Lead exposure, IgE, and the risk of asthma in children

Toxic metals and pediatric clinical immune dysfunction: A systematic review of the epidemiological evidence

BACKGROUND

Children are at high risk for exposure to toxic metals and are vulnerable to their effects. Significant research has been conducted evaluating the role of these metals on immune dysfunction, characterized by biologic and clinical outcomes. However, there are inconsistencies in these studies. The objective of the present review is to critically evaluate the existing literature on the association between toxic metals (lead, mercury, arsenic, and cadmium) and pediatric immune dysfunction.

METHODS

Seven databases (PubMed (NLM), Embase (Elsevier), CINAHL (Ebsco), Web of Science (Clarivate Analytics), ProQuest Public Health Database, and ProQuest Environmental Science Collection) were searched following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines in February 2024. Rayaan software identified duplicates and screened by title and abstract in a blinded and independent review process. The remaining full texts were reviewed for content and summarized. Exclusions during the title, abstract, and full-text reviews included: 1) not original research, 2) not epidemiology, 3) did not include toxic metals, 4) did not examine an immune health outcome, or 5) not pediatric (>18 years). This systematic review protocol followed the PRISMA guidelines. Rayaan was used to screen records using title and abstract by two blinded and independent reviewers. This process was repeated for full-text article screening selection.

RESULTS

The search criteria produced 7906 search results; 2456 duplicate articles were removed across search engines. In the final review, 79 studies were included which evaluated the association between toxic metals and outcomes indicative of pediatric immune dysregulation.

CONCLUSIONS

The existing literature suggests an association between toxic metals and pediatric immune dysregulation. Given the imminent threat of infectious diseases demonstrated by the recent COVID-19 epidemic in addition to increases in allergic disease, understanding how ubiquitous exposure to these metals in early life can impact immune response, infection risk, and vaccine response is imperative.

A case-control study on asthma and obese patients: Influence of lifestyle patterns, serum trace elements, heavy metals, and total antioxidants

Background and aim

Asthma is a chronic airway hyperresponsiveness disorder and Obese people have greater rates of asthma incidence and prevalence. Obesity, a complex condition, can cause nutritional metabolic problems that change trace elements and minerals. Trace element and antioxidant levels affect asthma aetiology. In this study, we aim to determine the serum levels of trace elements Zn, Fe, Cu, Mg, Co, Ni, Pb, Cd, and Cr, total antioxidants (TAS), and lifestyle that determine specific clinical conditions in asthma and obesity patients from Vellore City (Tamil Nadu, India).

Methods

A case-control study to determine the level of the serum trace elements with 838 subjects (n = 242 asthma patients, n = 140 asthmatic obese, n = 185 obese patients, and n = 271 controls) between the ages of 20 and 60 years was carried out. Asthma was diagnosed based on the clinical examination and pulmonary function tests. Trace element levels were determined by atomic absorption spectrophotometry (AAS) in serum, and a DPPH-free radical scavenging assay was used to determine the total antioxidant capacity level in serum.

Result

In asthma male patients, serum levels of Zn, Fe, Cu, Mg, and TAS were significantly lower and Pb, Cd, and Cr significantly higher, whereas in female asthma patients, serum levels of Zn, Fe, Mg, and TAS were significantly lower and Pb significantly higher. In asthmatic obese male patients, Fe, Cu, and TAS were significantly lower, and Pb, Cd, and Co were significantly higher; in asthmatic obese female patients, Zn, Fe, Cu, Mg, and TAS were significantly lower, and Ni was significantly higher. In obese male patients, Zn, Fe, Cu, and TAS were significantly lower and Cd was significantly higher, and in obese female patients, Zn, Fe, Cu, Mg, and TAS were significantly lower.

Conclusion

The influence of the level of trace elements, heavy metal, total antioxidant, and the lifestyle patterns, may increase the risk of asthma and obesity.

EAACI guidelines on environmental science for allergy and asthma: The impact of short-term exposure to outdoor air pollutants on asthma-related outcomes and recommendations for mitigation measures

The EAACI Guidelines on the impact of short-term exposure to outdoor pollutants on asthma-related outcomes provide recommendations for prevention, patient care and mitigation in a framework supporting rational decisions for healthcare professionals and patients to individualize and improve asthma management and for policymakers and regulators as an evidence-informed reference to help setting legally binding standards and goals for outdoor air quality at international, national and local levels. The Guideline was developed using the GRADE approach and evaluated outdoor pollutants referenced in the current Air Quality Guideline of the World Health Organization as single or mixed pollutants and outdoor pesticides. Short-term exposure to all pollutants evaluated increases the risk of asthma-related adverse outcomes, especially hospital admissions and emergency department visits (moderate certainty of evidence at specific lag days). There is limited evidence for the impact of traffic-related air pollution and outdoor pesticides exposure as well as for the interventions to reduce emissions. Due to the quality of evidence, conditional recommendations were formulated for all pollutants and for the interventions reducing outdoor air pollution. Asthma management counselled by the current EAACI guidelines can improve asthma-related outcomes but global measures for clean air are needed to achieve significant impact.

Heavy metal levels are positively associated with serum periostin and miRNA-125b levels, but inversely associated with miRNA-26a levels in pediatric asthma cases. A case-control study

BACKGROUND

The study investigated heavy metals levels [urinary cadmium (U-Cd), erythrocytic cadmium (E-Cd), urinary arsenic (U-As), and whole blood lead (WB-Pb)] in children with bronchial asthma (BA) and tested their associations with serum periostin, miRNA-125b and miRNA-26a levels, and with asthma severity clinically and laboratory [blood eosinophils count (BEC) and serum total immunoglobin E (IgE)]. Also, we tested cut-off points, for the studied parameters, to distinguish BA cases from healthy children.

METHODS

This case-control study included 158 children divided into control group; n = 72 and BA group; n = 86. Heavy metals were measured by an inductively coupled plasma-optical emission spectrophotometer. Serum periostin and IgE levels were measured by their corresponding ELISA kits. miRNAs relative expressions were estimated by RT-qPCR using the 2-ΔΔCT method.

RESULTS

Heavy metals, serum periostin, and miR-125b levels were significantly high in BA group (p < 0.001). Heavy metals levels correlated positively with serum periostin, miR-125b and IgE levels, BEC, and asthma severity. The reverse was observed regarding serum miR-26a levels. Receiver operating characteristics (ROC) curve analysis showed good to excellent abilities of U-Cd, E-Cd, U-As, WB-Pb, serum periostin, miRNA-125b, and miRNA - 26a, and total IgE levels to distinguish BA cases from healthy children.

CONCLUSIONS

Heavy metal toxicity in children is associated with BA severity, increased serum periostin and miRNA-125b levels, and decreased miRNA-26a levels. Specific measures to reduce children's exposure to heavy metals should be taken. Future research should consider blocking miRNA-125b action or enhancing miRNA-26a action to manage BA cases.

