Relationship between passive smoking exposure and urinary heavy metals and lung functions in preschool children

Reduction of haemoglobin is related to metal mixtures exposure in Chinese preschoolers: Joint effect models

Heavy metal exposure is a known risk factor for hematologic disorders in children, yet the impact of co-exposure to multiple metals remains underexplored. This cross-sectional study investigates the relationship between urinary levels of 23 metals and haemoglobin (Hb) in 1460 Chinese preschoolers. The concentrations of the 23 urinary metals were quantified using an inductively coupled plasma mass spectrometer, while Hb levels were assessed through finger prick blood samples. To evaluate the co-exposure effects, we employed three approaches: Generalized linear regression model, joint effect models including Quantile g-Computation and Bayesian Kernel Machine Regression (BKMR). From the generalized linear regression and Quantile g-computation, urinary uranium, thallium, aluminium, iron and tungsten were correlated negatively with Hb, while urinary barium was correlated positively (all P < 0.05). Moreover, significant negative associations between metal mixtures exposure with Hb were identified in both Quantile g-computation [β (95% CI): -0.083 (-0.132, -0.033), P = 0.0012] and BKMR [90th percentile vs. 50th percentile β (95% CI): -0.238 (-0.368, -0.107), P < 0.001] with aluminium emerging as the primary contributor to this joint effect (weight in Quantile g-computation = 0.399, PIPs in BKMR = 0.896). These findings provide a potential explanation for environmental exposure to metals and Hb-related disease in preschoolers.

Association of environmental tobacco smoke (ETS) with lead and cadmium concentrations in biological samples of children and women: systematic review and meta-analysis

OBJECTIVES

Previous literature has shown that heavy metals (HMs) in cigarette smoke have been overestimated, and second-hand smoke (SHS) has recently raised public concern. This study aimed to review the effects of passive tobacco exposure on lead (Pb) and cadmium (Cd) concentrations of children and women in different biological samples.

CONTENT

In this systematic review, two independent researchers assessed different databases/search engines including PubMed, Web of Science, Scopus, and Google Scholar using Mesh terms and Text Words. Studies between January 2000 and May 2022 were included. After quality assessment, studies with sufficient data were included in the meta-analysis. A fixed or random model was used to pool the results in a meta-analysis. Heterogeneity between the studies was assessed by using I-square and Q tests. Forest plots demonstrating the point and pooled estimates were provided.

SUMMARY

A total of 976 studies were obtained from different databases and finally 17 studies meet our criteria and were included in our systematic review. Out of 17 studies, six studies had sufficient data for analysis and were included in the meta-analysis. The results of the meta-analysis showed a significant difference in blood lead concentrations (BLC) between the children with SHS exposure and the control group (Hedges' g: 2.44, 95% CI: 1.01-3.86, p<0.05). Also, there were significant differences in hair levels of Cd (Hedges' g: 0.66, 95% CI: 0.04, 1.28, p<0.05) and Pb (Hedges' g: 0.94, 95% CI: 0.05, 1.83, p<0.05) between children with SHS exposure compared to the control group.

OUTLOOK

The results of the present meta-analysis showed that passive smokers had higher Pb and Cd concentrations than those who were not exposed to cigarette smoke.

Association of exposure to environmental vanadium and manganese with lung function among young children: A population-based study

Exposure to environmental metals has been associated with health outcomes including respiratory health. Little is known about the impact of exposure to environmental metals on lung function among young children in general population. This study aimed to investigate the associations of exposure to metals with lung function among young children in a population-based cohort. A total of 1488 children aged 5-8 years attended a follow-up visit as part of the Longitudinal Investigation of Global Health in Taiwanese Schoolchildren (LIGHTS) cohort. We measured urinary samples of vanadium (median: 1.21 ng/mL; interquartile range (IQR): 0.73-1.98), manganese (median: 0.23 ng/mL; IQR: 0.13-0.47), arsenic (median: 40.51 ng/mL; IQR: 21.66-70.49), nickel (median: 1.09 ng/mL; IQR: 0.31-3.60), and cadmium (median: 0.26 ng/mL; IQR: 0.11-0.43) and performed lung function tests. Urinary vanadium concentrations were inversely associated with FVC (β coefficient for the highest quartile versus the other quartiles: -33.40, p = 0.001), FEV1 (β: -41.31, p < 0.001), FEV1/FVC ratio (β: -1.00, p = 0.009), PEF (β: -92.12, p = 0.004), and FEF25-75 (β: -82.85, p < 0.001), after adjusting for relevant confounders. Urinary manganese concentrations were inversely associated with FVC (β: -26.60, p = 0.007), FEV1 (β: -31.62, p = 0.001), PEF (β: -84.86, p = 0.009), and FEF25-75 (β: -69.21, p = 0.002). Stratification analyses found inverse associations of urinary vanadium and manganese concentrations with lung function parameters predominantly among children exposed to environmental tobacco smoke. We did not find significant associations of urinary arsenic, nickel, and cadmium concentrations with lung function parameters. In conclusion, this study adds new evidence showing inverse associations of vanadium and manganese exposure with lung function among young children in the general population. Children with environmental tobacco smoke exposure are particularly vulnerable to adverse impact of vanadium and manganese exposure on lung function.

