitive development. In Bangladesh, multiple household-level lead exposures pose risks, including turmeric adulterated with lead chromate and food storage in lead-soldered cans. We developed and evaluated an intervention to reduce lead exposure among children and their caregivers in rural Bangladesh. We conducted formative research to inform theory-based behavioral recommendations. Lead exposure was one of several topics covered in the multi-component intervention focused on early child development. Community health workers (CHWs) delivered the lead component of the intervention during group sessions with pregnant women and mother-child dyads (<15 months old) in a cluster-randomized trial. We administered household surveys at baseline (control n = 301; intervention n = 320) and 9 months later at endline (control n = 279; intervention n = 239) and calculated adjusted risk and mean differences for primary outcomes. We conducted two qualitative assessments, one after 3 months and a second after 9 months, to examine the feasibility and benefits of the intervention. At endline, the prevalence of lead awareness was 52 percentage points higher in the intervention arm compared to the control (adjusted risk difference: 0.52 [95% CI 0.46 to 0.61]). Safe turmeric consumption and food storage practices were more common in the intervention versus control arm at endline, with adjusted risk differences of 0.22 [0.10 to 0.32] and 0.13 [0.00 to 0.19], respectively. Semi-structured interviews conducted with a subset of participants after the intervention revealed that the perceived benefit of reducing lead exposure was high because of the long-term negative impacts that lead can have on child cognitive development. The study demonstrates that a group-based CHW-led intervention can effectively raise awareness about and motivate lead exposure prevention behaviors in rural Bangladesh. Future efforts should combine similar awareness-raising efforts with longer-term regulatory and structural changes to systematically and sustainably reduce lead exposure.

Household interventions for secondary prevention of domestic lead exposure in children

BACKGROUND

Lead exposure is a serious health hazard, especially for children. It is associated with physical, cognitive and neurobehavioural impairment in children. There are many potential sources of lead in the environment, therefore trials have tested many household interventions to prevent or reduce lead exposure. This is an update of a previously published review.

OBJECTIVES

To assess the effects of household interventions intended to prevent or reduce further lead exposure in children on improvements in cognitive and neurobehavioural development, reductions in blood lead levels and reductions in household dust lead levels.

SEARCH METHODS

In March 2020, we updated our searches of CENTRAL, MEDLINE, Embase, 10 other databases and ClinicalTrials.gov. We also searched Google Scholar, checked the reference lists of relevant studies and contacted experts to identify unpublished studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs of household educational or environmental interventions, or combinations of interventions to prevent lead exposure in children (from birth to 18 years of age), where investigators reported at least one standardised outcome measure.