The Associations between Exposure to Multiple Heavy Metals and Total Immunoglobulin E in U.S. Adults

Immunoglobulin E (IgE) is a type of immunoglobulin, and elevated serum total IgE is often present in allergic diseases. Exposure to environmental heavy metals has been markedly linked to allergic diseases, leading to elevated total IgE levels. However, studies concerning the effects of multiple metal exposures on total IgE levels are limited. Therefore, the current study seeks to explore the correlation between heavy-metal co-exposure and total IgE levels based on the National Health and Nutrition Examination Survey (NHANES, 2005-2006). Participants possessed complete data on total IgE levels, 11 urinary metal concentrations and other covariates. The correlations between 11 metals and total IgE levels were analyzed using multiple linear regression, and total IgE levels were a continuous variable. Total IgE levels exceeding 150 kU/L were considered sensitized. Binary logistic regression analyses were employed to assess the correlation between metal exposure and the occurrence of an allergic state. Then, the association between co-exposure to the 11 metals and total IgE levels or the occurrence of sensitization status was further analyzed by Bayesian kernel machine regression (BKMR), a multi-contaminant model. There were 1429 adults with complete data included. Based on the median concentration, molybdenum (Mo) had the highest concentration (46.60 μg/L), followed by cesium (Cs), barium (Ba), lead (Pb), and mercury (Hg). And the median (interquartile range) for total IgE levels was 43.7 (17.3, 126.0) kU/L. Multiple linear regression results showed that Pb was significantly and positively associated with total IgE levels (β = 0.165; 95% CI: 0.046, 0.284). Binary logistic regression showed a significant positive correlation between urinary Pb (OR: 1.258; 95% CI: 1.052, 1.510) and tungsten (W) (OR: 1.251; 95% CI: 1.082, 1.447). Importantly, the BKMR model found a positive correlation between combined-metal exposure and total IgE levels and the occurrence of sensitization status. The mixed heavy-metal exposure was associated with increased total IgE levels, and this association may be driven primarily by the exposure of Pb and W. This study provides new insights into the relationship between heavy-metal exposure and allergic diseases. More research is needed to confirm these findings.

Associations of exposure to metals with total and allergen-specific IgE: An NHANES analysis (2005-2006)

BACKGROUND

Immunoglobulin E (IgE) is a diagnostic biomarker for allergic diseases. While some metal exposure has been found to be associated with allergic diseases, there are still a lot of knowledge gaps regarding the relationship between metal exposure and allergen-specific IgE antibodies, particularly in adults.

METHODS

We included a total of 1433 adult participants from the 2005-2006 National Health and Nutrition Examination Survey (NHANES), all of whom had concentrations of 10 metals (including Barium (Ba), Cadmium (Cd), Cobalt (Co), Cesium (Cs), Molybdenum (Mo), Lead (Pb), Antimony (Sb), Thallium (Tl), Tungsten (Tu), and Uranium (Ur)) in urine, as well as measurements of 19 allergen-specific IgE and total IgE antibodies. Linear regression, logistic regression, weighted quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR) were used to estimate associations between metals and total and allergen-specific IgE.

RESULTS

Linear regression models revealed a positive correlation between Pb and Cd levels and the total IgE levels. Furthermore, the WQS and BKMR models suggested a positive association between mixed metals and total IgE levels, with the WQS model highlighting Pb and Cd as the major contributors. Logistic regression models showed positive correlations between Pb and food sensitization, Ur and plant sensitization, negative correlations between Cs and plant sensitization, Co and dust mite and pet sensitization, Mo and dust mite and cockroach sensitization, and Tl and mold sensitization. Moreover, the BKMR results indicated a statistically significant negative correlation between mixed metals and mold sensitization.

CONCLUSION

According to the research findings, exposure to metals is associated with total and allergen-specific IgE in American adults. Further assessment of these relationships is necessary in representative populations of other countries.

Personal air pollution exposure and metals in the nasal epithelial lining fluid of COPD patients

Sampling of the nasal epithelial lining fluid is a potential method to assess exposure to air pollution within the respiratory tract among high risk populations. We investigated associations of short- and long-term particulate matter exposure (PM) and pollution-related metals in the nasal fluid of people with chronic obstructive pulmonary disease (COPD). This study included 20 participants with moderate-to-severe COPD from a larger study who measured long-term personal exposure to PM2.5 using portable air monitors and short-term PM2.5 and black carbon (BC) using in-home samplers for the seven days preceding nasal fluid collection. Nasal fluid was sampled from both nares by nasosorption, and inductively coupled plasma mass spectrometry was used to determine the concentration of metals with major airborne sources. Correlations of selected elements (Fe, Ba, Ni, Pb, V, Zn, Cu) were determined within the nasal fluid. Associations between personal long-term PM2.5 and seven day home PM2.5 and BC exposure and nasal fluid metal concentrations were determined by linear regression. Within nasal fluid samples, concentrations of vanadium and nickel (r = 0.8) and lead and zinc (r = 0.7) were correlated. Seven day and long-term PM2.5 exposure were both associated with higher levels of copper, lead, and vanadium in the nasal fluid. BC exposure was associated with higher levels of nickel in the nasal fluid. Levels of certain metals in the nasal fluid may serve as biomarkers of air pollution exposure in the upper respiratory tract.

Epidemiological evidence for the effect of environmental heavy metal exposure on the immune system in children

Heavy metals exist widely in daily life, and exposure to heavy metals caused by environmental pollution has become a serious public health problem worldwide. Due to children's age-specific behavioral characteristics and imperfect physical function, the adverse health effects of heavy metals on children are much higher than in adults. Studies have found that heavy metal exposure is associated with low immune function in children. Although there are reviews describing the evidence for the adverse effects of heavy metal exposure on the immune system in children, the summary of evidence from epidemiological studies involving the level of immune molecules is not comprehensive. Therefore, this review summarizes the current epidemiological study on the effect of heavy metal exposure on childhood immune function from multiple perspectives, emphasizing its risks to the health of children's immune systems. It focuses on the effects of six heavy metals (lead (Pb), cadmium (Cd), arsenic (As), mercury (Hg), nickel (Ni), and manganese (Mn)) on children's innate immune cells, lymphocytes and their subpopulations, cytokines, total and specific immunoglobulins, and explores the immunotoxicological effects of heavy metals. The review finds that exposure to heavy metals, particularly Pb, Cd, As, and Hg, not only reduced lymphocyte numbers and suppressed adaptive immune responses in children, but also altered the innate immune response to impair the body's ability to fight pathogens. Epidemiological evidence suggests that heavy metal exposure alters cytokine levels and is associated with the development of inflammatory responses in children. Pb, As, and Hg exposure was associated with vaccination failure and decreased antibody titers, and increased risk of immune-related diseases in children by altering specific immunoglobulin levels. Cd, Ni and Mn showed activation effects on the immune response to childhood vaccination. Exposure age, sex, nutritional status, and co-exposure may influence the effects of heavy metals on immune function in children.

