Occupational exposure to potentially toxic elements in the foundry industry: an integrated environmental and biological monitoring

Reduction of haemoglobin is related to metal mixtures exposure in Chinese preschoolers: Joint effect models

Heavy metal exposure is a known risk factor for hematologic disorders in children, yet the impact of co-exposure to multiple metals remains underexplored. This cross-sectional study investigates the relationship between urinary levels of 23 metals and haemoglobin (Hb) in 1460 Chinese preschoolers. The concentrations of the 23 urinary metals were quantified using an inductively coupled plasma mass spectrometer, while Hb levels were assessed through finger prick blood samples. To evaluate the co-exposure effects, we employed three approaches: Generalized linear regression model, joint effect models including Quantile g-Computation and Bayesian Kernel Machine Regression (BKMR). From the generalized linear regression and Quantile g-computation, urinary uranium, thallium, aluminium, iron and tungsten were correlated negatively with Hb, while urinary barium was correlated positively (all P < 0.05). Moreover, significant negative associations between metal mixtures exposure with Hb were identified in both Quantile g-computation [β (95% CI): -0.083 (-0.132, -0.033), P = 0.0012] and BKMR [90th percentile vs. 50th percentile β (95% CI): -0.238 (-0.368, -0.107), P < 0.001] with aluminium emerging as the primary contributor to this joint effect (weight in Quantile g-computation = 0.399, PIPs in BKMR = 0.896). These findings provide a potential explanation for environmental exposure to metals and Hb-related disease in preschoolers.

Multiple potentially toxic elements in urban gardens from a Brazilian industrialized city

Urban agriculture should be promoted as long as the food produced is safe for consumption. Located in the metropolitan region of São Paulo-Brazil, Santo André has intense industrial activities and more recently an increasing stimulus to urban gardening. One of the potential risks associated to this activity is the presence of potentially toxic elements (PTEs). In this study, the concentration of PTEs (As, Ba, Cd, Co, Cu, Cr, Ni, Mo, Pb, Sb, Se, V and Zn) was evaluated by soil (n = 85) and soil amendments (n = 19) in urban gardens from this municipality. Only barium was above regulatory limits in agricultural soil ranging from 20 to 112 mg kg-1. Geochemical indexes (Igeo, Cf and Er) revealed moderate to severe pollution for As, Ba, Cr, Cu, Pb Se and Zn, especialy in Capuava petrochemical complex gardens. A multivariate statistical approach discriminated Capuava gardens from the others and correlated As, Cr and V as main factors of pollution. However, carcinogenic and non-carcinogenic risks were below the acceptable range for regulatory purposes of 10-6-10-4 for adults. Soil amendments were identified as a possible source of contamination for Ba, Zn and Pb which ranged from 37 to 4137 mg kg-1, 20 to 701 mg kg-1 and 0.7 to 73 mg kg-1, respectively. The results also indicated the presence of six pathogenic bacteria in these amendments. Besides that, the occurrence of antimicrobial resistance for Shigella, Enterobacter and Citrobacter isolates suggests that soil management practices improvement is necessary.

Mitochondria in the Spotlight: C. elegans as a Model Organism to Evaluate Xenobiotic-Induced Dysfunction

Mitochondria play a crucial role in cellular respiration, ATP production, and the regulation of various cellular processes. Mitochondrial dysfunctions have been directly linked to pathophysiological conditions, making them a significant target of interest in toxicological research. In recent years, there has been a growing need to understand the intricate effects of xenobiotics on human health, necessitating the use of effective scientific research tools. Caenorhabditis elegans (C. elegans), a nonpathogenic nematode, has emerged as a powerful tool for investigating toxic mechanisms and mitochondrial dysfunction. With remarkable genetic homology to mammals, C. elegans has been used in studies to elucidate the impact of contaminants and drugs on mitochondrial function. This review focuses on the effects of several toxic metals and metalloids, drugs of abuse and pesticides on mitochondria, highlighting the utility of C. elegans as a model organism to investigate mitochondrial dysfunction induced by xenobiotics. Mitochondrial structure, function, and dynamics are discussed, emphasizing their essential role in cellular viability and the regulation of processes such as autophagy, apoptosis, and calcium homeostasis. Additionally, specific toxins and toxicants, such as arsenic, cadmium, and manganese are examined in the context of their impact on mitochondrial function and the utility of C. elegans in elucidating the underlying mechanisms. Furthermore, we demonstrate the utilization of C. elegans as an experimental model providing a promising platform for investigating the intricate relationships between xenobiotics and mitochondrial dysfunction. This knowledge could contribute to the development of strategies to mitigate the adverse effects of contaminants and drugs of abuse, ultimately enhancing our understanding of these complex processes and promoting human health.

