Air concentrations of trace elements in a municipality under the influence of Tarragona petrochemical complex: Human health risks.

One of the largest petrochemical complexes of southern Europe is located in Tarragona County (Catalonia, Spain). Despite environmental monitoring is routinely conducted in the area, the long-term occurrence of airborne trace elements has been poorly investigated. In the present study, the concentrations of arsenic (As), cadmium (Cd), chromium (Cr), nickel (Ni), lead (Pb) and vanadium (V) were analysed in air samples collected in El Morell, a town potentially impacted by the petrochemical. Air samples were simultaneously collected in the town of Cambrils, as a background site. Meteorological data and retro trajectories analysis were used to evaluate the impact of the petrochemical industry on the levels of trace elements in air. Subsequently, human health risks due to inhalation exposure to the trace elements were also assessed. Except for V, air concentrations were significantly higher near the oil refinery than the background levels. Human health risks were also estimated to be higher in the vicinity of the petrochemical complex. In turn, air inhalation of Pb and V was higher than their dietary intakes. The present data should be considered only as preliminary, since the sampling was taken during only three weeks, which is an insufficient period to extract reliable conclusions. Further long-term studies should be focused on assessing the influence of temporary variables, such as meteorological conditions and fugitive or sporadic emissions.

A review of the epidemiological and laboratory evidence of the role of aluminum exposure in pathogenesis of cardiovascular diseases.

The objective of the present study was to review the epidemiological and laboratory evidence on the role of aluminum (Al) exposure in the pathogenesis of cardiovascular diseases. Epidemiological data demonstrated an increased incidence of cardiovascular diseases (CVD), including hypertension and atherosclerosis in occupationally exposed subjects and hemodialysis patients. In addition, Al body burden was found to be elevated in patients with coronary heart disease, hypertension, and dyslipidemia. Laboratory studies demonstrated that Al exposure induced significant ultrastructural damage in the heart, resulting in electrocardiogram alterations in association with cardiomyocyte necrosis and apoptosis, inflammation, oxidative stress, inflammation, and mitochondrial dysfunction. In agreement with the epidemiological findings, laboratory data demonstrated dyslipidemia upon Al exposure, resulting from impaired hepatic lipid catabolism, as well as promotion of low-density lipoprotein oxidation. Al was also shown to inhibit paraoxonase 1 activity and to induce endothelial dysfunction and adhesion molecule expression, further promoting atherogenesis. The role of Al in hypertension was shown to be mediated by up-regulation of NADPH-oxidase, inhibition of nitric oxide bioavailability, and stimulation of renin-angiotensin-aldosterone system. It has been also demonstrated that Al exposure targets cerebral vasculature, which may be considered a link between Al exposure and cerebrovascular diseases. Findings from other tissues lend support that ferroptosis, pyroptosis, endoplasmic reticulum stress, and modulation of gut microbiome and metabolome are involved in the development of CVD upon Al exposure. A better understanding of the role of the cardiovascular system as a target for Al toxicity will be useful for risk assessment and the development of treatment and prevention strategies.

Levels and health risk assessment of twenty-one current-use pesticides in urban and riverside waters of the Brazilian Amazon Basin.

In Brazil, the favorable weather conditions and abundant land contribute to the thriving agricultural production. Brazilian crops extensively employ pesticides due to their high efficacy, cost-effectiveness, and permissive regulatory framework. However, pesticide use also endangers water resources, animal organisms, and human health. Due to the lack of data on pesticide use in the Amazonas forest-based Brazil, the present study aimed to assess the levels of twenty-one current-use pesticides (CUPs) from five different classes in river waters collected from urban and riverside areas in this region. Moreover, the non-carcinogenic risks associated with water consumption were also characterized. Thirteen CUPs were detected in concentrations above the limit of detection (LOD) in at least one of the water samples, and most pesticides were detected in riverside areas. In contrast, only 18% of the analyzed samples were considered "clean," with only one compound detected. Fenitrothion showed the highest concentration, with a mean value of 4.86 ng/mL (0.30-14.3 ng/mL). Up to 33% of the samples showed levels of fipronil above the LOD, an issue of environmental and human health concern, mainly because of the adverse effects observed in honeybees. Despite this, the human health risk assessment showed a target hazard quotient below one (HQ < 1) in adults for all substances, suggesting that pesticide exposure through water consumption should not mean risk for the riverside populations. Taking into account the large extension of Brazil, as well as its different agricultural practices throughout the country, it would be of great importance to conduct extensive research in other areas. It would help to gain knowledge in this field and to promote eco-friendly alternatives to mitigate pesticide use and, consequently, to reduce their potential adverse effects on human health and the ecosystems.

