Children's environmental health based on birth cohort studies of Asia (2) - air pollution, pesticides, and heavy metals

Exploring Heavy Metal and Metalloid Exposure in Children: A Pilot Biomonitoring Study near a Sugarcane Mill

Sugarcane production has been linked to the release of heavy metals and metalloids (HM/MTs) into the environment, raising concerns about potential health risks. This study aimed to assess the levels of 19 HM/MTs in children living near a sugarcane mill through a pilot biomonitoring investigation. We investigated sex-related differences in these element levels and their correlations. A cross-sectional study was conducted, analyzing data from 20 children in the latter part of 2023. Spearman correlation coefficients with 95% confidence intervals (CIs) were used to assess the relationships between urinary HM/MT levels. Detectable levels of 17 out of the 19 HM/MTs were found across the entire study sample, with arsenic and copper detectable in 95% of the children. Titanium exhibited higher levels in boys compared to girls (p = 0.017). We identified 56 statistically significant correlations, with 51 of them being positive, while the remaining coefficients indicated negative relationships. This study characterized HM/MT levels in school-aged children residing near a sugarcane mill through a pilot biomonitoring investigation. Further research employing larger sample sizes and longitudinal assessments would enhance our understanding of the dynamics and health impacts of HM/MT exposure in this vulnerable population.

Fabrication of engineered biochar for remediation of toxic contaminants in soil matrices and soil valorization

Biochar has emerged as an efficacious green material for remediation of a wide spectrum of environmental pollutants. Biochar has excellent characteristics and can be used to reduce the bioavailability and leachability of emerging pollutants in soil through adsorption and other physico-chemical reactions. This paper systematically reviewed previous researches on application of biochar/engineered biochar for removal of soil contaminants, and underlying adsorption mechanism. Engineered biochar are derivatives of pristine biochar that are modified by various physico-chemical and biological procedures to improve their adsorption capacities for contaminants. This review will promote the possibility to expand the application of biochar for restoration of degraded lands in the industrial area or saline soil, and further increase the useable area. This review shows that application of biochar is a win-win strategy for recycling and utilization of waste biomass and environmental remediation. Application of biochar for remediation of contaminated soils may provide a new solution to the problem of soil pollution. However, these studies were performed mainly in a laboratory or a small scale, hence, further investigations are required to fill the research gaps and to check real-time applicability of engineered biochar on the industrial contaminated sites for its large-scale application.

NRT1.2 overexpression enhances the synergistic interplay between ABA-generating bacteria and biochars in reducing heavy metal accumulation in pak choi

The agricultural sector faces severe challenges owing to heavy metal (HM) contamination of farmlands, requiring urgent preventive measures. To address this, we investigated the impact of the synergistic application of Azospirillum brasilense, a growth-promoting rhizobacterium producing abscisic acid (ABA), and biochar to minimize HM accumulation in pak choi, using three distinct expression levels of the ABA transporter NRT1.2 in pak choi and three different types of contaminated soils as experimental materials. The results revealed that pak choi with low, medium, and high NRT1.2 expression intensity, when subjected to bacterial strain-biochar treatment, exhibited an increasing trend in ABA content compared to the control. Correspondingly, the aboveground HM content decreased by 1-49 %, 22-52 %, and 15-96 %, whereas the fresh weight increased by 12-38 %, 88-126 %, and 152-340 %, respectively, showing a significant correlation with NRT1.2 expression. Pearson correlation analysis demonstrated that NRT1.2 expression intensity was inversely associated with the combined treatment's reduction in HM accumulation and positively correlated with the promotional effect. Simultaneously, soil discrepancies significantly affected the combined treatment, which was likely associated with variations in the active forms of HM in each soil. Consequently, when employing ABA-producing bacteria for mitigating crop HM accumulation, selecting plants with higher relative NRT1.2 expression intensity, combined with biochar, is recommended.

Urinary concentrations of heavy metals in pregnant women living near a petrochemical area according to the industrial activity

BACKGROUND

The progressive industrialization has resulted in an increase in heavy metal pollution in the environment, which has a dangerous impact on human health. Prenatal exposure to heavy metals, even at very low concentrations, may be especially harmful to pregnant women and their children. Different industrial activities can contribute to heavy metal pollution in a specific area.

OBJECTIVE

1) To explore the concentrations of heavy metals in urine samples of pregnant women, and 2) to evaluate the potential effect of different industrial activities in Tarragona (Spain).