Independent and combined associations of multiple-heavy-metal exposure with lung function: a population-based study in US children

Previous research has found relationships between some single metals and lung function parameters. However, the role of simultaneous multi-metal exposure is poorly understood. The crucial period throughout childhood, when people are most susceptible to environmental dangers, has also been largely ignored. The study aimed to evaluate the joint and individual associations of 12 selected urinary metals with pediatric lung function measures using multi-pollutant approaches. A total of 1227 children aged 6-17 years from the National Health and Nutrition Examination Survey database of the 2007-2012 cycles were used. The metal exposure indicators were 12 urine metals adjusted for urine creatinine, including arsenic (As), barium (Ba), cadmium (Cd), cesium (Cs), cobalt (Co), mercury (Hg), molybdenum (Mo), lead (Pb), antimony (Sb), thallium (Tl), tungsten (Tu), and uranium (Ur). The outcomes of interest were lung function indices, including the 1st second of a forceful exhalation (FEV₁), forced vital capacity (FVC), forced expiratory flow between 25 and 7% of vital capacity (FEF_25-75%), and peak expiratory flow (PEF). Multivariate linear regression, quantile g-computation (QG-C), and Bayesian kernel machine regression models (BKMR) were adopted. A significantly negative overall effect of metal mixtures on FEV₁ (β = - 161.70, 95% CI - 218.12, - 105.27; p < 0.001), FVC (β = - 182.69, 95% CI - 246.33, - 119.06; p < 0.001), FEF_25-75% (β = - 178.86 (95% CI - 274.47, - 83.26; p < 0.001), and PEF (β = - 424.17, 95% CI - 556.55, - 291.80; p < 0.001) was observed. Pb had the largest negative contribution to the negative associations, with posterior inclusion probabilities (PIPs) of 1 for FEV₁, FVC, and FEF_25-75%, and 0.9966 for PEF. And Pb's relationship with lung function metrics showed to be nonlinear, with an approximate "L" shape. Potential interactions between Pb and Cd in lung function decline were observed. Ba was positively associated with lung function metrics. Metal mixtures were negatively associated with pediatric lung function. Pb might be a crucial element. Our findings highlight the need for prioritizing children's environmental health to protect them from later respiratory disorders and to guide future research into the toxic mechanisms of metal-mediated lung function injury in the pediatric population.

Unintentional Tobacco Smoke Exposure in Children

Secondhand smoke (SHS) exposure increases the prevalence and severity of sinopulmonary diseases in children. The primary source of SHS exposure in children is through adults who live in the same house; however, the level of exposure may vary based on the adult smoking habits at home. This prospective cross-sectional study in Alberta, Canada, investigated the relationship between self-reported caregiver smoking, location, outdoor temperature and children’s’ urine cotinine: creatinine ratio (CCR), a marker of nicotine metabolism. Participants aged 0−9 were recruited from the Child Health Clinics at the Misericordia Community Hospital in Edmonton, Alberta, from 8 January to 24 February 2016 and 30 June to 18 August 2016. Participant CCR levels were compared to caregiver-reported smoking location and environmental factors such as temperature and season. Of the 233 participants who reported smoking status, 21% reported smoking, in keeping with local smoking rates. More participants smoked indoors during the winter than the summer; however, some families limited indoor smoking to a garage. Of the 133 parent−child dyads who provided smoking information and a child urine sample, 18 had an elevated cotinine:creatinine ratio, suggestive of significant tobacco smoke exposure, 15 of whom were from homes that reported smoking. Age < 1 year and number of cigarettes smoked in the home weekly were risks for significant exposure while season, outdoor temperature and smoking location in the home did not reach significance. Smokers should be counseled to protect children, particularly infants, from exposure by limiting the number of cigarettes smoked and isolating smoking to outside the home. Segregated areas such as a garage may provide a useful harm mitigation strategy for indoor smokers, provided the garage does not share ventilation or is not in close proximity to high-traffic areas of the home.

Monthly Motivational Interview Counseling and Nicotine Replacement Therapy for Smoking Parents of Pediatric Patients: A Randomized Controlled Trial

BACKGROUND

Parental smoking is the dominant source of passive smoke exposure in the pediatric population. The current randomized controlled trial (RCT) study aimed to evaluate the effectiveness of a multi-component smoking reduction intervention in parental smoking reduction and children's environmental tobacco smoke exposure reduction in clinical settings.