Molecular mechanisms of environmental pollutant-induced cartilage damage: from developmental disorders to osteoarthritis.

The objective of the present study was to review the molecular mechanisms of the adverse effects of environmental pollutants on chondrocytes and extracellular matrix (ECM). Existing data demonstrate that both heavy metals, including cadmium (Cd), lead (Pb), and arsenic (As), as well as organic pollutants, including polychlorinated dioxins and furans (PCDD/Fs) and polychlorinated biphenyls (PCB), bisphenol A, phthalates, polycyclic aromatic hydrocarbons (PAH), pesticides, and certain other organic pollutants that target cartilage ontogeny and functioning. Overall, environmental pollutants reduce chondrocyte viability through the induction apoptosis, senescence, and inflammatory response, resulting in cell death and impaired ECM production. The effects of organic pollutants on chondrocyte development and viability were shown to be mediated by binding to the aryl hydrocarbon receptor (AhR) signaling and modulation of non-coding RNA expression. Adverse effects of pollutant exposures were observed in articular and growth plate chondrocytes. These mechanisms also damage chondrocyte precursors and subsequently hinder cartilage development. In addition, pollutant exposure was shown to impair chondrogenesis by inhibiting the expression of Sox9 and other regulators. Along with altered Runx2 signaling, these effects also contribute to impaired chondrocyte hypertrophy and chondrocyte-to-osteoblast trans-differentiation, resulting in altered endochondral ossification. Several organic pollutants including PCDD/Fs, PCBs and PAHs, were shown to induce transgenerational adverse effects on cartilage development and the resulting skeletal deformities. Despite of epidemiological evidence linking human environmental pollutant exposure to osteoarthritis or other cartilage pathologies, the data on the molecular mechanisms of adverse effects of environmental pollutant exposure on cartilage tissue were obtained from studies in laboratory rodents, fish, or cell cultures and should be carefully extrapolated to humans, although they clearly demonstrate that cartilage should be considered a putative target for environmental pollutant toxicity.

Influence of gut microbiota on the development of most prevalent neurodegenerative dementias and the potential effect of probiotics in elderly: A scoping review.

Dementia is one of today's greatest public health challenges. Its high socio-economic impact and difficulties in diagnosis and treatment are of increasing concern to an aging world population. In recent years, the study of the relationship between gut microbiota and different neurocognitive disorders has gained a considerable interest. Several studies have reported associations between gut microbiota dysbiosis and some types of dementia. Probiotics have been suggested to restore dysbiosis and to improve neurocognitive symptomatology in these dementias. Based on these previous findings, the available scientific evidence on the gut microbiota in humans affected by the most prevalent dementias, as well as the probiotic trials conducted in these patients in recent years, have been here reviewed. Decreased concentrations of short-chain fatty acids (SCFA) and other bacterial metabolites appear to play a major role in the onset of neurocognitive symptoms in Alzheimer disease (AD) and Parkinson disease dementia (PDD). Increased abundance of proinflammatory taxa could be closely related to the more severe clinical symptoms in both, as well as in Lewy Bodies dementia. Important lack of information was noted in Frontotemporal dementia behavioral variant. Moreover, geographical differences in the composition of the gut microbiota have been reported in AD. Some potential beneficial effects of probiotics in AD and PDD have been reported. However, due to the controversial results further investigations are clearly necessary.

Scientific evidence on the origin of SARS-CoV-2.

