Chronic Toxic Effects Research Articles

Cyanobacteria toxicity in aquaculture system and its impact on fish physiology

Algae and some Cyanobacteria, being a core part of primary production, act as a food organism for many fishes and other aquatic organisms. But they can also be responsible for fish kill or illness. Review on Cyanobacteria effect on fish growth, survival, and recruitment is the need of the hour. The mechanisms of toxicity of cyanotoxins and their toxic metabolites in fish have been scarcely covered. The effects may be sublethal on growth, physiology, survival, recruitment, and in long run, it may have a role in the fish’s adaptive response to abiotic and other biotic stressors. Around 46 species from genera of Microcystis, Cylindrospermopsis, Synechococcus, Anabaena, Lyngbya, Oscillatoria, etc. have been shown to cause toxic effects in aquatic system. The bloom of these cyanobacteria is primarily associated with altered temperature and nutrient load in water bodies due to effluents from municipal discharge and aquaculture. Their acute or chronic toxic effects may vary depending on the species, type of toxin produced, and concentration. The various cyanotoxins are grouped as hepatotoxins like microcystin, nodularin cylindrospermopsin, neurotoxins; like anatoxins, homoanatoxins, dermatotoxins; like aplysiatoxin, debromoaplysiatoxins, lyngbyatoxins, and pyrogenic component; like lipopolysaccharides (LPS). The concentration of the specific cyanotoxin in the fish body and the water along with other factors such as the length of exposure, fish metabolic processes, water parameters like dissolved oxygen and temperature, are likely to impact cyanotoxin toxicity in freshwater fish. The impact of such toxicity may be reflected on the individual species level, ecosystem level, and even at the culture system level.

Chronic effects of TiO2 and ZnO nanoparticles to earthworm Eisenia fetida

The present study focuses on the effects of TiO2 and ZnO nanoparticles to the earthworm, Eisenia fetida. Upon 48 h of exposure of earthworms to TiO2/ ZnO nanoparticles in filter paper (0.1, 1, 10, 100, 500, 1000 mg L−1), no acute toxicity was evidenced. Two soil types (sandy loam soil and clay loam soil) with different characteristics were used in the chronic toxicity study. Following 28 days of exposure to soils amended with TiO2 and ZnO nanoparticles (0.1, 1, 10, 100, 500, 1000 mg Kg-1), no significant chronic toxic effects on earthworms were observed in terms of survival, growth, and bioaccumulation. Reproduction of earthworms was only affected at the high concentrations of nanoparticles. TiO2 nanoparticles (1000 mg Kg−1) in sandy loam soil and ZnO nanoparticles (500 and 1000 mg Kg−1) in clay loam soil caused reproductive toxicity in earthworms. Our findings show that both nanoTiO2 and nano ZnO in the soil are likely to cause reproductive toxicity to earthworms at high dosages. More research on the fate and bioavailability of nanoparticles in the soil is required to understand the differences between different soils.

Radiologically Identified Morphologic Changes of Maxillary and Mandibular Bones among Diagnosed Cases of Skeletal Fluorosis in Ethiopia

In 1937, the chronic toxic effect of fluoride on skeletal fluorosis was demonstrated for the first time in history in the Indian state of Madras. Exposure to fluoride concentrations greater than eight ppm in water is reported to cause skeletal fluorosis. Skeletal fluorosis is a chronic metabolic bone disease resulting from prolonged ingestion of large amounts of fluoride. Bone knee syndrome, osteosclerosis, pathological fractures, calcification of ligaments, joint stiffness, immobility, muscle atrophy, and severe forms of neurological deficits are some of the consequences of skeletal fluorosis. Skeletal fluorosis, as such, is a highly morbid disease. Yet, the condition is overlooked, and, most importantly, little is known about its effects on the facial skeleton. This unique, investigative, crosssectional study was initiated to evaluate the morphologic changes in the jawbone caused by skeletal fluorosis in adults diagnosed with skeletal fluorosis. A two-dimensional radiograph was used to evaluate the possible skeletal fluorosis-related morphological changes in the maxillary and mandibular bones. A total of 9 patients diagnosed with skeletal fluorosis underwent panoramic radiography of the maxillary bones and mandibular. Several skeletal fluorosis-related morphological changes were detected in the jaw bones of 6 study participants, including exostosis, osteosclerosis, thickened cortical bone, narrowed bone marrow, and periosteal plaques. According to studies, these morphological changes pose a serious threat to the healing process of the bone. Therefore, surgeons practicing in the Oro-craniofacial region must be alert to potential perioperative and postoperative complications when treating patients diagnosed with skeletal fluorosis.

