Ecotoxicological and metabolomic investigation of chronic exposure of Daphnia magna (Straus, 1820) to yttrium environmental concentrations.

In order to estimate the effects on aquatic organisms of long-term exposure to low doses of yttrium (Y) as a potential emerging contaminant, ecotoxicological and metabolomic data were collected on the model organism Daphnia magna, a keystone species in freshwater ecosystems. Following an initial acute toxicity assessment, a 21-day chronic exposure experiment was conducted using a sublethal concentration of 27 µg L⁻¹ of Y, corresponding to the effective concentrations inducing 10 % effect (EC10) value for mortality endpoint and simulating the environmental Y level in aquatic systems. Results from the 21-day two-factor experiment combining microcrustacean survival, growth and reproduction bioassays and targeted gas chromatography-mass spectrometry (GC-MS) metabolomics indicated significant adverse effects of chronic exposure to Y on D. magna. Daphnids exposed to Y exhibited a significantly lower survival at day 21, delayed the maturity stage, including their first breeding, and decreased clutch size. On the side of metabolomics, a clear and general increase over time of both the number and the level of detected metabolites in the hydroalcoholic extracts of the whole organisms was observed. However, emerging from this broad temporal pattern, several bioactive metabolites were identified (e.g., 2,4-di­tert­butylphenol, itaconic acid, 3-hydroxybutyric acid, and trehalose) whose levels in extracts are linked to the presence of Y. These results emphasize the necessity of considering low-dose, long-term exposure scenarios in environmental risk assessments of rare earth elements (REEs), which have often been overlooked in favour of higher concentration studies.

The Chronic Toxicity of Endocrine-Disrupting Chemical to Daphnia magna: A Transcriptome and Network Analysis of TNT Exposure.

Endocrine-disrupting chemicals (EDCs) impair growth and development. While EDCs can occur naturally in aquatic ecosystems, they are continuously introduced through anthropogenic activities such as industrial effluents, pharmaceutical production, wastewater, and mining. To elucidate the chronic toxicological effects of endocrine-disrupting chemicals (EDCs) on aquatic organisms, we collected experimental data from a standardized chronic exposure test using Daphnia magna (D. magna), individuals of which were exposed to a potential EDC, trinitrotoluene (TNT). The chronic toxicity effects of this compound were explored through differential gene expression, gene ontology, network construction, and putative adverse outcome pathway (AOP) proposition. Our findings suggest that TNT has detrimental effects on the upstream signaling of Tcf/Lef, potentially adversely impacting oocyte maturation and early development. This study employs diverse bioinformatics approaches to elucidate the gene-level toxicological effects of chronic TNT exposure on aquatic ecosystems. The results provide valuable insights into the molecular mechanisms of the adverse impacts of TNT through network construction and putative AOP proposition.

The Respiratory Effects of Chronic Exposure to Gas Faring Among Residents of Some Communities in the Niger Delta Region of Nigeria.

BACKGROUND: This study presents the pattern of respiratory effects seen among residents chronically exposed to gas flaring in some communities in the Niger Delta Region, Nigeria. The other health challenges associated with this chronic exposure to gas were also evaluated in the study. METHODS: A total of three hundred and eighty-six 386 adult residents in Ibeno, Niger Delta Region who have been residents for at least two years. Four hundred and fourteen (414) age, sex, and height-matched control unexposed residents in Etinan were recruited for a cross-sectional survey study comparing their respiratory symptoms and other related health challenges. Past and current smokers were excluded from the study in both groups. The study was conducted using a questionnaire as the investigative tool. Both descriptive and inferential statistics were used to analyze the data. RESULTS: Most of the respondents in both exposed and control communities were aged 18-30 years, with a height range of 161-170 cm. Both exposed and control subjects experienced similar symptoms suggestive of respiratory disorders, however, the prevalence was significantly higher among exposed subjects than controls: Cough 57(14.8%) vs. 39(10.1%); breathlessness 58(15%) vs. 28(7.3); wheezing 22(5.7) vs. 12(3.1). The respondents from the exposed community were mostly traders and fishermen while the controls were predominantly farmers. CONCLUSION: There is substantial evidence from the data presented that prolonged exposure to air pollution from gas flaring has significant respiratory and other health implications on residents in these communities reflected as increased frequency of symptoms of cough, chest pain, difficulty in breathing, wheezing, chest tightness, Skin and eye irritation. There is therefore an urgent need for intensified efforts and commitment by the government to speed up the implementation of policies regarding the reduction of flaring of natural gas associated with oil production and the adoption of measures to mitigate the effect of the exposure on human health.

