Exposure to metal mixture and growth indicators at 4-5 years. A study in the INMA-Asturias cohort

Associations between paediatric obesity, chemical mixtures and environmental factors, in a national cross-sectional study of Canadian children

BACKGROUND

Whilst single chemical exposures are suspected to be obesogenic, the combined role of chemical mixtures in paediatric obesity is not well understood.

OBJECTIVES

We aimed to evaluate the potential associations between chemical mixtures and obesity in a population-based sample of Canadian children.

METHODS

We ascertained biomonitoring and health data for children aged 3-11 from the cross-sectional Canadian Health Measures Survey from 2007 to 2019. Several chemicals of interest were measured in blood or urine and paediatric obesity was defined based on measured anthropometrics. Using quantile-based G computational analysis, we quantified the effects of three chemical mixtures selected a priori. Models were adjusted for sociodemographic and environmental factors identified through a directed acyclic graph. Results are presented through adjusted relative risks (RR) with 95% confidence intervals (95% CI).

RESULTS

We included 9147 children. Of these, 24.1% were overweight or obese. Exposure to the mixture of bisphenol A, acrylamide, glycidamide, metals, parabens and arsenic increased the risk of childhood overweight or obesity by 45% (95% CI 1.09, 1.93), obesity by 109% (95% CI 1.27, 3.42) and central obesity by 82% (95% CI 1.30, 2.56).

CONCLUSIONS

Our findings support the role of early childhood chemical exposures in paediatric obesity and the potential combined effects of chemicals.

Associations between prenatal metal exposure and growth rate in children: Based on Hangzhou Birth Cohort Study

BACKGROUND

It has been reported that prenatal metal exposure is associated with child anthropometry. However, studies focusing on the growth rate of anthropometry among children have not been conducted. This study aimed to examine associations between the exposure of multiple metals during pregnancy and the growth rate of anthropometry among offspring.

METHODS

743 mother-child pairs from the Hangzhou Birth Cohort Study (HBCS) were included. Levels of eleven metals in mother's blood during pregnancy were measured. Offspring had a mean of 5.7 measurements on anthropometric indicators including weight, length/height, head circumference, and body mass index (BMI) within 1.5 years of birth. Generalized estimating equation (GEE) model was used to investigate the associations between maternal metal exposure and growth rate of anthropometric indicators in children. Stratification analysis by sex was also examined.

RESULTS

Levels of selenium (Se, β = 0.213, 95 % CI = 0.017 to 0.409, P = 0.033) were positively associated with length/height gain per month in children. Levels of chromium (Cr, β = 0.025, 95 % CI = 0.018 to 0.033, P < 0.001) were positively associated with the rate of weight gain. Levels of manganese (Mn, β = -0.030, 95 % CI = -0.052 to -0.008, P = 0.009) and cobalt (Co, β = -0.012, 95 % CI = -0.024 to -0.000, P = 0.044) were inversely associated with growth rate of head circumference. Children with higher maternal Mn levels had a lower BMI change rate. Associations between metals and growth rate were stronger in girls than in boys. Besides, significant associations between metal mixtures and growth rate were found.

CONCLUSION

Prenatal exposure to Se, Cr, Mn, and Co was associated with growth rate in children, with sex-specific disparities. Our results suggested important effects of maternal exposure to multiple metals on development in offspring.

Assessment of sources and health risks of heavy metals in metropolitan household dust among preschool children: The LEAPP-HIT study

The most common construction material used in Taiwan is concrete, potentially contaminated by geologic heavy metals (HMs). Younger children spend much time indoors, increasing HM exposure risks from household dust owing to their behaviors. We evaluated arsenic (As), cadmium (Cd), and lead (Pb) concentrations in fingernails among 280 preschoolers between 2017 and 2023. We also analyzed HM concentrations, including As, Cd, Pb, chromium (Cr), nickel (Ni), copper (Cu), zinc (Zn), iron (Fe), and manganese (Mn), in 90 household dust and 50 road dust samples from a residential area where children lived between 2019 and 2021 to deepen the understanding of sources and health risks of exposure to HMs from household dust. The average As, Cd, and Pb concentrations in fingernails were 0.12 ± 0.06, 0.05 ± 0.05, and 0.95 ± 0.77 μg/g, respectively. Soil parent materials, indoor construction activities, vehicle emissions, and mixed indoor combustion were the pollution sources of HMs in household dust. Higher Cr and Pb levels in household dust may pose non-carcinogenic risks to preschoolers. Addressing indoor construction and soil parent materials sources is vital for children's health. The finding of the present survey can be used for indoor environmental management to reduce the risks of HM exposure and avoid potential adverse health effects for younger children.