METHODS

Urinary levels of four heavy metals (nickel (Ni), cadmium (Cd), mercury (Hg), and lead (Pb)) from 368 pregnant women recruited in the ECLIPSES study were analyzed. Home addresses and all the industries potentially releasing heavy metals were geo-referenced. Buffer zones were established within a 1.5, 3, and 5 km radius at the center of each industry. Subsequently, the number of participants living in and out of each buffer zone was recorded.

RESULTS

Urinary levels of Ni and Cd, but not those of Hg and Pb, were obviously increased in pregnant women living near most of the industrial sites. After adjustment for potential co-variates, only Cd showed notable differences according to the industrial activity. Compared to women living outside the buffer, Cd levels were increased in those living within 1.5 and 3 km of chemical industries, within 5 km of energy industries, within 1.5, 3, and 5 km of mineral industries, and within 3 and 5 km of metal processing industries.

CONCLUSION

Among the analyzed heavy metals, Cd showed an increasing trend in urinary concentrations in women living near chemical, energy, mineral, and metal processing industries. This study highlights the need to develop legislative measures to minimize Cd exposure, especially by sensitive populations. Moreover, additive or synergistic effects of co-exposure to other air pollutants should not be disregarded.

Airborne Pesticides from Agricultural Practices: A Critical Review of Pathways, Influencing Factors, and Human Health Implications

This critical review examines the release of pesticides from agricultural practices into the air, with a focus on volatilization, and the factors influencing their dispersion. The review delves into the effects of airborne pesticides on human health and their contribution to anthropogenic air pollution. It highlights the necessity of interdisciplinary research encompassing science, technology, public policy, and agricultural practices to effectively mitigate the risks associated with pesticide volatilization and spray dispersion. The text acknowledges the need for more research to understand the fate and transport of airborne pesticides, develop innovative application technologies, improve predictive modeling and risk assessment, and adopt sustainable pest management strategies. Robust policies and regulations, supported by education, training, research, and development, are crucial to ensuring the safe and sustainable use of pesticides for human health and the environment. By providing valuable insights, this review aids researchers and practitioners in devising effective and sustainable solutions for safeguarding human health and the environment from the hazards of airborne pesticides.

Associations between serum trace elements and the risk of nasopharyngeal carcinoma: a multi-center case-control study in Guangdong Province, southern China

Background

Associations between trace elements and nasopharyngeal carcinoma (NPC) have been speculated but not thoroughly examined.

Methods

This study registered a total of 225 newly diagnosed patients with NPC and 225 healthy controls matched by sex and age from three municipal hospitals in Guangdong Province, southern China between 2011 and 2015. Information was collected by questionnaire on the demographic characteristics and other possibly confounding lifestyle factors. Eight trace elements and the level of Epstein-Barr virus (EBV) antibody were measured in casual (spot) serum specimens by inductively coupled plasma-mass spectrometry (ICP-MS) and enzyme-linked immunosorbent assay (ELISA), respectively. Restricted cubic splines and conditional logistic regression were applied to assess the relationship between trace elements and NPC risk through single-and multiple-elements models.

Results

Serum levels of chromium (Cr), cobalt (Co), nickel (Ni), arsenic (As), strontium (Sr) and molybdenum (Mo) were not associated with NPC risk. Manganese (Mn) and cadmium (Cd) were positively associated with NPC risk in both single-and multiple-element models, with ORs of the highest tertile compared with the reference categories 3.90 (95% CI, 1.27 to 7.34) for Mn and 2.30 (95% CI, 1.26 to 3.38) for Cd. Restricted cubic splines showed that there was a linear increasing trend between Mn and NPC risk, while for Cd there was a J-type correlation.

Conclusion

Serum levels of Cd and Mn was positively related with NPC risk. Prospective researches on the associations of the two trace elements with NPC ought to be taken into account within the future.

Nano-based smart formulations: A potential solution to the hazardous effects of pesticide on the environment

Inefficient usage, overdose, and post-application losses of conventional pesticides have resulted in severe ecological and environmental issues, such as pesticide resistance, environmental contamination, and soil degradation. Advances in nano-based smart formulations are promising novel methods to decrease the hazardous impacts of pesticide on the environment. In light of the lack of a systematic and critical summary of these aspects, this work has been structured to critically assess the roles and specific mechanisms of smart nanoformulations (NFs) in mitigating the adverse impacts of pesticide on the environment, along with an evaluation of their final environmental fate, safety, and application prospects. Our study provides a novel perspective for a better understanding of the potential functions of smart NFs in reducing environmental pollution. Additionally, this study offers meaningful information for the safe and effective use of these nanoproducts in field applications in the near future.

