Effects Of Long-term Exposure Research Articles

Effect of short and long-term cadmium exposure on behaviour and cardiac function in Drosophila.

Cadmium is a non-essential heavy metal and environmental pollutant that causes a range of pathologies across different species. In humans, cadmium exposure has recently been directly linked to heart disease. Understanding how long-term cadmium exposure affects cardiac physiology is therefore important. In this work we employed a tractable Drosophila melanogaster model to study the effects of cadmium exposure on behaviour, lifespan and cardiac physiology. Dietary experiments established that cadmium at 10μM and 100μM was tolerated for several weeks, whereas doses in the mM range caused lethality within days. It was estimated that 10μM dietary exposure represented an approximately 60-fold excess of the maximum exposure recommended for humans. Although 10μM cadmium had no impact on lifespan compared to the control diet, it did cause significant daytime hyperactivity. Direct exposure of the heart to cadmium caused reversible cardiac arrest and disrupted calcium signalling. Compared to controls, 10μM dietary cadmium had no impact on the rate of cardiac ageing over a six-week period. The higher dose of 100μM shortened the flies' lifespan but it slowed the rate of cardiac ageing. The findings indicate that Drosophila can be used to model the direct effects of cadmium on cardiomyocyte function and also demonstrate the existence of cardioprotective pathways triggered by dietary cadmium exposure. The data also indicate that cadmium at doses that do not affect lifespan or heart function, do cause daytime hyperactivity. Identifying the cardioprotective mechanismsof cadmium and understanding the hyperactivity phenotype in Drosophila may yield important findings of applied relevance to insects in general, as well as humans exposed to cadmium.

Independent effects of long and short-term exposures to non-optimal increased temperature on mortality

Although the short-term heat effects are well-established, longer-term effects, beyond those, have recently received attention, in the context of climate change. Our study aims to investigate the potential effects of long-term exposure to non-optimal warm period temperatures on all-cause mortality in four large regions in the UK, Norway, Italy, and Greece. Daily all-cause mortality counts from 1996 to 2018 for four European NUTS2 regions including 52-662 small areas were collected and associated with spatiotemporal temperature estimates. A NUTS2 region–specific mixed quasi-Poisson over-dispersed model, with a random intercept per small area within NUTS2 regions, was applied to investigate the association between long-term temperature exposure and mortality during the warm period (May to September), adjusting for short-term temperature, seasonality, long-term trends, and small-area population characteristics. As long-term temperature exposure indices per small area, we considered: 1) the warm period annual average temperature, 2) the annual standard deviation (SD) of warm period temperature, and 3) the coefficient of variation of warm period temperature (CV). We found consistent results following short-term temperature exposure on mortality, with higher effects in southern areas. Results on the shape of the long-term association between average temperature and mortality differed by country, while the different temperature metrics produced inconsistent findings. Increased mortality was associated with increased annual warm season temperature, lower SD and increased CV in Greece, with higher SD and decreased CV in Italy and with decreased annual temperature and CV in Norway. Effects in the UK did not reach the nominal level of statistical significance. Although our study implies an impact on mortality resulting from longer-term temperature exposure, its direction varied across areas and on the temperature metric used. Further research is warranted, applying non-ecological study designs and covering various geographical areas to capture the impact of individual and area-specific characteristics.

Long-term effects of Nε-carboxymethyllysine intake on intestinal barrier permeability: Associations with gut microbiota and bile acids.

Advanced glycation end products (AGEs) in processed foods are closely linked to intestinal injury. However, the long-term effects of exposure to free Nɛ-carboxymethyl lysine (CML), a prevalent AGE molecule, on intestinal barrier integrity have been rarely evaluated. This study investigated the temporal effects of CML exposure on intestinal barrier permeability in C57BL/6N mice at diet-related doses over 12, 14, and 16weeks. No significant changes were observed at 12weeks, but CML exposure significantly increased intestinal permeability at 14 and 16weeks, accompanied by elevated serum LPS levels, colonic histological damage, and reduced tight junction protein expression at 16weeks. CML exposure also altered gut microbiota composition and intestinal bile acid (BA) profiles, specifically reducing TDCA, GDCA, and GCDCA levels. Given the important role of colonic BA receptor signaling in maintaining the intestinal barrier integrity, the impact of CML on BA receptor signaling was assessed. CML exposure significantly downregulated BA receptor TGR5-YAP signaling in mice, while no significant effects were observed in vitro, suggesting that the changes observed in TGR5-YAP signaling in vivo may not result from the direct effects of CML. Spearman's correlation analysis revealed strong associations between altered gut microbiota, BA levels, TGR5-YAP signaling, and intestinal barrier injury. This study highlighted the chronic health risks of long-term CML intake and provided new insights into the links between CML-induced intestinal toxicity, gut microbiota, BA profiles, and BA receptor signaling.

