Combined exposure to heavy metals in PM2.5 and pediatric asthma

Modulation of Adverse Health Effects of Environmental Cadmium Exposure by Zinc and Its Transporters

Zinc (Zn) is the second most abundant metal in the human body and is essential for the function of 10% of all proteins. As metals cannot be synthesized or degraded, they must be assimilated from the diet by specialized transport proteins, which unfortunately also provide an entry route for the toxic metal pollutant cadmium (Cd). The intestinal absorption of Zn depends on the composition of food that is consumed, firstly the amount of Zn itself and then the quantity of other food constituents such as phytate, protein, and calcium (Ca). In cells, Zn is involved in the regulation of intermediary metabolism, gene expression, cell growth, differentiation, apoptosis, and antioxidant defense mechanisms. The cellular influx, efflux, subcellular compartmentalization, and trafficking of Zn are coordinated by transporter proteins, solute-linked carriers 30A and 39A (SLC30A and SLC39A), known as the ZnT and Zrt/Irt-like protein (ZIP). Because of its chemical similarity with Zn and Ca, Cd disrupts the physiological functions of both. The concurrent induction of a Zn efflux transporter ZnT1 (SLC30A1) and metallothionein by Cd disrupts the homeostasis and reduces the bioavailability of Zn. The present review highlights the increased mortality and the severity of various diseases among Cd-exposed persons and the roles of Zn and other transport proteins in the manifestation of Cd cytotoxicity. Special emphasis is given to Zn intake levels that may lower the risk of vision loss and bone fracture associated with Cd exposure. The difficult challenge of determining a permissible intake level of Cd is discussed in relation to the recommended dietary Zn intake levels.

Characterization and childhood exposure assessment of toxic heavy metals in household dust under true living conditions from 10 China cities

Health hazards caused by metal exposure in household dust are concerning environmental health problems. Exposure to toxic metals in household dust imposes unclear but solid health risks, especially for children. In this multicenter cross-sectional study, a total of 250 household dust samples were collected from ten stratified cities in China (Panjin, Shijiazhuang, Qingdao, Lanzhou, Luoyang, Ningbo, Xi'an, Wuxi, Mianyang, Shenzhen) between April 2018 and March 2019. Questionnaire was conducted to gather information on individuals' living environment and health status in real-life situations. Multivariate logistic regression and principal component analysis were conducted to identify risk factors and determine the sources of metals in household dust. The median concentration of five metals in household dust from 10 cities ranged from 0.03 to 73.18 μg/g. Among the five heavy metals, only chromium in household dust of Mianyang was observed significantly both higher in the cold season and from the downwind households. Mercury, cadmium, and chromium were higher in the third-tier cities, with levels of 0.08, 0.30 and 97.28 μg/g, respectively. There were two sources with a contribution rate of 38.3 % and 25.8 %, respectively. Potential risk factors for increased metal concentration include long residence time, close to the motorway, decoration within five years, and purchase of new furniture within one year. Under both moderate and high exposure scenarios, chromium showed the highest level of exposure with 6.77 × 10-4 and 2.28 × 10-3 mg·kg-1·d-1, and arsenic imposed the highest lifetime carcinogenic risk at 1.67 × 10-4 and 3.17 × 10-4, respectively. The finding highlighted the priority to minimize childhood exposure of arsenic from household dust.

Update on asthma biology

This is an exciting time to be conducting asthma research. The recent development of targeted asthma biologics has validated the power of basic research to discover new molecules amenable to therapeutic intervention. Advances in high-throughput sequencing are providing a wealth of "omics" data about genetic and epigenetic underpinnings of asthma, as well as about new cellular interacting networks and potential endotypes in asthma. Airway epithelial cells have emerged not only as key sensors of the outside environment but also as central drivers of dysregulated mucosal immune responses in asthma. Emerging data suggest that the airway epithelium in asthma remembers prior encounters with environmental exposures, resulting in potentially long-lasting changes in structure and metabolism that render asthmatic individuals susceptible to subsequent exposures. Here we summarize recent insights into asthma biology, focusing on studies using human cells or tissue that were published in the past 2 years. The studies are organized thematically into 6 content areas to draw connections and spur future research (on genetics and epigenetics, prenatal and early-life origins, microbiome, immune and inflammatory pathways, asthma endotypes and biomarkers, and lung structural alterations). We highlight recent studies of airway epithelial dysfunction and response to viral infections and conclude with a framework for considering how bidirectional interactions between alterations in airway structure and mucosal immunity can lead to sustained lung dysfunction in asthma.