The effects of short-term, long-term, and reapplication of biochar on the remediation of heavy metal-contaminated soil

Biochar, a cost-effective amendment, has been reported to play pivotal roles in improving soil fertility and immobilizing soil pollutants due to its well-developed porous structure and tunable functionality. However, the properties of biochar and soils can vary inconsistently after field application. This may affect the remediation of biochar on heavy metal (HM)-contaminated soil being altered. Therefore, we selected lettuce as a model crop to determine the effects of short-term, long-term, and reapplication of biochar on soil physicochemical properties, microbial community, HM bioavailability, and plant toxicity. Our investigation revealed that the long-term application of biochar remarkably improved soil fertility, increased the relative abundance of the phylum Proteobacteria which was highly resistant to HMs, and reduced the abundance of phylum Acidobacteria. These changes in soil properties decreased the accumulation of Cd and Pb in lettuce tissues. The short- and long-term applications of biochar had no substantial effects on biomass, quality, and photosynthesis of lettuce. Moreover, the short-term and reapplication of biochar had no significant effects on soil bacterial communities but decreased the accumulation of Cd and Pb in lettuce tissues. It showed that the changes in the physical, chemical, and biological properties of soil after long-term application of biochar promoted the remediation of HM-contaminated soil. Furthermore, microbial community compositions varied with metal stress and biochar application, while the relative abundance of the phylum Actinobacteria in HM-contaminated soil with long-term biochar application was markedly higher than in HM-contaminated soil without biochar application.

Progress towards the 2030 sustainable development goals: direct and indirect impacts on neurological disorders

The United Nations' Sustainable Development Goals (SDGs) were set forth in 2015 as a blueprint for all nations to create a more sustainable future together. These 17 social, environmental, and economic goals have established targets to meet globally by the year 2030, with a focus on pro-poor initiatives, gender equality, and ending hunger. The relationship of the SDGs with neurological disorders and how the achievement of the SDGs intersects with the future of neurological practice have not been comprehensively examined. However, the incidence of neurological disorders, the outcomes of people living with neurological disorders, and the training of future neurologists can be interlinked, directly or indirectly, with programming for the SDGs and their eventual achievement. Each SDG is reviewed in the context of neurology. This lens can inform programming and policy, enhance research and training, and improve inter-sectoral action for neurological disorders worldwide.

Association of serum bisphenol AF concentration with depressive symptoms in adolescents: A nested case-control study in China

BACKGROUND

As an important alternative to bisphenol A (BPA), bisphenol AF (BPAF) is widely used and can be detected in multiple human biological samples. However, there are few studies on neurotoxicity of BPAF at present. In particular, no epidemiological studies have investigated BPAF in relation to depressive symptoms in adolescents. Here, our study aimed to evaluate the associations between serum BPAF concentrations and depressive symptoms in adolescents.

METHODS

A nested case-control study within an ongoing longitudinal prospective adolescent cohort that was established in Huaibei, China was conducted. A total of 175 participants who had new-onset depressive symptoms (cases) and 175 participants without depressive symptoms (controls) were included. Serum BPAF concentrations was measured using ultra-high-performance liquid chromatography-tandem mass spectrometry. The associations between BPAF exposure and the risk of depressive symptoms in adolescents were assessed using conditional logistic regression. The dose-response relationship between BPAF level and depressive symptoms was estimated using restricted cubic spline analyses.

RESULTS

In this study, the detection rate of serum BPAF was 100%, and the median (interquartile range, IQR) serum BPAF concentration was 5.24 (4.41-6.11) pg/mL in the case group and 4.86 (4.02-5.77) pg/mL in the control group (P = 0.009). Serum BPAF exposure was a risk factor for depressive symptoms (odds ratio (OR)= 1.132, 95% confidence interval (CI):1.013-1.264). After adjustment for all for confounders, compared with the low-exposure group, the high-exposure group had a 2.806-fold increased risk of depressive symptoms (OR=2.806, 95% CI: 1.188-6.626). Stratified analysis by sex revealed that males were more vulnerable to BPAF exposure than females. After adjustment for all confounders, compared with the low-exposure group, the relative risk of depressive symptoms in the high-exposure group was 3.858 (95% CI: 1.118-12.535) for males, however, no significant association between BPAF exposure and depressive symptoms was found in females. In addition, there was a marked linear association between BPAF exposure and the risk of depressive symptoms in the total population and in males.