CONTEXTE: Cette étude présente les effets respiratoires observés chez les résidents chroniquement exposés au torchage de gaz dans certaines communautés de la région du delta du Niger, au Nigeria. Les autres problèmes de santé associés à cette exposition chronique au gaz ont également été évalués dans cette étude. MÉTHODES: Un total de 386 résidents adultes d'Ibeno, dans la région du delta du Niger, ayant résidé pendant au moins deux ans, ont été inclus dans l'étude. Quatre cent quatorze (414) résidents non exposés, appariés en fonction de l'âge, du sexe et de la taille, à Etinan ont été recrutés pour une étude transversale comparant leurs symptômes respiratoires et d'autres problèmes de santé associés. Les fumeurs passés et actuels ont été exclus de l'étude dans les deux groupes. L'étude a été menée à l'aide d'un questionnaire comme outil d'investigation. Des statistiques descriptives et inférentielles ont été utilisées pour analyser les données. RÉSULTATS: La plupart des répondants dans les communautés exposées et témoins avaient entre 18 et 30 ans, avec une taille allant de 161 à 170 cm. Les sujets exposés et témoins ont présenté des symptômes similaires suggérant des troubles respiratoires, cependant, la prévalence était significativement plus élevée chez les sujets exposés que chez les témoins : Toux - 57 (14,8 %) contre 39 (10,1 %) ; essoufflement 58 (15 %) contre 28 (7,3 %) ; sifflement 22 (5,7 %) contre 12 (3,1 %). Les répondants de la communauté exposée étaient principalement des commerçants et des pêcheurs, tandis que les témoins étaient principalement des agriculteurs. CONCLUSION: Les données présentées fournissent des preuves substantielles que l'exposition prolongée à la pollution de l'air due au torchage de gaz a des implications respiratoires et autres sur la santé des résidents de ces communautés, se traduisant par une fréquence accrue des symptômes de toux, douleur thoracique, difficulté à respirer, sifflement, oppression thoracique, irritation de la peau et des yeux. Il est donc urgent d'intensifier les efforts et l'engagement du gouvernement pour accélérer la mise en œuvre des politiques visant à réduire le torchage du gaz naturel associé à la production de pétrole et à adopter des mesures pour atténuer les effets de l'exposition sur la santé humaine. MOTS CLÉS: Effet respiratoire, Exposition chronique, Torchage de gaz, Delta du Niger.

Chronic polystyrene microplastics exposure-induced changes in thick-shell mussel (Mytilus coruscus) metaorganism: A holistic perspective.

Microplastics have emerged as a significant global concern, particularly in marine ecosystems. While extensive research has focused on the toxicological effects of microplastics on marine animals and/or their associated microorganisms as two separate entities, the holistic perspective of the adaptability and fitness of a marine animal metaorganism-comprising the animal host and its microbiome-remains largely unexplored. In this study, mussel metaorganisms subjected chronic PS-MPs exposure experienced acute mortality but rapidly adapted. We investigated the response of innate immunity, digestive enzymes and their associated microbiomes to chronic PS-MPs exposure. We found that PS-MPs directly and indirectly interacted with the host and microbe within the exposure system. The adaptation was a joint effort between the physiological adjustments of mussel host and genetic adaptation of its microbiome. The mussel hosts exhibited increased antioxidant activity, denser gill filaments and increased immune cells, enhancing their innate immunity. Concurrently, the gill microbiome and the digestive gland microbiome respective selectively enriched for plastic-degrading bacteria and particulate organic matter-utilizing bacteria, facilitating the microbiome's adaptation. The microbial adaptation to chronic PS-MPs exposure altered the ecological roles of mussel microbiome, as evidenced by alterations in microbial interactions and nutrient cycling functions. These findings provided new insights into the ecotoxicological impact of microplastics on marine organisms from a metaorganism perspective.

Single-cell RNA-seq Reveals that Methamphetamine Inhibits Liver Immunity with Involvement of Dopamine Receptor D1.