Possible Risk Factors and Their Potential Associations with Combined Heavy Metal Exposures in Pregnant Women in the Republic of Suriname

Background

The exposure of pregnant women to multiple environmental pollutants may be more disadvantageous to birth outcomes when compared to single-compound contaminations.

Objective

This study investigated the mixed exposures to mercury, manganese, or lead in 380 pregnant Surinamese women. The factors that might be associated with the heavy metal exposures and the relative risk of the potential factors to cause the mixed exposures were explored. The influencing factors of exposures to mixed contaminants assessed were living in Suriname's rural regions, several parts of which are contaminated with heavy metals emitted from artisanal and small-scale gold mining and agricultural activities; the consumption of potentially contaminated foods; advanced maternal age; as well as a relatively low formal educational level and monthly household income.

Methods

Descriptive statistics were used to calculate frequency distributions and χ2-contingency analyses to calculate associations and relative risks (RR) with 95% confidence intervals (CI).

Findings

Blood levels of two or three of the heavy metals above public health limits were observed in 36% of the women. These women were more often residing in the rural regions, primarily consumed potentially contaminated food items, were 35 years or older, were lower educated, and more often had a lower household income. However, only living in the rural regions (RR = 1.48; 95% CI 1.23-1.77) and a low household income (RR = 1.38; 95% CI 1.15-1.66) significantly increased the risk of exposure exceeding levels of concern to two or three of the heavy metals (by 48% and 38%, respectively).

Conclusion

More comprehensive pharmacological, ecological, and epidemiological studies about exposures to mixed heavy metal contaminations in pregnant women are warranted.

Heavy metal levels are positively associated with serum periostin and miRNA-125b levels, but inversely associated with miRNA-26a levels in pediatric asthma cases. A case-control study

BACKGROUND

The study investigated heavy metals levels [urinary cadmium (U-Cd), erythrocytic cadmium (E-Cd), urinary arsenic (U-As), and whole blood lead (WB-Pb)] in children with bronchial asthma (BA) and tested their associations with serum periostin, miRNA-125b and miRNA-26a levels, and with asthma severity clinically and laboratory [blood eosinophils count (BEC) and serum total immunoglobin E (IgE)]. Also, we tested cut-off points, for the studied parameters, to distinguish BA cases from healthy children.

METHODS

This case-control study included 158 children divided into control group; n = 72 and BA group; n = 86. Heavy metals were measured by an inductively coupled plasma-optical emission spectrophotometer. Serum periostin and IgE levels were measured by their corresponding ELISA kits. miRNAs relative expressions were estimated by RT-qPCR using the 2-ΔΔCT method.

RESULTS

Heavy metals, serum periostin, and miR-125b levels were significantly high in BA group (p < 0.001). Heavy metals levels correlated positively with serum periostin, miR-125b and IgE levels, BEC, and asthma severity. The reverse was observed regarding serum miR-26a levels. Receiver operating characteristics (ROC) curve analysis showed good to excellent abilities of U-Cd, E-Cd, U-As, WB-Pb, serum periostin, miRNA-125b, and miRNA - 26a, and total IgE levels to distinguish BA cases from healthy children.

CONCLUSIONS

Heavy metal toxicity in children is associated with BA severity, increased serum periostin and miRNA-125b levels, and decreased miRNA-26a levels. Specific measures to reduce children's exposure to heavy metals should be taken. Future research should consider blocking miRNA-125b action or enhancing miRNA-26a action to manage BA cases.