METHODS

A single-blinded, 6-month randomized controlled trial recruited smoking parents (N = 210) of children who attended the pediatric wards or clinics at the Prince of Wales Hospital. Participants allocated to the intervention group (n = 105) received monthly motivational interviews on smoking reduction with emphasis on health hazards related to children's passive smoke exposure, 8-week nicotine replacement therapy, and referral to smoking cessation service if the parents preferred. The control group (n = 105) received simple verbal advice on smoking cessation. Primary outcomes were parental urine cotinine validated and self-reported ≥50% smoking reduction rates at 6 months.

RESULTS

Smoking parents in the intervention group had significantly more biochemically validated ≥50% smoking reduction than the control: 27.1 vs. 10.0% (OR = 3.34, 95% CI: 1.16-9.62, P = 0.02). The rate of self-reported ≥50% smoking reduction was also significantly higher in the intervention group than the control: 51.9 vs. 20.2% (OR = 4.40, 95% CI: 2.38-8.12, P < 0.001). For secondary outcomes, the rate of parental self-reported smoking cessation was higher in the intervention arm: 10.5 vs. 1.0% (OR = 12.17, 95% CI: 1.54-96.07, P < 0.001), however, no differences were detected in biochemically validated cessation and changes in children's passive smoke exposure between the groups.

CONCLUSION

Monthly smoking reduction counseling together with nicotine replacement therapy is more effective than simple verbal cessation advice in the smoking reduction for parents of pediatric patients. However, this study did not demonstrate differences in smoking cessation or reduction in children's passive smoke exposure with a 6-month follow-up. Achievement of a smoke-free environment remains challenging.

TRIAL REGISTRATION

Clinicaltrials.gov, identifier: NCT03879889.

The Association between the Concentration of Heavy Metals in the Indoor Atmosphere and Atopic Dermatitis Symptoms in Children Aged between 4 and 13 Years: A Pilot Study

BACKGROUND

A correlation between the harmful effects of air pollutants and atopic dermatitis has been reported. There are few studies on the correlation between the concentration of heavy metals in the indoor atmosphere and symptoms of atopic dermatitis.

METHODS

Twenty-two homes of children showing atopic dermatitis symptoms were enrolled, and eighteen homes with similarly aged children without symptoms or a history of atopic dermatitis participated as a control group. We measured the concentrations of various air pollutants (particulate matter 10, carbon dioxide, carbon monoxide, formaldehyde, nitrogen dioxide, volatile organic compounds (VOCs), ozone, radon, bacterial aerosols, and mold) as well as various heavy metals, such as lead, cadmium, and mercury, in the living room and children's bedroom of each home.

RESULTS

Lead was more commonly detected in the indoor air in houses of children with atopic dermatitis (15/22) as compared to in the control group (3/18) (chi square test, p = 0.002). In adjusted logistic regression analysis, VOCs and lead were significantly associated with atopic dermatitis (p < 0.05).

CONCLUSION

Our study shows that lead in indoor air might be associated with atopic dermatitis, even if the concentrations of airborne lead are below the safety levels suggested by health guidelines.

Effects of early and recent mercury and lead exposure on the neurodevelopment of children with elevated mercury and/or developmental delays during lactation: A follow-up study

This follow-up study of 82 children investigated the potential impact of early and recent exposure to mercury and lead on their neurodevelopmental performance at 5-8 years of age (2017-2018). Early exposure of these children to mercury, methylmercury, and lead was assessed during lactation at 3-12 months old, as well as their mother's exposure using measurements from a cross-sectional study (2011-2013). Only infants who failed to pass the neurodevelopment screening tools and/or had elevated mercury were included in this study. Urine and hair were sampled during the follow-up study to assess the children's recent exposure to mercury, methylmercury, and lead. Their cognitive performance and visual-motor integration were also measured using the Test of Non-Verbal Intelligence (TONI) and the Beery-Visual-Motor Integration (Beery VMI), respectively. The association between alterations in urinary porphyrins excretion and exposure to metals was analyzed and their influence on the children's neurodevelopment was explored. Linear regression models revealed a significant negative association between the infants' mercury exposure during lactation and the TONI Quotient (β = -0.298, 95%CI = -4.677, -0.414) and Beery VMI Age Equivalent scores at age 5-8 (β = -0.437, 95%CI = -6.383, -1.844). The mothers' blood methylmercury was inversely and significantly associated with their children's TONI Quotient (β = -0.231, 95%CI = -8.184, -0.331). In contrast, the children's Beery VMI Age Equivalent scores were positively and significantly associated with the hair methylmercury of the mothers (β = 0.214, 95%CI = 0.088, 3.899) and their infants (β = 0.256, 95%CI = 0.396, 4.488). These relationships suggest the presence of negative confounding that we did not take into account. Unlike mercury, there was some evidence that lead in breast milk had an inverse relationship with the children's visual-motor coordination skills. Our study did not show a clear association between children's recent exposure to metals and neurodevelopment. However, a significant inverse association was observed between the TONI Quotient and the interaction of hair methylmercury × ∑porphyrins (ß = -0.224, 95%CI = -0.86, -0.049), implying that porphyrins are a sensitive measure of low body-mercury burden. Although lead induced higher ∑porphyrins excretion in urine (β = 0.347, 95%CI = 0.107, 0.525), their interaction did not influence children's neurodevelopmental scores. The interactions between metals and porphyrins might provide insights into their potential contributory role in the pathogenesis associated with neurological disorders or other diseases. Despite the small sample size of the present study, its findings about the association between toxic metal exposure and the high risk of poor neurodevelopmental performance are worrying, particularly at an early age, and additional research is needed using larger sample sizes.