Even reaching the end of the year 2022, there is still a controversy on the origin of the SARS-CoV-2 virus. This Virtual Special Issue (VSI), focused on the "Scientific evidence on the origin of SARS-CoV-2", was launched some months ago with the aim of stimulating the submission of new high quality scientific research papers on the matter, to shed light on it. As indicated in the call for papers, the Editors involved in the VSI were aware of the difficulties of presenting concluding facts on that issue, however, bearing in mind that some teams of researchers had started investigations regarding this subject, a VSI like this (searching for stimulating the scientific controversy while requiring scientific evidence), could help to elucidate complicated aspects, going a step ahead in this way. The Editors made a call encouraging interested teams of researchers having solid results to submit high quality manuscripts dealing with this crucial theme. We thought -and we still think-that it is of maximum interest for the scientific community, as well as for the whole society, now and probably for the future. The VSI have received 50 submissions, which could be considered a limited number highlighting the difficulties of elaborating new high-quality manuscripts providing solid evidence on the matter. After a careful peer-review, those manuscripts considered to reach the highest scientific value were accepted for publication. The Editors think that the set of papers included in this VSI constitute interesting and high-quality contributions, providing further scientific knowledge on this issue. In this editorial piece, the Editors make some comments on the papers published, including some additional reflections.

Lack of association between endocrine disrupting chemicals and male fertility: A systematic review and meta-analysis.

The incidence of infertility currently affects about 15% of the world's population. Male factors are estimated to be responsible for up to 40-50% of these cases. While the cause of these reproductive disorders is still unclear, the exposure to a family of ubiquitous compounds in our daily life, named endocrine disrupting chemicals (EDCs) could be involved. This paper was aimed at performing a systematic review and meta-analysis of population studies exploring whether human male exposure to EDCs affects male fertility. Clinical and observational studies assessing the exposure to EDCs along with sperm quality, the most common reproductive disorders, sperm DNA damage, sperm oxidative stress, fertilization rate, implantation rate, clinical pregnancy rate, live birth rate, and miscarriage rate were included. The quality assessment tool from the NHLBI-NIH was used to assure that studies met standardized quality criteria. Sensitivity analysis and heterogeneity among studies was assessed. Overall, the 32 selected articles, including 7825 individuals in the systematic review, explored 12 families of EDCs. The results revealed a high heterogeneity among studies in relation to the association between exposure to EDCs and the endpoints analyzed. Meta-analyses were performed with data from 7 articles including 479 individuals, 4 articles assessing the association between BPA in urine and sperm quality, and 3 articles evaluating PCB153 in serum and sperm quality. In the meta-analysis, we identified an unpredicted significant positive association between PCB153 exposure and sperm concentration. However, it would not be clinically relevant. No positive or inverse associations were found neither for BPA, nor for PCB153 and the rest of sperm parameters analyzed. The high disparity between studies made difficult to draw conclusions on the potential harmful effects of EDCs on male fertility. Consequently, to delineate the potential relationship that EDCs can have on male fertility, an important condition stressing the health system, further investigations are required.

Clothing as a potential exposure source of trace elements during early life.

In recent years, the interest in determining the chemical composition of textile products has increased among the scientific community and regulatory agencies, driven by toxicological issues and environmental concerns. Chemical elements are naturally present in clothing as natural fibers or intentionally added during manufacture. Some of them show physical-chemical properties that allow their absorption through the skin. In addition, chronic situations increase the dermal exposure capacity. Because of age-specific behavioral characteristics and underdeveloped physiological function, children may be especially sensitive to exposure to trace elements. This study aimed to analyze the levels of twenty trace elements in 120 clothing items commercialized in Spain. Textile products for pregnant women and children <36 months old were included. The potential health implication of this dermal exposure in early life was also evaluated. Aluminum, zinc, and titanium showed the highest concentrations, with median levels of 27.6, 5.6, and 4.2 mg/kg, respectively. Since chromium is employed as a metal complex dye in synthetic fibers, high levels of this element were found in black polyester. Dermal exposure to titanium, which is a ubiquitous element in clothes made of synthetic fibers, was associated with a hazard quotient (HQ) higher than the threshold value (HQ > 1), with values of 1.13 for pregnant women and 1.22 for newborns. On the other hand, HQ values of other elements and cancer risks were lower than the recommended values. Assessing early-life exposure to toxic elements can help to identify potential sources and to prevent or reduce human exposure, mainly in vulnerable groups.

Exposure to chlorpyrifos during pregnancy differentially affects social behavior and GABA signaling elements in an APOE- and sex-dependent manner in a transgenic mouse model.