DATA COLLECTION AND ANALYSIS

Two authors independently reviewed all eligible studies for inclusion, assessed risk of bias and extracted data. We contacted trialists to obtain missing information. We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included 17 studies (three new to this update), involving 3282 children: 16 RCTs (involving 3204 children) and one quasi-RCT (involving 78 children). Children in all studies were under six years of age. Fifteen studies took place in urban areas of North America, one in Australia and one in China. Most studies were in areas with low socioeconomic status. Girls and boys were equally represented in those studies reporting this information. The duration of the intervention ranged from three months to 24 months in 15 studies, while two studies performed interventions on a single occasion. Follow-up periods ranged from three months to eight years. Three RCTs were at low risk of bias in all assessed domains. The other 14 studies were at unclear or high risk of bias; for example, we considered two RCTs and one quasi-RCT at high risk of selection bias and six RCTs at high risk of attrition bias. National or international research grants or governments funded 15 studies, while the other two did not report their funding sources. Education interventions versus no intervention None of the included studies in this comparison assessed effects on cognitive or neurobehavioural outcomes, or adverse events. All studies reported data on blood lead level outcomes. Educational interventions showed there was probably no evidence of a difference in reducing blood lead levels (continuous: mean difference (MD) -0.03, 95% confidence interval (CI) -0.13 to 0.07; I² = 0%; 5 studies, 815 participants; moderate-certainty evidence; log-transformed data), or in reducing floor dust levels (MD -0.07, 95% CI -0.37 to 0.24; I² = 0%; 2 studies, 318 participants; moderate-certainty evidence). Environmental interventions versus no intervention Dust control: one study in this comparison reported data on cognitive and neurobehavioural outcomes, and on adverse events in children. The study showed numerically there may be better neurobehavioural outcomes in children of the intervention group. However, differences were small and the CI included both a beneficial and non-beneficial effect of the environmental intervention (e.g. mental development (Bayley Scales of Infant Development-II): MD 0.1, 95% CI -2.1 to 2.4; 1 study, 302 participants; low-certainty evidence). The same study did not observe any adverse events related to the intervention during the eight-year follow-up, but observed two children with adverse events in the control group (1 study, 355 participants; very low-certainty evidence). Meta-analysis also found no evidence of effectiveness on blood lead levels (continuous: MD -0.02, 95% CI -0.09 to 0.06; I² = 0%; 4 studies, 565 participants; moderate-certainty evidence; log-transformed data). We could not pool the data regarding floor dust levels, but studies reported that there may be no evidence of a difference between the groups (very low-certainty evidence). Soil abatement: the two studies assessing this environmental intervention only reported on the outcome of 'blood lead level'. One study showed a small effect on blood lead level reduction, while the other study showed no effect. Therefore, we deem the current evidence insufficient to draw conclusions about the effectiveness of soil abatement (very low-certainty evidence). Combination of educational and environmental interventions versus standard education Studies in this comparison only reported on blood lead levels and dust lead levels. We could not pool the studies in a meta-analysis due to substantial differences between the studies. Since the studies reported inconsistent results, the evidence is currently insufficient to clarify whether a combination of interventions reduces blood lead levels and floor dust levels (very low-certainty evidence).

AUTHORS' CONCLUSIONS

Based on available evidence, household educational interventions and environmental interventions (namely dust control measures) show no evidence of a difference in reducing blood lead levels in children as a population health measure. The evidence of the effects of environmental interventions on cognitive and neurobehavioural outcomes and adverse events is uncertain too. Further trials are required to establish the most effective intervention for reducing or even preventing further lead exposure. Key elements of these trials should include strategies to reduce multiple sources of lead exposure simultaneously using empirical dust clearance levels. It is also necessary for trials to be carried out in low- and middle-income countries and in differing socioeconomic groups in high-income countries.

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.

Lead in New York City's soils: Population growth, land use, and contamination

Soil is an important exposure pathway for lead (Pb) and predictor of blood lead levels (BLL) among children. Over the past two decades, many areas within New York City (NYC) have undergone a transition from industrial and manufacturing land use to residential housing. This can bring new residents to areas which contain the legacy of historic Pb contamination. The objective of this study was to evaluate the difference in soil Pb concentrations between community parks and greenspaces in areas undergoing rapid redevelopment and land use changes and stable areas without redevelopment. Three high- and three low-risk Pb contaminated areas within NYC were identified based on an additive index that included population growth, industrial land use, and new construction. Soil samples (n=358) were collected across 34 parks and analyzed with an XRF with a subset also analyzed by ICP-MS. Areas within NYC, evaluated in this study, with a high-risk index had significantly (p<0.0001) larger mean concentrations of Pb in soil (374 mg/kg vs. 150 mg/kg, respectively) and double the rate of children under the age of six years with BLL > 5ug/dL (37.94 vs. 18.72 per 1000, respectively) compared to low-risk areas. There was a statistically significant (p <0.05) positive correlation between street density, manufacturing/industrial land density and population density change within 0.40 km of a park and soil Pb concentrations. However, we were unable to estimate the source-specific contribution of Pb concentrations in soil, since many of the variables assessed were correlated with one another. Regardless of the source, large population increases are occurring in areas with elevated soil Pb levels. In the three high-risk areas investigated in this study, the population has increased by over 35,000 residents between 2010 to 2017 compared to just 8,500 in the low-risk areas.

More Guidelines than states: variations in U.S. lead screening and management guidance and impacts on shareable CDS development

BACKGROUND

Pediatric lead exposure in the United States (U.S.) remains a preventable public health crisis. Shareable electronic clinical decision support (CDS) could improve lead screening and management. However, discrepancies between federal, state and local recommendations could present significant challenges for implementation.