Association between Exposure to Selected Heavy Metals and Blood Eosinophil Counts in Asthmatic Adults: Results from NHANES 2011-2018

(1) Background: Heavy metals are widely used and dispersed in the environment and people's daily routines. Many studies have reported an association between heavy metal exposure and asthma. Blood eosinophils play a crucial role in the occurrence, progression, and treatment of asthma. However, there have thus far been few studies that aimed to explore the effects of heavy metal exposure on blood eosinophil counts in adults with asthma. Our study aims to discuss the association between metal exposure and blood eosinophil counts among asthmatic adults. (2) Methods: A total of 2026 asthmatic individuals were involved in our research from NHANES with metal exposure, blood eosinophils, and other covariates among the American population. A regression model, the XGBoost algorithm, and a generalized linear model (GAM) were used to explore the potential correlation. Furthermore, we conducted a stratified analysis to determine high-risk populations. (3) Results: The multivariate regression analysis indicated that concentrations of blood Pb (log per 1 mg/L; coefficient β, 25.39; p = 0.010) were positively associated with blood eosinophil counts. However, the associations between blood cadmium, mercury, selenium, manganese, and blood eosinophil counts were not statistically significant. We used stratified analysis to determine the high-risk group regarding Pb exposure. Pb was identified as the most vital variable influencing blood eosinophils through the XGBoost algorithm. We also used GAM to observe the linear relationship between the blood Pb concentrations and blood eosinophil counts. (4) Conclusions: The study demonstrated that blood Pb was positively correlated with blood eosinophil counts among asthmatic adults. We suggested that long-time Pb exposure as a risk factor might be correlated with the immune system disorder of asthmatic adults and affect the development, exacerbation, and treatment of asthma.

Assessment of house dust trace elements and human exposure in Ankara, Turkey

One of the impacts of the COVID-19 pandemic is leading people remain at homes longer than ever. Considering the elongation of the time people spend indoors, the potential health risks caused by contaminants including heavy metals in indoor environments have become even more critical. The purpose of this study was to evaluate the levels and sources of heavy metals in indoor dust, to assess the exposure to heavy metals via indoor dust, and to estimate the associated health risk. The highest median value was measured for Zn (263 μg g^-1), while the lowest median concentration value was observed for Cd (0.348 μg g^-1). The levels of elements measured in the current study were found to be within the ranges reported in the other parts of the world, mostly close to the lower end of the range. House characteristics such as proximity to the main street, presence of pets, number of occupants, and age of the building were the house characteristics influencing the observed higher concentrations of certain heavy metals in houses. Enrichment factor values range between 1.79 (Cr) and 20.4 (Zn) with an average EF value of 8.80 ± 6.80 representing that the targeted elements are enriched (EF>2) in indoor dust in Ankara. Positive matrix factorization results showed that the heavy metals in the house dust in the study area are mainly contributed from sources namely outdoor dust, carpets/furniture, solders, wall paint/coal combustion, and cigarette smoke. Carcinogenic and non-carcinogenic risk values from heavy metals did not exceed the safe limits recommended by EPA. The highest carcinogenic risk level was caused by Cr. The risk through ingestion was higher than inhalation, and the risk levels were higher for children than for adults.

Lung function decline associated with individual short-term exposure to PM1, PM2.5 and PM10 in patients with allergic rhinoconjunctivitis

BACKGROUND

The susceptibility of allergic rhinoconjunctivitis (ARC) patients to air pollution has yet to be clarified.

OBJECTIVES

Based on a repeated measurement panel study, we explored the association of short-term PM exposure with lung function in ARC patients and to further identify the susceptible populations.

METHODS

Personal PM exposure, including PM₁, PM_2.5 and PM₁₀, was monitored consecutively for three days before outcomes measurements. Lung function indices including forced vital capacity (FVC), forced expiratory volume in 1 s (FEV₁), peak expiratory flow (PEF), and forced expiratory flow at 25-75 % of the vital capacity (FEF_25-75) were measured. Serum total immunoglobulin E (IgE), specific-allergen IgE, blood eosinophil and basophils, and the symptoms severe scores were tested in each visit. Linear mixed effect models were applied to estimate the association between PM exposure and lung function. Furthermore, stratified and overlapping grouped populations based on IgE levels were implemented to characterize the modification role and the modulating threshold of IgE at which the association turned significantly negative.

RESULTS

Short-term PM personal exposure was associated with a significant decrease in lung function in ARC patients, especially for small airway respiratory indexes. The highest estimates occurred in PM₁, specifically a 10 μg/m³ increase reduced FEV₁/FVC, PEF and FEF_25-75 by 1.36 % (95 %CI: -2.29 to -0.43), 0.23 L/s (95 %CI: -0.42 to -0.03) and 0.18 L/s (95 %CI: -0.30 to -0.06), respectively. Notably, PM-induced decreases in lung function were stronger in patients with higher IgE levels (IgE ≥ 100 IU/mL), which were related to higher inflammatory cytokines and symptoms scores. Further, PM-associated lung function declines enhanced robustly and monotonically with increasing IgE concentration. Potential modulating thresholds of IgE occurred at 46.8-59.6 IU/mL for significant PM-lung function associations.

CONCLUSION

These novel findings estimated the short-term effects of PM on lung function in ARC patients, and the threshold values of IgE for the significant and robust associations.

Exposure to Heavy Metals and Allergic Outcomes in Children: a Systematic Review and Meta-analysis

It has been reported that heavy metals have adverse effects on the immune system. However, the relationship between heavy metal exposure and allergic outcomes remains unclear. This systematic review was conducted to examine whether heavy metal exposure is associated with allergic outcomes during childhood. We performed a systematic search of all relevant articles in Web of Science, EMBASE, and PubMed, from inception through to November 2020. We used odds ratio (OR) and the standard mean differences (SMDs) with 95% confidence intervals (CIs) to present estimates from individual studies. In addition, random-effects meta-analysis was used to pool the data. We also conducted the meta-regression and subgroup analysis to explore potential sources of heterogeneity. After duplicate removal, we finally included 35 articles in the systematic review and meta-analysis from an initial 11,181 articles. The overall results showed that copper (Cu) was associated with asthma (pooled SMD = 1.50, 95% CI = 0.13-2.86); in the subgroup analysis, the results indicated that lead (Pb) was associated with asthma (pooled OR = 6.27, 95% CI = 2.24-17.56), and Cu and Pb were connected with atopic dermatitis (SMD =  - 1.05, 95% CI =  - 1.45 to - 0.65; SMD = 5.68, 95% CI = 5.05-6.32), respectively. Mercury (Hg) was associated with atopic dermatitis (pooled OR = 1.13, 95% CI = 1.04-1.22) and wheeze (OR = 1.20, 95% CI = 1.05-1.37). The meta-analysis results indicate that Cu might be connected with childhood asthma, but not with other allergic diseases; Hg and Pb may have no association with allergic diseases during childhood. Given some limits observed in the current studies, more prospective cohort studies are still needed to verify our findings. Review registration: PROSPERO CRD42020222167.