The massive use of chlorpyrifos (CPF) has been associated with an increased prevalence of neurodevelopmental disorders. Some previous studies have shown that prenatal, but not postnatal, CPF exposure causes social behavior deficits in mice depending on sex while others have found that in transgenic mice models carrying the human apolipoprotein E (APOE) ε3 and ε4 allele confer different vulnerabilities to either behavioral or metabolic disorders after CPF exposure. This study aims to evaluate, in both sexes, how prenatal CPF exposure and APOE genotype impact on social behavior and its relation to changes in GABAergic and glutamatergic systems. For this purpose, apoE3 and apoE4 transgenic mice were exposed through the diet to 0 or 1 mg/kg/day of CPF, between gestational day 12 and 18. A three-chamber test was used to assess social behavior on postnatal day (PND) 45. Then, mice were sacrificed, and hippocampal samples were analyzed to study the gene expression of GABAergic and glutamatergic elements. Results showed that prenatal exposure to CPF impaired social novelty preference and increased the expression of GABA-A α1 subunit in females of both genotypes. In addition, the expression of GAD1, the ionic cotransporter KCC2 and the GABA-A α2 and α5 subunits were increased in apoE3 mice, whereas CPF treatment only accentuated the expression of GAD1 and KCC2. Nevertheless, future research is needed to evaluate whether the influences detected in the GABAergic system are present and functionally relevant in adults and old mice.

Occurrence of trace elements in print paper products: Non-carcinogenic risk assessment through dermal exposure.

Over time, the risk assessment of dermal exposure to pollutants in print paper products has received considerable attention. Most studies have focused on organic pollutants, especially bisphenol A (BPA). However, little is known about the levels of trace elements in print paper products, despite the knowledge that these elements are components of printing inks and toners. This study was aimed at determining the concentrations of trace elements in 5 types of paper products, namely bulletins, magazines, special events program booklets, handbills, and newspapers. The average daily intake (ADI) of each element was subsequently estimated through dermal exposure to the papers. The detection frequency of the elements of interest was high (nearly 100%) in most paper products, with the exception of chromium, whose detection was low. In contrast, Ag was not detected in any sample. The levels of the elements in the paper products were low and comparable to those found in other personal and consumer products with the potential for skin contact. The range values of estimated ADIs were 1.70-3.90E-08, 2.30-18.2E-10, 2.60-16.4E-09, 3.65-5.75E-08, 1.29-4.38E-08, 6.23-15.6E-10, 1.51-2.80E-10, 1.43-9.16E-09, 0.00-9.47E-09, and 4.68-220E-08 mg/kg bw/day for Mn, Co, Ni, Cu, Zn, As, Cd, Pb, Cr and Fe respectively. These values were well below the dermal standard reference doses (RfD) for each element. The present results indicate that dermal exposure to trace elements from print paper products was low and does not pose significant risks for toxic (non-carcinogenic) effects on humans.

Multidrug-resistant Enterobacter spp. in wastewater and surface water: Molecular characterization of ß-lactam resistance and metal tolerance genes.

Among the ESKAPE group pathogens, Enterobacter spp. is an opportunistic Gram-negative bacillus, widely dispersed in the environment, that causes infections. In the present study, samples of hospital wastewater, raw and treated urban wastewater, as well as surface receiving water, were collected to assess the occurrence of multidrug-resistant (MDR) Enterobacter spp. A molecular characterization of ß-lactam antibiotic resistance and metal tolerance genes was performed. According to identification by MALDI-TOF MS, 14 isolates were obtained: 7 E. bugandensis, 5 E. kobei, and 2 E. cloacae. The isolates showed resistance mainly to ß-lactam antibiotics, including those used to treat infections caused by MDR bacteria. Multiple antibiotic resistance index was calculated for all isolates. It allowed verify whether sampling points showed a high risk due to antibiotic resistant Enterobacter spp., as well as to determine if the isolates have been in environments with a frequent antibiotic use. Twelve isolates showed ß-lactam antibiotic resistance gene, being the blaKPC widely detected. Regarding metal tolerance, 13 isolates showed at least two genes that encode metal tolerance mechanisms. Overall, metal tolerance mechanisms to silver, copper, mercury, arsenic and tellurium were found. New data on metal tolerance mechanisms dispersion and antibiotic-resistance characterization of the E. bugandensis and E. kobei species were here provided. The occurrence of MDR Enterobacter spp. in analyzed samples draws attention to an urgent need to put control measures into practice. It also evidences waterborne spread of clinically important antibiotic-resistant bacteria recognized as critical priority pathogens.