Effects of long-term exposure to sulfamethoxazole on the sediments in sewage pipe: Extracellular polymeric substance, microbial communities, and antibiotic resistance genes

Effects of long-term exposure to sulfamethoxazole on the sediments in sewage pipe: Extracellular polymeric substance, microbial communities, and antibiotic resistance genes

Effect and prediction of long-term weather and pollutant exposure on hemorrhagic fever with renal syndrome: based on statistical models

Effect and prediction of long-term weather and pollutant exposure on hemorrhagic fever with renal syndrome: based on statistical models

Long-term effects of combined exposures to simulated microgravity and galactic cosmic radiation on the mouse lung: sex-specific epigenetic reprogramming.

Most studies on the effects of galactic cosmic rays (GCR) have relied on terrestrial irradiation using spatially homogeneous dose distributions of mono-energetic beams comprised of one ion species. Here, we exposed mice to novel beams that more closely mimic GCR, namely, comprising poly-energetic ions of multiple species. Six-month-old male and female C57BL/6J mice were exposed to 0 Gy, 0.5 Gy, or 1.5 Gy simplified simulated 5 ion GCR (GCRsim). Exposure to microgravity was simulated using hindlimb unloading (HLU). At nine months post exposure, the mice were terminated to assess for the presence of exposure-induced epigenetic alterations. DNA hypermethylation in the 5'-untranslated regions of Lx_III, MdFanc_I, and MdMus_II families of the Long Interspersed Nucleotide Element 1 (LINE-1) was observed in the lungs of male mice. These effects were accompanied by increases in the expression of DNA methyltransferases Dnmt1 and Dnmt3a, and methyl-binding protein, MecP2. Trends towards DNA hypomethylation, although insignificant, were observed in the lungs of female mice in the HLU + 1.5Gy GCRsim group. Altogether, our findings suggest persistent and sex-specific epigenetic reprogramming in the mouse lung and suggests that the DNA methylation status of LINE-1 can serve as a robust and reliable biomarker of previous radiation exposure.

Effects of short and long-term exposure to benzene, toluene, ethylbenzene, and xylenes (BTEX) in indoor environment air on human health: A systematic review and meta-analysis

Today, because of the increasing level of people's need to improve well- being in social and individual life, air pollutants have been released that have Pollution harms both human health and the environment. This research examined Benzene, Toluene, Ethylbenzene, and Xylenes (BTEX) levels in indoor air across different global locations from 1963 to 2023. The investigation employed both; a systematic review and meta-analysis method. The health risks associated with long and short-terms exposure to benzene, toluene, ethylbenzene, and xylene were assessed. That average concentration benzene was 23.07 μg⁄m3, toluene was 131.60, ethylbenzene was 28.91, and xylene was 63.87. Also, the health risk assessment based on a 95% confidence level showed that the pollutants in question play a role in causing diseases such as lung neoplasm, stomach neoplasm, colon neoplasm, liver neoplasm, headache, dizziness, nausea, insomnia, etc. Consequently, it is crucial to implement stringent measures aimed at lowering the levels of these contaminants in indoor spaces.

Transgenerational Reproductive and Developmental Toxicity Induced by N-Nitrosodimethylamine and Its Metabolite Formaldehyde in Drosophila melanogaster.

