The role of dietary factors on blood lead concentration in children and adolescents - Results from the nationally representative German Environmental Survey 2014-2017 (GerES V)

Association between breakfast skipping and blood levels of lead and cadmium in children and adolescents aged 6-17 years: Results from the National Health and Nutrition Examination Survey 2013-2018

INTRODUCTION

Previous research suggests that fasting increases lead absorption in the gastrointestinal tract, and that regularly eating meals may reduce blood lead. However, there is insufficient evidence linking breakfast status and blood-metal levels in children. We assessed the cross-sectional association between breakfast consumption status and children and adolescent's blood levels of lead and cadmium. We also explored blood hemoglobin, serum ferritin, and age group as potential effect modifiers of these associations.

METHODS

This analysis included children and adolescents aged 6-17 years who participated in the National Health and Nutrition Examination Survey (NHANES) cycles 2013-2018 with complete data on breakfast consumption status (consumers vs. skippers), blood metals, and covariates (N=3722). Blood metal variables were log-transformed. Crude and covariate-adjusted, survey-weighted linear regression models were conducted for each blood metal outcome. Potential effect modification was explored using stratification.

RESULTS

Overall fewer participants reported skipping breakfast (n=719) than eating breakfast (n=3003). Mean (SE) concentrations of blood lead and cadmium (µg/L) were 0.63 (0.01) µg/dL and 0.13 (0.00) µg/L, respectively. Children and adolescents who skipped breakfast were more likely to be female (51.2%), older (mean 12.2 years, SE = 0.1), have a higher body mass index (mean 22.8 kg/m2, SE = 0.2), and a lower income-poverty ratio (mean 1.7, SE = 0.1) than breakfast consumers. No associations between breakfast consumption and any of the blood metals were found. When stratified by age (≤ 10, 11-13, and 14-17 years), children aged 11-13 years who consumed breakfast had lower log-transformed blood lead levels [β = -0.14 µg/L; 95% CI: (-0.25, -0.03)] compared to children of the same age who skipped breakfast.

CONCLUSION

Children 11-13 years-old who were breakfast consumers had lower blood lead levels compared to children of the same age who skipped breakfast. Our results support that encouraging breakfast consumption among school-age children may contribute to lower blood lead levels.

A revised concept for deriving reference values for internal exposures to chemical substances and its application to population-representative biomonitoring data in German children and adolescents 2014-2017 (GerES V)

HBM reference values, in contrast to toxicologically derived values, are statistically derived values that provide information on the exposure of the population. The exceedance frequency (if applicable for individual population groups) is often a first assessment standard for the local exposure situation for municipalities. More than 25 years have passed since the German Human Biomonitoring Commission (HBMC) formulated the first recommendations for the derivation of population-based reference values (HBM reference values, RV95) for substance concentrations based on HBM studies. A fundamental revision is timely, for several reasons. There have been considerable advances in relevant statistical methods, which meant that previously time-consuming and inaccessible procedures and calculations are now widely available. Furthermore, not all steps for the derivation of HBM reference values were clearly elaborated in the first recommendations. With this revision we intended to achieve a rigorous standardization of the entire process of deriving HBM reference values, also to realise a higher degree of transparency. In accordance with established international practice, it is recommended to use the 95th percentile of the reference distribution as the HBM reference value. To this end, the empirical 95th percentile of a suitable sample should be rounded, ensuring that the rounded value is within the two-sided 95% confidence interval of the percentile. All estimates should be based on distribution-free methods, and the confidence interval should be estimated using a bootstrap approach, if possible, according to the BCa ("bias-corrected and accelerated bootstrap"). A minimum sample size of 80 observations is considered necessary. The entire procedure ensures that the derived HBM reference value is robust against at least two extreme values and can also be used for underlying mixed distributions. If it is known in advance that certain subgroups (different age groups, smokers, etc.) show differing internal exposures, it is recommended that group-specific HBM reference values should be derived. Especially when the sample sizes for individual subgroups are too small, individual datasets with potential outliers can be excluded in advance to homogenize the reference value population. In the second part, new HBM reference values based on data of the German Environmental Survey for Children and Adolescents (GerES V, 2014-2017) were derived in accordance with the revised recommendations. The GerES V is the most recent population-representative monitoring of human exposure to pollutants in Germany on children and adolescents aged 3-17 years (N = 2294). RV95 for GerES V are reported for four subgroups (males/females and 3-11/12-17 years) for 108 different substances including phthalates and alternative plasticisers, metals, organochlorine pesticides, polychlorinated biphenyls (PCB), per- and polyfluoroalkyl substances (PFAS), parabens, aprotic solvents, chlorophenols, polycyclic aromatic hydrocarbons (PAH) and UV filter, in total 135 biomarkers. Algorithms implemented in R were used for the statistics and the determination of the HBM reference values. To facilitate a quality control of the study data, the corresponding R source code is given, together with graphical representations of results. The HBM reference values listed in this article replace earlier RV95 values derived by the HBMC for children and adolescents from data of precedent GerES studies (e.g. published in Apel et al., 2017).