Evaluation of the Concentration of Selected Elements in the Serum of Patients with Degenerative Stenosis of the Lumbosacral Spine

In humans, 23 elements have been shown to have biological activity. The purpose of this study was to evaluate the concentrations of iron (Fe), zinc (Zn), sodium (Na), potassium (K), magnesium (Mg), phosphorus (P), and calcium (Ca) in the serum of patients diagnosed with lumbar degenerative stenosis when compared to the concentrations of those elements in the serum of healthy volunteers. The study group consisted of 60 patients who were diagnosed with degenerative stenosis of the lumbosacral spine and who qualified for hemilaminectomy. The control group included 60 healthy volunteers without degenerative spinal stenosis. The clinical specimens studied had sera collected from both groups. The quantitative analysis of the selected elements revealed statistically significant (p < 0.05) lower concentrations of Zn (740 ± 110 µg/L vs. 880 ± 160 µg/L) and Mg (22,091 ± 4256 µg/L vs. 24,100 ± 4210 µg/L) in the serum of the patients from the study group when compared to the controls. By contrast, K (16,230 µg/L ± 1210 µg/L vs. 13,210 µg/L ± 1060 µg/L) and Fe (141.87 µg/L ± 11.22 µg/L vs. 109.1 µg/L ± 26.43 µg/L) levels were significantly higher in the study group compared to the controls (p < 0.05). No statistically significant changes were detected in the concentrations of the assessed micronutrients and macronutrients in both sexes in either the study group, the control group, or those based on body mass index (p > 0.05). In the serum samples from the study group, the strongest correlations were noted between the concentrations. In the study group, we showed a significant relationship between the levels of Fe/Zn (r = 0.41), Fe/Na (r = 0.41), Fe/P (r = 0.55), Zn/P (r = 0.68), Zn/K (r = 0.48), Zn/Ca (r = 0.94), Mg/Ca (r = 0.79), and Na/K (r = 0.67). We showed that only Mg concentration varied statistically significantly with the severity of pain (p < 0.05). These findings suggest that the assessment of Fe, Zn, Mg, and K concentrations can be helpful in predicting the onset of degenerative changes in the spine.

Exposure to metal mixtures and young children's growth and development: A biomonitoring-based study in Eastern China

Exposure to metal mixtures may affect children's health but the conclusions are controversial. We aimed to investigate the associations of metal mixture exposure with children's physical and behavioral development. 15 metals were detected in the urine samples of 278 preschoolers aged 3-6 years from eastern China. Multiple linear models and restricted cubic splines were used to evaluate dose-response relationships between single metal and children's physical and behavioral development. The Bayesian Kernel Machine Regression (BKMR) models, the weighted quantile sum (WQS) models and Quantile G-Computation were applied to evaluate the joint effects of metal mixtures. The results showed that arsenic (As) was negatively associated with z score of height for age (HAZ) in individual-metal models [β (95%CI): - 0.22 (-0.38, -0.06), P = 0.006]. Concerning children's behavioral development, multiple-metal models demonstrated a negative association with strontium (Sr) [β (95%CI): - 0.82 (-1.38, -0.26), P = 0.004], and a positive association with tin (Sn) [β (95%CI): 0.69 (0.16, 1.21), P = 0.010]. Notably, these associations remained significant or suggestive even after adjustments for multiple tests, sensitivity analyses, and application of different statistical models, including BKMR, WQS, and Quantile G-Computation. Furthermore, the study identified a negative joint effect of the metal mixture on HAZ, as demonstrated by BKMR and Quantile G-Computation models, with As playing an irreplaceable role in this observed impact. In summary, exposure to As appears to have adverse effects on HAZ, while exposure to Sn may hinder children's behavioral development. Conversely, exposure to Sr may have a protective effect on children's behavioral development. Additionally, the combined impact of metal mixtures is implicated in potentially impairing children's physical development, particularly in terms of HAZ.