Host Susceptibility of CIMMYT’s International Spring Wheat Lines to Crown and Root Rot Caused by Fusarium culmorum and F. pseudograminearum

The destructive soilborne Fusarium species is one of the most serious challenges facing agriculture. Mycotoxins produced by Fusarium spp. can induce both acute and chronic toxic effects on humans and animals. Massive investments have been made in the last few decades to develop an appropriate management strategy to control Fusarium species in cereals, particularly in wheat, using genetic resistance and other practices, with varied outcomes. The purpose of this research was to find new sources of resistance to both Fusarium culmorum and F. pseudograminearum, which are wheat’s most destructive pathogens in seedlings and adult plants stages. In this study, 26 lines were selected and promoted from a total of 200 spring wheat germplasm received from CIMMYT Mexico plus 6 local check lines. The 32 lines were screened for their resistance reactions to both Fusarium species under different environmental conditions. The discriminant factorial analysis indicated that 7, 12, and 5 were resistant lines against F. culmorum under field, greenhouse, and growth room conditions, respectively. Four lines, L12, L19, L21, and L26, were found to be jointly resistant at the adult and seedling stages in the field and greenhouse. On the other hand, only moderately resistant lines were found for F. pseudograminearum but not completely resistant, which was limited to growth room conditions. Interestingly, five lines (L10, L13, L17, L25, and L28) have shown resistant properties to both Fusarium species. To further evaluate the yield performance of the best-selected 26 lines plus 6 check lines, field trials were conducted under ± F. culmorum inoculum. The highest yield values were obtained from three check lines, as well as the L26, which showed consistency in its reaction to F. culmorum under both field and greenhouse conditions, and produced a high yield (5342 kg/ha). Based on the result obtained, L26 showed a high potential to improve wheat yield and resistance to F. culmorum-caused root and crown rot; therefore, it should be used in wheat crossing programs. Having Fusarium-resistant varieties will ultimately reduce crown rot symptoms and increase grain quality by reducing mycotoxin levels.

Toxicity Profiles and Survival Outcomes Among Patients With Nonmetastatic Oropharyngeal Carcinoma Treated With Intensity-Modulated Proton Therapy vs Intensity-Modulated Radiation Therapy

Patients with oropharyngeal carcinoma (OPC) treated with radiotherapy often experience substantial toxic effects, even with modern techniques such as intensity-modulated radiation therapy (IMRT). Intensity-modulated proton therapy (IMPT) has a potential advantage over IMRT due to reduced dose to the surrounding organs at risk; however, data are scarce given the limited availability and use of IMPT. To compare toxic effects and oncologic outcomes among patients with newly diagnosed nonmetastatic OPC treated with IMPT vs IMRT with or without chemotherapy. This retrospective cohort study included patients aged 18 years or older with newly diagnosed nonmetastatic OPC who received curative-intent radiotherapy with IMPT or IMRT at a single-institution tertiary academic cancer center from January 1, 2018, to December 31, 2021, with follow-up through December 31, 2021. IMPT or IMRT with or without chemotherapy. The main outcomes were the incidence of acute and chronic (present after ≥6 months) treatment-related adverse events (AEs) and oncologic outcomes, including locoregional recurrence (LRR), progression-free survival (PFS), and overall survival (OS). Fisher exact tests and χ2 tests were used to evaluate associations between toxic effects and treatment modality (IMPT vs IMRT), and the Kaplan-Meier method was used to compare LRR, PFS, and OS between the 2 groups. The study included 292 patients with OPC (272 [93%] with human papillomavirus [HPV]-p16-positive tumors); 254 (87%) were men, 38 (13%) were women, and the median age was 64 years (IQR, 58-71 years). Fifty-eight patients (20%) were treated with IMPT, and 234 (80%) were treated with IMRT. Median follow-up was 26 months (IQR, 17-36 months). Most patients (283 [97%]) received a dose to the primary tumor of 70 Gy. Fifty-seven of the patients treated with IMPT (98%) and 215 of those treated with IMRT (92%) had HPV-p16-positive disease. There were no significant differences in 3-year OS (97% IMPT vs 91% IMRT; P = .18), PFS (82% IMPT vs 85% IMRT; P = .62), or LRR (5% IMPT vs 4% IMRT; P = .59). The incidence of acute toxic effects was significantly higher for IMRT compared with IMPT for oral pain of grade 2 or greater (42 [72%] IMPT vs 217 [93%] IMRT; P < .001), xerostomia of grade 2 or greater (12 [21%] IMPT vs 68 [29%] IMRT; P < .001), dysgeusia of grade 2 or greater (16 [28%] IMPT vs 134 [57%] IMRT; P < .001), grade 3 dysphagia (4 [7%] IMPT vs 29 [12%] IMRT; P < .001), mucositis of grade 3 or greater (10 [53%] IMPT vs 13 [70%] IMRT; P = .003), nausea of grade 2 or greater (0 [0%] IMPT vs 18 [8%] IMRT; P = .04), and weight loss of grade 2 or greater (22 [37%] IMPT vs 138 [59%] IMRT; P < .001). There were no significant differences in chronic toxic effects of grade 3 or greater, although there was a significant difference for chronic xerostomia of grade 2 or greater (6 IMPT [11%] vs 22 IMRT [10%]; P < .001). Four patients receiving IMRT (2%) vs 0 receiving IMPT had a percutaneous endoscopic gastrostomy tube for longer than 6 months. In this study, curative-intent radiotherapy with IMPT for nonmetastatic OPC was associated with a significantly reduced acute toxicity burden compared with IMRT, with few chronic toxic effects and favorable oncologic outcomes, including locoregional recurrence of only 5% at 2 years. Prospective randomized clinical trials comparing these 2 technologies and of patient-reported outcomes are warranted.