Methamphetamine (METH) is a highly addictive psychostimulant that causes physical and psychological damage and immune system disorder, especially in the liver that contains a significant number of immune cells. Dopamine, a key neurotransmitter in METH addiction and immune regulation, plays a crucial role in this process. Here, we developed a chronic METH administration model and conducted single-cell RNA sequencing (scRNA-seq) to investigate the effect of METH on liver immune cells and involvement of dopamine receptor D1 (DRD1). Our findings reveal that chronic exposure to METH induces immune cell identity shifts from Ifitm3+Macrophage (Mac) and Ccl5+Mac to Cd14+Mac, and from Fyn+CD4+T effector (Teff), CD8+T, and natural killer T cells (NKT) to Fos+CD4+T and Rora+ group 2 innate lymphoid cells (ILC2), along with suppression of multiple functional immune pathways. DRD1 is implicated in regulating certain pathways and identity shifts among the hepatic immune cells. Our results provide valuable insights into development of targeted therapies to mitigate METH-induced immune impairment.

Hepatic and metabolic outcomes induced by sub-chronic exposure to polystyrene microplastics in mice.

Microplastics (MPs) have attracted significant attention due to their global distribution in living environments. Although some studies have reported MP-induced hepatotoxicity in mouse models, a systematic approach to MP-mediated liver toxicity was still lacking. Therefore, we used a mouse model to study the sub-chronic effects of MP exposure on the liver. Female C57BL/6 mice, aged 6 weeks, received an oral administration of 0.3 mg of Nile Red-labeled polystyrene (PS) microplastics, with particle sizes of 0.5 µm (submicron) and 5 µm (micron), via gavage, while control mice received vehicle only. Each mouse was exposed to MPs twice a week for 12 weeks. After sacrifice, the levels of MP accumulation, oxidative stress, inflammation, and pathological changes were measured in the mouse liver, and blood samples were collected for serum biochemistry analysis. Our results demonstrated that 0.5 µm PS-MPs were accumulated in mouse livers post-MP exposure, but not in the 5 µm MP exposure group. Simultaneously, increased levels of glucose, triglyceride, alanine transaminase (ALT), aspartate transaminase (AST), superoxide dismutase, 4-hydroxy-2-nonenal-mercapturic acid (HNE-MA), interleukin-6, and lipid droplets were found in the 0.5 µm MP exposure group, while the fewer responses, including elevated liver weight index, glucose, high-density lipoprotein, AST, and decreased HNE-MA were observed in 5 µm MP exposure group. These results indicate that sub-chronic exposure to submicron MPs causes MP deposition in mouse livers, which further induces oxidative stress, increases inflammatory cytokines and perturbs glucose and lipid homeostasis, which might trigger more severe metabolic dysfunction or non-alcoholic steatohepatitis-like hepatotoxicity.

Hepatic histopathological and morphometric changes in male mice exposed to rosuvastatin from pre-puberty to adulthood: a possible adaptive hepatic response.

Lifestyle changes, such as poor eating habits and a reduction in physical exercise, have impaired human lipid profiles. Statins are widely used to treat dyslipidemias, of which rosuvastatin shows greater improvement in the lipid profile and may be used since childhood. This study aimed to assess the hepatic effects when male mice were given 0.9% saline solution or doses of rosuvastatin of 1.5 or 5.5 mg/kg/day from postnatal day (PND) 23 until PND 80. Body mass gain and water and food consumption were monitored during the treatment. Mice were euthanized on PND 80 when blood was collected for serum obtainment, and several organs were collected and weighed. Serum was used for evaluating lipid profiles and markers of hepatic injuries. The liver was assessed for histopathological, morphometric, and stereological changes. There was a temporary reduction in body mass gain and water and food consumption in the rosuvastatin-exposed groups. Both rosuvastatin-treated groups exhibited reduced total cholesterol levels and showed signs of hepatic tissue adaptation in response to prolonged exposure, such as sinusoidal dilation, inflammatory infiltrates, and cell death of hepatocytes. These results are considered side effects of the treatment and may indicate a hepatic adaptation to the chronic exposure.

Sulfuric acid-induced skin neoplasms in immunocompetent mice.