Recent trends in pesticides in crops: A critical review of the duality of risks-benefits and the Brazilian legislation issue.

Due to the increasing population worldwide, in recent years, an exponential increase in agricultural practices has occurred in order to attend to the growing demand for food. Unfortunately, this increase is not associated with the supply of foodstuffs free of environmental pollutants. In Brazil, agriculture is one of the most important economic pillars, making the country one of the largest consumers of pesticides around the world. The intense use of pesticides, mainly glyphosate, 2,4-D, and atrazine, constitutes an essential factor in the viability of this great agricultural productivity. Sugarcane, corn, soybean, and citrus crops consume around 66% of the total pesticides worldwide, representing 76% of the planted area. Pesticide residues have been frequently detected in food and the environment, becoming a significant concern for human health. Monitoring programs for pesticide use are essential to reduce the potential negative impacts on the environment and improve the overall efficiency and sustainability of their use. However, in Brazil, the approval status of pesticide-active ingredients is very discrepant compared to other agricultural countries. Moreover, the duality of benefits and risks of pesticide application creates an economic and toxicological conflict. In this paper, we have critically reviewed the duality of risks-benefits of the use of pesticides in agriculture and the current Brazilian legislation issues. We have also compared this flawed legislation with other countries with high economic potential. Due to the negative environmental impacts on soil and water by the high levels of pesticides, remediation techniques, sustainable agriculture, and the development of new technologies can be considered some viable alternatives to reduce the levels in these compartments. Besides, this paper includes some recommendations that can be included in the coming years.

Association between urinary concentrations of toxic metals/metalloids and oxidative stress in Brazilians living in areas affected by the Fundão dam failure.

The Fundão Dam failure has been the most significant environmental disaster in Brazil. The catastrophe released large amounts of mining waste into the environment, including toxic metals/metalloids, which are recognized to induce carcinogenic effects. The urinary levels of 8-hydroxy-2'-deoxyguanosine (8OHdG), a widely accepted oxidative stress and carcinogenesis biomarker, provide a potential tool for assessing the disaster's health implications. This study investigated the association between urinary levels of some toxic metals/metalloids and 8OHdG in Brazilian individuals living in areas affected by the Fundão dam failure. Urinary concentrations of arsenic (As), cadmium (Cd), mercury (Hg), nickel (Ni), and lead (Pb) were determined using inductively coupled plasma mass spectrometry, while 8OHdG was analyzed by liquid chromatography-tandem mass spectrometry. Non-parametric bootstrap regression was used to estimate the associations between the urinary levels of toxic elements and 8OHdG. The results showed that except for Hg, urinary concentrations of all metals/metalloids analyzed here exceeded the reference ranges for the Brazilian population. The regression analysis revealed that As (0.337; CI 95%: 0.203; 0.474), Cd (0.268; CI 95%: 0.036; 0.520), and Ni (0.296; CI 950.108; 0.469) were positively associated with creatinine-adjusted urinary 8OHdG levels. Associations were not found for Hg (0.0122; CI 95%: -0.155; 0.183) and Pb (0.201; CI 95%: -0.040; 0.498). The current findings suggest that high exposure to toxic metals/metalloids might increase 8OHdG levels with potential adverse health effects. This study is the first one in which the relationship between toxic metals/metalloids and oxidative stress biomarkers is investigated in populations affected by environmental disasters. Further prospective studies are necessary to monitor exposure levels and explore additional health impacts.

Developmental brain lipidomics is influenced by postnatal chlorpyrifos exposure and APOE genetic background in mice.