Micronuclei frequency and exposure to chemical mixtures in three Colombian mining populations

The Colombian mining industry has witnessed significant growth. Depending on the scale and mineral extracted, complex chemical mixtures are generated, impacting the health of occupationally exposed populations and communities near mining projects. Increasing evidence suggests that chromosomal instability (CIN) is an important link between the development of certain diseases and exposure to complex mixtures. To better understand the effects of exposure to complex mixtures we performed a biomonitoring study on 407 healthy individuals from four areas: three located in municipalities exploiting different-scale mining systems and a reference area with no mining activity. Large, medium, and small-scale mining systems were analyzed in Montelibano (Córdoba), artisanal and small-scale mining (ASGM) in Nechí (Antioquia), and a closed mining system in Aranzazu (Caldas). The reference area with no mining activity was established in Montería (Córdoba). ICP-MS measured multi-elemental exposure in hair, and CIN was evaluated using the cytokinesis-block micronucleus technique (MNBN). Exposure to mixtures of chemical elements was comparable in workers and residents of the mining areas but significantly higher compared to reference individuals. In Montelibano, increased MNBN frequencies were associated with combined exposure to Se, Hg, Mn, Pb, and Mg. This distinct pattern significantly differed from other areas. Specifically, in Nechí, Cr, Ni, Hg, Se, and Mg emerged as the primary contributors to elevated frequencies of MNBN. In contrast, a combination of Hg and Ni played a role in increasing MNBN in Aranzazu. Interestingly, Se consistently correlated with increased MNBN frequencies across all active mining areas. Chemical elements in Montelibano exhibit a broader range compared to other mining zones, reflecting the characteristics of the high-impact and large-scale mining in the area. This research provides valuable insights into the effects of exposure to chemical mixtures, underscoring the importance of employing this approach in the risk assessment of communities, especially those from residential areas.

Urinary metal profiles in mother-offspring pairs and their association with early dysglycemia in the International Hyperglycemia and Adverse Pregnancy Outcome Follow Up Study (HAPO-FUS)

BACKGROUND

Variations in dietary intake and environmental exposure patterns of essential and non-essential trace metals influence many aspects of human health throughout the life span.

OBJECTIVE

To examine the relationship between urine profiles of essential and non-essential metals in mother-offspring pairs and their association with early dysglycemia.

METHODS

Herein, we report findings from an ancillary study to the international Hyperglycemia and Adverse Pregnancy Outcome Follow-Up Study (HAPO-FUS) that examined urinary essential and non-essential metal profiles from mothers and offspring ages 10-14 years (1012 mothers, 1013 offspring, 968 matched pairs) from 10 international sites.

RESULTS

Our analysis demonstrated a diverse exposure pattern across participating sites. In multiple regression modelling, a positive association between markers of early dysglycemia and urinary zinc was found in both mothers and offspring after adjustment for common risk factors for diabetes. The analysis showed weaker, positive, and negative associations of the 2-h glucose value with urinary selenium and arsenic respectively. A positive association between 2-h glucose values and cadmium was found only in mothers in the fully adjusted model when participants with established diabetes were excluded. There was a high degree of concordance between mother and offspring urinary metal profiles. Mother-to-offspring urinary metal ratios were unique for each metal, providing insights into changes in their homeostasis across the lifespan.

SIGNIFICANCE

Urinary levels of essential and non-essential metals are closely correlated between mothers and their offspring in an international cohort. Urinary levels of zinc, selenium, arsenic, and cadmium showed varying degrees of association with early dysglycemia in a comparatively healthy cohort with a low rate of preexisting diabetes.

IMPACT STATEMENT

Our data provides novel evidence for a strong correlation between mother and offspring urinary metal patterns with a unique mother-to-offspring ratio for each metal. The study also provides new evidence for a strong positive association between early dysglycemia and urinary zinc, both in mothers and offspring. Weaker positive associations with urinary selenium and cadmium and negative associations with arsenic were also found. The low rate of preexisting diabetes in this population provides the unique advantage of minimizing the confounding effect of preexisting, diabetes related renal changes that would alter the relationship between dysglycemia and renal metal excretion.