This study investigates the carcinogenic potential of chronic dermal exposure (16 weeks) to sulfuric acid (SA) in immunocompetent mice. Clinical assessments, histopathological analyses, immunohistochemical analyses and biochemical assays were conducted to evaluate skin irritation, oxidative stress biomarkers and the potential carcinogenic effect of SA. Results indicated that prolonged exposure to SA leads to various alterations in skin structure, notably inflammation, preneoplastic and neoplastic proliferation in hair follicles, as well as hyperkeratosis and acanthosis, resulting in an increased epidermal thickness of 98.50 ± 21.6 µm. Immunohistochemistry analysis further corroborates these observations, showcasing elevated nuclear expression of p53 and Ki-67, with a significant mitotic index of (57.5% ± 2.5%). Moreover, biochemical analyses demonstrate that SA induces lipid peroxidation in the skin, evidenced by a high level of Malondialdehyde and a consequential reduction in catalase activity. These findings suggest that prolonged exposure to SA can induce skin neoplasms, highlighting the need for stringent safety measures in environments where SA is frequently used. This study underscores the potential occupational health risks associated with SA exposure.

Phallusia nigra-mediated vanadium removal from brine: Assessment and optimization.

The rejected brines from desalination plants contain significant amounts of heavy metals. In this study, we evaluated the effectiveness of Phallusia nigra Savigny, 1816 (P. nigra) in removing vanadium from the rejected brines of desalination plants through the bioaccumulation process. Initial assessments revealed a remarkably high accumulation rate of vanadium in P. nigra with a bioaccumulation factor exceeding 4.7 × 104 in the tunic and 5.1 × 105 in the mantle body. Acclimation experiments demonstrated that P. nigra could survive salinities up to 56 practical salinity units (psu), temperatures of ≤32 °C, and pH of 6.5-8.5. We employed the L-16 Taguchi approach in experimental design to optimize environmental conditions for vanadium removal by P.nigra. Our results indicated that temperature has the most significant effect on increasing vanadium bioaccumulation in P. nigra, followed by salinity and pH. Under optimal conditions, the vanadium concentration reached 1892.30 ppm in the entire body of P. nigra compared to 350 ppm in natural conditions. Considering that, a high concentration of vanadium is toxic to the environment and the conventional methods of its removal from brine are costly and include the use of chemicals that pollute the environment, therefore, vanadium removal from brine using P. nigra can be considered a cost-effective and environmentally friendly method in the future, as opposed to some chemical methods.

Reproductive Capacity, but not Food Consumption, is Reduced by Continuous Exposure to Typical Genotoxic Stressor γ-Rays in the sentinel species Gammarus fossarum.

The long-term impacts of radiocontaminants (and the associated risks) for ecosystems are still subject to vast societal and scientific debate while wildlife is chronically exposed to various sources and levels of either environmental or anthropogenic ionizing radiation from the use of nuclear energy. The present study aimed to assess induced phenotypical responses in both male and female gammarids after short-term continuous γ-irradiation, acting as a typical well-characterized genotoxic stressor that can interact directly with living matter. In particular, we started characterizing the effects using standardized measurements for biological effects on few biological functions for this species, especially feeding inhibition tests, molting, and reproductive ability, which have already been proven for chemical substances and are likely to be disturbed by ionizing radiation. The results show no significant differences in terms of the survival of organisms (males and females), of their short-term food consumption which is linked to the general health status (males and females), and of the molting cycle (females). In contrast, exposure significantly affected fecundity (number of embryos produced) at the highest dose rates for irradiated females (51 mGy h-1) and males (5 and 51 mGy h-1). These results showed that, in gammarids, reproduction, which is a critical endpoint for population dynamics, is the most radiosensitive phenotypic endpoint, with significant effects recorded on male reproductive capacity, which is more sensitive than in females. Environ Toxicol Chem 2024;43:2071-2079. © 2024 SETAC.

The arsenic eaters of Styria, the toxicophagi.

INTRODUCTION: From at least the fifteenth to late nineteenth centuries, peasants in the Austrian province of Styria ate up to several hundred milligrams of arsenic trioxide or sulfide daily or weekly for periods up to a number of years. Taking these doses of arsenic was believed to increase muscular power and enhance the beauty and sexual attractiveness of peasant girls. There do not appear to be contemporaneous records of the known consequences of chronic arsenic exposure. The historical records of arsenic eating there are reviewed and appear to be valid. The benefits are subjective judgements by arsenic eaters. The lack of objective reports of the anticipated external and internal clinical and pathological effects of arsenic poisoning depends on a smaller number of clinical accounts and autopsy reports and the general medical literature of those times, so it is weaker, but it is consistent. CAN THE CLAIMED BENEFITS OF ARSENIC EATING AND THE APPARENT ABSENCE OF HARMFUL TOXIC EFFECTS BE TRUE?: Why the arsenic eaters did not show the well-known consequences of prolonged exposure to high doses of arsenic is not known. Possible explanations include increases in detoxifying metabolism in the consumers due to induced genomic changes and selection in people and in the gut microbiome, as shown in other populations. Whether these effects would suffice to protect people against their high doses of arsenic has not been explored. CONCLUSION: Although the nature and mechanisms of arsenic toxicity have been extensively described, much still remains to be discovered.