Urinary Arsenic Concentration and Its Relationship with Bronchial Asthma in Children from Arica, Chile

In the city of Arica, northern Chile, the population has been involuntarily exposed to arsenic of natural and anthropogenic origin. This study aims to evaluate the association between urinary arsenic concentration and bronchial asthma diagnosis in the children of Arica. A cross-sectional analysis of a database of 1892 subjects under 18 years of age enrolled in the Environmental Health Centre between 2009 and 2021 was carried out. Arsenic exposure was obtained from a urine sample and bronchial asthma diagnosis from the database of the system for the management of explicit health guarantees. Logistic regression models were used to assess the association between inorganic arsenic and asthma. The median inorganic arsenic was 15 μg/L, and the prevalence of asthma was 7.4%. After adjusting for sex, age, ethnicity, and urinary creatinine, children with the highest tertile of urinary arsenic concentration (≥21.4 μg/L) had a greater chance of developing asthma (odds ratio (OR) 1.90; 95% confidence interval (CI) [1.13-3.18]). When exploring the modifying effect of ethnicity, the association increased among children belonging to any ethnic group (OR 3.51, 95%CI [1.43-8.65]). These findings suggest a relationship between arsenic exposure and bronchial asthma in children. While further studies are needed to assess the impact of arsenic on respiratory health, mitigation efforts to reduce arsenic exposure should be maintained.

Rosa laevigata Attenuates Allergic Asthma Exacerbated by Water-Soluble PM by Downregulating the MAPK Pathway

Exposure to water-soluble particulate matter (WPM) containing heavy metals can cause severe inflammatory responses and trigger and exacerbate the onset of asthma. As a follow-up study of Rosa laevigata (RL), this study analyzed the therapeutic effects and mechanisms of oral and intratracheal administration of RL and demonstrated anti-inflammatory effects in asthma models. Worse T-helper cell type 2 (Th2)-related inflammatory and pro-inflammatory responses were observed after simultaneous challenge with ovalbumin (OVA) and WPM. To establish a model of asthma exacerbated by WPM, BALB/c mice were sensitized with OVA + aluminum hydroxide and challenged with OVA + WPM. To confirm the therapeutic efficacy of RL, it was administered both orally and intratracheally. Histopathological analysis of H&amp;E staining confirmed that oral and intratracheal administration of RL alleviated inflammatory cell infiltration in the airways aggravated by OVA + WPM. RL effectively reduced the number of inflammatory cells obtained from the bronchoalveolar lavage fluid. In addition, enzyme-linked immunosorbent assay (ELISA) and multiplex analysis of serum samples confirmed that the administration of RL reduced the levels of immuno-globulin E (IgE), Th2-related cytokines, and pro-inflammatory cytokines. Furthermore, real-time PCR analysis of lung tissue samples confirmed that the release of MUC5AC (Mucin 5AC, Oligomeric Mucus/Gel-Forming) and pro-inflammatory cytokines was reduced by RL, and western blotting confirmed that the administration of RL reduced the phosphorylation of ERK and p38 in the MAPK pathway. In conclusion, oral and intratracheal administration of RL appears to have an anti-asthmatic effect by reducing the secretion of Th2-related cytokines, pro-inflammatory cytokines, and IgE by downregulating the MAPK pathway. Thus, RL has further demonstrated potential for development as an oral and inhaled therapeutic for asthma symptoms exacerbated by WPM exposure.

Association between prenatal metal exposure and adverse respiratory symptoms in childhood

INTRODUCTION

Manganese and lead have been cross-sectionally associated with adverse respiratory outcomes in childhood but there is limited data on their combined effects starting in utero. We examined associations between in utero exposure to metals and childhood respiratory symptoms.

METHODS

We assessed 633 mother-child dyads enrolled in the Programming Research in Obesity, Growth, Environment, and Social Stressors (PROGRESS) birth cohort in Mexico City. Blood manganese (BMn) and lead (BPb) were measured in mothers at 2^nd and 3^rd trimester. Ever wheeze, current wheeze and asthma diagnosis were ascertained at 4-5 and 6-7 year visits through the International Study of Asthma and Allergies in Childhood survey. Logistic mixed model regression was used to assess the association between prenatal metals and respiratory outcomes in children across the 4-5 and 6-7 year visits. Covariates included mother's age, education and asthma, environmental tobacco smoke, child's sex and assessment time.

RESULTS

In adjusted models, higher 2^nd trimester BPb had a significant association with elevated odds of ever wheeze (Odds Ratio (OR): 1.97, 95% CI: 1.05, 3.67). BMn at 2nd trimester was associated with decreased (OR: 0.06, 95% CI: 0.01, 0.35) odds of current wheeze. We did not find any statistically significant associations with 3rd trimester blood metals.

CONCLUSION

Prenatal exposure to Pb was associated with higher odds of ever wheeze while Mn was negatively associated with odds of current wheeze. These findings underscore the need to consider prenatal metal exposure, including low exposure levels, in the study of adverse respiratory outcomes.

Prenatal lead exposure and childhood lung function: Influence of maternal cortisol and child sex

INTRODUCTION

Maternal hypothalamic-pituitary-adrenal (HPA) axis disruption in pregnancy may contribute to the programming of childhood respiratory disease and may modify the effect of chemical toxins, like lead (Pb), on lung development. Child sex may further modify these effects. We sought to prospectively examine associations between maternal HPA axis disruption, prenatal Pb and childhood lung function and explore potential effect modification by maternal cortisol and child sex on the association between prenatal Pb and lung function outcomes.

MATERIALS AND METHODS

Analyses included 222 mothers and children enrolled in a longitudinal birth cohort study in Mexico City. Maternal diurnal salivary cortisol was assessed in pregnancy; cortisol awakening response (CAR) and diurnal slope were calculated. Blood Pb was measured during the second trimester of pregnancy. Post-bronchodilator lung function was tested at ages 8-11 years. Associations were modeled using generalized linear models with interaction terms, adjusting for covariates.

RESULTS

A higher (flatter) diurnal slope was associated with lower FEV₁/FVC ratio (β: 0.433, 95%CI [-0.766, -0.101]). We did not find any main effect associations between prenatal Pb and lung function outcomes. We report an interaction between Pb and cortisol in relation to FEV₁/FVC and FEF_25-75% (p_interaction<0.05 for all). Higher prenatal Pb was associated with reduced FEV₁/FVC only in children whose mothers had a high CAR. Higher prenatal Pb was also associated with reduced FEV₁/FVC and FEF_25-75% in mothers with a flatter diurnal slope. A 3-way interaction between prenatal Pb, CAR and sex on FEV₁/FVC, indicated that boys born to women with high CAR and higher prenatal Pb levels had lower FEV₁/FVC ratios (p_interaction = 0.067).

CONCLUSIONS

Associations between prenatal Pb and childhood lung function were modified by disrupted maternal cortisol in pregnancy and child sex. These findings underscore the need to consider complex interactions to fully elucidate effects of prenatal Pb exposure on childhood lung function.