CONCLUSIONS

The adolescents in this study were widely exposed to low levels of BPAF. A significant positive association was found between serum BPAF levels and the risk of depressive symptoms. The association was significantly modified by sex, and males were more vulnerable to BPAF exposure than females.

Prenatal and postnatal exposures to four metals mixture and IQ in 6-year-old children: A prospective cohort study in South Korea

BACKGROUND

Humans are exposed to a mixture of metals during their lifetime; however, evidence of neurotoxicity of such mixtures in critical time windows is still insufficient. We aimed to elucidate the associations of four metals mixture across multiple time points with children's intelligence quotient (IQ) in a prospective cohort study.

METHODS

Prenatal exposure and exposure at age 4 and 6 years to four types of blood metals, namely lead, mercury, cadmium, and manganese were quantified in 502 pregnant women and their children who participated in the Environment and Development Cohort study. Children' s IQ scores were assessed using the Wechsler Intelligence Scale at age 6. Bayesian kernel machine regression (BKMR), quantile g-computation models, and elastic net (ENET) models were used to assess the associations of their blood metals mixture with IQ scores.

RESULTS

Multivariate linear regression models indicated that postnatal blood manganese exposure at the age of 4 years was significantly negatively associated with children's IQ [β =  - 5.99, 95% confidence interval (CI): -11.37 to - 0.61]. In the multi-chemical BKMR and quantile g-computation model, statistically significant inverse associations were found between the mixture of prenatal and postnatal metals and children's IQ score (Difference in children' IQ per quartile increase: -2.83; 95% CI: -5.28, -0.38). Interestingly, we found that manganese levels at both age of 4 and 6 years were contributing factors to children's IQ in the mixture models, namely, BKMR, quantile g-computation, and ENET models.

CONCLUSIONS

Multi-pollutant mixtures of prenatal and postnatal exposures to four metals affected child IQ at 6 years of age. We found a relationship between manganese exposure at both age 4, and 6 years and children's IQ. Additional studies are warranted to confirm these associations and to control the exposure to different metals during pregnancy and preschool childhood.

Prenatal exposure to air pollutants and childhood atopic dermatitis and allergic rhinitis adopting machine learning approaches: 14-year follow-up birth cohort study

The incidence of childhood atopic dermatitis (AD) and allergic rhinitis (AR) is increasing. This warrants development of measures to predict and prevent these conditions. We aimed to investigate the predictive ability of a spectrum of data mining methods to predict childhood AD and AR using longitudinal birth cohort data. We conducted a 14-year follow-up of infants born to pregnant women who had undergone maternal examinations at nine selected maternity hospitals across Taiwan during 2000-2005. The subjects were interviewed using structured questionnaires to record data on basic demographics, socioeconomic status, lifestyle, medical history, and 24-h dietary recall. Hourly concentrations of air pollutants within 1 year before childbirth were obtained from 76 national air quality monitoring stations in Taiwan. We utilized weighted K-nearest neighbour method (k = 3) to infer the personalized air pollution exposure. Machine learning methods were performed on the heterogeneous attributes set to predict allergic diseases in children. A total of 1439 mother-infant pairs were recruited in machine learning analysis. The prevalence of AD and AR in children up to 14 years of age were 6.8% and 15.9%, respectively. Overall, tree-based models achieved higher sensitivity and specificity than other methods, with areas under receiver operating characteristic curve of 83% for AD and 84% for AR, respectively. Our findings confirmed that prenatal air quality is an important factor affecting the predictive ability. Moreover, different air quality indices were better predicted, in combination than separately. Combining heterogeneous attributes including environmental exposures, demographic information, and allergens is the key to a better prediction of children allergies in the general population. Prenatal exposure to nitrogen dioxide (NO₂) and its concatenation changes with time were significant predictors for AD and AR till adolescent.