Extending Regulatory Biokinetic Lead Models towards Food Safety: Evaluation of Consumer Baby Food Contribution to Infant Blood Lead Levels and Variability

The U.S. Food and Drug Administration released proposed lead (Pb) action levels for foods intended for babies and young children in January 2023 based on the agency's interim reference value of 2.2 µg/day for dietary Pb. Since the 1980s, biokinetic models have estimated blood lead levels (BLLs) associated with environmental contamination, but their use in food safety assessment has been limited. We compared three recent biokinetic models (IEUBK Model, ICRP Model Version 5, and AALM) to develop insights on contributors to variability in potential exposures to Pb in consumer baby food products. While modest variation was observed for babies, the predictions trended to convergence for children aged 3 and older, approaching the U.S. FDA dietary conversion factor of 0.16 µg Pb/dL blood per µg Pb intake/day. We applied the IEUBK model in a probabilistic exposure assessment framework characterizing the distribution of Pb in soil, dust, water, and food intake in the United States. Soil and dust were the primary contributors to variance in infant BLLs, while food and water contributed <15% combined. Thus, reductions in upper-bound soil and dust concentrations will be necessary before achieving appreciable reductions in the frequency of BLLs greater than the BLRV of 3.5 µg/dL.

The Association Between Blood Lead Levels and Coronary Artery Calcium Score Determined by Using Coronary Computed Tomography Angiography

BACKGROUND

Lead exposure is a known risk factor for cardiovascular disease (CVD), and coronary artery calcification (CAC) is a biomarker for diagnosing atherosclerotic CVD. This study investigated the association between blood lead level (BLL) and CAC using coronary computed tomography (CT) angiography.

METHODS

This study enrolled 2,189 participants from the general population with no history or symptoms of CVD. All participants underwent coronary CT angiography, health examination, and BLL testing. The association between coronary artery calcium score (CACS) and BLL was analyzed.

RESULTS

The arithmetic mean of BLL was 2.71 ± 1.26 μg/dL, and the geometric mean was 2.42 (1.64) μg/dL, ranging from 0.12 to 10.14 μg/dL. There was a statistically significant positive correlation between CACS and BLL (r = 0.073, P < 0.001). Mean BLLs among predefined CACS categories were as follows: absent grade (CACS = 0), 2.67 ± 1.23 μg/dL; minimal grade (> 0, < 10), 2.81 ± 1.25 μg/dL; mild grade (≥ 10, < 100), 2.74 ± 1.29 μg/dL; moderate grade (≥ 100, < 400), 2.88 ± 1.38 μg/dL; severe grade (≥ 400): 3.22 ± 1.68 μg/dL. The odds ratio for severe CAC was 1.242 in association with an 1 μg/dL increase in BLL (P = 0.042).

CONCLUSION

Using coronary CT angiography, we determined a positive correlation between BLL and CAC among participants without CVD from the general population. To reduce the burden of CVD, efforts and policies should be geared toward minimizing environmental lead exposure.

Reference intervals for cd, hg, Mn and Pb in the general children population (3-14 years) of Kinshasa, Democratic Republic of Congo (DRC) between June 2019 and June 2020

The reference intervals (RIs), proposed by the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) and the International Union of Pure and Applied Chemistry (IUPAC), were derived for Cd, Hg, Mn and Pb in the blood and urine of the children population living in Kinshasa (n = 200, aged 3-14 years with 97 girls). Levels of metals were measured using coupled plasma mass (ICP-MS). In blood, the proposed RIs [P5-P95 (GM)] were 0.022-1.112 μg/L (0.074), 35.69-144.50 μg/L (71.43), 0.060 to 1.161 μg/L (0.208) and 6.597-15.740 μg/L (9.882) for Cd, Pb, Hg and Mn, respectively. Urinary levels [(P5-P95 (GM)] were 0.082-1.530 μg/L (0.366) for Cd, 1.827-18.500 μg/L (5.458) for Pb, 0.323-1.953 μg/L (0.709) for Hg and 0.070 to 1.703 μg/L (0.186) for Mn. As compared to the CDC updated blood Pb reference value (35 μg/L), Pb levels remain higher of public health concern. Cd and Mn levels were similar to those found in the same city in 2015 and databases involving non-occupationally exposed populations from other countries. Hg levels significantly lower than those found in the same city in 2015, probably due to exclusion criteria of metal exposure applying in the present survey (occupationally exposed to the studied metals, smoking habits, amalgam tooth fillings, fish consumption habit more than one time per week, etc.). These background metal exposures will be useful for future occupational and/or environmental surveys as well as undertaking a reliable regulation of chemical exposure in Kinshasa via a national HBM program.