Low concentrations of lead disturb phenotypical markers of the inflammatory and the anti-inflammatory profile of bone marrow-derived macrophages from BALB/c mice

Lead (Pb) is a ubiquitous toxic metal that decreases resistance to infections, in which the macrophages have an essential role. Pb adverse effects on nitric oxide (NO^-) production and variable effects on inflammatory cytokines in activated macrophages have been reported, but no effects have been reported in anti-inflammatory macrophages. We studied Pb (0.03-6 μg/dL equivalent to 0.014-2.89 μM) effects on the function of bone marrow-derived macrophages (BMDM) induced to either inflammatory or anti-inflammatory phenotypes, with LPS + IFNγ or IL-4+IL-13, respectively, and whether these effects are related. Pb did not induce cytotoxicity at any concentration in both macrophage phenotypes. In inflammatory BMDM, Pb (6 μg/dL) inhibited NO^- production without affecting inducible nitric oxide synthase (iNOS) levels or basal arginase activity. At 3 and 6 μg/dL, Pb enhanced the major histocompatibility complex class II (MHC II) membrane expression but did not modify CD86 expression, TNFα, or IL-1β production and secretion. In anti-inflammatory BMDM, Pb did not alter arginase activity, but at 3 and 6 μg/dL, increased TGF-β1 and mannose receptor expression. Results showed that environmentally relevant concentrations of Pb alter functional outcomes or phenotypic markers of anti-inflammatory for the first time. The Pb effects on the inflammatory macrophages are not dependent on negative feedback resulting from the Pb effect on the anti-inflammatory phenotype. The Pb affected only some molecules or specific pathways related to both phenotypes. These effects could be related to Pb effects on immune defense against intracellular pathogens and allergy susceptibility.

Prenatal heavy metal exposure, total immunoglobulin E, trajectory, and atopic diseases: A 15-year follow-up study of a Taiwanese birth cohort

Prenatal exposure to heavy metals may cause atopic diseases. Little association between cord blood total immunoglobulin E (CB-tIgE) levels and the occurrence of atopic diseases has been found. This study investigated the atopic status and tIgE trajectory trend in a Taiwanese birth cohort over 15 years. We also assessed the effect of maternal heavy metal exposure on maternal serum cytokine and CB-tIgE levels. We recruited 430 pregnant women during their third trimester in 2000-2001. Maternal urinary heavy metal concentrations and serum cytokine levels were measured. The CB-tIgE and serum tIgE levels of the women's children when they were aged 5, 8, 11, and 14 years were measured. The upper quartile of the maternal urinary arsenic concentration was associated with an increased risk of a CB-tIgE level higher than 1 IU/mL (odds ratio, 1.845; 95% confidence interval, 1.003-3.395). Serum tIgE trajectory levels were the highest in children with asthma, followed by those with atopic dermatitis and allergic rhinitis at the age of 5-14 years. Serum tIgE levels tended to peak at the age of 11 years in the atopic children but were stable from the age of 8 years in the non-atopic children. We first demonstrated that serum tIgE levels reached a trajectory peak in the atopic children aged 11 years. Prenatal exposure to arsenic may increase the risk of elevated CB-tIgE levels. Further investigation is warranted to elucidate the mechanism through which maternal serum cytokines affect the occurrence of atopic diseases in children.

Assessment of Metal Concentrations and Associations with Pulmonary Function among Children with Asthma in Chicago, Illinois

Individuals living in areas with the potential for elevated metal exposure from industrial sources may have reduced pulmonary function. We evaluated cross-sectional associations of toenail concentrations of 17 metals within a community area of residence and asthma control in 75 children, and pulmonary function measures [forced expiratory volume in one second (FEV1; liters), forced vital capacity (FVC; liters), FEV1 to FVC ratio (FEV1:FVC), and mid-exhalation forced expiratory flow rate (FEF 25-75%; liters/second)], in a subsample of 39 children with diagnosed asthma in Chicago, Illinois. Linear regression models were used to estimate adjusted regression coefficients and standard errors (SE) for the associations between ≥ median versus Collapse

Key Words

• asthma
• children
• metals
• pulmonary function
• respiratory function

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MESH Headings

• Asthma/epidemiology
• Chicago/epidemiology
• Child
• Cross-Sectional Studies
• Forced Expiratory Volume
• Humans
• Lung
• Vital Capacity

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Grants

• T42 OH008672 NIOSH CDC HHS
• P42 ES007373 NIEHS NIH HHS
• P30 CA023108 NCI NIH HHS
• R01 ES02442304 NIEHS NIH HHS
• P30 ES027792 NIEHS NIH HHS

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Affiliation(s)

Jessica M. Madrigal Division of Epidemiology and Biostatistics, School of Public Health, University of Illinois Chicago, Chicago, IL 60612, USA; (J.M.M.); (V.P.)
Victoria Persky Division of Epidemiology and Biostatistics, School of Public Health, University of Illinois Chicago, Chicago, IL 60612, USA; (J.M.M.); (V.P.)
Brian P. Jackson Department of Earth Sciences, Dartmouth College, Hanover, NH 03755, USA;
Amy Bain Mobile Care Chicago, Chicago, IL 60609, USA; (A.B.); (M.S.)
Matt Siemer Mobile Care Chicago, Chicago, IL 60609, USA; (A.B.); (M.S.)
Andrea A. Pappalardo Department of Pediatrics, College of Medicine, University of Illinois Chicago, Chicago, IL 60612, USA; Department of Medicine, College of Medicine, University of Illinois Chicago, Chicago, IL 60612, USA
Maria Argos Division of Epidemiology and Biostatistics, School of Public Health, University of Illinois Chicago, Chicago, IL 60612, USA; (J.M.M.); (V.P.)

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Risk assessment of soil heavy metal contamination at the census tract level in the city of Santa Ana, CA: implications for health and environmental justice

(1) Background: exposure to heavy metals is associated with adverse health effects and disproportionately impacts low-income communities and communities of color. We carried out a community-based participatory research study to examine the distribution of heavy metal concentrations in the soil and social vulnerabilities to soil heavy metal exposures across Census tracts in Santa Ana, CA. (2) Methods: soil samples (n = 1528) of eight heavy metals including lead (Pb), arsenic (As), manganese (Mn), chromium (Cr), nickel (Ni), copper (Cu), cadmium (Cd), and zinc (Zn) were collected in 2018 across Santa Ana, CA, at a high spatial resolution and analyzed using XRF analysis. Metal concentrations were mapped out and American Community Survey data was utilized to assess metals throughout Census tracts in terms of social and economic variables. Risk assessment was conducted to evaluate carcinogenic and non-carcinogenic risk. (3) Results: concentrations of soil metals varied according to landuse type and socioeconomic factors. Census tracts where the median household income was under $50 000 had 390%, 92.9%, 56.6%, and 54.3% higher Pb, Zn, Cd, and As concentrations compared to high-income counterparts. All Census tracts in Santa Ana showed hazard index >1, implying the potential for non-carcinogenic health effects, and nearly all Census tracts showed a cancer risk above 10-4, implying a greater than acceptable risk. Risk was predominantly driven by childhood exposure. (4) Conclusions: findings inform initiatives related to environmental justice and highlight subpopulations at elevated risk of heavy metal exposure, in turn underscoring the need for community-driven recommendations for policies and other actions to remediate soil contamination and protect the health of residents.

Evaluation of blood and tooth element status in asthma cases: a preliminary case-control study

Background

Asthma is a common respiratory disorder; some data were present on the correlation between increased levels of trace elements and the risk of asthma development. It was aimed to evaluate the levels of 13 selected blood and tooth elements (magnesium, phosphorus, calcium, chromium, manganese, iron, copper, zinc, strontium, molybdenum, cadmium, lead, mercury) in a well-controlled asthma group and the control group.