Associations between molybdenum exposure and ultrasound measures of fetal growth parameters: A pilot study

Previous studies have suggested the association of molybdenum (Mo) exposure with some adverse outcomes. However, limited epidemiological studies have been performed to explore the association between maternal Mo exposure level and fetal growth. This study recruited 220 pregnant women during their second trimester. The mother's urinary Mo concentration was measured by inductively coupled plasma mass spectrometry (ICP-MS). The fetal biometric parameters, including head circumference (HC), biparietal diameter (BPD), femur diaphysis length (FL), and abdominal circumference (AC) were assessed by prenatal ultrasound. Estimated fetal weight (EFW) was evaluated using the formula of Hadlock. Multivariable linear regression models were applied to estimate the relationships between Mo level and fetal biometric parameters, and potential confounders were adjusted. A one-unit increment in natural-logarithm transformed urinary Mo level was significantly associated with reductions in fetal AC of -0.34 cm (95%CI: -0.63, -0.04), and was negatively related to EFW (β = -18.2, 95%CI: -40.5, 4.2). Furthermore, when participants were stratified by copper (Cu) level, the results showed that the magnitude of negative association between Mo and AC (β = -0.55, 95%CI: -1.13, 0.04) was greater in pregnant women with Cu level below median value, comparing with those with Cu level above median value (β = -0.08, 95%CI: -0.57, 0.42), and a similar pattern was found for EFW, although the interaction between Mo and Cu was not significant. Our data suggested an inverse association of maternal urinary Mo level with fetal AC and EFW during the second trimester of pregnancy. These associations might be stronger in pregnant women with relatively lower Cu levels.

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

Background

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

Methods

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

Results

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

Conclusions

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

Supplementary Information

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

Role of metallic pollutants in neurodegeneration: effects of aluminum, lead, mercury, and arsenic in mediating brain impairment events and autism spectrum disorder

Autism spectrum disorder (ASD) is a developmental disorder of the brain characterized by shortfall in the social portfolio of an individual and abbreviated interactive and communication aspects rendering stereotypical behavior and pitfalls in a child's memory, thinking, and learning capabilities. The incidence of ASD has accelerated since the past decade, portraying environment as one of the primary assets, comprising of metallic components aiming to curb the neurodevelopmental pathways in an individual. Many regulations like Clean Air Act and critical steps taken by countries all over the globe, like Sweden and the USA, have rendered the necessity to study the effects of environmental metallic components on ASD progression. The review focuses on the primary metallic components present in the environment (aluminum, lead, mercury, and arsenic), responsible for accelerating ASD symptoms by a set of general mechanisms like oxidative stress reduction, glycolysis suppression, microglial activation, and metalloprotein disruption, resulting in apoptotic signaling, neurotoxic effects, and neuroinflammatory responses. The effect of these metals can be retarded by certain protective strategies like chelation, dietary correction, certain agents (curcumin, mangiferin, selenium), and detoxification enhancement, which can necessarily halt the neurodegenerative effects.

A case-control study on the association of mineral elements exposure and thyroid tumor and goiter

Thyroid tumor and thyroid goiter are prevalent disease around the world. In this case-control study, we investigated the association between exposure to a total of twelve mineral elements and thyroid disease as well as thyroid functions. Participants with thyroid tumor or goiter (N = 197) were matched with a healthy population (N = 197) by age (± 2 years old) and same sex. Questionnaires were used to collect data about the demographic characteristics and information of subjects. Serum and urine samples were collected simultaneously for each of the subjects. Mineral elements, iodine level of urine and levels of the total seven thyroid function indexes in serum were detected respectively. Conditional logistic regression was applied to estimate the associations between mineral elements and the risk of thyroid tumor and goiter through single-element models and multiple-element models. Multiple linear regression was used to evaluate relationships between mineral elements and percentage changes of thyroid functions. Higher concentrations of mineral elements in the recruited population were found in this study than other comparable studies, and the levels of chromium (Cr), manganese (Mn), nickel (Ni), arsenic (As), cadmium (Cd), selenium (Se), antimony (Sb), thallium (Tl) and lead (Pb) in the case group were lower than the control group. According to the single-element models, Cr, Mn, Ni, Sb and Tl showed significant negative associations with the risk of thyroid tumor and goiter, and, Cd showed nonmonotonic dose response. Cd and mercury (Hg) showed a nonmonotonic percentage change with T4, while Tl was associated with the increased FT4 in the control group. Therefore, Cd, Hg and Tl may disturb the balance of thyroid function to some extent, and Cr, Mn, Ni, Cd, Sb, and Tl may become potential influencing factors for the risk of thyroid tumor and goiter.