Reference intervals of spot urine copper excretion in preschool children and potential application in pre-symptomatic screening of Wilson disease

The objectives were to determine the reference intervals of spot urine copper excretion indexes in pre-school children and to evaluate their utility in screening for Wilson disease (WD). With spot urine collected from a control sample of preschool children (aged 3-7 years, n=153), the reference intervals of spot urine copper excretion indexes and their biological variation were defined. In order to investigate their utility performance in screening for WD in this age group, multiple spot urine samples from six WD patients who were diagnosed at presymptomatic stage were also analysed and compared. Cut-off values useful for detection of WD were defined by receiver operator curve (ROC) analysis. Biological (inter-individual) variation of spot urine copper indexes expressed as coefficient of variation (CVg) were around 60% at this age group, which was moderate and similar to other clinically useful urine tests, such as urine albumin excretion ratio. Spot urine copper excretion strongly correlated with both urine creatinine and osmolality. Linear regression against both creatinine and osmolality showed that ∼94% of data points in healthy preschool children fell within the prediction interval, suggesting that both were useful normalisation factors. ROC showed that copper to osmolality ratio was the best index with an area under curve (AUC) greater than 0.98. Cut-off values of 0.5 μmol/L, 0.1 μmol/mmol and 0.00085 μmol/mOsmol (32 μg/L, 56 μg/g creatinine and 0.054 μg/mOsmol, respectively, in conventional units) for spot urine copper concentration, copper to creatinine ratio and copper to osmolality ratio, respectively, have potential application in the differentiation of WD patients. Based on the data, a new WD screening strategy targeting preschool children is proposed. Application of a bivariate screening strategy using spot urine copper concentration and urine osmolality may be useful in a population-wide screening program for WD among preschool children.

Household environmental tobacco smoke exposure in healthy young children in Hong Kong: Prevalence and risk factors

Background

Environmental tobacco smoke (ETS) exposure attributable respiratory illness burden is huge in paediatric population. Understanding the epidemiology of ETS exposure is important to guide health promotion planning. Therefore, we designed this study to determine the prevalence of household ETS exposure in healthy young children under 2 years of age in Hong Kong, and to explore risk factors associated with the exposure. Our secondary goal was to characterise children’s exposure profile to maternal smoking.

Methods

A secondary analysis was performed based on the data collected from our 2013–2014 territory-wide cross-sectional pneumococcal carriage surveillance study, with a sample size of 1541. We conducted descriptive analysis for exposure prevalence, univariate and multivariate analysis for identification of risk factors.

Results

1541 children (mean age: 11.2 ± 6.4 months, male: 50.7%) were included in the analysis. The overall prevalence of current household ETS exposure was 31.5%, prevalence of prenatal and postnatal maternal smoking was 3.5% and 1.6% respectively. Independent factors associated with children’s ETS exposure were: never breastfed (AOR: 1.48, 95% CI: 1.13–1.93, p = 0.004); prenatal maternal smoking (AOR: 7.46, 95% CI: 2.73–20.39, p< 0.001); overcrowding of household living place (AOR: 3.17, 95% CI: 2.02–4.96, P< 0.001); lower household income (AOR: 1.34, 95% CI: 1.04–1.72, p = 0.02). Interestingly, children residing in Kowloon (AOR: 1.66, 95% CI: 1.19–2.33, p = 0.003) and New Territories West (AOR: 1.54, 95% CI: 1.11–2.15, p = 0.01) were associated with exposure compared with children residing in Hong Kong Island.

Conclusion

Exposure to household ETS is prevalent among Hong Kong young children, particularly in children with maternal unfavourable behaviour and lower socioeconomic status. The identified risk factors should be considered while tobacco control interventions and legislations are planned.