The Associations between Exposure to Multiple Heavy Metals and Total Immunoglobulin E in U.S. Adults

Immunoglobulin E (IgE) is a type of immunoglobulin, and elevated serum total IgE is often present in allergic diseases. Exposure to environmental heavy metals has been markedly linked to allergic diseases, leading to elevated total IgE levels. However, studies concerning the effects of multiple metal exposures on total IgE levels are limited. Therefore, the current study seeks to explore the correlation between heavy-metal co-exposure and total IgE levels based on the National Health and Nutrition Examination Survey (NHANES, 2005-2006). Participants possessed complete data on total IgE levels, 11 urinary metal concentrations and other covariates. The correlations between 11 metals and total IgE levels were analyzed using multiple linear regression, and total IgE levels were a continuous variable. Total IgE levels exceeding 150 kU/L were considered sensitized. Binary logistic regression analyses were employed to assess the correlation between metal exposure and the occurrence of an allergic state. Then, the association between co-exposure to the 11 metals and total IgE levels or the occurrence of sensitization status was further analyzed by Bayesian kernel machine regression (BKMR), a multi-contaminant model. There were 1429 adults with complete data included. Based on the median concentration, molybdenum (Mo) had the highest concentration (46.60 μg/L), followed by cesium (Cs), barium (Ba), lead (Pb), and mercury (Hg). And the median (interquartile range) for total IgE levels was 43.7 (17.3, 126.0) kU/L. Multiple linear regression results showed that Pb was significantly and positively associated with total IgE levels (β = 0.165; 95% CI: 0.046, 0.284). Binary logistic regression showed a significant positive correlation between urinary Pb (OR: 1.258; 95% CI: 1.052, 1.510) and tungsten (W) (OR: 1.251; 95% CI: 1.082, 1.447). Importantly, the BKMR model found a positive correlation between combined-metal exposure and total IgE levels and the occurrence of sensitization status. The mixed heavy-metal exposure was associated with increased total IgE levels, and this association may be driven primarily by the exposure of Pb and W. This study provides new insights into the relationship between heavy-metal exposure and allergic diseases. More research is needed to confirm these findings.

Prenatal exposure to metal mixtures and lung function in children from the New Hampshire birth cohort study

Prenatal exposure to metals/metalloids, even at common US population levels, may pose risks to fetal health, and affect children's lung function. Yet, the combined effects of simultaneous prenatal exposures on children's lung function remain largely unexplored. This study analyzed 11 metals (As speciation, Cd, Co, Cu, Mo, Ni, Pb, Sb, Se, Sn, Zn) in maternal urine during weeks 24-28 of gestation and evaluated lung function, including forced vital capacity (FVC) and forced expiratory volume in the first second of expiration (FEV1), in 316 US mother-child pairs at around age 7. We used Bayesian Kernel Machine Regression (BKMR), weighted quantile sum regression (WQSR), and multiple linear regression to examine the association between metal mixture exposure and children's lung function, adjusting for maternal smoking, child age, sex, and height. In BKMR models assessing combined exposure effects, limited evidence of metal non-linearity or interactions was found. Nevertheless, Co, As species, and Pb showed a negative association, while Mo exhibited a positive association with children's FVC and FEV1, with other metals held constant at their medians. The weighted index, from WQSR analysis assessing the cumulative impact of all metals, highlighted prenatal Mo with the highest positive weight, and Co, As, and Sb with the most substantial negative weights on children's FVC and FEV1. Urinary Co and Pb were negatively associated with FVC (β = -0.09, 95% confidence interval (CI) (-0.18; -0.01) and β = -0.07, 95% CI (-0.13; 0.00), respectively). Co was also negatively associated with FEV1 (β = -0.09, 95% CI (-0.18; 0.00). There was a negative association between As and FVC, and a positive association between Mo and both FVC and FEV1, though with wide confidence intervals. Our findings suggest that prenatal trace element exposures may impact children's lung function, emphasizing the importance of reducing toxic exposures and maintaining adequate nutrient levels.