Distribution, sources and health risks of heavy metals in indoor dust across China

The potential effects of heavy metals on human health have attracted increasing attention as most people spend up to 90% of their time indoors. Human exposure to heavy metals in indoor dust have only been characterised for limited regions in China, and full-scale data for different functional areas are not available. Therefore, this review analysed the concentrations, contamination characteristics, and potential health risks of seven heavy metals (including zinc (Zn), lead (Pb), copper (Cu), chromium (Cr), nickel (Ni), arsenic (As), and cadmium (Cd)) in indoor dust at 3392 sampling sites in 55 cities across 27 provincial regions of China based on literature data. Results revealed that the median heavy metal concentrations in indoor dust throughout China decreased in the following order: Zn > Pb > Cu > Cr > Ni > As > Cd. Traffic emissions and decorative materials are the primary sources of heavy metal pollution in indoor dust. No considerable non-carcinogenic risk was found for Zn, Cu, Cr, Ni, and Cd in indoor dust, while Pb and As exhibited potential non-carcinogenic risks to children, primarily distributed in cities across Southern China. Meanwhile, the carcinogenic risks posed by Cr and Ni were higher than those posed by As and Cd, especially in Southern China. Therefore, effective measures in Southern China should prioritised for controlling Pb, Cr, Ni and As pollution in indoor dust to reduce human health risk. This review is useful for policy decision-making and protecting human from exposure to heavy metals in indoor dust across China.

Estimation of blood lead levels in the French population using two complementary approaches: Esteban (2014-2016) as part of the human biomonitoring program and the national surveillance system for childhood lead poisoning (2015-2018)

BACKGROUND

Used widely for centuries, lead is a common environmental pollutant. As a cumulative toxic, its presence in the body is always evidence of exposure, and health effects occur without threshold. Though regulated by European directives, lead requires close monitoring due to its environmental persistence and toxicity.

METHODS

The first data source was the French surveillance system for monitoring childhood lead poisoning, which records the screening results of children (-18 years), providing data on their temporal and geographical distribution, characteristics, and risk factors. The second data source was Esteban, a cross-sectional study conducted in 2014-2016 on a random sample of the French population as part of the human biomonitoring program. The Esteban lead study concerns 904 children (6-17 years) and 999 adults (18-74 years), providing data on biological samples, sociodemographic characteristics, occupational exposure, environmental and dietary factors.

RESULTS

The surveillance system highlighted that lead poisoning affected 10% of children screened between 2015 and 2018. The main risk factor remains housing. Esteban confirmed this observation, finding a general mean of blood lead level (BLL) at 9.9 and 18.5 μg/L for children and adults, respectively. In children, parents' occupation increased BLLs. In adults, the greatest exposure factors were smoking, age, place of residence, alcohol, bread-based products, and homegrown livestock products. In both, drinking tap water and year of housing construction increased BLLs.

CONCLUSIONS

The surveillance system showed a high number of children with lead poisoning despite the implementation of prevention measures, which mainly concern lead paints in old and degraded homes. To help identify children at risk, healthcare providers need to know about exposure from housing and the emerging sources identified in the Esteban survey. Despite lower BLLs, the well-known risk factors of lead exposure persist, meaning prevention efforts must continue in order to limit their impact on the population.

Toxic metal exposures from infant diets: Risk prevention strategies for caregivers and health care professionals

Concerns are growing regarding the presence of toxic elements such as arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) in the ingredients and prepared foods for infants and young children. There are few clear, evidence-based, guidelines on the maximum tolerable limits of toxicants in foods and little understanding of toxicant exposure or adverse health effects attributable to dietary exposure. Caregivers are faced with the burden of making decisions about which foods to select, how often to feed them to their children, and what foods to limit. This article reviews the current literature and existing recommendations on dietary exposure to toxic elements in children under 2 years of age, and their health effects in early childhood-focusing on growth, neurodevelopment, and immune function. The article also outlines best practices for healthcare providers to address the concerns of toxic element exposure through the diet in young children. Several foods consistently appear in the literature as potential sources of toxic element exposure. Contaminated drinking and cooking water, including water used to prepare infant formula, could also be a major exposure source. In the absence of stronger evidence on effects of dietary modification, exclusive breastfeeding until six months of age, followed by a diverse diet are some strategies to reduce dietary toxic element exposure while ensuring an adequate and balanced nutrient intake. Healthcare providers can support families by sharing information and encouraging blood Pb testing, the only element for which such testing is currently recommended.