Lipids are a major component of the brain, and are involved in structural and neurodevelopmental processes such as neurogenesis, synaptogenesis and signaling. Apolipoprotein E (apoE) is the main lipoprotein involved in lipid transport in the brain. The apoE isoforms can determine vulnerability to the toxic effects of the pesticide chlorpyrifos (CPF), which can interfere with normal neurodevelopment. We aimed to study the effects of postnatal exposure to CPF and of the APOE genotype on the lipid composition of the brain at early ages. For it, we used apoE3 and apoE4 targeted-replacement (TR) male mice, as well as wild-type C57BL/6. The mice were orally exposed to 1 mg/kg/day of CPF on postnatal days 10-15 and, four hours after the treatment, we obtained samples to assess the cerebral lipid composition. Differences between APOE genotypes were found in the cerebral lipid profile in the postnatal period. ApoE4-TR mice exhibited higher lipid concentrations compared to the other groups in most of the cases. CPF exposure led to a decrease in cholesteryl ester and triglyceride concentrations, while modulating the levels of phosphatidylcholine species based on the apoE isoform. Specifically, CPF treatment decreased the concentration of some species of this lipid (PC30:0, PC31:0, PC32:2, PC36:5, PC40:4 and PC40:5) in C57BL/6 mice exposed to CPF, increased (PC31:0 and PC37:6) in apoE3-TR exposed mice while exposed apoE4-TR mice remained unaltered. These results provide further insights into the lipid composition of the brain at early ages, and how it can be modulated by environmental and genetic factors.

Non-regulated aromatic amines in clothing purchased in Spain and Brazil: Screening-level exposure and health impact assessment.

The staggering amount of chemicals in clothes and their harmful effects on human health and the environment have attracted the attention of regulatory agencies and the scientific community worldwide. Azo dyes are synthetic dyestuffs with widespread use in textile industries, currently classified as emerging pollutants of great health concern to consumers. These compounds may release one or more aromatic amines (AAs) after reductive cleavage of their azo bounds. Twenty-two AAs have already been regulated due to their carcinogenic effects. However, since information on their potential toxicity is not currently available, several AAs have not been still regulated by the European Union. Considering this gap, the present study aimed to assess the levels of forty non-regulated AAs in 240 clothing items from Spain and Brazil. The potential impact on the health of vulnerable population groups after dermal exposure to those garments was also evaluated. In Brazil, at least one AA was detected in the clothes, while in samples obtained in Spain, only two of them showed values below the limit of detection for AAs. In 75 clothes, at least one of the measured AAs was higher than the hazardous threshold (30 mg/kg), which can mean risks to human health since these compounds are suspected to be mutagenic. Aniline, the most common AA, showed a high detection rate (82%) in clothes, with significantly higher concentrations in items commercialized in Brazil (0.35 vs. 0.17 mg/kg; p = 0.032). Moreover, o-aminobenzenesulfonic and p-phenylenediamine, suspected mutagenic, were found at relevant concentrations in several clothes, mainly made of synthetic fibers. In this study, the hazard index associated with exposure to AAs through clothing was low (0.006-0.13) for all the population groups of both countries in the medium-bound scenario. However, its value was close to 1 for Brazilian pregnant women (0.998) when the maximum concentration value was considered under an upper-bound scenario. The risk of exposure to non-regulated AAs may be underestimated since only dermal exposure was considered for risk assessment. Moreover, the co-occurrence of other carcinogenic and non-carcinogenic substances present in skin-contact clothes should mean an additional source of potential risk.

An updated review of the scientific literature on the origin of SARS-CoV-2.

More than two and a half years have already passed since the first case of COVID-19 was officially reported (December 2019), as well as more than two years since the WHO declared the current pandemic (March 2020). During these months, the advances on the knowledge of the COVID-19 and SARS-CoV-2, the coronavirus responsible of the infection, have been very significant. However, there are still some weak points on that knowledge, being the origin of SARS-CoV-2 one of the most notorious. One year ago, I published a review focused on what we knew and what we need to know about the origin of that coronavirus, a key point for the prevention of potential future pandemics of a similar nature. The analysis of the available publications until July 2021 did not allow drawing definitive conclusions on the origin of SARS-CoV-2. Given the great importance of that issue, the present review was aimed at updating the scientific information on that origin. Unfortunately, there have not been significant advances on that topic, remaining basically the same two hypotheses on it. One of them is the zoonotic origin of SARS-CoV-2, while the second one is the possible leak of this coronavirus from a laboratory. Most recent papers do not include observational or experimental studies, being discussions and positions on these two main hypotheses. Based on the information here reviewed, there is not yet a definitive and well demonstrated conclusion on the origin of SARS-CoV-2.

Positive association between outdoor air pollution and the incidence and severity of COVID-19. A review of the recent scientific evidences.