N-Nitrosodimethylamine (NDMA) is a known water disinfection byproduct (DBP) characterized as a potent hepatotoxin, promutagen, and probable human carcinogen; this is because of the metabolites associated with its biotransformation. The metabolism of NDMA produces formaldehyde, another alkylating agent and DBP. Both compounds are generated from natural and anthropogenic sources, but the safety restrictions applied to NDMA do not extend to the uses of formaldehyde. Hence, potential health and ecological risks are of concern. Due to limited information on the long-term effects of exposure to these compounds at environmentally relevant concentrations, this work aimed to compare the transgenerational reproductive and developmental toxicity of separate exposures to NDMA or its metabolite formaldehyde in Drosophila melanogaster over four generations. The parental flies were fed NDMA or formaldehyde (1.19E-06 to 5 mM) for 48 h during the third larval instar. Subsequent offspring (F1-F3) were grown under compound-free conditions. In the parental generation, both exposures modified the time to emergence and reduced the number of progenies. NDMA, but not formaldehyde, was lethal, affected fertility, and weakly induced malformations. In the next generations, both exposures induced malformed flies and modified the number of offspring. Reproductive toxicity and malformations were maintained for at least three generations, suggesting that detrimental effects could extend to unexposed offspring. This is the first study reporting the associated individual transgenerational effects on reproduction and development between NDMA and its metabolite formaldehyde in D. melanogaster, highlighting the relevance of evaluating multiple generations to accurately determine the health and environmental risks of pollutants.

Metabolic and molecular Characterization, following dietary exposure to DINCH, Reveals new Implications for its role as a Metabolism-Disrupting chemical.

Plastic materials are ubiquitous, leading to constant human exposure to plastic additives such as plasticizers. There is growing evidence that plasticizers may contribute to obesity due to their disruptive effects on metabolism. Alternatives like diisononylcyclohexane-1,2-dicarboxylate (DINCH) are replacing traditional phthalates such as di-(2-ethylhexyl) phthalate (DEHP), which are now banned due to their proven harmful health effects. While DINCH is considered a safer alternative to DEHP and no adipogenic effects have been demonstrated in in vivo studies, recent research suggests that the primary metabolite, monoisononylcyclohexane-1,2-dicarboxylic acid ester (MINCH), promotes adipocyte differentiation and dysfunction in vitro. However, metabolic and molecular effects are not fully understood in vivo. Here, we performed a comprehensive in vivo analysis using C57BL/6N mice to investigate the effects of DINCH on adipose tissue physiology and function. Mice were exposed to two doses of DINCH for 16weeks, followed by a 10-week recovery period. Tissue analysis confirmed the presence of DINCH and MINCH in liver and adipose tissue after treatment and recovery. After the recovery period, elevated DINCH concentrations in adipose tissue depots indicated possible bioaccumulation. Although no changes were observed in body composition and energy expenditure, sex-specific metabolic effects were identified. Female mice exhibited impaired whole-body insulin sensitivity and higher triglyceride levels, while male mice showed an altered insulin/C-peptide ratio and elevated cholesterol, HDL, and LDL levels. Proteomic profiling of serum, adipose and liver tissues revealed changes in pathways related to central energy metabolism and immune response, highlighting the systemic impact of DINCH, potentially on inflammatory processes. Most effects of DINCH, such as changes in insulin response and serum lipid levels, were diminished after the recovery period. Despite many findings consistent with the existing literature suggesting DINCH as a safer DEHP substitute, the observed sex-specific effects on insulin sensitivity, lipid metabolism and inflammatory processes, as well as potential bioaccumulation and long-term metabolic effects of DINCH exposure warrant careful consideration in further risk assessment.

Association between exposure to pyrethroids and chlorpyrifos at age 5 years and IQ at age 7 years among children from the Odense Child Cohort, a prospective birth cohort study.