Are glyphosate and glyphosate-based herbicides endocrine disruptors that alter female fertility?

Numerous evidences have alerted on the toxic effects of the exposure to glyphosate on living organisms. Glyphosate is the herbicide most used in crops such as maize and soybean worldwide, which implies that several non-target species are at a high risk of exposure. Although the Environmental Protection Agency (EPA-USA) has reaffirmed that glyphosate is safe for users, there are controversial studies that question this statement. Some of the reported effects are due to exposure to high doses; however, recent evidences have shown that exposure to low doses could also alter the development of the female reproductive tract, with consequences on fertility. Different animal models of exposure to glyphosate or glyphosate-based herbicides (GBHs) have shown that the effects on the female reproductive tract may be related to the potential and/or mechanisms of actions of an endocrine-disrupting compound. Studies have also demonstrated that the exposure to GBHs alters the development and differentiation of ovarian follicles and uterus, affecting fertility when animals are exposed before puberty. In addition, exposure to GBHs during gestation could alter the development of the offspring (F1 and F2). The main mechanism described associated with the endocrine-disrupting effect of GBHs is the modulation of estrogen receptors and molecules involved in the estrogenic pathways. This review summarizes the endocrine-disrupting effects of exposure to glyphosate and GBHs at low or "environmentally relevant" doses in the female reproductive tissues. Data suggesting that, at low doses, GBHs may have adverse effects on the female reproductive tract fertility are discussed.

Prenatal exposure to bisphenol - A is associated with dysregulated perinatal innate cytokine response and elevated cord IgE level: A population-based birth cohort study

BACKGROUND

Reports on the relationship between prenatal exposure to bisphenol-A (BPA) and the development of childhood allergy have been conflicting. This study aimed to investigate the impact of prenatal BPA exposure on several objective outcomes such as cytokine profile, atopic sensitization, and infant lung function (ILF) tests in addition to clinical allergic symptoms.

METHODS

A subset of 274 children from the PATCH cohort study with available cord BPA data were followed until 3 years of age. Total and specific IgE level and Toll-like receptor (TLR) stimulated cytokine production were assessed yearly since birth. ILF such as tidal volume, Vmax_FRC, airway resistance and compliance were performed at least once before the age of 2 years. Allergic outcome was determined by questionnaires and physician's assessment.

RESULTS

There was significant association between BPA concentration and IgE level in the cord blood (p < 0.01), but the correlation was no longer significant at ages 1 through 3 years. In addition, cord BPA concentration was associated with dysregulated TLR stimulated TNF-α and IL-6 production, but the correlation was significant only at birth. No relationship was found between cord BPA concentration and ILF measurements or allergic symptoms (wheezing, rhino-conjunctivitis, or eczema) throughout early childhood.

CONCLUSION

Results showed that prenatal exposure to BPA was not associated with increased risk of childhood allergy or impaired ILF. However, with its impact on biomarkers for allergy such as alterations in perinatal cytokine profile and elevated cord IgE level, the potential role of prenatal BPA exposure on the development of allergy cannot be disregarded.

Zebrafish (Danio rerio) as an excellent vertebrate model for the development, reproductive, cardiovascular, and neural and ocular development toxicity study of hazardous chemicals

In the past decades, the type of chemicals has gradually increased all over the world, and many of these chemicals may have a potentially toxic effect on human health. The zebrafish, as an excellent vertebrate model, is increasingly used for assessing chemical toxicity and safety. This review summarizes the efficacy of zebrafish as a model for the study of developmental toxicity, reproductive toxicity, cardiovascular toxicity, neurodevelopmental toxicity, and ocular developmental toxicity of hazardous chemicals, and the transgenic zebrafish as biosensors are used to detect the environmental pollutants.