METHODS

We identified publically available guidance on lead screening and management. We extracted definitions for elevated lead and recommendations for screening, follow-up, reporting, and management. We compared thresholds and level of obligation for management actions. Finally, we assessed the feasibility of development of shareable CDS.

RESULTS

We identified 54 guidance sources. States offered different definitions of elevated lead, and recommendations for screening, reporting, follow-up and management. Only 37 of 48 states providing guidance used the Center for Disease Control (CDC) definition for elevated lead. There were 17 distinct management actions. Guidance sources indicated an average of 5.5 management actions, but offered different criteria and levels of obligation for these actions. Despite differences, the recommendations were well-structured, actionable, and encodable, indicating shareable CDS is feasible.

CONCLUSION

Current variability across guidance poses challenges for clinicians. Developing shareable CDS is feasible and could improve pediatric lead screening and management. Shareable CDS would need to account for local variability in guidance.

Quantifying soil contamination and identifying interventions to limit health risks

Numerous toxicants contaminate soil and negatively affect the environments that children explore. Accurately measuring these toxicants and characterizing the level of soil contamination may be difficult and must include measurements of both the environmental concentrations and the exposure responses of human populations. This article reviews the current methods and technologies available for quantifying soil contamination. Several intervention strategies exist for limiting human exposure to contaminated soils and the strengths and weaknesses of these methods are discussed. Lastly, current policies on soil contamination and the importance of protecting vulnerable populations by developing means to improve health conditions for children are reviewed.

The concurrent decline of soil lead and children's blood lead in New Orleans

The inextricable link between topsoil lead (Pb) and children’s blood lead (BPb) has not been widely accepted. Pb is associated with multiple health adversities. Urban residents are at risk from exposure to legacy Pb dust in topsoil resulting from smelting, industrial discharges, leaded gasoline emissions, leaded paint, and incineration. In New Orleans, topsoil median Pb decreased in ∼15 y from 99 mg/kg to 54 mg/kg, or ∼2.4 mg⋅kg⋅y⁻¹. In ∼12 y, children’s median BPb declined from 3.6 μg/dL to 1.3 μg/dL, or ∼0.2 μg⋅dL⋅y⁻¹. We argue that depletion of topsoil Pb is an important factor in the continuous decline of children’s BPb. Similar processes are expected in all US cities. Primary prevention requires curtailing Pb in all sources, including topsoil.

Lead (Pb) is extremely toxic and a major cause of chronic diseases worldwide. Pb is associated with health disparities, particularly within low-income populations. In biological systems, Pb mimics calcium and, among other effects, interrupts cell signaling. Furthermore, Pb exposure results in epigenetic changes that affect multigenerational gene expression. Exposure to Pb has decreased through primary prevention, including removal of Pb solder from canned food, regulating lead-based paint, and especially eliminating Pb additives in gasoline. While researchers observe a continuous decline in children’s blood lead (BPb), reservoirs of exposure persist in topsoil, which stores the legacy dust from leaded gasoline and other sources. Our surveys of metropolitan New Orleans reveal that median topsoil Pb in communities (n = 274) decreased 44% from 99 mg/kg to 54 mg/kg (P value of 2.09 × 10⁻⁰⁸), with a median depletion rate of ∼2.4 mg⋅kg⋅y⁻¹ over 15 y. From 2000 through 2005 to 2011 through 2016, children’s BPb declined from 3.6 μg/dL to 1.2 μg/dL or 64% (P value of 2.02 × 10⁻⁸⁵), a decrease of ∼0.2 μg⋅dL⋅y⁻¹ during a median of 12 y. Here, we explore the decline of children’s BPb by examining a metabolism of cities framework of inputs, transformations, storages, and outputs. Our findings indicate that decreasing Pb in topsoil is an important factor in the continuous decline of children’s BPb. Similar reductions are expected in other major US cities. The most contaminated urban communities, usually inhabited by vulnerable populations, require further reductions of topsoil Pb to fulfill primary prevention for the nation’s children.