Exacerbated interfacial impacts of nanoplastics and 6:2 chlorinated polyfluorinated ether sulfonate by natural organic matter in adult zebrafish: Evidence through histopathology, gut microbiota, and transcriptomic analysis.

Nanoplastics (NPs) interact with cooccurring chemicals and natural organic matter (NOM) in the environment, forming complexes that can change their bioavailability and interfacial toxicity in aquatic organisms. This study aims to elucidate the single and combined impacts of 21-day chronic exposure to low levels of polystyrene NPs (size 80 nm) at 1 mg/L and 6:2 chlorinated polyfluorinated ether sulfonate (Cl-PFAES or F53B) at 200 µg/L in the presence and absence of NOM (humic acid-HA and bovine serum albumin-BSA at 10 mg/L) in adult zebrafish (Danio rerio). Our findings through multiple bioassays, revealed that the mixture group (M), comprising of NPs, F53B, HA, and BSA, caused a higher level of toxicity compared to the single NPs (AN), single F53B (AF), and combined NPs+F53B (ANF) groups. The mixture exposure caused the highest level of vacuolization and nuclear condensation in hepatocytes, and most of the intestinal villi were fused and highly reduced in villi length and crypt depth. Further, the T-AOC levels were significantly lower (p < 0.05), while the MDA levels in the liver and intestine were significantly higher (p < 0.05) in the M group with downregulation of nfkbiaa, while upregulation of prkcda, csf1ra, and il1b apoptosis genes in the liver. Pairwise comparison of gut microbiota showed significantly higher (p < 0.05) abundances of various genera in the M group, including Gordonia, Methylobacterium, Tundrisphaera, GKS98, Pedomicrobium, Clostridium, Candidatus and Anaerobacillus, as well as higher abundance of genera including pathogenic strains, while control group showed higher abundance of probiotic genus ZOR0006 than exposed group (p < 0.01). The transcriptomic analysis revealed highest number of DEGs in the M group (2815), followed by the AN group (506) and ANF group (206) with the activation of relaxin signaling pathway-RSP (slc9a1, slc9a2) and AMP-activated protein kinase (AMPK) pathway (plin1), and suppression of the toll-like receptor (TLR) pathway (tlr4a, tlr2, tlr1), cytokine-cytokine receptor interaction (CCRI) pathway (tnfb, il21r1, il21, ifng1), and peroxisome proliferator-activated receptors (PPAR) pathway (pfkfb3). Overall, toxicity in the M group was higher, indicating that the HA and BSA elevated the interfacial impacts of NPs and F53B in adult zebrafish after chronic environmentally relevant exposure, implying the revisitation of the critical interaction of NOM with co-occurring chemicals and associated impacts.

Toxic effects and mechanisms of chronic cadmium exposure on Litopenaeus vannamei growth performance based on combined microbiome and metabolome analysis.

Cadmium (Cd) pollution seriously affects marine organisms' health and poses a threat to food safety. Although Cd pollution has attracted widespread attention in aquaculture, little is known about the toxic mechanisms of chronic Cd exposure on shrimp growth performance. The study investigated the combined effects of chronic exposure to Cd of different concentrations including 0, 75, 150, and 300 µg/L for 30 days on the growth performance, tissue bioaccumulation, intestinal microbiology, and metabolic responses of Litopenaeus vannamei. The results revealed that the growth was significantly inhibited under exposure to 150 and 300 µg/L Cd2+. The bioaccumulation in gills and intestines respectively showed an increasing and inverted "U" shaped trend with increasing Cd2+ concentration. Chronic Cd altered the intestinal microflora with a significant decrease in microbial richness and increasing trends in the abundances of the potentially pathogenic bacteria Vibrio and Maribacter at exposure to 75 and 150 µg/L Cd2+, and Maribacter at 300 µg/L. In addition, chronic Cd interfered with intestinal metabolic processes. The expressions of certain metabolites associated with growth promotion and enhanced antioxidant power, including N-methyl-D-aspartic acid, L-malic acid, guanidoacetic acid, betaine, and gluconic acid were significantly down-regulated, especially at exposure to 150 and 300 µg/L Cd2+, and were negatively correlated with Vibrio and Maribacter abundance levels. In summary, chronic Cd exposure resulted in severe growth inhibition and increased Cd accumulation in shrimp tissues. Increased levels of intestinal pathogenic bacteria and decreased levels of growth-promoting metabolites may be the key causes of growth inhibition. Harmful bacteria Vibrio and Maribacter may be associated with the inhibition of growth-promoting metabolite expression and may be involved in disrupting intestinal metabolic functions, ultimately impairing shrimp growth potential. This study sheds light on the potential toxicological mechanisms of chronic Cd inhibition on shrimp growth performance, offering new insights into Cd toxicity studies in aquaculture.