Selenium status in lactating mothers-infants and its potential protective role against the neurotoxicity of methylmercury, lead, manganese, and DDT

A total of 206 lactating mothers and their infants (3-12 months) were included in this study to evaluate postnatal exposure to neurotoxic pollutants such as methylmercury (MeHg), lead (Pb), manganese (Mn), dichlorodiphenyltrichloroethane (DDT) and its metabolites [dichlorodiphenyldichloroethane (DDD), and dichlorodiphenyldichloroethylene (DDE)] and their association with delayed neurological development and to explore the protective role of selenium (Se) against chemical neurotoxicity. Neurodevelopmental performance was evaluated using Denver Developmental Screening Test II and Parents' Evaluation of Developmental Status (PEDS). Multivariate log-binomial regression modeling was applied for both single and multiple exposures to chemicals using a principal component analysis that generated six principal components. Both mothers and their infants had been exposed to metals and DDT metabolites, with some exceeding the accepted permissible limits. The geometric means of MeHg, Pb, Mn, DDD, DDE and DDT levels in breast milk were 1.333, 45.327, 15.576, 0.069, 0.542 and 1.08 μg/l, respectively. A single-exposure model identified a high risk of reduced PEDS performance significantly associated with DDD in breast milk [relative risk (RR) = 1.484; 95% confidence interval (95%CI) = 1.091-2.019] and marginally significantly associated with Pb in the mothers' blood (RR = 2.164; 95%CI = 0.87-5.382). We did not find a protective role of Se in neurodevelopment due to its high levels in the mothers. Models of multi-chemical exposure indicated that Mn in blood and breast milk, Se in blood and Pb in the mothers' urine were marginally significantly associated with a high risk of reduced PEDS performance (RR = 0.424; 95%CI = 0.176-1.022). The use of multi-chemical exposure approach in early life risk assessments is important because it indicates real-world exposure. Our results were not conclusive because the sample size was small, so future studies examining the implications to health of the impact of prenatal/postnatal exposure to a mixture of chemicals in the Saudi population are merited.

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.

Biomarkers of Exposure to Secondhand and Thirdhand Tobacco Smoke: Recent Advances and Future Perspectives

Smoking is the leading preventable disease worldwide and passive smoking is estimated to be the cause of about 1.0% of worldwide mortality. The determination of tobacco smoke biomarkers in human biological matrices is key to assess the health effects related to the exposure to environmental tobacco smoke. The biomonitoring of cotinine, the main nicotine metabolite, in human biofluids-including urine, serum or saliva-has been extensively used to assess this exposure. However, the simultaneous determination of cotinine together with other tobacco biomarkers and the selection of alternative biological matrices, such as hair, skin or exhaled breath, would enable a better characterization of the kind and extent of tobacco exposure. This review aims to perform a critical analysis of the up-to-date literature focused on the simultaneous determination of multiple tobacco smoke biomarkers studied in different biological matrices, due to the exposure to secondhand smoke (SHS) and thirdhand smoke (THS). Target biomarkers included both tobacco-specific biomarkers-nicotine and tobacco specific nitrosamine biomarkers-and tobacco-related biomarkers, such as those from polycyclic aromatic hydrocarbons, volatile organic compounds, metals and carbon monoxide. To conclude, we discuss the suitability of determining multiple biomarkers through several relevant examples of SHS and THS exposure.

Biomarkers of exposure to new and emerging tobacco delivery products

Accurate and reliable measurements of exposure to tobacco products are essential for identifying and confirming patterns of tobacco product use and for assessing their potential biological effects in both human populations and experimental systems. Due to the introduction of new tobacco-derived products and the development of novel ways to modify and use conventional tobacco products, precise and specific assessments of exposure to tobacco are now more important than ever. Biomarkers that were developed and validated to measure exposure to cigarettes are being evaluated to assess their use for measuring exposure to these new products. Here, we review current methods for measuring exposure to new and emerging tobacco products, such as electronic cigarettes, little cigars, water pipes, and cigarillos. Rigorously validated biomarkers specific to these new products have not yet been identified. Here, we discuss the strengths and limitations of current approaches, including whether they provide reliable exposure estimates for new and emerging products. We provide specific guidance for choosing practical and economical biomarkers for different study designs and experimental conditions. Our goal is to help both new and experienced investigators measure exposure to tobacco products accurately and avoid common experimental errors. With the identification of the capacity gaps in biomarker research on new and emerging tobacco products, we hope to provide researchers, policymakers, and funding agencies with a clear action plan for conducting and promoting research on the patterns of use and health effects of these products.