Over the past decade, the use of organophosphate insecticides including chlorpyrifos has faced increasing restrictions due to health concerns, leading to a rise in use of pyrethroids. Concerns about neurodevelopmental insults following pyrethroids exposure exist, but few studies have examined the long-term effects of childhood exposure to chlorpyrifos and pyrethroids on IQ. To investigate the prospective associations between pyrethroids and chlorpyrifos exposure at age 5 years and IQ scores assessed at age 7. A total of 1083 children from the Odense Child Cohort (OCC), born between 2010 and 2012, were included. Chlorpyrifos metabolite chlorpyrifos-methyl, 3,5,6-trichloro-2-pyridinol (TCPy) and pyrethroid metabolite 3-phenoxy-benzoic acid (3-PBA) were measured in urine at age 5. An abbreviated version of the Danish Wechsler Intelligence Scale for Children fifth edition (WISC-V) was administered at age 7 years. Median urine concentrations of 3-PBA and TCPy at age 5 were 0.18μg/L and 1.15μg/L, respectively. Higher childhood urine TCPy concentration was associated with a reduction in IQ at 7 years (-0.80 (95%CI: -1.29, -0.31)) for each doubling of TCPy. The association was more pronounced in girls (-1.09 (95%CI: -1.80, -0.38)) than in boys. (-0.54 (95%CI: -1.21, -0.14)). No association was observed for 3-PBA. Even in this low exposed cohort, early childhood exposure to chlorpyrifos was associated with lower IQ at age 7. Our results align with previous reports in both animals and humans suggesting that chlorpyrifos exposure may adversely affect neurodevelopment. No association between pyrethroid exposure (3-PBA) and IQ scores was found. The lack of association for 3-PBA is likely due to the low and uniform exposure levels among the participants. To establish a definitive exposure-response relationship, studies or combined datasets with greater variability in exposure levels are required. Continued monitoring and regulation of insecticide use are recommended to protect the health of children.

Species- and tissue-specific profiles and potential risks of polychlorinated biphenyls (PCBs) and their metabolites in dogs and cats.

In recent years, there has been growing concern about the long-term health effects of chemical exposure in pets, particularly dogs and cats, from sources such as pet food and house dust. Domestic cats (Felis silvestris catus) and dogs (Canis lupus familiaris) are continuously exposed to polychlorinated biphenyls (PCBs), with particular attention being paid to the toxicity of their metabolites, hydroxylated PCBs (OH-PCBs) and methylsulfonyl PCBs (MeSO2-PCBs). However, the tissue distribution and species-specific differences of these PCB metabolites in domestic animals have not been fully elucidated. This study investigates the tissue-specific profiles of PCBs, OH-PCBs, and MeSO2-PCBs by analyzing blood, brain, liver, and bile samples from dogs and cats. The analysis revealed that hexa- to octa-chlorinated OH-PCBs were the predominant congeners in the brain, liver and bile of dogs. In contrast, tri- to penta-chlorinated OH-PCBs were more prevalent in cats, with lower-chlorinated OH-PCBs tending to accumulate due to limited UDP-glucuronosyltransferase activity. In cats, OH-PCBs are more readily excreted in the bile than in dogs, probably because there are fewer higher-chlorinated thyroxine-like OH-PCBs, which are known to bind to and persist in proteins in the liver and blood. MeSO2-PCBs were detected at lower concentrations than parent PCBs and OH-PCBs and primarily accumulated in the liver due to their lipophilic nature. The consistent concentrations of MeSO2-PCBs across species, despite variations in parent PCB and OH-PCB levels, underscore species-specific differences in metabolic capacity and excretion pathways. In addition, some OH-PCB concentrations in both dog and cat brains exceeded levels known to affect neurons, suggesting the potential for neurotoxicity in these species. Therefore, continued biomonitoring and further investigation of the toxic effects of these compounds in pets is imperative.

Cold and longevity: Can cold exposure counteract aging?

Aging is a multifaceted biological process characterized by a progressive decline in physiological functions and heightened vulnerability to diseases, shaped by genetic, environmental, and lifestyle factors. Among these, cold exposure has garnered interest for its potential anti-aging benefits. This review examines the impact of cold exposure on aging, focusing on key physiological processes such as inflammation, oxidative stress, metabolic regulation, and cardiovascular health. Cold exposure has been shown to reduce chronic inflammation, enhance antioxidant defenses, and improve metabolic health by activating brown adipose tissue. Furthermore, findings from hibernating mammals and model organisms suggest a connection between lower environmental temperatures and increased longevity. However, the potential long-term health risks of extended cold exposure, particularly in older adults, remain a significant concern. Epidemiological studies reveal increased rates of mortality and morbidity in populations living in cold climates, emphasizing the complexity of the relationship between cold exposure and aging. This review underscores the need for further research to elucidate the long-term effects of cold exposure on aging and to establish guidelines for leveraging its benefits while mitigating cold-induced risks.