Methods

During the study period, 17 asthma patients and 26 age and gender-matched healthy children donated shed deciduous teeth having neither decay nor filling and enrolled for the study. The element levels in blood and teeth matrixes were analyzed with inductively coupled plasma mass spectrometry. Differences in blood and tooth elements in groups were evaluated with generalized linear models after adjusting confounding factors.

Results

After adjusting the child’s “z scores of body mass index for age”, history of iron deficiency anemia, and status of parental smoking, the generalized linear model revealed significantly lower tooth magnesium levels, lower blood zinc levels, and lower blood zinc/copper ratio in the asthma group than the control group (p = 0.042, p = 0.034, p = 0.002, respectively). Other studied elements for tooth and blood matrixes were similar in groups.

Conclusion

Our study revealed some differences in tooth and blood element levels in the asthma group. Further studies on zinc and magnesium levels of severe asthma cases are necessary for the interpretation of the results.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01565-9.

Maternal metal concentration during gestation and pediatric morbidity in children: an exploratory analysis

Background

The majority of studies linking exposure to metals with certain health outcomes focus on known toxic metals. Alternatively, this study assesses the extent to which exposure to a wider range of metals during gestation is associated with childhood morbidity.

Methods

We analyzed the concentrations of 25 metals found in urine samples of 111 pregnant women of Arab-Bedouin origin collected prior to birth. In addition, we collected medical records on their offspring for six years following birth, including every interaction with HMOs, local hospitals, and pharmacies.

Results

The main types of morbidities diagnosed and treated during this period were preterm births, malformations, asthma-like morbidity, cardiovascular and behavioral problems, and obesity. Multivariable analysis showed that offspring born before term were more likely to have been exposed to elevated maternal concentrations of zinc, thallium, aluminum, manganese, and uranium, all with adjusted relative risk above 1.40 for an increase by each quintile. Likewise, children with asthma had been exposed to higher levels of magnesium, strontium, and barium at gestation, while behavioral outcomes were associated with elevated biometals, i.e., sodium, magnesium, calcium, selenium, and zinc, as well as higher levels of lithium, cobalt, nickel, strontium, cadmium, vanadium, arsenic, and molybdenum. A heatmap of adjusted relative risk estimates indicates the considerable implications that exposure to metals may have for preterm birth and developmental outcomes.

Conclusions

The current study shows that perinatal exposure to metals is adversely associated with pediatric morbidity. Further such analyses on additional samples are warranted.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12199-021-00963-z.

Scoping Review-The Association between Asthma and Environmental Chemicals

Asthma is one of the most common chronic diseases worldwide affecting all age groups from children to the elderly. In addition to other factors such as smoking, air pollution and atopy, some environmental chemicals are shown or suspected to increase the risk of asthma, exacerbate asthma symptoms and cause other respiratory symptoms. In this scoping review, we report environmental chemicals, prioritized for investigation in the European Human Biomonitoring Initiative (HBM4EU), which are associated or possibly associated with asthma. The substance groups considered to cause asthma through specific sensitization include: diisocyanates, hexavalent chromium Cr(VI) and possibly p-phenylenediamine (p-PDA). In epidemiological studies, polyaromatic hydrocarbons (PAHs) and organophosphate insecticides are associated with asthma, and phthalates, per- and polyfluoroalkyl substances (PFASs), pyrethroid insecticides, mercury, cadmium, arsenic and lead are only potentially associated with asthma. As a conclusion, exposure to PAHs and some pesticides are associated with increased risk of asthma. Diisocyanates and Cr(VI) cause asthma with specific sensitization. For many environmental chemicals, current studies have provided contradicting results in relation to increased risk of asthma. Therefore, more research about exposure to environmental chemicals and risk of asthma is needed.

Early life blood lead levels and asthma diagnosis at age 4-6 years

The USA has a high burden of childhood asthma. Previous studies have observed associations between higher blood lead levels and greater hypersensitivity in children. The objective of the present study was to estimate the association between blood lead concentrations during early childhood and an asthma diagnosis between 48 and 72 months of age amongst a cohort with well-characterized blood lead concentrations. Blood lead concentrations were measured at 6, 12, 18, 24, 36, and 48 months of age in 222 children. The presence of an asthma diagnosis between 48 and 72 months was assessed using a questionnaire which asked parents or guardians whether they had been told by a physician, in the past 12 months, that their child had asthma. Crude and adjusted risk ratios (RR) of an asthma diagnosis were estimated for several parameterizations of blood lead exposure including lifetime average (6 to 48 months) and infancy average (6 to 24 months) concentrations. After adjustment for child sex, birthweight, daycare attendance, maternal race, education, parity, breastfeeding, income, and household smoking, age-specific or composite measures of blood lead were not associated with asthma diagnosis by 72 months of age in this cohort.

Associations between prenatal and postnatal lead exposure and preschool children humoral and cellular immune responses

Studies have shown that lead exposure affected the immune function, but few studies have examined the relationships between in utero lead exposure, a sensitive period that is important for immune development, and later immune responses. To investigate the effects of prenatal and childhood lead exposure on the preschool-aged children's immune responses, a prospective birth cohort study was established in Wuhan, China, in which lead concentrations were analyzed in maternal urine during the third trimester and in plasma samples from children aged about 3 years. We assessed immune responses by measuring immune cytokines in the children's plasma (n = 326) and peripheral blood T lymphocyte subsets (n = 394) at 3 years of age. Each unit increase in maternal urinary lead concentration (μg/g creatinine) was associated with reduced IL-10 (β = -5.93%, 95%CI: -11.82%, -0.03%) and reduced IL-4 levels (β = -5.62%, 95%CI: -10.44%, -0.80%). Lead in children's plasma (μg/L) was associated with significant increase in TNF-α (β = 10.78%, 95%CI: 3.97%, 17.59%). No statistically significant relationship of childhood lead exposure with T lymphocyte subsets was observed. The study suggested prenatal and childhood lead exposure was associated with changes in preschool children's plasma cytokine levels.

Combined exposure to heavy metals in PM2.5 and pediatric asthma

BACKGROUND

Asthma is the most common chronic allergic disease in children; it affects more than 300 million people worldwide. Information on the association between exposure to ambient heavy metals and incidence of pediatric asthma is limited.

OBJECTIVE

We sought to evaluate the effects of heavy metals during pregnancy and infancy periods with asthma and identify a sensitive time window, clarifying the effect of ambient heavy metals on lung development.

METHODS

A total of 171,281 children, who were born from 2004 to 2011 in Taichung City, were followed until 2014. Concentrations of ambient heavy metals such as arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) were obtained from the Weather Research and Forecasting/Chem model, considering the top 75 emission sources in Taiwan. The distributed lag nonlinear model was used to investigate the relationship between combined exposure to heavy metals in 2.5 μm particulate matter and asthma in pregnant women and 1-year-old infants.

RESULTS

We identified 31,277 new asthma cases from the birth cohort. After adjustment for socioeconomic status, maternal age, maternal atopy, maternal anemia, and maternal kidney disease, distributed lag nonlinear model results revealed positive associations of asthma with exposure to Pb during gestational weeks 1 to 14 and 21 to 40, and 1 to 3 weeks after birth. Regarding the sensitivity analyses, coexposure to Pb and As, coexposure to Pb and Cd, and coexposure to Pb and Hg were positively associated with asthma onset as well.