Arsenic exposure and lung function decline in chronic obstructive pulmonary disease patients: The mediating influence of systematic inflammation and oxidative stress

Lung tissue is one of the target sites of arsenic (As). The goal of this investigation was to assess the associations of blood As concentration with pulmonary function indicators in patients with chronic obstructive pulmonary disease (COPD), as well as the roles of systemic inflammation and oxidative stress in this relationship. All 791 COPD patients were selected. Blood As concentration, and tumour necrosis factor-α (TNF-α) and 8-iso-prostaglandin-F2α (8-iso-PGF2α) were detected in the serum of COPD cases. Blood As was robustly related to pulmonary function parameters in an inverse dose-dependent manner. Multivariate linear regression analyses verified that a 1-unit increase of blood As was linked to declines of 0.263 L in FVC, 0.288 L in FEV1, 3.454 in FEV1/FVC%, and 0.538 in predicted FEV1%, respectively. The potential for pulmonary function decline gradually increased across the elevated tertiles of blood As. Nonsmokers were susceptible to As-induced pulmonary function reduction. Blood As was positively linked to the levels of TNF-α and 8-iso-PGF2α. Increased TNF-α and 8-iso-PGF2α partially mediated As-induced the reductions in FEV1 and FVC among COPD patients. As exposure is intensely linked to pulmonary function reduction. Systematic inflammation and oxidative stress partially mediate such associations in COPD patients.

Prevalence, associated factors, and impact of adolescent asthma in Taiwan: Global Asthma Network phase I survey

Background

The prevalence of asthma in Taiwan was increasing in the past 30 years, causing a great impact on adolescent health. This study aimed to investigate the current prevalence, impact, and associated factors of asthma in Taiwanese adolescents.

Material and methods

Parents or guardians provided passive consent at home prior to the survey. Adolescents aged 13-14 years completed a questionnaire survey in 2017 in Taipei, Taiwan. The prevalence, impact, and associated factors of asthma were analyzed. We also compared the asthma prevalence with the prevalence in 1995 and 2001.

Results

We analyzed 3474 validated questionnaires. The prevalence of physician-diagnosed asthma was 12.4%. The prevalence of current wheezing was 9.2% in 2017, which was 5.2% in 1995 and 7.0% in 2001. 3.3% of 13-14-year-old adolescents had severe asthma symptoms. Asthma significantly impacted the lives of adolescents. Of the students with asthma, 10.9% had school absenteeism, 16.5% urgently needed to see a doctor, 9.5% went to the emergency department, and 3.5% were admitted to hospitals within the preceding 12 months. The associated factors for physician-diagnosed asthma in Taiwanese adolescents were male (prevalence ratio [PR], 1.38; 95% confidence interval [CI], 1.05-1.83; p = 0.02), maternal history of asthma (PR, 2.61; 95% CI, 1.69-4.02; p < 0.01), and recent paracetamol use at least once per month (PR, 2.60; 95% CI, 1.24-5.42; p = 0.01). The associated factors for school absenteeism were nocturnal cough (PR, 1.99; 95% CI, 1.16-3.41; p = 0.01), current wheezing (PR, 7.52; 95% CI, 4.39-12.9; p < 0.01), and recent paracetamol use (at least once per month, PR, 3.16; 95% CI, 1.10-9.06; p = 0.03; at least once per year, PR, 2.19; 95% CI, 1.25-3.83; p < 0.01).

Conclusions

The prevalence of physician-diagnosed asthma was 12.4%. Asthma substantially impacted the lives of adolescents. Reducing nocturnal cough, wheezing frequency, and paracetamol usage might help decrease school absenteeism.

Early-life cadmium exposure elevates susceptibility to allergic asthma in ovalbumin-sensitized and challenged mice