Risk assessment of environmental exposure to heavy metals in mothers and their respective infants

Exposure to heavy metals can cause renal injury, which has been well documented in occupational exposure. Studies of low exposure in the general population, however, are still scarce, particularly for vulnerable populations such as mothers and young children. This study evaluated exposure to heavy metals, and biomarkers of renal function and oxidative stress in 944 lactating mothers and their infants and investigated the role of the interaction between heavy metals and oxidative stress in altering renal function. Mother and infant urine samples were analyzed to measure mercury (Hg), cadmium (Cd), and lead (Pb) concentrations for determining body-burden exposure; N-acetyl-β-d-glucosaminidase (NAG), α₁-microglobulin (α₁-MG), albumin (ALB), and creatinine (Cr) concentrations for determining early renal injury; and 8-hydroxy-2-deoxyguanosine (8-OHdG) and malondialdehyde (MDA) concentrations for determining oxidative stress. The median concentrclearlyations in mothers presented as μg/g Cr (infants as μg/l) for Hg, Cd, and Pb were 0.695 (0.716), 0.322 (0.343), and 3.97 (5.306) respectively. The mothers and their infants had clearly been exposed to heavy metals and had levels higher than the reference values reported for the general populations of USA, Germany, and Canada. Multiple regression analyses clearly demonstrated associations between urinary heavy metals in quartiles and several renal and oxidative biomarkers in mothers and to a lesser extent their infants. ß coefficients for urinary excretions of MDA, 8-OHdG, ALB, α₁-MG, NAG, and Cr in mothers were high in the highest quartile of Hg (1.183-51.29μg/g Cr or 1.732-106.95μg/l), Cd (0.565-765.776μg/g Cr or 0.785-1347.0μg/l), and Pb (6.606-83.937μg/g Cr or 9.459-80.826μg/l), except Pb was not associated with ALB. Infants in the highest Pb quartile (9.293-263.098μg/l) had the highest ß coefficients of urinary excretion of MDA, 8-OHdG, ALB, NAG, and Cr. Significant increasing trend in biomarkers across the quartiles of the three metals was seen in both mothers and infants (p_trend <0.001). A receiver operating characteristic analysis supported the predictive abilities of the four renal biomarkers in discriminating between low versus high metal quartiles. The interaction between heavy metals and oxidative stress contributed to the high excretions of renal biomarkers, but the mechanism remains unclear. These findings add to the limited evidence that low exposure to heavy metals in the general population is associated with alterations in renal function that could eventually progress to renal damage if exposure continues and that children are more susceptible due to the immaturity of their body organs.

Impulse oscillometry, spirometry, and passive smoking in healthy children and adolescents

OBJECTIVE

To identify changes in the forced and quiet breathing parameters of lung function in healthy children and adolescents exposed to passive smoking (PS).

METHOD

Comparative cross-sectional study. Healthy schoolchildren aged 6 to 14 years. We collected anthropometric data, lung function parameters using spirometry (forced breathing), and quiet breathing parameters using impulse oscillometry. The sample was divided into two groups according to exposure to PS: passive smoking group (PSG) and non-passive smoking group (NPSG). For the statistical analysis, the Shapiro-Wilk test was used to verify data normality and the T-test or Mann-Whitney test to compare spirometric and oscillometric parameters between groups (p≤0.05).

MAIN FINDINGS

The study included 78 children and adolescents, with 14 boys and 25 girls in each group. There were differences in the mean values for peak expiratory flow (p=0.01). There were no significant differences between the groups in values for z-score and lower limit of normal. The PSG had higher mean absolute values for reactance area (X5=0.05) and significant percentage of predicted values for the following impulse oscillometry parameters: central airway resistance (R20%, p=0.03) and for the indicators of presence of airway obstruction (Fres%, p=0.01; X5%=0.01% and AX%, p=0.01).

CONCLUSION

Children and adolescents exposed to PS had lower values for the spirometric variables and higher values for the oscillometric variables, indicating changes in forced and quiet parameters of lung function compared to the NPSG.

The association between environmental tobacco smoke exposure and childhood respiratory disease: a review

INTRODUCTION

Childhood respiratory illness is a major cause of morbidity and mortality particularly in low and middle-income countries. Environmental tobacco smoke (ETS) exposure is a recognised risk factor for both acute and chronic respiratory illness. Areas covered: The aim of this paper was to review the epidemiology of ETS exposure and impact on respiratory health in children. We conducted a search of 3 electronic databases of publications on ETS and childhood respiratory illness from 1990-2015. Key findings were that up to 70% of children are exposed to ETS globally, but under-reporting may mask the true prevalence. Maternal smoking and ETS exposure influence infant lung development and are associated with childhood upper and lower respiratory tract infection, wheezing or asthma. Further, exposure to ETS is associated with more severe respiratory disease. ETS exposure reduces lung function early in life, establishing an increased lifelong risk of poor lung health. Expert commentary: Urgent and effective strategies are needed to decrease ETS exposure in young children to improve child and long-term lung health in adults especially in low and middle income countries where ETS exposure is increasing.