Trends in Elevated Blood Lead Levels Using 5 and 10 µg/dL Levels of Concern Among Refugee Children Resettled in Massachusetts, 1998-2015

OBJECTIVES

Refugee children are known to have a high prevalence of elevated blood lead levels (EBLLs). We sought to determine trends in EBLLs among refugee children during an 18-year period and examine relationships between descriptive characteristics and EBLLs by using 10 µg/dL and 5 µg/dL levels of concern.

METHODS

We retrospectively evaluated refugee health screening data from Massachusetts for 1998 through 2015 for refugee children aged <7 years. We performed bivariate and multivariate analyses of variables including sex, age, region of origin, anemia, intestinal parasites, tuberculosis test results, and anthropometric measurements and used both 5 µg/dL and 10 µg/dL levels of concern for EBLLs.

RESULTS

Of 3421 eligible refugee children, 3054 (88.2%) were tested. Using 5 µg/dL and 10 µg/dL levels of concern, 1279 (41.9%) and 241 (7.9%) children, respectively, had EBLLs. Mean BLLs declined steadily from 7.58 µg/dL in 2004 to 4.03 µg/dL in 2015. African (adjusted odds ratio [aOR] = 2.49; 95% confidence interval [CI], 1.81-3.43), East Asian and Pacific (aOR = 1.98; 95% CI, 1.35-2.91), and South-Central Asian (aOR = 2.47; 95% CI, 1.53-4.01) regions of origin and anemia (aOR = 1.50; 95% CI, 1.14 -1.97) were significantly associated with BLLs ≥5 µg/dL.

CONCLUSIONS

The prevalence of EBLLs among refugees compared with US-born children is high. Because EBBLs increase the risk for neurocognitive impairment in children, public health professionals, policy makers, researchers, refugee resettlement staff members, and health care providers must remain vigilant in screening for lead poisoning and educating refugees about the hazards posed to young children by lead.

Childhood lead poisoning from domestic products in China: A case study with implications for practice, education, and policy

OBJECTIVE

This study aimed to report three representative childhood lead poisoning cases in China from domestic products exposure and to highlight their critical implications for practice, education, and policy in prevention and treatment of childhood lead poisoning by health care providers, especially public health nurses.

DESIGN AND SAMPLE

Three representative childhood lead poisoning cases occurring in 2017 were collected and analyzed.

RESULTS

The lead exposure sources of three cases were evaluated by experts in the field and determined to be tin pots, home factories for tinfoil, and contamination of folk medicine, respectively. These cases demonstrated that the lack of lead exposure risk assessment, insufficient knowledge of potential lead exposure sources, underdeveloped policy, and regulations were areas for improvement.

CONCLUSIONS

The best strategies for preventing lead poisoning include an appropriate risk assessment of lead exposure, implementation of comprehensive parental health education, conduction of further research by public health providers, and the application of policy strategies by the government. It was determined that public health nurses are at the frontline of prevention of lead poisoning in children.

Potential dietary factors for reducing lead burden of Chinese preschool children

Dietary approaches to treat children's low lead exposure are implemented routinely in China, while evidence for the effect could not be provided until now. The aim of this study was to examine the relationship between diets including nutrition supplementation and blood lead level of preschool children of China. In total, 17,859 preschool children from 14 cities were recruited, and their social-demography, living environment, and dietary intakes were collected, and capillary blood sample was tested for lead concentration. The average blood lead concentration was 34.5 μg/L, and after adjusting children's social-demography factors, the consumption of milk or dairy production, fruits, and calcium supplementation had negative dose-response relationships with blood lead level. Conversely, intake of iron-rich food and supplementation was not associated. Further studies are needed to prove the causal relationships.