Increasing evidence have demonstrated that early-life exposure to environmental toxicants elevates risk of allergic asthma. Cadmium (Cd) is widely present in the environment. The purposes of this study were to evaluate the impact of early-life Cd exposure on susceptibility to ovalbumin (OVA)-evoked allergic asthma. Newly weaned mice were subjected to a low concentration of CdCl₂ (1 mg/L) by drinking water for 5 consecutive weeks. Penh value, an index of airway obstruction, was increased in OVA-stimulated and challenged pups. Abundant inflammatory cells were observed in the lung of OVA-exposed pups. Goblet cell hyperplasia and mucus secretion were shown in the airway of OVA-stimulated and challenged pups. Early-life Cd exposure exacerbated OVA-evoked airway hyperreactivity, Goblet cell hyperplasia and mucus secretion. The in vitro experiments showed that mucoprotein gene MUC5AC mRNA was upregulated in Cd-exposed bronchial epithelial cells. Mechanistically, endoplasmic reticulum (ER) stress-related molecules GRP78, p-eIF2α, CHOP, p-IRE1α and spliced XBP-1 (sXBP-1) were elevated in Cd-subjected bronchial epithelial cells. The blockade of ER stress, using chemical inhibitor 4-PBA or sXBP-1 siRNA interference, attenuated Cd-induced MUC5AC upregulation in bronchial epithelial cells. These results indicate that early-life Cd exposure aggravates OVA-induced allergic asthma partially through inducing ER stress in bronchial epithelial cells.

Epidemiological evidence for the effect of environmental heavy metal exposure on the immune system in children

Heavy metals exist widely in daily life, and exposure to heavy metals caused by environmental pollution has become a serious public health problem worldwide. Due to children's age-specific behavioral characteristics and imperfect physical function, the adverse health effects of heavy metals on children are much higher than in adults. Studies have found that heavy metal exposure is associated with low immune function in children. Although there are reviews describing the evidence for the adverse effects of heavy metal exposure on the immune system in children, the summary of evidence from epidemiological studies involving the level of immune molecules is not comprehensive. Therefore, this review summarizes the current epidemiological study on the effect of heavy metal exposure on childhood immune function from multiple perspectives, emphasizing its risks to the health of children's immune systems. It focuses on the effects of six heavy metals (lead (Pb), cadmium (Cd), arsenic (As), mercury (Hg), nickel (Ni), and manganese (Mn)) on children's innate immune cells, lymphocytes and their subpopulations, cytokines, total and specific immunoglobulins, and explores the immunotoxicological effects of heavy metals. The review finds that exposure to heavy metals, particularly Pb, Cd, As, and Hg, not only reduced lymphocyte numbers and suppressed adaptive immune responses in children, but also altered the innate immune response to impair the body's ability to fight pathogens. Epidemiological evidence suggests that heavy metal exposure alters cytokine levels and is associated with the development of inflammatory responses in children. Pb, As, and Hg exposure was associated with vaccination failure and decreased antibody titers, and increased risk of immune-related diseases in children by altering specific immunoglobulin levels. Cd, Ni and Mn showed activation effects on the immune response to childhood vaccination. Exposure age, sex, nutritional status, and co-exposure may influence the effects of heavy metals on immune function in children.

Health threat of PM2.5-bound trace elements exposure on asthma hospital admission: A time-stratified case-crossover study

Environmental pollution of trace elements has become of main concern due to the adverse effects. To estimate the impact of PM_2.5-bound trace elements on human health, a time-stratified case-crossover study has been designed to examine the short-term associations between 28 elements and asthma hospitalizations from January 2019 to November 2021 in Xiamen, China. This research summarized the major components that pose health risks in different seasons and took risk assessment for different groups. We found that an inter-quartile range (IQR) increase of Ca, Fe, Mn, Pd, Si, and Ti was positively associated with the incidence of asthma in the lag of 0-4 days. In winter, the elements that predisposed the population to asthma attack were the most, such as Al, Ba, Ca, Cr, Cu, Fe, K, Mn, Pd, Si, and Ti, and these elements are at higher risk for longer periods of time. The discrepancy in risk levels and major elements of asthma diagnosis among various age groups were also found in this work. Our results provided insights into the development of specific policies to reduce the risk of asthma attacks due to exposure to PM_2.5-bound trace elements.