Evaluation of the concentration of selected elements in serum patients with intervertebral disc degeneration

Quantitative analysis of the trace element content of human intervertebral discs (IVDs) is essential because it can identify specific enzymes or metabolites that may be related to human intervertebral disc degeneration (IVDD). The goal of this study was to assess the concentrations of copper (Cu), iron (Fe), manganese (Mn), lead (Pb), zinc (Zn), sodium (Na), magnesium (Mg), potassium (K), phosphorus (P), and calcium (Ca) in serum samples obtained from patients with IVDD in comparison to healthy volunteers (a control group). The study group consisted of 113 Caucasian patients qualified by a specialist neurosurgeon for microdiscectomy. The control group consisted of 113 healthy volunteers who met the eligibility criteria for blood donors. The examined clinical material was the serum samples obtained from both groups.Based on the quantitative analysis of selected elements, there were statistically significantly (p 0.05) higher concentrations of Cu (1180 μg/L±800 μg/L vs. 1230 μg/L±750 μg/L), Zn (790 μg/L±300 μg/L vs. 850 μg/L±200 μg/L), and Mg (21730 μg/L±4360 μg/L vs. 23820 μg/L±4990 μg/L) in the serum of healthy volunteers compared to those in the study group. In addition, statistically significant changes were not detected in the concentrations of any elements among either sex in either the study or control group or in their body mass index (BMI) values (p > 0.05). In the serum samples from the study group, the strongest relationships were noted between the concentrations of Zn and Pb (r = 0.61), Zn and P (r = 0.69), Zn and Ca (r = 0.84), Zn and Cu (r = 0.83), Mg and Ca (r = 0.74), and Ca and P (r = 0.98).It has been indicated that, above all, the concentrations of Cu, Zn, Ca, and Mg depend on the advancement of radiological changes, according to the Pfirrmann scale. However, no influence on pain intensity was found, depending on the concentration of the assessed elements.The analysis indicates that the determination of serum Cu, Zn, Ca, and Mg concentrations may have diagnostic significance in predicting the onset of lumbosacral IVDD. The predictive evaluation of changes in the concentrations of selected elements in patients with degenerative lumbar IVD lesions appears to be a promising, cost-effective strategy.

Dietary Exposure to Toxic Elements and the Health of Young Children: Methodological Considerations and Data Needs

Concerns have been raised regarding toxic-element (arsenic, cadmium, lead, and mercury) contamination of commercially available infant foods around the world. Young children are vulnerable to the effects of toxic elements, based on higher absorption levels and potentially poorer detoxification capacities. Toxic-element exposures in early life exact high societal costs, but it is unclear how much dietary exposure to these elements contributes to adverse health outcomes. Well-designed epidemiological studies conducted in different geographical and socioeconomic contexts need to estimate dietary toxicant exposure in young children and to determine whether causal links exist between toxicants in children's diets and health outcomes. This commentary outlines the methodological considerations and data needs to advance such research.

Dietary Exposure to Essential and Non-essential Elements During Infants' First Year of Life in the New Hampshire Birth Cohort Study

Even the low levels of non-essential elements exposure common in the US may have health consequences especially early in life. However, little is known about the infant's dynamic exposure to essential and non-essential elements. This study aims to evaluate exposure to essential and non-essential elements during infants' first year of life and to explore the association between the exposure and rice consumption. Paired urine samples from infants enrolled in the New Hampshire Birth Cohort Study (NHBCS) were collected at approximately 6 weeks (exclusively breastfed) and at 1 year of age after weaning (n = 187). A further independent subgroup of NHBCS infants with details about rice consumption at 1 year of age also was included (n = 147). Urinary concentrations of 8 essential (Co, Cr, Cu, Fe, Mn, Mo, Ni, and Se) and 9 non-essential (Al, As, Cd, Hg, Pb, Sb, Sn, V, and U) elements were determined as a measure of exposure. Several essential (Co, Fe, Mo, Ni, and Se) and non-essential (Al, As, Cd, Hg, Pb, Sb, Sn, and V) elements had higher concentrations at 1 year than at 6 weeks of age. The highest increases were for urinary As and Mo with median concentrations of 0.20 and 1.02 µg/L at 6 weeks and 2.31 and 45.36 µg/L at 1 year of age, respectively. At 1 year of age, As and Mo urine concentrations were related to rice consumption. Further efforts are necessary to minimize exposure to non-essential elements while retaining essential elements to protect and promote children's health.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12403-022-00489-x.