CONCLUSIONS

Our study suggested that combined exposure to Pb with As, Cd, and Hg during early and late gestational weeks was associated with the incidence of pediatric asthma.

Social and spatial distribution of soil lead concentrations in the City of Santa Ana, California: Implications for health inequities

BACKGROUND

Lead (Pb) exposure is a problem that disproportionately impacts low-income communities and communities of color. We applied a community-based participatory research approach to assess the distribution of soil Pb concentrations and related social vulnerabilities across Census tracts in Santa Ana, CA.

METHODS

Soil Pb samples (n = 1528) were collected by the ¡Plo-NO! Santa Ana! Lead-Free Santa Ana! partnership in 2018 across Santa Ana, CA, at a high spatial resolution and measured using XRF analysis. Pb concentrations were mapped and spatial interpolation was conducted to generate a continuous smoothed map of soil Pb concentrations across the city. American Community Survey data was used to examine Pb across Census tracts based on social and economic factors, and to allow for the development of a Cumulative Risk Index to identify areas at high risk of health impacts.

RESULTS

Soil Pb concentrations varied by landuse type and socioeconomic factors. Census tracts with a median household income below $50,000 had over five times higher soil Pb concentrations than high-income Census tracts. Soil samples collected in tertiles with the highest percent children, residents without health insurance, renter-occupied housing units, and lowest percent college educated residents had 90.0%, 96.1%, 75.2%, and 87.0% higher Pb concentrations on average, respectively, compared to their counterparts. Overall, 52.7% of residential samples had Pb concentrations in excess of the 80 ppm California EPA recommendation, and 11 Census tracts were characterized as high risk according to our Cumulative Risk Index.

DISCUSSION

This study underscores the need for precautionary measures relating to disturbances of the soil, particularly for areas where children play outside, given children's higher absorption of lead. It also informs environmental justice initiatives and identifies vulnerable subpopulations at greater risk of Pb exposure, thus warranting community-driven recommendations for policies and initiatives to remediate soil Pb and protect public health and health equity.

Sex Difference Between Trace Elements and Pulmonary Functions in Children

It has been defined that deficiency of trace elements plays an important role in the progression of asthma. However, the relationship between blood zinc (Zn), selenium (Se), and magnesium (Mg) and pulmonary functions in children remains to be clarified. A cross-sectional study was conducted in Wuxi, China, and a total of 202 healthy children were recruited. The forced vital capacity volume (FVC) and forced expiratory volume in the 1 s (FEV1) were measured. Blood samples were collected, and the levels of blood zinc, selenium, and magnesium were measured by inductively coupled plasma mass spectrometry (ICP-MS). Meanwhile, the concentrations of serum total IgE was also determined. The associations between trace elements and pulmonary functions were analyzed by multiple linear regression models. After stratified by sex, there was a positive association between blood Zn and pulmonary functions in boys. In addition, blood Zn was also negatively associated with serum total IgE concentrations in boys, but not in girls after adjusting for potential confounders. Our findings indicated that zinc deficiency was significantly related to children's pulmonary functions and that screening of trace elements may be a potential solution to decrease the risks of asthma in children.

E-waste lead exposure and children's health in China

China is one of the countries worldwide confronted with serious e-waste pollution and associated detrimental health effects, which has aroused public, academic and governmental concerns. Most local residents are exposed to hazardous substances such as lead (Pb) and other persistent organic pollutants because of informal e-waste recycling activities. This study reviews recent studies on children exposed to e-waste Pb in China focusing on health-related effects in children (e.g. growth and development, cardiovascular, immune, nervous, respiratory, reproductive, skeletal, and urinary systems) and evaluating the evidence for the association between e-waste Pb exposure and the children health outcomes in China. Children are one of most sensitive and vulnerable groups when facing e-waste Pb exposure. Previous data indicate that exposure to e-waste Pb has adverse effect on human health such as delayed and damaged physical and nervous development. It is the time to take effective measures, such as upgrading e-waste recycling technology, enhancing government policy guidance and support, and strengthening environmental protection and health awareness of the local inhabitants, to prevent the adverse effects of e-waste.

Effects of Lead, Mercury, and Cadmium Co-exposure on Children's Pulmonary Function

Accumulating evidence has shown that toxic metals exposure can have adverse effects on children, but the effects of blood Pb, Hg, and Cd co-exposure on pulmonary function in children remains to be clarified. This cross-sectional multicenter study was conducted in Wuxi City, China. A total of 221 healthy children free from chronic obstructive pulmonary disease were recruited. The blood samples were collected while blood Pb, Hg, and Cd levels were determined. The forced vital capacity volume (FVC) and forced expiratory volume in the 1 s (FEV1) were measured. The associations between metals concentration and pulmonary function were analyzed by multiple linear regression models. The geometric means of the blood Pb, Hg, and Cd levels in our study were 37.27 μg/L, 1.41 μg/L, and 0.28 μg/L, respectively. After adjusting for age, sex, maternal education, annual family income, fish consumption, and second-hand smoking exposure, only the blood Pb levels were significantly negatively associated with the pulmonary function. In addition, a significantly positive interaction between blood Pb and blood Cd on pulmonary function were also detected. Although causal relationship cannot be confirmed in this study, at least higher levels of Pb in blood are associated with decreased pulmonary parameters in children.

Exposure to lead and vaccine-specific IgG titers in South African children participating in the Venda Health Examination of Mothers, Babies and their Environment (VHEMBE): A longitudinal study

BACKGROUND

While successes have been achieved in reducing global exposure to lead, few studies have investigated the potential health effects of low-level exposure (e.g. blood lead levels [BLLs] below the CDC reference level of 5 μg/dL), particularly among children from low- and middle-income countries. In addition, lead is immunotoxic in animals but human data on immune response to vaccines is limited. Our aim was to determine whether low-level exposure to lead is associated with humoral response to vaccines among rural South African children.

METHODS

We used data from the Venda Health Examination of Mothers, Babies and their Environment (VHEMBE), a birth cohort study conducted in Limpopo, South Africa. BLLs were measured in whole blood collected at age 1 year and IgG titers for measles, tetanus and Haemophilus influenzae type B (Hib) were determined at age 3.5 years among 425 fully-vaccinated children.

RESULTS

BLLs were low (median = 1.90 μg/dL) and 94% of children had a BLL below 5 μg/dL. Overall, BLLs were associated with higher risks of having IgG titers below the protective limit for tetanus (RR = 1.88 per 10-fold increase; 95%CI = 1.08, 3.24) but not measles (RR = 1.02; 95%CI = 0.26, 3.95) or Hib (RR = 0.96; 95%CI = 0.54, 1.71). BLLs were also associated with low Hib IgG titers among children exposed to HIV in utero and with low measles IgG titers among females. In contrast, the association with measles IgG titers was positive among males.

CONCLUSION

Low-level exposure to lead may compromise the humoral response to vaccines. Children exposed to HIV in utero and females may be particularly susceptible.

