Low Serum Testosterone Levels Are Associated with Elevated Urinary Mandelic Acid, and Strontium Levels in Adult Men According to the US 2011-2012 National Health and Nutrition Examination Survey

Breast-Milk Rubidium and Other Trace Elements are Associated with Neurocognitive Development in Infants at Age of 8 Months

BACKGROUND

Trace elements may affect neurodevelopment. There is a lack of data on breast-milk rubidium (Rb) in relation to neurodevelopment in infants. The associations of copper (Cu), zinc (Zn) and strontium (Sr) with neurodevelopment in infants remain uncertain.

OBJECTIVES

We sought to evaluate the associations of breast-milk Rb (primary exposure), Cu, Zn, and Sr with neurodevelopment in infants at age 8 months.

METHODS

The study cohort included 117 breastfed infants. Breast-milk samples were collected at 42 days and 8 months postpartum. Breast-milk Rb, Zn, Cu, and Sr were measured by inductively coupled plasma mass spectrometer. Neurodevelopment was assessed at age 8 months. The primary outcomes were attention and working memory scores, as evaluated by the A-not-B task. Other outcomes included the Mental Development Index (MDI) and Psychomotor Development Index (PDI) as evaluated by the Bayley Scale of Infant Development III. Generalized linear models and restricted cubic spline regression were used to assess the associations between trace elements and neurodevelopment indices. Bonferroni correction was conducted on all data presented.

RESULTS

A nonlinear association was observed between breast-milk Rb at 42 days and infant's attention at age 8 months (nonlinearity P = 0.037). Positive associations were observed with infant MDI scores and breast-milk Rb at 42 days (β = 4.46; P = 0.06) and 8 months (β = 3.79; P = 0.009) postpartum. Breast-milk Zn at 42 days was positively associated with infant's attention (β = 0.31; P = 0.039). Sr at 42 days was positively correlated with attention (β = 0.18; P = 0.043) and MDI scores (β = 2.18; P = 0.015) at 8 months. Inverted U-shape associations were observed for breast-milk Cu at 42 days with infant attention and PDI scores. All associations were not significant after correction for multiple tests.

CONCLUSIONS

Our data suggest that Rb, Zn, Cu, and Sr in breast milk at certain concentrations are associated with neurodevelopment in breastfed infants. Further studies are warranted to validate the findings.

Associations of Semen Quality with Seminal Non-essential Heavy Metals in Males from the Canary Islands

Semen quality and levels of non-essential metals such as strontium (Sr), aluminum (Al), lead (Pb), nickel (Ni), and vanadium (V) were measured. Metals were determined by ICP-OES (inductively coupled plasma - optical emission spectrometry) in semen samples from 102 men who were recruited in a Reproduction Unit in the Canary Islands. The presence of each metal was as follows: Sr: 56.9%, Al: 73.5%, Pb: 45.1%, Ni: 15.7%, and V: 79.4% of the samples. No significant differences were found in the relationship between the spermiogram, the sperm motility, and the concentration of spermatozoa levels of non-essential metals. It is noteworthy that Ni levels tend to be lower in patients with oligozoospermia (t (46.4) = 1.84; p = 0.070). Between lifestyle and non-essential metals, there was a significant relationship between the level of occupational exposure to metals and Ni (χ²(2) = 13.91; p = 0.001). We did not find significant differences in non-essential seminal metal content and smoking status but, there were differences between drinkers and the concentration of V in semen (t (100) = -1.99; p = 0.050). The occupational exposure to metals and place of residence have effects on Al and V levels in semen. Regarding obesity, significant differences were found in Pb levels (t (18.0) = 2.34; p = 0.031). Obese patients have a lower Pb level, and the percentage of progressive sperm motility was lower in obese men (t (98) = 2.14; p = 0.035). The detection of metals in semen opens a new field in the study of male infertility with the possibility of performing treatments aimed at correcting these possible anomalies.

Untapped potentials of hazardous nanoarchitectural biopolymers

The First Industrial Revolution began when manual labour transitioned to machines. Fossil fuels and steam eventually replaced wood and water as an energy source used predominantly for the mechanized production of textiles and iron. The emergence of the required numerous enormous factories gave rise to smoke pollution due to the immense growth in coal consumption. The manufactured gas industry produced highly toxic effluent that was released into sewers and rivers polluting the water. Many pieces of legislation were introduced to overcome this issue, but with varying degrees of effectiveness. Alongside our growth in world population, the problems that we had with waste remained, but together with our increase in number the waste produced has also increased additionally. The immense volume of waste materials generated from human activity and the potentially detrimental effects on the environment and on public health have awakened in ourselves a critical need to embrace current scientific methods for the safe disposal of wastes. We are informed daily that our food waste must be better utilized to ensure enough food is available to feed the world's growing population in a sustainable way (Thyberg and Tonjes, 2016). Some things are easy, like waste food and cellulose products can be turned into compost, but how do we recycle sheep's wool? Or shrimp shells? Despite the fact that both these substances are hazardous, and have caused environmental and economic impact from being incinerated; but we anticipate that those substances may have the potential to convert into added value applications.We have been working in this area for over 15 years, working towards managing them and seeking their added value applications. We take the biological products, process (reconstitute) and engineer them into added value products such as functional and nanostructure materials including edible films, foams and composites including medical devices useful in the human body. Anything that we can ingest, should not cause an immune response in the human system. Natural biomacromolecules display the inherent ability to perform very specific chemical, mechanical or structural roles. Specifically, protein- and polysaccharide-based biomaterials have come to light as the most promising candidates for many biomedical applications due their biomimetic and nanostructured arrangements, their multi-functional features, and their capability to function as matrices that are capable of facilitating cell-cell and cell-matrix interactions.