Urinary Arsenic Concentration and Its Relationship with Bronchial Asthma in Children from Arica, Chile

In the city of Arica, northern Chile, the population has been involuntarily exposed to arsenic of natural and anthropogenic origin. This study aims to evaluate the association between urinary arsenic concentration and bronchial asthma diagnosis in the children of Arica. A cross-sectional analysis of a database of 1892 subjects under 18 years of age enrolled in the Environmental Health Centre between 2009 and 2021 was carried out. Arsenic exposure was obtained from a urine sample and bronchial asthma diagnosis from the database of the system for the management of explicit health guarantees. Logistic regression models were used to assess the association between inorganic arsenic and asthma. The median inorganic arsenic was 15 μg/L, and the prevalence of asthma was 7.4%. After adjusting for sex, age, ethnicity, and urinary creatinine, children with the highest tertile of urinary arsenic concentration (≥21.4 μg/L) had a greater chance of developing asthma (odds ratio (OR) 1.90; 95% confidence interval (CI) [1.13-3.18]). When exploring the modifying effect of ethnicity, the association increased among children belonging to any ethnic group (OR 3.51, 95%CI [1.43-8.65]). These findings suggest a relationship between arsenic exposure and bronchial asthma in children. While further studies are needed to assess the impact of arsenic on respiratory health, mitigation efforts to reduce arsenic exposure should be maintained.

Health Outcomes in Children Associated with Prenatal and Early-Life Exposures to Air Pollution: A Narrative Review

(1) Background: The developmental origins of health and disease (DOHaD) hypothesis links adverse fetal exposures with developmental mal-adaptations and morbidity later in life. Short- and long-term exposures to air pollutants are known contributors to health outcomes; however, the potential for developmental health effects of air pollution exposures during gestation or early-childhood have yet to be reviewed and synthesized from a DOHaD lens. The objective of this study is to summarize the literature on cardiovascular and metabolic, respiratory, allergic, and neuropsychological health outcomes, from prenatal development through early childhood, associated with early-life exposures to outdoor air pollutants, including traffic-related and wildfire-generated air pollutants. (2) Methods: We conducted a search using PubMed and the references of articles previously known to the authors. We selected papers that investigated health outcomes during fetal or childhood development in association with early-life ambient or source-specific air pollution exposure. (3) Results: The current literature reports that prenatal and early-childhood exposures to ambient and traffic-related air pollutants are associated with a range of adverse outcomes in early life, including cardiovascular and metabolic, respiratory and allergic, and neurodevelopmental outcomes. Very few studies have investigated associations between wildfire-related air pollution exposure and health outcomes during prenatal, postnatal, or childhood development. (4) Conclusion: Evidence from January 2000 to January 2022 supports a role for prenatal and early-childhood air pollution exposures adversely affecting health outcomes during development. Future studies are needed to identify both detrimental air pollutants from the exposure mixture and critical exposure time periods, investigate emerging exposure sources such as wildfire, and develop feasible interventional tools.

Antagonistic effect of selenium on mercuric chloride in the central immune organs of chickens: The role of microRNA-183/135b-FOXO1/TXNIP/NLRP3 inflammasome axis

Mercury (Hg) is a persistent environmental and industrial pollutant that accumulated in the body and induces oxidative stress and inflammation damage. Selenium (Se) has been reported to antagonize immune organs damage caused by heavy metals. Here, we aimed to investigate the prevent effect of Se on mercuric chloride (HgCl₂ )-induced thymus and bursa of Fabricius (BF) damage in chickens. The results showed that HgCl₂ caused immunosuppression by reducing the relative weight, cortical area of the thymus and BF, and the number of peripheral blood lymphocytes. Meanwhile, HgCl₂ induced oxidative stress and imbalance in cytokines expression in the thymus and BF. Further, we found that thioredoxin-interacting protein (TXNIP) and the NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome mediated HgCl₂ -induced oxidative stress and inflammation. Mechanically, the targeting and inhibitory effect of microRNA (miR)-135b/183 on forkhead box O1 (FOXO1) were an upstream event for HgCl₂ -activated TXNIP/NLRP3 inflammasome pathway. Most importantly, Se effectively attenuated the aforementioned damage in the thymus and BF caused by HgCl₂ and inhibited the TXNIP/NLRP3 inflammasome pathway by reversing the expression of FOXO1 through inhibiting miR-135b/183. In conclusion, the miR-135b/183-FOXO1/TXNIP/NLRP3 inflammasome axis might be a novel mechanism for Se to antagonize HgCl₂ -induced oxidative stress and inflammation in the central immune organs of chickens.