Exploring the Influence of PCBs Exposure on Neonatal Birth Outcomes and Neurobehavioral Development after 20 years of prohibition.

Despite polychlorinated biphenyls (PCBs) have been banned in Taiwan for two decades, epidemiological studies indicated that prenatal PCBs exposure may still affect newborns and their birth outcomes. The study aimed to investigate the association between PCB concentrations in umbilical cord blood and infants' birth outcomes and neurodevelopment. We recruited 100 pairs of mothers and infants, residing in Changhua and Yunlin countries in Taiwan from 2014-2016. Maternal questionnaire surveys conducted to collect demographic data, and the Chinese version of the Neonatal Neurobehavioral Assessment Scale was used to assess the development of their neurological behavior in newborns within one to two weeks after birth. Additionally, the Infant Temperament Questionnaire was used to evaluate newborns' responses to stimuli. The measured levels of 23 PCBs congeners were analyzed using gas chromatography-electron capture negative ionization quadrupole mass spectrometry (GC-NICI-qMS). Multiple regression explored correlations between prenatal PCBs exposure and neonatal birth outcomes, neurobehavioral, and temperament. Additionally, we used the Weighted Quantile Sum (WQS) regression model analysis to identify the major contributing congener. The results revealed that 9 PCB congeners were commonly found in the study participants, specifically PCB138, PCB153, PCB180, PCB156, PCB170, PCB177, PCB187, PCB194, and PCB201. The top three PCBs congeners by levels were PCB138, PCB153, and PCB180 (17.28±16.84, 11.50±15.12, 8.09±14.10 pg/g wet weight, respectively). The decrease in birth weight and head circumference in newborns were each associated with 7 different PCB congeners, with 6 of them being correlated with both, including PCB153, PCB156, PCB177, PCB180, PCB187, and PCB194. Specifically, PCB153 was associated with delayed neurobehavioral development in newborns. Exposure to PCB153, PCB177, and PCB180 influenced the temperament development of newborns. The WQS results indicated that PCB156 and PCB177 were the major contributors to decreased birth weight and head circumference. In conclusion, despite the prohibition of PCB usage, prenatal exposure to PCBs may still affect neonatal health. It is recommended that Taiwan should monitor local newborns' long-term PCB exposure and track potential adverse health effects in their future development.

Effect of long-term exposure to non-biodegradable and biodegradable microplastics in continuous anoxic/aerobic bioreactors: Nitrogen removal performance, microbial communities and functional gene responses.

The environmental hazards caused by microplastics (MPs) have received widespread attention, but the effects of non-biodegradable and biodegradable MPs of long-term presence on continuously operating sewage treatment bioreactors are not well known. In this study, we investigated the effect of a representative non-biodegradable MP, polyethylene terephthalate (PET), and a biodegradable MP, polylactic acid (PLA), on the nitrogen removal performance of conventional anoxic/aerobic (A/O) process. The NH4+-N removal efficiencies were suppressed to 91.7±5.5% and 80.8±4.1% at concentrations of 10 and 100mg/L PLA, significantly (p<0.05) lower than 96.3±1.0% and 95.0±1.5% with the presence of PET. PLA resulted in a significant (p<0.05) decrease in adenosine triphosphate of living cells (cATP) and dehydrogenase activities. PLA enhanced redox stress and induced a series of oxidative stress reactions that were detrimental to the normal growth and metabolism of microorganisms. The relative abundance of several functional microorganisms (Nitrosomonas,Nitrospira and Ellin6067) and genes (amoA, amoB and amoC) associated with NH4+-N conversion were reduced. The potential risk of biodegradable MPs to the long-term wastewater treatment process cannot be ignored and needs to be emphasized.

Long-term exposure to PM2.5 and its constituents and visual impairment in schoolchildren: A population-based survey in Guangdong province, China.