The association between body lead levels and childhood rickets: A meta-analysis based on Chinese cohort

China has serious lead pollution and a high incidence of childhood rickets. High lead levels have been reported in childhood rickets, but the results were inconsistent.To evaluate the association between body lead levels and childhood rickets.After a systematic literature search, we identified 15 studies determining body lead levels between rickets children and healthy controls, and 4 studies focusing on the cases of different disease severity. Standard mean differences (SMD) and the corresponding 95% confidence intervals (CI) were pooled to compare the lead levels between different groups.Sixteen case-control studies were included with a total of 5082 cases and 6054 controls. Compared with healthy controls, the body lead levels in rickets children were significantly higher (SMD (95%CI): 0.67 (0.41-0.93)), and subgroup analyses showed consistent results. The cases with moderate-to-severe disease activity also had a significantly higher lead level than mild-to-moderate cases (SMD (95%CI): 0.64 (0.31-0.97)).This meta-analysis suggested an association between body lead levels and childhood rickets, and lead exposure might be a risk factor for rickets.

First aid interventions by laypeople for acute oral poisoning

BACKGROUND

Oral poisoning is a major cause of mortality and disability worldwide, with estimates of over 100,000 deaths due to unintentional poisoning each year and an overrepresentation of children below five years of age. Any effective intervention that laypeople can apply to limit or delay uptake or to evacuate, dilute or neutralize the poison before professional help arrives may limit toxicity and save lives.

OBJECTIVES

To assess the effects of pre-hospital interventions (alone or in combination) for treating acute oral poisoning, available to and feasible for laypeople before the arrival of professional help.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, CINAHL, ISI Web of Science, International Pharmaceutical Abstracts, and three clinical trials registries to 11 May 2017, and we also carried out reference checking and citation searching.

SELECTION CRITERIA

We included randomized controlled trials comparing interventions (alone or in combination) that are feasible in a pre-hospital setting for treating acute oral poisoning patients, including but potentially not limited to activated charcoal (AC), emetics, cathartics, diluents, neutralizing agents and body positioning.

DATA COLLECTION AND ANALYSIS

Two reviewers independently performed study selection, data collection and assessment. Primary outcomes of this review were incidence of mortality and adverse events, plus incidence and severity of symptoms of poisoning. Secondary outcomes were duration of symptoms of poisoning, drug absorption, and incidence of hospitalization and ICU admission.

MAIN RESULTS

We included 24 trials involving 7099 participants. Using the Cochrane 'Risk of bias' tool, we assessed no study as being at low risk of bias for all domains. Many studies were poorly reported, so the risk of selection and detection biases were often unclear. Most studies reported important outcomes incompletely, and we judged them to be at high risk of reporting bias.All but one study enrolled oral poisoning patients in an emergency department; the remaining study was conducted in a pre-hospital setting. Fourteen studies included multiple toxic syndromes or did not specify, while the other studies specifically investigated paracetamol (2 studies), carbamazepine (2 studies), tricyclic antidepressant (2 studies), yellow oleander (2 studies), benzodiazepine (1 study), or toxic berry intoxication (1 study). Eighteen trials investigated the effects of activated charcoal (AC), administered as a single dose (SDAC) or in multiple doses (MDAC), alone or in combination with other first aid interventions (a cathartic) and/or hospital treatments. Six studies investigated syrup of ipecac plus other first aid interventions (SDAC + cathartic) versus ipecac alone. The collected evidence was mostly of low to very low certainty, often downgraded for indirectness, risk of bias or imprecision due to low numbers of events.First aid interventions that limit or delay the absorption of the poison in the bodyWe are uncertain about the effect of SDAC compared to no intervention on the incidence of adverse events in general (zero events in both treatment groups; 1 study, 451 participants) or vomiting specifically (Peto odds ratio (OR) 4.17, 95% confidence interval (CI) 0.30 to 57.26, 1 study, 25 participants), ICU admission (Peto OR 7.77, 95% CI 0.15 to 391.93, 1 study, 451 participants) and clinical deterioration (zero events in both treatment groups; 1 study, 451 participants) in participants with mixed types or paracetamol poisoning, as all evidence for these outcomes was of very low certainty. No studies assessed SDAC for mortality, duration of symptoms, drug absorption or hospitalization.Only one study compared SDAC to syrup of ipecac in participants with mixed types of poisoning, providing very low-certainty evidence. Therefore we are uncertain about the effects on Glasgow Coma Scale scores (mean difference (MD) -0.15, 95% CI -0.43 to 0.13, 1 study, 34 participants) or incidence of adverse events (risk ratio (RR) 1.24, 95% CI 0.26 to 5.83, 1 study, 34 participants). No information was available concerning mortality, duration of symptoms, drug absorption, hospitalization or ICU admission.This review also considered the added value of SDAC or MDAC to hospital interventions, which mostly included gastric lavage. No included studies investigated the use of body positioning in oral poisoning patients.First aid interventions that evacuate the poison from the gastrointestinal tractWe found one study comparing ipecac versus no intervention in toxic berry ingestion in a pre-hospital setting. Low-certainty evidence suggests there may be an increase in the incidence of adverse events, but the study did not report incidence of mortality, incidence or duration of symptoms of poisoning, drug absorption, hospitalization or ICU admission (103 participants).In addition, we also considered the added value of syrup of ipecac to SDAC plus a cathartic and the added value of a cathartic to SDAC.No studies used cathartics as an individual intervention.First aid interventions that neutralize or dilute the poison No included studies investigated the neutralization or dilution of the poison in oral poisoning patients.The review also considered combinations of different first aid interventions.