In June 2020, we published a review focused on assessing the influence of various air pollutants on the transmission of SARS-CoV-2, and the severity of COVID-19 in patients infected by the coronavirus. The results of most of those reviewed studies suggested that chronic exposure to certain air pollutants might lead to more severe and lethal forms of COVID-19, as well as delays/complications in the recovery of the patients. Since then, a notable number of studies on this topic have been published, including also various reviews. Given the importance of this issue, we have updated the information published since our previous review. Taking together the previous results and those of most investigations now reviewed, we have concluded that there is a significant association between chronic exposure to various outdoor air pollutants: PM2.5, PM10, O3, NO2, SO2 and CO, and the incidence/risk of COVID-19 cases, as well as the severity/mortality of the disease. Unfortunately, studies on the potential influence of other important air pollutants such as VOCs, dioxins and furans, or metals, are not available in the scientific literature. In relation to the influence of outdoor air pollutants on the transmission of SARS-CoV-2, although the scientific evidence is much more limited, some studies point to PM2.5 and PM10 as potential airborne transmitters of the virus. Anyhow, it is clear that environmental air pollution plays an important negative role in COVID-19, increasing its incidence and mortality.

The environment, epidemics, and human health.

In this editorial piece, the Editors of the Virtual Special Issue (VSI) "The environment, epidemics, and human health" comment on the papers accepted for publication, which were selected after peer-reviewing among all those manuscripts submitted to the Special Issue. In view of the title of the VSI, it is clear that its aim goes beyond the COVID-19 pandemic, trying to explore relations among environmental aspects, any kind of epidemics, and human health. However, COVID-19 is still hitting as a global and current main issue, causing that manuscripts dealing with this disease and the SARS-CoV-2 virus are of high relevance in the whole set of research papers published.

Framework for risk assessment of PFAS utilizing experimental studies and in-silico models.

Perfluoroalkyl substances (PFAS), especially PFOS and PFOA, are two widely used synthetic chemicals that can impact human health based on evidence from animal and epidemiologic studies. In this paper, we have reviewed and summarized the influence of PFAS exposure on health, pointing the quality of evidence, and applied translational techniques to integrate evidence for PFAS policy making. This is the first review where highly referred articles on PFAS used for policymaking by several regulatory agencies were collected and evaluated based on the review guidelines developed by the US National Toxicology Program's Office of Health Assessment and Translation (OHAT) review guidelines. Several limitations were observed, including co-exposure to multiple chemicals and limited measurement of primary and secondary outcomes related to specific toxicity. However, data from all the studies provided a moderate to strong level of confidence for link between PFAS exposure and different adverse outcomes. Secondly, for translating the risk to humans, an in-silico model and scaling approach was utilized. Physiologically based pharmacokinetic model (PBPK) was used to calculate the human equivalent dose (HED) from two widely accepted studies and compared with tolerable daily intakes (TDIs) established by various regulatory agencies. Inter-species dose extrapolation was done to compare with human the relevance of dosing scenarios used in animals. Overall, a framework for translation of risk was proposed based on the conclusions of this review with the goal of improving policymaking. The current paper can improve the methodological protocols for PFAS experimental studies and encourage the utilization of in-silico models for translating risk.

Human dietary exposure to metals in the Niger delta region, Nigeria: Health risk assessment.

The contamination profile and the human health risk assessment of various heavy metals (Cd, Cr, Mn, Ni and Pb) in vegetable oils, palm oils, butter and shea butter purchased from the Nigerian market were evaluated. Univariate and multivariate analyses including the principal component analysis (PCA), hierarchical cluster analysis (HCA) and heat map visualization were used to evaluate correlation, similarity and source of metals. Dietary intake and dermal absorption through the application in skin were also assessed. The heavy metals 5th and 95th percentile interval range (in mg/kg) were 0.003-0.208, 0.003-0.392, 0.003-1.344, 0.003-0.369 and 0.006-0.531 for Cd, Cr, Mn, Ni and Pb, respectively. Concentrations of Cr and Mn were significantly different across sample categories, being the levels of Mn and Ni positively correlated in both oil and butter samples. The result of PCA, HCA and heat map revealed the profile of heavy metals in oils was different from that of butters, with Pb mainly associated to oils, and Cd, Cr, Mn and Ni to butters. In some samples, the international maximum levels for Cd, Ni and Pb in edible oils were exceeded. Cadmium and Pb dietary intake through Nigerian oils and butters should not be considered negligible for human health protection.