Exposure to fine particulate matter (PM2.5) has been linked to visual impairment. Nevertheless, evidence associating PM2.5 constituents with visual impairment in schoolchildren is sparse. To explore the effects of long-term exposure to PM2.5 and its constituents on visual impairment. We conducted a large cross-sectional population-based study to recruit 59,054 schoolchildren from four cities in Guangdong province, China, and used the ChinaHighAirPollutants (CHAP) dataset to estimate 3-year average concentrations of PM2.5 and its constituents (black carbon (BC), organic matter (OM), nitrate (NO3-), sulfate (SO42-) and ammonium (NH4+)) based on individuals' home addresses. Visual acuity was measured with a standardized logarithmic chart, and visual impairment was defined as visual acuity below 4.9 (Snellen 5/6 equivalent) in at least one eye. We utilized generalized linear mixed models and weighted quantile sum regression to assess the association between PM2.5 constituents and visual impairment. The observed associations typically displayed a nonlinear pattern. Compared to the lowest quartile of PM2.5 and its constituents, the fourth quartile was associated with higher odds of visual impairment in schoolchildren (e.g., the adjusted odds ratio (OR) was 1.23 (95% CI: 1.13, 1.33) for PM2.5, 1.53 (95% CI: 1.40, 1.67) for OM, and 1.35 (95% CI: 1.27, 1.44) for BC), respectively. Similarly, joint exposure to PM2.5 constituents was associated with visual impairment (OR = 1.17, 95% CI: 1.13, 1.22), while BC and OM contributed more to the observed associations. Long-term exposure to PM2.5 and its constituents was significantly associated with higher rates of visual impairment in schoolchildren, with combustion-related BC and OM potentially driving the observed associations.

Polyherbal dentifrice: A review of literature

Overall well-being depends on one's oral health. It impacts not just our general health but also our capacity to eat; speak; and smile with assurance. Numerous systemic disorders; Poor oral health has been linked to conditions including diabetes; heart disease; and respiratory infections. Toothpaste is essential for preserving dental health. Plaque and germs are eliminated; cavities are avoided; foul breath is lessened; and gum disease is avoided. Certain toothpastes have components that can help whiten teeth and get rid of surface stains. Growing knowledge of natural components: People are looking for natural substitutes for synthetic chemicals as they become more aware of the substances in the items they consume. Concerns about chemical exposure is the Many people are concerned about the potential long-term health effects of exposure to chemicals found in conventional toothpastes. Polyherbal toothpastes; composed of a blend of natural herbs; offer a range of pharmacological activities that contribute to oral health. People are trying to replace these products with safe; affordable; and natural alternatives that have notable effects. The effectiveness of natural excipients as teeth-whitening agents was the main topic of this paper.

The Impact of Electromagnetic Field Exposure on Diabetes: A Narrative Review

Introduction: This literature review investigates the complex relationship between electromagnetic fields (EMFs) and diabetes, highlighting both therapeutic potentials and associated health risks. Emerging evidence suggests that exposure to specific types of EMFs, particularly pulsed EMFs (PEMF), may enhance insulin sensitivity and promote healing in diabetic patients. Materials and Methods: Studies have indicated significant improvements in microvascular blood flow and pancreatic function, suggesting a potential role for EMF therapy in diabetes management. Conversely, prolonged exposure to high-frequency EMFs, such as those that cell phones emanate and wireless devices, raises concerns regarding their impact on glucose metabolism. Results: A correlation was observed between chronic EMF exposure and increased insulin resistance, oxidative stress, and disruptions in hormonal balance, which can exacerbate hyperglycemia. Mechanistic insights reveal that elevated levels of reactive oxygen species (ROS) and alterations in cortisol and glucagon levels may contribute to these adverse effects. Conclusion: Despite the promising therapeutic applications of certain EMFs, the existing literature presents significant variability in methodologies, limiting the generalizability of findings. Future research should focus on large-scale, longitudinal studies that encompass diverse populations to clarify the long-term effects of EMF exposure on diabetes. This review underscores the need for a balanced approach to EMF exposure, recognizing both its potential benefits and risks for individuals with diabetes, thereby informing clinical practices and public health policies.