The Danish National Database for Asthma: establishing clinical quality indicators

Asthma is one of the most common chronic diseases worldwide affecting more than 300 million people. Symptoms are often non-specific and include coughing, wheezing, chest tightness, and shortness of breath. Asthma may be highly variable within the same individual over time. Although asthma results in death only in extreme cases, the disease is associated with significant morbidity, reduced quality of life, increased absenteeism, and large costs for society. Asthma can be diagnosed based on report of characteristic symptoms and/or the use of several different diagnostic tests. However, there is currently no gold standard for making a diagnosis, and some degree of misclassification and inter-observer variation can be expected. This may lead to local and regional differences in the treatment, monitoring, and follow-up of the patients. The Danish National Database for Asthma (DNDA) is slated to be established with the overall aim of collecting data on all patients treated for asthma in Denmark and systematically monitoring the treatment quality and disease management in both primary and secondary care facilities across the country. The DNDA links information from population-based disease registers in Denmark, including the National Patient Register, the National Prescription Registry, and the National Health Insurance Services register, and potentially includes all asthma patients in Denmark. The following quality indicators have been selected to monitor trends: first, conduction of annual asthma control visits, appropriate pharmacological treatment, measurement of lung function, and asthma challenge testing; second, tools used for diagnosis in new cases; and third, annual assessment of smoking status, height, and weight measurements, and the proportion of patients with acute hospital treatment. The DNDA will be launched in 2016 and will initially include patients treated in secondary care facilities in Denmark. In the nearby future, the database aims to include asthma diagnosis codes and clinical data registered by general practitioners and specialised practitioners as well.

Low-dose oral cadmium increases airway reactivity and lung neuronal gene expression in mice

Inhalation of cadmium (Cd) is associated with lung diseases, but less is known concerning pulmonary effects of Cd found in the diet. Cd has a decades-long half-life in humans and significant bioaccumulation occurs with chronic dietary intake. We exposed mice to low-dose CdCl2 (10 mg/L in drinking water) for 20 weeks, which increased lung Cd to a level similar to that of nonoccupationally exposed adult humans. Cd-treated mice had increased airway hyperresponsiveness to methacholine challenge, and gene expression array showed that Cd altered the abundance of 443 mRNA transcripts in mouse lung. In contrast to higher doses, low-dose Cd did not elicit increased metallothionein transcripts in lung. To identify pathways most affected by Cd, gene set enrichment of transcripts was analyzed. Results showed that major inducible targets of low-dose Cd were neuronal receptors represented by enriched olfactory, glutamatergic, cholinergic, and serotonergic gene sets. Olfactory receptors regulate chemosensory function and airway hypersensitivity, and these gene sets were the most enriched. Targeted metabolomics analysis showed that Cd treatment also increased metabolites in pathways of glutamatergic (glutamate), serotonergic (tryptophan), cholinergic (choline), and catecholaminergic (tyrosine) receptors in the lung tissue. Protein abundance measurements showed that the glutamate receptor GRIN2A was increased in mouse lung tissue. Together, these results show that in mice, oral low-dose Cd increased lung Cd to levels comparable to humans, increased airway hyperresponsiveness and disrupted neuronal pathways regulating bronchial tone. Therefore, dietary Cd may promote or worsen airway hyperresponsiveness in multiple lung diseases including asthma.

Ambient and household air pollution: complex triggers of disease

Concentrations of outdoor air pollution are on the rise, particularly due to rapid urbanization worldwide. Alternatively, poor ventilation, cigarette smoke, and other toxic chemicals contribute to rising concentrations of indoor air pollution. The World Health Organization recently reported that deaths attributable to indoor and outdoor air pollutant exposure are more than double what was originally documented. Epidemiological, clinical, and animal data have demonstrated a clear connection between rising concentrations of air pollution (both indoor and outdoor) and a host of adverse health effects. During the past five years, animal, clinical, and epidemiological studies have explored the adverse health effects associated with exposure to both indoor and outdoor air pollutants throughout the various stages of life. This review provides a summary of the detrimental effects of air pollution through examination of current animal, clinical, and epidemiological studies and exposure during three different periods: maternal (in utero), early life, and adulthood. Additionally, we recommend future lines of research while suggesting conceivable strategies to curb exposure to indoor and outdoor air pollutants.

Investigating the effects of arctic dietary intake on lung health

BACKGROUND/OBJECTIVE

Preservation of lung health requires understanding the modifiable risk factors of airflow limitation. This study investigates the association between diet and lung function in a population of Greenland Inuit residing in the Arctic (Greenland) or Western Europe (Denmark).

SUBJECTS/METHODS

Two unselected Inuit populations were recruited, one living in Greenland (Urban (Nuuk) n=358; Rural (Uummannaq) n=207) and the other in Denmark (n=539). Lung function was measured using spirometry and diet by a food frequency questionnaire. Factors associated with airflow limitation were assessed using multiple linear regression models.