AUTHORS' CONCLUSIONS

The studies included in this review provided mostly low- or very low-certainty evidence about the use of first aid interventions for acute oral poisoning. A key limitation was the fact that only one included study actually took place in a pre-hospital setting, which undermines our confidence in the applicability of these results to this setting. Thus, the amount of evidence collected was insufficient to draw any conclusions.

Long-Term in Situ Reduction in Soil Lead Bioavailability Measured in a Mouse Model

Effects of different treatments on the bioavailability of lead (Pb) in soil from a smelter emission contaminated site in Joplin, Missouri, were evaluated in a mouse model. Similar estimates of relative bioavailability for Pb in untreated or treated soil were obtained in mice and in the well-established juvenile swine model. In the mouse model, treatments that used phosphate (phosphoric acid or triple superphosphate) combined with iron oxide or biosolids compost significantly reduced soil Pb bioavailability. Notably, effects of these remediation procedures were persistent, given that up to 16 years had elapsed between soil treatment and sample collection. Remediation of soils was associated with changes in Pb species present in soil. Differences in Pb species in ingested soil and in feces from treated mice indicated that changes in Pb speciation occurred during transit through the gastrointestinal tract. Use of the mouse model facilitates evaluation of remediation procedures and allows monitoring of the performance of procedures under laboratory and field conditions.

Lead Toxicity: an Australian Perspective

Plumbism refers to the clinical features of lead toxicity, a condition which has been identified and then forgotten in a depressingly cyclical fashion since ancient times. For the past 6000 years antiquarians have described the human use of lead despite the well documented and severe adverse effects of exposure. As the analytical methods of lead measurement bring improved detection capability, it is clear that there is no safe amount of lead in the body. Sadly, we continue to identify affected patients in contemporary Australia, including young children. While there is little evidence that chelation therapy improves outcomes in affected individuals, it is recommended for use in patients with acute encephalopathy or in those with particularly elevated levels. The paucity of evidence supporting active treatment of plumbism highlights the importance of primary prevention, particularly in our most vulnerable.

An Update on Childhood Lead Poisoning

Childhood lead poisoning is a multi-faceted, complex condition, which affects not only the child's health and well-being, but also the family's housing security, economic status, job security, and stress level. This review updates the emergency department clinician on the management of childhood lead poisoning. Infants and children are at higher risk than adults for lead exposure due to their smaller size and proportionately larger dose of ingested toxins, their proximity to ground dirt and indoor dust, their energy and curiosity, their oral exploratory and pica behaviors, their proportionately larger daily water and milk intake, and dietary preferences that differ markedly from those of adults. Pediatric health care providers working in the emergency department can provide medical management, as well as preventive counseling and guidance, to parents of children presenting with evidence of acute or chronic lead poisoning.