Detrimental effects of amitraz exposure in honey bees (Apis mellifera) infected with Nosema ceranae.

In recent years, there has been growing concern on the potential weakening of honey bees and their increased susceptibility to pathogens due to chronic exposure to xenobiotics. The present work aimed to study the effects on bees undergoing an infection by Nosema ceranae and being exposed to a frequently used in-hive acaricide, amitraz. To achieve this, newly emerged bees were individually infected with N. ceranae spores and/or received a sublethal concentration of amitraz in their diets under laboratory conditions. Mortality, food intake, total volume excrement, body appearance, and parasite development were registered. Bees exposed to both stressors jointly had higher mortality rates compared to bees exposed separately, with no difference in the parasite development. An increase in sugar syrup consumption was observed for all treated bees while infected bees fed with amitraz also showed a diminishment in pollen intake. These results coupled with an increase in the total number of excretion events, alterations in behavior and body surface on individuals that received amitraz could evidence the detrimental action of this molecule. To corroborate these findings under semi-field conditions, worker bees were artificially infected, marked, and released into colonies. Then, they were exposed to a commercial amitraz-based product by contact. The recovered bees showed no differences in the parasite development due to amitraz exposure. This study provides evidence to which extent a honey bee infected with N. ceranae could potentially be weakened by chronic exposure to amitraz treatment.

Dynamic model of changes in the trophic structure of an ecosystem affected by chronic radiation exposure.

The conceptual dynamic ecosystem model was developed to evaluate the self-organization of trophic structure in ecosystems during the course of biogenic succession. This model was applied to analyze the possible changes in the ecosystem under impact of the anthropogenic physical stressor - chronic exposure to ionizing irradiation. The model predicts that amount of the limiting biogenic nutrient in the environment can modify the ecological effects of ionizing radiation. Negative effects of the chronic exposure are less significant in ecosystems with high food supply. The model does not show presence of any ecological effect of radiation at the exposure rates less than the derived consideration reference levels, obtained by International Commission on Radiological Protection for individual nature organisms. If the dose rates are higher than those levels, radiation exposure can affect ecological interactions between species. The model shows that environmental hormesis can exist in the ecosystems, impacted by the chronic radiation exposure. The reason of this effect is change of the ecological coefficients (for example, decrease of the predation rate), which in the certain range of parameters leads to the increase of biomasses of all species at the same amount of the limiting biogenic nutrient in ecosystem. Trigger regimes exist in the model ecosystem with mixed-feeding consumers. Within the trigger area, the realization of a particular trophic structure depends on initial species biomasses. A hysteresis phenomenon exists in such ecosystems, which means that the successive changes in the trophic structures realized following the increase of the influencing factor are not reproduced in the same order if the influencing factor was gradually decreased back to its previous values. The model predicts for this case, that the radioactively contaminated ecosystem does not necessarily return to its initial trophic structure, despite the dose rate decreases to the initial levels.

Evaluation of oxidative stress and genetic instability among residents near mobile phone base stations in Germany.