RESULTS

The dietary composition differed significantly in the two regions, with higher whale, seal and wild meat intake and lower fruit and vegetable intake in the Arctic regions compared with Denmark. Consumption of vegetables (P=0.004) and whale and/or seal (P<0.0001) was significantly and positively associated with FEV1, as well as with FVC (vegetables: P=0.001, whale and/or seal: P=0.002). Regular fruit intake was included in the statistical models; however, it did not reach statistical significance (FEV1: P=0.053; FVC: P=0.055).

CONCLUSIONS

High dietary intake of vegetables as well as intake of arctic marine mammals had independent positive associations with lung function in this cohort of Greenlandic Inuit. These findings suggest an additive role of dietary intake of antioxidants and unsaturated fatty acids in lung health, which warrants prospective evaluation.

Urinary proteomics and metabolomics in the diagnosis of pediatric disorders

Proteomics is the study of structures and functions of proteins, while metabolomics is the study of small-molecule metabolites in the cells, tissues, and organs of the organism. Proteomic technologies have wide applications in medical field. The current revolution in proteomics has led to the discovery of several new protein markers for various disorders. Urinary proteomics and metabolomics have also evolved in the recent years, for the diagnosis of both renal and nonrenal disorders. The urinary proteome varies in normal and abnormal conditions. Different techniques are employed for the analysis of pediatric urinary proteome, the commonest being MS. Before introduction into clinical use, there is the need for careful standardization. Available data suggest that there are differences in urinary proteome between adult and pediatric populations. It is noted that infant urine contains proteins involved in translation and transcription, cellular growth, and metabolic processes, which are not predominant in adult urine. Available data on urinary proteomic and metabolomic profile in common pediatric disorders are also reviewed here.

The association between blood cadmium level and airflow obstruction in Korean men

BACKGROUND

Most humans are exposed to environmental contaminants via inhalation. Various toxic inhalants cause lung damage with pathologic changes to the airway system. Lung function decline is an important cause of morbidity and mortality worldwide.

AIM

To consider the potential burden of cadmium on pulmonary disease, this study examined the relationship between blood cadmium levels and airflow obstruction in a Korean general population.

SUBJECTS AND METHODS

Data from the Korean National Health and Nutrition Examination Surveys from 2008-2011 were used. Male participants were selected who were older than 40 years, who had completed a reliable pulmonary function test and for who measurements of blood cadmium levels were available (n = 1974). The pulmonary function tests were undertaken and airflow obstruction was defined when forced vital capacity/forced expiratory volume in 1 second ratio < 0.7.

RESULTS

In an age-adjusted logistic regression model, blood cadmium levels correlated with the risk of obstructive airflow pattern in total participants as well as in smokers or never smokers. Further adjustment for BMI, current occupation and educational level did not attenuate these associations among total participants, smokers and never smokers (OR = 2.53, 95% CI = 1.83-3.50 in total; OR = 2.17, 95% CI = 1.55-3.02 in smokers; OR = 3.71, 95% CI = 1.48-9.33 in never smokers).

CONCLUSIONS

In conclusion, blood cadmium level was associated with airflow obstruction independently of smoking history and that association was still significant in never smokers. Careful attention is needed for the general population who are potentially exposed to cadmium.

Blood and urine levels of heavy metal pollutants in female and male patients with coronary artery disease

BACKGROUND

Heavy metal pollutants such as cadmium (Cd), lead (Pb), and mercury (Hg) are rarely the subjects of cardiovascular research although they have been suspected for decades to negatively impact the circulatory system.

METHODS

Apart from detailed anamnestic data, urinary levels of Cd and full blood levels of Pb and Hg were measured in 53 female (mean age: 68.04±7.03 years) and 111 male (mean age: 60.68±11.43 years) nonsmoking or never-smoking patients with angiographically verified and precisely quantified coronary artery disease (CAD).

RESULTS

Although Cd was quantifiable in 68.3% of subjects, only 34.1% of these patients exceeded the critical 1 μg/L Human Biomonitoring (HBM)-I level. Median Pb (20 μg/L) and Hg (0.55 μg/L) levels were lower than the HBM-I, as well as reference levels of Pb. Wine consumption was the main source for Pb, fish and wine consumption for Hg, and previous nicotine abuse for Cd. There was no correlation between Cd, Pb, or Hg and severity of CAD although severity correlated positively with atherosclerosis parameters (uric acid, creatinine, triglycerides, blood urea nitrogen, C-reactive protein) and negatively with high density lipoprotein cholesterol.

CONCLUSION

Cd levels detected in CAD patients were high compared to German and European reference levels but it could not be proven that urine levels of Cd and blood levels of Hg or Pb played a major role in the genesis of CAD, particularly when compared to well-known biomarkers such as blood pressure, glucose, and lipids.