Early exposure to food contaminants reshapes maturation of the human brain-gut-microbiota axis

Early childhood growth and development is conditioned by the consecutive events belonging to perinatal programming. This critical window of life will be very sensitive to any event altering programming of the main body functions. Programming of gut function, which is starting right after conception, relates to a very well-established series of cellular and molecular events associating all types of cells present in this organ, including neurons, endocrine and immune cells. At birth, this machinery continues to settle with the establishment of extra connection between enteric and other systemic systems and is partially under the control of gut microbiota activity, itself being under the densification and the diversification of microorganisms' population. As thus, any environmental factor interfering on this pre-established program may have a strong incidence on body functions. For all these reasons, pregnant women, fetuses and infants will be particularly susceptible to environmental factors and especially food contaminants. In this review, we will summarize the actual understanding of the consequences of repeated low-level exposure to major food contaminants on gut homeostasis settlement and on brain/gut axis communication considering the pivotal role played by the gut microbiota during the fetal and postnatal stages and the presumed consequences of these food toxicants on the individuals especially in relation with the risks of developing later in life non-communicable chronic diseases.

Urine metals concentrations and dyslexia among children in China

BACKGROUND

Exposures to heavy metals has been linked to many developmental disorders. However, few studies have investigated the effects of exposure and co-exposure to metals on dyslexia, especially with regard to dyslexics in China.

OBJECTIVES

To investigate the association between urine metal concentrations and dyslexia in a case-control study among children in China.

METHODS

A case-control study was conducted in the Tongji Reading Environment and Dyslexia (READ) research program. A total of 228 dyslexics and 228 controls were matched on gender, age (within one year), and grade. The concentrations of 21 urine metals were measured by an inductively coupled plasma-mass spectrometer (ICP-MS). Multivariable conditional logistic regression models were applied to estimate the adjusted odds ratios (ORs) of Chinese dyslexia.

RESULTS

After adjusting for potential confounders, two metals (selenium and argentum) were significantly associated with dyslexia in single-metal multivariable models. Argentum was positively associated with the risk of dyslexia, while selenium was negatively associated. In the multiple-metal model, compared with extreme quartiles, the ORs (95% CIs) for selenium was 0.36 (95% CI: 0.14-0.93; P_trend = 0.029). In the joint association analysis, children with higher levels of urine argentum and lower level of urine selenium had a significantly higher risk of dyslexia than those with low levels of argentum and selenium (OR = 5.06, 95% CI: 1.67-18.84).

CONCLUSIONS

The findings suggest that exposure to selenium and argentum may relate to dyslexia in China. Longitudinal studies are needed to further evaluate these relationships and investigate potential mechanisms.

Influence of Freeze-Thaw Cycles and Binder Dosage on the Engineering Properties of Compound Solidified/Stabilized Lead-Contaminated Soils

The solidification/stabilization (S/S) method is the usual technique for the remediation of soils polluted by heavy metal in recent years. However, freeze–thaw cycles, an important physical process producing weathering of materials, will affect the long-term stability of engineering characteristics in solidified contaminated soil. In addition, it is still questionable whether using large dosages of binders can enhance the engineering properties of solidified/stabilized contaminated soils. In this study, the three most commonly used binders (i.e., cement, quicklime, and fly ash), alone and mixed in different ratios, were thus added to lead-contaminated soil in various dosages, making a series of cured lead-contaminated soils with different dosages of binders. Afterward, unconfined compression strength tests, direct shear tests, and permeability tests were employed on the resulting samples to find the unconfined compressive strength (UCS), secant modulus (E50), internal friction angle (φ), cohesion (c), and permeability coefficient (k) of each solidified/stabilized lead-contaminated soil after 0, 3, 7, and 14 days of freeze–thaw cycles. This procedure was aimed at evaluating the influence of freeze–thaw cycle and binder dosage on engineering properties of solidified/stabilized lead-contaminated soils. Results of our experiments showed that cement/quicklime/fly ash could remediate lead-contaminated soils. However, it did not mean that the more the dosage of binder, the better the curing effect. There was a critical dosage. Excessive cementation of contaminated soils caused by too much binder would result in loss of strength and an increase in permeability. Furthermore, it was found that UCS,  E50, φ, c, and k values generally decreased with the increase in freeze–thaw cycle time—a deterioration effect on the engineering characteristics of solidified lead-contaminated soils. Avoiding excessive cementation, 2.5% cement or quicklime was favorable for the value of E50 while a 2.5% fly ash additive was beneficial for the k value. It is also suggested that if the freeze–thaw cycle continues beyond the period supported by excessive cementation, such a cycle will rapidly destroy the original structure of the soil and create large cracks, leading to an increase in permeability. The results also showed that the contaminated soils with a larger dosage of binders exhibited more significant deterioration during freeze–thaw cycles.