Child lead poisoning in South Africa: implications for psychological research

Lead is a toxic heavy metal that is associated with lowered intelligence quotient scores, behavioural problems, and physical health impairments in children. Current consensus is that there is no safe level of child lead exposure and that even low doses of lead can have negative effects. Several reviews conducted in South Africa have revealed the sources and potential risk factors associated with child lead poisoning. However, no South African reviews have focused on the quality of studies focusing on child lead poisoning and psychological outcomes (intelligence, cognitive, and behavioural outcomes). This study reviews epidemiological studies of child lead poisoning with a particular focus on the association between child lead poisoning and psychological outcomes in South Africa over a 30-year time span (1986–2016). The review pays particular attention to study design, measurement, sampling, and confounding variables. Nine studies that measured child lead poisoning were included in the review. Just two of the nine studies (one cross-sectional and one follow-up) measured psychological outcomes and neither study adequately adjusted for confounding. In all studies, sampling was purposive and lead exposure indicators were suited to short-term acute exposure. There is, therefore, insufficient evidence to determine the magnitude of the association between child lead poisoning and psychological outcomes in South Africa. More rigorous epidemiological studies are needed to strengthen the evidence base. The article also highlights opportunities for psychological research in intervention studies and studies that are framed by an environmental justice agenda.

Soil Lead and Children's Blood Lead Disparities in Pre- and Post-Hurricane Katrina New Orleans (USA)

This study appraises New Orleans soil lead and children’s lead exposure before and ten years after Hurricane Katrina flooded the city. Introduction: Early childhood exposure to lead is associated with lifelong and multiple health, learning, and behavioral disorders. Lead exposure is an important factor hindering the long-term resilience and sustainability of communities. Lead exposure disproportionately affects low socioeconomic status of communities. No safe lead exposure is known and the common intervention is not effective. An essential responsibility of health practitioners is to develop an effective primary intervention. Methods: Pre- and post-Hurricane soil lead and children’s blood lead data were matched by census tract communities. Soil lead and blood lead data were described, mapped, blood lead graphed as a function of soil lead, and Multi-Response Permutation Procedures statistics established disparities. Results: Simultaneous decreases occurred in soil lead accompanied by an especially large decline in children’s blood lead 10 years after Hurricane Katrina. Exposure disparities still exist between children living in the interior and outer areas of the city. Conclusions: At the scale of a city, this study demonstrates that decreasing soil lead effectively reduces children’s blood lead. Primary prevention of lead exposure can be accomplished by reducing soil lead in the urban environment.

What are the blood lead levels of children living in Latin America and the Caribbean?

INTRODUCTION

Information on the prevalence of lead exposure is essential to formulate efficient public health policies. Developed countries have implemented successful public policies for the prevention and control of lead poisoning. In the United States, Canada, Japan and the European Union, for instance, periodically repeated prevalence studies show that blood lead levels (BLLs) in children have decreased overall. Although BLL of Latino children in the U.S. have also dropped in recent years, the geometric mean remains higher than that of white children. Little is known about lead exposure in children in Latin America and the Caribbean (LAC). In this review, we responded to two questions: What is currently known about lead sources and levels in children in LAC? Are there public policies to prevent children's exposure to lead in LAC?

METHOD

We conducted a literature review covering the period from January 2000 to March 2014 in the PubMed and Lilacs databases to obtain English, Portuguese and Spanish language studies reporting the prevalence of BLLs in children aged 0-18years living in LAC countries. No specific analytical method was selected, and given the scarcity of data, the study was highly inclusive.

RESULTS

Fifty-six papers were selected from 16 different LAC countries. The children's BLLs found in this review are high (≥10μg/dL) compared to BLLs for the same age group in the U. S. However, most studies reported an association with some type of "lead hot spot", in which children can be exposed to lead levels similar to those of occupational settings. Only Peru and Mexico reported BLLs in children from population-based studies.

CONCLUSIONS

Most BLLs prevalence studies carried out in LAC were in areas with known emission sources. The percentage of children at risk of lead poisoning in LAC is unknown, and probably underestimated. Thus, there is an urgent need to establish public health policies to quantify and prevent lead poisoning, specifically by prioritizing the identification and control of "hot spots".