Ecogenetics of lead toxicity and its influence on risk assessment

Lead (Pb) toxicity is a public health problem affecting millions worldwide. Advances in 'omic' technology have paved the way to toxico-genomics which is currently revolutionizing the understanding of interindividual variations in susceptibility to Pb toxicity and its functional consequences to exposure. Our objective was to identify, comprehensively analyze, and curate all the potential genetic and epigenetic biomarkers studied to date in relation to Pb toxicity and its association with diseases. We screened a volume of research articles that focused on Pb toxicity and its association with genetic and epigenetic signatures in the perspective of occupational and environmental Pb exposure. Due to wide variations in population size, ethnicity, age-groups, and source of exposure in different studies, researchers continue to be skeptical on the topic of the influence of genetic variations in Pb toxicity. However, surface knowledge of the underlying genetic factors will aid in elucidating the mechanism of action of Pb. Moreover, in recent years, the application of epigenetics in Pb toxicity has become a promising area in toxicology to understand the influence of epigenetic mechanisms such as DNA methylation, chromatin remodeling, and small RNAs for the regulation of genes in response to Pb exposure during early life. Growing evidences of ecogenetic understanding (both genetic and epigenetic processes) in a dose-dependent manner may help uncover the mechanism of action of Pb and in the identification of susceptible groups. Such studies will further help in refining uncertainty factors and in addressing risk assessment of Pb poisoning.

The State of Public Health Lead Policies: Implications for Urban Health Inequities and Recommendations for Health Equity

Although lead has been removed from paint and gasoline sold in the U.S., lead exposures persist, with communities of color and residents in urban and low-income areas at greatest risk for exposure. The persistence of and inequities in lead exposures raise questions about the scope and implementation of policies that address lead as a public health concern. To understand the multi-level nature of lead policies, this paper and case study reviews lead policies at the national level, for the state of California, and for Santa Ana, CA, a dense urban city in Southern California. Through a community-academic partnership process, this analysis examines lead exposure pathways represented, the level of intervention (e.g., prevention, remediation), and whether policies address health inequities. Results indicate that most national and state policies focus on establishing hazardous lead exposure levels in settings and consumer products, disclosing lead hazards, and remediating lead paint. Several policies focus on mitigating exposures rather than primary prevention. The persistence of lead exposures indicates the need to identify sustainable solutions to prevent lead exposures in the first place. We close with recommendations to reduce lead exposures across the life course, consider multiple lead exposure pathways, and reduce and eliminate health inequities related to lead.

Association of heavy metals with measures of pulmonary function in children and youth: Results from the National Health and Nutrition Examination Survey (NHANES)

INTRODUCTION

Exposure to cadmium, cobalt, lead, and manganese has been associated with decreased pulmonary function in adults. Little is known about the magnitude of these associations among children in the United States.

OBJECTIVES

We evaluated cross-sectional associations of blood and urinary concentrations of cadmium, cobalt, lead, and manganese with pulmonary function measures [forced expiratory volume in one second (FEV1; milliliters), forced vital capacity (FVC; milliliters), ratio of FEV1 to FVC (FEV1:FVC), and mid-exhalation forced expiratory flow rate (FEF 25-75%; milliliters/second)] in a sample of 1234 6-17 year olds, who participated in the 2011-2012 survey cycle of the National Health and Nutrition Examination Survey (NHANES).

METHODS

Survey-weighted linear regression was used to estimate beta coefficients and 95% confidence intervals (CIs) for the associations between metal exposure tertiles or quartiles and pulmonary function test parameters, with adjustment for relevant covariates.

RESULTS

Blood manganese concentration was inversely associated with FVC (β for highest versus lowest quartile = -97.1, 95% CI = -230.6, 36.4; p for trend = 0.03). Urinary manganese was inversely associated with FEV1:FVC and FEF 25-75% (p for trend = 0.05 and 0.02, respectively). Urinary lead was inversely associated with FEF 25-75% (p for trend = 0.01). The associations between blood manganese and both FEV1 and FVC differed by age (p for interaction = 0.04 and 0.04, respectively), indicating an inverse trend that was strongest among older youth.

CONCLUSIONS

Environmental exposure to manganese and lead may adversely impact the pulmonary function of young people in the United States. Our findings highlight a need to prioritize children's environmental health and evaluate these associations prospectively.

Associations between environmental heavy metal exposure and childhood asthma: A population-based study

BACKGROUND/PURPOSE

The health risks of environmental heavy metals have been of concern are well known. The greater likelihood of heavy metal contamination in the physical environment increases the risk of asthma, especially in children. This cross-sectional, population-based study sought to investigate associations between heavy metal exposure and childhood asthma or wheezing.

METHODS

Data from 5866 subjects, stratified into age groups of 2-5, 6-11, and 12-15 years, from the National Health and Nutrition Examination Survey 2007-2012 conducted by the Centers for Disease Control and Prevention were analyzed retrospectively. The primary outcome was active asthma. Variables included demographics, anthropometric, and clinical data. Univariate and multivariate logistic regression analyses were used to identify associations between blood heavy metal concentrations and adjusted odds (aORs) of active asthma.

RESULTS

Higher concentration of blood lead was associated with higher adjusted odds of having asthma (aOR = 1.08, 95% CI = 1.00-1.16), but no significant effect was shown for current wheezing or whistling. Age-stratified analysis showed that higher blood lead concentration was associated with higher risk for active asthma (aOR = 1.24, 95% CI = 1.08-1.42) and current wheezing or whistling (aOR = 1.19, 95% CI = 1.04-1.38) in the 6-11 years age group, while higher blood mercury concentration was associated with lower risk of current wheezing or whistling (aOR = 0.95, 95% CI = 0.90-0.99). The medium concentration of blood lead was associated with decreased risks of current wheezing or whistling (aOR = 0.54, 95% CI = 0.30-0.96) in the 2-5 years age group.

CONCLUSION

Higher concentrations of blood lead are associated with higher odds of asthma in children aged 2-15 years.

A selective and sensitive nanosensor for fluorescent detection of specific IgEs to purified allergens in human serum

Food allergies are increasingly recognized as a major healthcare concern. In order to sensitively and specifically detect allergies from blood samples of at-risk allergic patients, an effective magnetic fluorescence sensing platform (EMFP) was constructed. The EMFP incorporated hollow mesoporous silica nanospheres (HMNs) to amplify signal from the target IgE in addition to magnetic nanoparticles (MNPs) to capture and separate the target IgE. The application of EMFP to immunoassays indicated a detection limit of 0.0159 ng mL⁻¹ for low concentration specific immunoglobulin E (sIgE) against purified shellfish Metapenaeus ensis (Meta. E.) allergens, which is 15 fold more sensitive than the commercially available Food and Drug Administration-approved analyzers. Notably, EMFP was specific for the targeted sIgE even with interference by other sIgEs. In addition, the detection time is only 75 min, considerably faster than current commercial ELISA kits for IgE assays. Together, these results demonstrated that EMFP has excellent sensitivity and selectivity for the rapid detection of sIgE. The method thus exhibits potential toward the rapid monitoring of sIgE against Meta. E. allergens in clinical application.

The effective magnetic fluorescence sensing platform was employed to amplify signal and capture target IgE in one step.