Histopathological alteration in Zebrafish: Unravelling the Effects of Long-Term Copper Oxide Nanoparticle Exposure

Copper Oxide nanoparticles (CuO-NPs) are widely used and they build up in the aquatic environment and can be harmful to aquatic life. Aquatic creatures are affected by CuO NPs, yet the consequences of these particles have not been well explored despite contentious toxicological results. Therefore, this study aimed to investigate the effects of chronic exposure to CuO-NPs on adult zebrafish. The study was carried out by conducting physicochemical characterization of commercially procured CuO-NPs using UV/Vis, ICP-OES spectroscopy, Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), and Fourier Transform Infrared Spectroscopy(FTIR). Following characterization, adult zebrafish were chronically exposed to 0.5, 1, and 3 mg/l of CuO-NPs. Characterization revealed a heterogeneous population of nanoparticles in the size ranges of 10–50 nm. Oxidative stress indicators and functional markers were studied in addition to tissue histology. Chronic exposure to adult Fish at concentrations of 1 and 3 mg/l exhibited increased levels of stress compared to lower concentrations of 0.5 mg/l. Observations from histology showed that the extent of tissue damage and injuries increased with the concentration of CuO-NPs. In conclusion, chronic exposure to ≤50nm-sized CuO-NPs exhibited toxic repercussions in adult zebrafish.

Facts of the main rigorous heavy metals affecting Waterfowls health, genetics, and migration habits

Swans, geese, and ducklings falling under the Anatedae group are important waterfowls to water systems. In this study, migratory birds that cover long distances are affected by some environmental stressors, especially heavy metal contamination. Al, Pb, Hg, Cd, Ni, and other similar metals are received by water structures and are natural in water, but these metals in high concentrations negatively affect the quality of water. Birds drink the polluted water and feed on polluted food, which results in the bioaccumulation of these metals in their body tissues. It leads to several diseases in body organs such as the liver, kidneys, and brain, respiratory disorders, oxidative stress, and alterations in metabolism activities. Some heavy metals known include lead and mercury, which poison the enzymes, which are crucial in the energy metabolism, hence survival. Effects of long-term exposure are DNA change, hereditary disorders, and reproductive problems such as eggshell hardness and fertility. Birds and waterfowl in particular, which may act as bioassays of the ecosystem, have experienced falls in their population because of contamination from heavy metals, which affects food chains through migration. This can only be done through concerted efforts among nations, constant monitoring of the quality of water in these habitats, and controlling water pollution with a view to preserving these birds and their habitats.

Cardiopulmonary exercise response at high altitude in patients with congenital heart disease: a systematic review and meta-analysis.

An increasing number of patients with congenital heart disease (CHD) engage in physical activities and may exercise at high altitudes (HA). The physiological adaptations required at HA and their implications on individuals with CHD, especially during exercise, remain underexplored. This systematic review aims to investigate cardiopulmonary exercise responses to short-term HA exposure in individuals with CHD. A literature search was performed across PubMed, Cochrane Library, Scopus, Embase, and SPORTDiscus. The search focused on studies comparing patients with CHD to healthy controls, specifically assessing cardiorespiratory responses during cardiopulmonary exercise testing at HA (≥2,500 m) and low altitude (LA). A meta-analysis of the differences in the main cardiorespiratory adaptations during exercise from LA to HA was performed, comparing patients with CHD and controls. Of the initial 4,500 articles, four studies met the inclusion criteria, encompassing 150 participants (74 with CHD and 76 controls). Almost all the patients with CHD had lower cardiorespiratory fitness and efficiency both at LA and HA compared to the controls. Nevertheless, the patients with CHD showed a smaller decrease in peak workload [10.61 W (95% CI: 2.33-18.88)] and peak saturation [1.22% (95% CI: 0.14-2.30)] between LA and HA compared to the controls. No participants presented exercise-induced symptoms. Short-term exposure to HA appears to be relatively well-tolerated by individuals with low-risk CHD, without a significantly different impact on cardiorespiratory response compared to healthy controls. Further research should confirm these outcomes and explore the long-term effects of higher altitude exposure as comprehensive recommendations for these patients are lacking.