Human exposure to radiofrequency electromagnetic fields (RF-EMF) is restricted to prevent thermal effects in the tissue. However, at very low intensity exposure "non-thermal" biological effects, like oxidative stress, DNA or chromosomal aberrations, etc. collectively termed genomic-instability can occur after few hours. Little is known about chronic (years long) exposure with non-thermal RF-EMF. We identified two neighboring housing estates in a rural region with residents exposed to either relatively low (control-group) or relatively high (exposed-group) RF-EMF emitted from nearby mobile phone base stations (MPBS). 24 healthy adults that lived in their homes at least for 5 years volunteered. The homes were surveyed for common types of EMF, blood samples were tested for oxidative status, transient DNA alterations, permanent chromosomal damage, and specific cancer related genetic markers, like MLL gene rearrangements. We documented possible confounders, like age, sex, nutrition, life-exposure to ionizing radiation (X-rays), occupational exposures, etc. The groups matched well, age, sex, lifestyle and occupational risk factors were similar. The years long exposure had no measurable effect on MLL gene rearrangements and c-Abl-gene transcription modification. Associated with higher exposure, we found higher levels of lipid oxidation and oxidative DNA-lesions, though not statistically significant. DNA double strand breaks, micronuclei, ring chromosomes, and acentric chromosomes were not significantly different between the groups. Chromosomal aberrations like dicentric chromosomes (p=0.007), chromatid gaps (p=0.019), chromosomal fragments (p<0.001) and the total of chromosomal aberrations (p<0.001) were significantly higher in the exposed group. No potential confounder interfered with these findings. Increased rates of chromosomal aberrations as linked to excess exposure with ionizing radiation may also occur with non-ionizing radiation exposure. Biological endpoints can be informative for designing exposure limitation strategies. Further research is warranted to investigate the dose-effect-relationship between both, exposure intensity and exposure time, to account for endpoint accumulations after years of exposure. As established for ionizing radiation, chromosomal aberrations could contribute to the definition of protection thresholds, as their rate reflects exposure intensity and exposure time.

Grouped mixtures of air pollutants and seasonal temperature anomalies and cardiovascular hospitalizations among U.S. Residents.

BACKGROUND: Air pollution is a recognized risk factor for cardiovascular disease (CVD). Temperature is also linked to CVD, with a primary focus on acute effects. Despite the close relationship between air pollution and temperature, their health effects are often examined separately, potentially overlooking their synergistic effects. Moreover, fewer studies have performed mixture analysis for multiple co-exposures, essential for adjusting confounding effects among them and assessing both cumulative and individual effects. METHODS: We obtained hospitalization records for residents of 14 U.S. states, spanning 2000-2016, from the Health Cost and Utilization Project State Inpatient Databases. We used a grouped weighted quantile sum regression, a novel approach for mixture analysis, to simultaneously evaluate cumulative and individual associations of annual exposures to four grouped mixtures: air pollutants (elemental carbon, ammonium, nitrate, organic carbon, sulfate, nitrogen dioxide, ozone), differences between summer and winter temperature means and their long-term averages during the entire study period (i.e., summer and winter temperature mean anomalies), differences between summer and winter temperature standard deviations (SD) and their long-term averages during the entire study period (i.e., summer and winter temperature SD anomalies), and interaction terms between air pollutants and summer and winter temperature mean anomalies. The outcomes are hospitalization rates for four prevalent CVD subtypes: ischemic heart disease, cerebrovascular disease, heart failure, and arrhythmia. RESULTS: Chronic exposure to air pollutant mixtures was associated with increased hospitalization rates for all CVD subtypes, with heart failure being the most susceptible subtype. Sulfate, nitrate, nitrogen dioxide, and organic carbon posed the highest risks. Mixtures of the interaction terms between air pollutants and temperature mean anomalies were associated with increased hospitalization rates for all CVD subtypes. CONCLUSIONS: Our findings identified critical pollutants for targeted emission controls and suggested that abnormal temperature changes chronically affected cardiovascular health by interacting with air pollution, not directly.

Understanding the toxicity risk of antibiotic emissions of aquaculture from the perspective of fluctuations concentration.

Organisms are generally exposed to target contaminant with stable concentrations in traditional ecotoxicological studies. However, it is difficult to truly represent the dynamics and complexity of actual aquatic pollution for risk management. Contaminants may enter nearby aquatic systems in pulsed exposure, thus resulting in that aquatic organisms will be exposed to contaminants at fluctuating concentrations. Especially during the season of summer, due to the changes in displacement or periodic emissions of veterinary antibiotics in aquaculture, algal blooms occur frequently in surrounding waters, thus leading to eutrophication of the water. Florfenicol (FFC) is currently widely used as a veterinary antibiotic, but the aquatic ecological risks of FFC under concentration fluctuations are still unknown. Therefore, the acute exposure, chronic exposure and pulsed exposure effects of FFC on Microcystis aeruginosa were investigated to comprehensively evaluate the ecological risk of FFC and raise awareness of the pulsed exposure mode. Results indicated that the toxic effects of FFC on M. aeruginosa were dominated by exposure mode, exposure duration, exposure frequency, and exposure concentration. The maximum growth inhibition rate of the 10 µg/L FFC treatment amounted to 4.07% during chronic exposure of 18 days. However, the growth inhibition rate decreased from 55.1% to 19.31% when algae was exposure to 10 µg/L FFC during the first pulsed exposure (8 h). Therefore, when the concentration of FFC was equal under chronic and pulsed exposure, FFC exhibited greater toxicity on M. aeruginosa in short pulsed exposure than in continuous exposure. In addition, repetitive pulsed exposure strengthened the resistance of M. aeruginosa on FFC. The adaptive regulation of algae was related to the duration and frequency of exposure. Above results suggested that traditional toxicity assessments lacked consideration for fluctuating concentrations during pollutant emissions, thus underestimating the environmental risk of contaminant. This investigation aims to facilitate the standardization of pulsed exposure.