Heavy metal ion concentration in the amniotic fluid of preterm and term pregnancies from two cities with different industrial output

The growth and development of the fetus is a complex phenomenon that can be influenced by several variables. High quantities of heavy metal ions in the amniotic fluid have been linked to poor health, especially in industrial, polluted and poor areas. The aim of the present study was to assess the differences in the concentration of these ions between preterm (weeks 15-37) and term pregnancies (starting at week 37). Another objective was to compare pregnancies from two cities with different industry levels. Two sample lots from two Romanian cities were analyzed. A total of 100 patients from Timisoara were compared with 60 from Petrosani, a heavy industry city in Romania. Demographic data were collected, and amniocentesis was performed on all women. Lead (Pb), copper (Cu), nickel (Ni), cadmium (Cd), arsenic (As), iron (Fe) and zinc (Zn) concentrations were assessed. Descriptive and analytical statistics were performed using the Mann-Whitney U test for non-parametric data and the Fisher's exact test for categorical data. In addition, categorical data was represented graphically. In the Timisoara cohort, the differences in heavy metal concentrations between preterm and term pregnancies were not statistically significant. In the Petrosani cohort, however, the concentrations of Zn (P=0.02606) and Cd (P=0.01512) were higher in preterm than in term pregnancies. When comparing the two cohorts as a whole, the concentration of Pb (P=0.04513), Cd (P=0.00002), As (P=0.03027) and Zn (P<0.00001) were higher in the patients from Petrosani than in those from Timisoara. Only Cu concentrations were higher in the Timisoara cohort (P<0.00001). The concentrations of Ni (P=0.78150) and Fe (P=0.44540) did not differ statistically. Thus, amniocentesis is an important diagnostic and exploratory tool in determining differences in the concentrations of elements such as heavy metal ions. Research over a longer period of time should be carried out to examine the relation between heavy metal ions concentration and possible postnatal health outcomes.

Machine learning-driven identification of early-life air toxic combinations associated with childhood asthma outcomes

Air pollution is a well-known contributor to asthma. Air toxics are hazardous air pollutants that cause or may cause serious health effects. Although individual air toxics have been associated with asthma, only a limited number of studies have specifically examined combinations of air toxics associated with the disease. We geocoded air toxic levels from the US National Air Toxics Assessment (NATA) to residential locations for participants of our AiRway in Asthma (ARIA) study. We then applied Data-driven ExposurE Profile extraction (DEEP), a machine learning-based method, to discover combinations of early-life air toxics associated with current use of daily asthma controller medication, lifetime emergency department visit for asthma, and lifetime overnight hospitalization for asthma. We discovered 20 multi-air toxic combinations and 18 single air toxics associated with at least 1 outcome. The multi-air toxic combinations included those containing acrylic acid, ethylidene dichloride, and hydroquinone, and they were significantly associated with asthma outcomes. Several air toxic members of the combinations would not have been identified by single air toxic analyses, supporting the use of machine learning-based methods designed to detect combinatorial effects. Our findings provide knowledge about air toxic combinations associated with childhood asthma.

Multiomics Landscape Uncovers the Molecular Mechanism of the Malignant Evolution of Lung Adenocarcinoma Cells to Chronic Low Dose Cadmium Exposure