Low level prenatal exposure to a mixture of Sr, Se and Mn and neurocognitive development of 2-year-old children

The excess or deficiency of trace metals can cause adverse neurocognitive development. Evidence of health effect of trace metal mixtures on neurocognitive development is limited in children. We evaluated associations of prenatal exposure to trace metals and metal mixtures with neurocognitive development of 2-year-old children. A total of 544 mother-child pairs were included in the study. The concentrations of 10 trace metals in maternal urine were monitored before delivery. Neurocognitive development indexes, including mental development index (MDI) and psychomotor development index (PDI), were assessed using the Bayley Scales of Infant Development. Linear regression analysis was performed to explore the effects of single-metal and multi-metal exposures. Bayesian Kernel Machine regression (BKMR) was used to investigate overall effect of exposure to metal mixtures and potential interactions among mixture components. We found positive associations of urinary strontium (Sr) and Selenium (Se) levels with MDI scores among all children in the single-metal model. Sr was positively related to MDI, while Manganese (Mn) was negatively associated with PDI in the multi-metal model. The results from BKMR model in girls revealed that MDI scores were improved with the increasing concentrations of Sr, Se and Mn mixture until the concentrations reached their 30th percentiles (Sr: 149.49 μg/g creatinine, Se:18.38 μg/g creatinine, Mn:1.96 μg/g creatinine), with no effect after that threshold level. Sr played a positive role in mental development among mixture components, which was consistent with the results of Sr in the multi-metal models. No signification association of mixture with MDI/PDI was found in boys. The study suggested potential sex-specific association of Sr, Se and Mn mixture levels (at or below their 30th percentiles) with improved mental development, and beneficial role of Sr.

Associations between lead concentrations and cardiovascular risk factors in U.S. adolescents

Little is known regarding the effects of environmental lead exposure on cardiovascular risk factors in the adolescent population. We studied 11,662 subjects included in the National Health and Nutrition Examination Survey (NHANES) 1999–2012. Blood lead levels were analysed for their association with cardiovascular risk factors (CVRF). Regression coefficients (Beta) and 95% confidence intervals (CIs) of blood lead in association with CVRF (e.g., total cholesterol, HDL-cholesterol, LDL-cholesterol, triglyceride, fasting glucose, glycohemoglobin, fasting insulin, and blood pressure) were estimated using multivariate and generalized linear regression after adjusting for age, gender, ethnicity, serum cotinine, body mass index (BMI), physical activity, and household income. We identified a strong positive association between blood lead (coefficient = 0.022, 95% CI 0.003, 0.041; P = 0.022) and LDL-cholesterol in adolescents (age 12–19 years). However, no associations with other CVRFs were found in the overall population. In the generalized linear models, participants with the highest lead levels demonstrated a 1.87% (95% CI 0.73%, 3.02%) greater increase in serum LDL-cholesterol (p for trend = 0.031) when compared to participants with the lowest lead levels. These results provide epidemiological evidence that low levels of blood lead are positively associated with LDL-cholesterol in the adolescent population.

Relationship between Selected Serum Metallic Elements and Obesity in Children and Adolescent in the U.S

The prevalence of obesity has increased at an alarming rate worldwide. Metallic elements are involved in the pathogenesis of obesity and related diseases. To date, whether environmental exposure to metallic elements has effects on obesity in children and adolescents is still unclear. The aim of the current study was to investigate the association of blood metallic elements with obesity in U.S. children and adolescents. This cross-sectional study was performed with 5404 children and adolescents (6-19 years, 2745 males and 2659 females) who participated in the US National Health and Nutrition Examination Survey 2011-2014. Blood lead, mercury, selenium, manganese, copper, and zinc, as well as biochemical parameters including triglyceride (TG), cholesterol, low-density lipoprotein (LDL), and homeostasis model assessment of insulin resistance (HOMA-IR) were assessed for all subjects. Multivariate logistic regression and linear regression were applied to assess associations of metallic elements and overweight, obesity status, and serum metabolites as distinct outcomes adjusted for age, gender, ethnicity, and the poverty income ratio. When stratified by age and sex, significant associations were found between the highest quartile of copper concentrations in blood with obesity status (OR = 9.27, 95% CI: 5.43, 15.82, p_{for trend} < 0.001) and cholesterol (OR = 3.08, 95% CI: 1.43, 6.63, p_{for trend} < 0.001). The highest concentrations of manganese in the blood was associated with obesity in those aged 6-19 years (OR = 2.29, 95% CI: 1.74, 3.02, p_{for trend} < 0.001). Moreover, blood mercury and selenium showed positive relationships with cholesterol. Further, a negative association existed between blood zinc and obesity. The National Health and Nutrition Examination Survey data provide epidemiological evidence that blood metallic elements are positively associated with obesity in children and adolescents. However, the underlying mechanisms still need further exploration.