Association of ambient air pollution with hemoglobin levels and anemia in the general population of Korean adults.

BACKGROUND: Emerging evidence has suggested significant associations between ambient air pollution and changes in hemoglobin levels or anemia in specific vulnerable groups, but few studies have assessed this relationship in the general population. This study aimed to evaluate the association between long-term exposure to air pollution and hemoglobin concentrations or anemia in general adults in South Korea. METHODS: A total of 69,830 Korean adults from a large-scale nationwide survey were selected for our final analysis. Air pollutants included particulate matter with an aerodynamic diameter less than or equal to 10 micrometers (PM10), particulate matter with an aerodynamic diameter less than or equal to 2.5 micrometers, nitrogen dioxide, sulfur dioxide (SO2), and carbon monoxide (CO). We measured the serum hemoglobin concentration to assess anemia for each participant. RESULTS: In the fully adjusted model, exposure levels to PM10, SO2, and CO for one and two years were significantly associated with decreased hemoglobin concentrations (all p < 0.05), with effects ranging from 0.15 to 0.62% per increase in interquartile range (IQR) for each air pollutant. We also showed a significant association of annual exposure to PM10 with anemia (p = 0.0426); the odds ratio (OR) [95% confidence interval (CI)] for anemia per each increase in IQR in PM10 was estimated to be 1.039 (1.001-1.079). This association was also found in the 2-year duration of exposure (OR = 1.046; 95% CI = 1.009-1.083; adjusted Model 2). In addition, CO exposure during two years was closely related to anemia (OR = 1.046; 95% CI = 1.004-1.091; adjusted Model 2). CONCLUSIONS: This study provides the first evidence that long-term exposure to air pollution, especially PM10, is significantly associated with reduced hemoglobin levels and anemia in the general adult population.

Effects of chronic home radon exposure on cognitive, behavioral, and mental health in developing children and adolescents.

Introduction: It is well-established that chronic exposure to environmental toxins can have adverse effects on neuropsychological health, particularly in developing youths. However, home radon, a ubiquitous radiotoxin, has been seldom studied in this context. In the present study, we investigated the degree to which chronic everyday home radon exposure was associated with alterations in transdiagnostic mental health outcomes. Methods: A total of 59 children and adolescents ages 6- to 14-years-old (M = 10.47 years, SD = 2.58; 28 males) completed the study. Parents completed questionnaires detailing aspects of attention and executive function. We used a principal components analysis to derive three domains of neuropsychological functioning: 1) task-based executive function skills, 2) self-and emotion-regulation abilities, and 3) inhibitory control. Additionally, parents completed a home radon test kit and provided information on how long their child had lived in the tested home. We computed a radon exposure index per person based on the duration of time that the child had lived in the home and their measured home radon concentration. Youths were divided into terciles based on their radon exposure index score. Using a MANCOVA design, we determined whether there were differences in neuropsychological domain scores across the three groups, controlling for age, sex, and socioeconomic status. Results: There was a significant multivariate effect of radon group on neuropsychological dysfunction (λ = 0.77, F = 2.32, p = 0.038, ηp2 = 0.12). Examination of univariate effects revealed specific increases in self-and emotion-regulation dysfunction among the youths with the greatest degree of chronic home radon exposure (F = 7.21, p = 0.002, ηp2 = 0.21). There were no significant differences by group in the other tested domains. Discussion: The data suggest potential specificity in the neurotoxic effects of everyday home radon exposure in developing youths, with significant aberrations in self-and emotion-regulation faculties. These findings support the need for better public awareness and public health policy surrounding home radon safety and mitigation strategies.