Cadmium (Cd) from cigarette smoke and polluted air can lead to lung adenocarcinoma after long-term inhalation. However, most studies are based on short-term exposure to this toxic metal at high concentrations. Here, we investigate the effects of long-term exposure of A549 cells (lung adenocarcinoma) to cadmium at low concentrations using morphological and multiomics analyses. First, we treated A549 cells continuously with CdCl2 at 1μM for 8 months and found that CdCl2 promoted cellular migration and invasion. After that, we applied transmission electron and fluorescence microscopies and did not observe significant morphological changes in Golgi apparatus, endoplasmic reticulum, lysosomes, or mitochondria on Cd treated cells; microfilaments, in contrast, accumulated in lamellipodium and adhesion plaques, which suggested that Cd enhanced cellular activity. Second, by using whole-exome sequencing (WES) we detected 4222 unique SNPs in Cd-treated cells, which included 382 unique non-synonymous mutation sites. The corresponding mutated genes, after GO and KEGG enrichments, were involved mainly in cell adhesion, movement, and metabolic pathways. Third, by RNA-seq analysis, we showed that 1250 genes (784 up and 466 down), 1623 mRNAs (1023 up and 591 down), and 679 lncRNAs (375 up and 304 down) were expressed differently. Furthermore, GO enrichment of these RNA-seq results suggested that most differentially expressed genes were related to cell adhesion and organization of the extracellular matrix in biological process terms; KEGG enrichment revealed that the differentially expressed genes took part in 26 pathways, among which the metabolic pathway was the most significant. These findings could be important for unveiling mechanisms of Cd-related cancers and for developing cancer therapies in the future.

Concentrations, Source Characteristics, and Health Risk Assessment of Toxic Heavy Metals in PM2.5 in a Plateau City (Kunming) in Southwest China

To explore the mass concentration levels and health risks of heavy metals in the air in dense traffic environments, PM_2.5 samples were collected at three sites in the city of Kunming in April and October 2013, and January and May 2014. Ten heavy metals––V, Cr, Mn, Co, Ni, Cu, Zn, As, Cd and Pb––were analyzed by ICP–MS, and the results showed PM_2.5 concentrations significantly higher in spring and winter than in summer and autumn, especially for Zn and Pb. The concentration of heavy metals on working days is significantly higher, indicating that vehicle emissions are significant contributors. An enrichment factor analysis showed that Cr, Mn, Ni, Cu, Zn, As, Cd and Pb come mainly from anthropogenic sources, while V and Co may be both anthropogenic and natural. The correlation and principal component analysis (PCA) showed that Ni, Cu, Zn, Cd and Pb mainly come from vehicles emissions and metallurgical industries; Cr and Mn, from vehicles emissions and road dust; and As, mainly from coal combustion. The health risk assessment shows that the non-carcinogenic risk thresholds of the heavy metals in PM_2.5 to children and adult men and women are all less than 1. The carcinogenic risk of Cr for men and women in traffic-intensive areas exceeds 10⁻⁴, reaching 1.64 × 10⁻⁴ and 1.4 × 10⁻⁴, respectively.

PM2.5-Bound Heavy Metals in Southwestern China: Characterization, Sources, and Health Risks

The health risks of PM2.5-bound heavy metals have attracted extensive attention recently. In order to evaluate those deleterious effects on human health more accurately, and to propose proper measures to reduce health risks of air pollution, the conduction of a source-specific health risk assessment is necessary. Based on daily collected PM2.5 samples at different functional sites during winter 2019 in a megacity Chongqing, China, combining source apportionment results from PMF and health risk assessment from the U.S. EPA, the source-specific health risks from PM2.5-bound heavy metals were given. Six types of PM2.5 sources have been identified, coal burning (25.5%), motor vehicles (22.8%), industrial emissions (20.5%), biomass burning (15.9%), dust (7.8%), and ship emissions (7.5%). Results showed that the total hazard quotient (HQ) was 0.32 and the total carcinogenic risks (CR) were 2.09 × 10−6 for children and 8.36 × 10−6 for adults, implying certain risks for local residents. Industrial emissions related with Cr posed both the highest carcinogenic risk and noncarcinogenic risk (contributing 25% CR and 36% HQ). Coal combustion (associated with Cr, As, and Mn) contributed 15.46% CR and 20.64% HQ, while biomass burning and motor vehicles shared 19.99% and 19.05% of the total CR, respectively. This work indicated that health risks of air pollution sources were the combined effects of the source contribution and chemical components. In order to control the health risks of PM2.5 to the local residents, the priority of targeted emission sources should be adopted for industrial emissions, biomass burning, vehicle emissions, and coal combustion sources.