Carcinogenic and non-carcinogenic risk of exposure to metal fume in different types of welding processes

The international agency for cancer research (IARC) has classified welding fumes as definitive carcinogens. The aim of the present study was to assess health risk due to exposure to welding fumes in different welding types. In this study, exposure to fumes of iron (Fe), chromium (Cr), and nickel (Ni) in the breathing zone air of 31 welder engaged in arc, argon and CO2 welding was assessed. Carcinogenic and non-carcinogenic risk assessments due to exposure to fumes were performed using the method proposed by the Environmental Protection Agency (EPA) by Monte Carlo simulation. The results showed that in the CO2 welding, concentration of Ni, Cr, and Fe was lower than the 8-h Time-Weighted Average Threshold Limit Value (TWA-TLV), recommended by the American Conference of Governmental Industrial Hygienists (ACGIH). In argon welding, Cr and Fe concentrations were higher than the TWA-TLV. In arc welding, concentrations of Ni and Fe were more than the TWA-TLV. In addition, the risk of non-carcinogenicity due to exposure to Ni and Fe in all three types of welding was more than standard level (HQ>1). The results indicated that the welders are at health risk due to exposure to metal fumes. Preventive exposure control measures such as local ventilation need to be implemented in welding workplaces.

Long-term cadmium exposure induces chronic obstructive pulmonary disease-like lung lesions in a mouse model

Accumulating evidences demonstrate that long-term exposure to atmospheric fine particles and air pollutants elevates the risk of chronic obstructive pulmonary disease (COPD). Cadmium (Cd) is one of the important toxic substances in atmospheric fine particles and air pollutants. In this study, we aimed to establish a mouse model to evaluate whether respiratory Cd exposure induces COPD-like lung injury. Adult male C57BL/6 mice were exposed to CdCl₂ (10 mg/L, 4 h per day) by inhaling aerosol for either 10 weeks (short-term) or 6 months (long-term). The mean serum Cd concentration was 6.26 μg/L in Cd-exposed mice. Lung weight and coefficient were elevated in long-term Cd-exposed mice. Pathological scores and alveolar destructive indices were increased in long-term Cd-exposed mouse lungs. Mean linear intercept and airway wall thickness were accordingly elevated in Cd-exposed mice. Inflammatory cell infiltration was obvious and inflammatory cytokines, including TNF-α, IL-1β, IL-6, IL-8, IL-10 and TGF-β, were up-regulated in Cd-exposed mouse lungs. α-SMA, N-cadherin and vimentin, epithelial-mesenchymal transition markers, and extracellular matrix collagen deposition around small airway, determined by Masson's trichrome staining, were shown in Cd-exposed mouse lungs. COPD-characteristic lung function decline was observed in long-term Cd-exposed mice. These outcomes show that long-term respiratory exposure to Cd induces COPD-like lung lesions for the first time.

Single and Combined Associations of Plasma and Urine Essential Trace Elements (Zn, Cu, Se, and Mn) with Cardiovascular Risk Factors in a Mediterranean Population

Trace elements are micronutrients that are required in very small quantities through diet but are crucial for the prevention of acute and chronic diseases. Despite the fact that initial studies demonstrated inverse associations between some of the most important essential trace elements (Zn, Cu, Se, and Mn) and cardiovascular disease, several recent studies have reported a direct association with cardiovascular risk factors due to the fact that these elements can act as both antioxidants and pro-oxidants, depending on several factors. This study aims to investigate the association between plasma and urine concentrations of trace elements and cardiovascular risk factors in a general population from the Mediterranean region, including 484 men and women aged 18−80 years and considering trace elements individually and as joint exposure. Zn, Cu, Se, and Mn were determined in plasma and urine using an inductively coupled plasma mass spectrometer (ICP-MS). Single and combined analysis of trace elements with plasma lipid, blood pressure, diabetes, and anthropometric variables was undertaken. Principal component analysis, quantile-based g-computation, and calculation of trace element risk scores (TERS) were used for the combined analyses. Models were adjusted for covariates. In single trace element models, we found statistically significant associations between plasma Se and increased total cholesterol and systolic blood pressure; plasma Cu and increased triglycerides and body mass index; and urine Zn and increased glucose. Moreover, in the joint exposure analysis using quantile g-computation and TERS, the combined plasma levels of Zn, Cu, Se (directly), and Mn (inversely) were strongly associated with hypercholesterolemia (OR: 2.03; 95%CI: 1.37−2.99; p < 0.001 per quartile increase in the g-computation approach). The analysis of urine mixtures revealed a significant relationship with both fasting glucose and diabetes (OR: 1.91; 95%CI: 1.01−3.04; p = 0.046). In conclusion, in this Mediterranean population, the combined effect of higher plasma trace element levels (primarily Se, Cu, and Zn) was directly associated with elevated plasma lipids, whereas the mixture effect in urine was primarily associated with plasma glucose. Both parameters are relevant cardiovascular risk factors, and increased trace element exposures should be considered with caution.