Sorption behaviour and toxicity of an herbicide safener “cyprosulfamide”

Cyprosulfamide is a herbicide safener that works against the injurious effects of herbicides such as isoxaflutole, dicamba, nicosulfuron, tembotrione, thiencarbazone-methyl. However, its sorption behaviour in soils and toxicity to aquatic organisms are yet to be thoroughly examined. This study determined the octanol-water partition coefficient, sorption properties, acute and chronic toxic effects, and potency of cyprosulfamide to the cladoceran water flea (Daphnia magna). The influence of soil properties such as organic carbon content, cation exchange capacity, pH, and field capacity on adsorption and desorption properties were also examined. The Log Kow (0.55) of cyprosulfamide was less than that of some other safeners, such as benoxacor or furilazole, found in aquatic environments. The sorption of cyprosulfamide to the soil was driven by pH, so sorption decreased with an increase in pH. Other characteristics, such as cation exchange capacity (CEC), organic carbon content, and field capacity, do not directly correlate with the distribution coefficient. Cyprosulfamide generally has a low affinity for soil and is thus mobile and prone to transport to surrounding surface waters. No lethality was observed at the highest concentration (120 mg/L) tested for acute toxicity to D. magna; hence the LC50 will be >120 mg/L. During chronic exposures, cyprosulfamide caused adverse effects at a concentration of 120 mg/L on the number of neonates and brood size. The death rate for the chronic study was a function of concentration and increased with days of exposure. Cyprosulfamide is unlikely to cause lethality to D. magna at relevant environmental concentrations.

Bi-etched MIL-125 promotes visible-light-driven photocatalytic performance based on the surface plasmon resonance and spatial confinement effects

Constructing stable, efficient, and affordable visible-light-driven catalysts is a promising technique to remediate water pollution from released antibiotics. In this research, etched Bi@MIL-125 composites were manufactured using a simple hydrothermal method, and their photocatalytic efficacy was tested using tetracycline (TC) as the target contaminant. Morphological analyses indicated that Bi nanoparticles (NPs) were consistently wrapped around the MIL-125 surface, introducing mesoporous structures in MIL-125 by Bi etching. Among different mass ratios (Bi: MIL-125), the Bi@MIL-125 sample with a 1:1 mass ratio (BM100) showed the greatest photodegradation rate (98.6 %) of TC upon visible light illumination. The BM100 exhibited the greatest apparent deterioration rate constant for TC (0.036 min−1), 74 times higher than that of pristine MIL-125. The absorption enhancement of Bi@MIL-125 in the visible range was ascribed to the surface plasmon resonance effect of Bi NPs. The mesoporous structure of Bi@MIL-125 provided channels through which TC entered the composite's interior, and the confined space enabled more opportunities for the interaction of •O2– and h+ active species and TC pollutant molecules. In addition, liquid chromatography-tandem mass spectrometry was used to determine potential intermediates of the photodegradation reaction of TC and BM100, and two distinct degradation routes were hypothesized. Ultimately, combining ECOSAR predictions with zebrafish behavioral tests to assess the toxicity changes in degradation processes and the acute and chronic toxic effects on aquatic animals, the inhibition of the locomotive behavior of zebrafish was significantly decreased after 120 min of photocatalytic degradation, suggesting that the BM100 sample can effectively degrade TC and detoxify the aquatic environment.

Hyperspectral imagery reveals large spatial variations of heavy metal content in agricultural soil - A case study of remote-sensing inversion based on Orbita Hyperspectral Satellites (OHS) imagery

The widespread heavy metal contamination in soil induced by extensive human disturbance has been a global significant issue because of its chronic toxic effects on human health. However, the establishment of effective monitoring and assessing methods for heavy metal content in the soil remain a long-term challenge due to the intrinsic limitation of the current multi-band remote sensing technology and field measurement methods. Prompted by this significant technique gap, we represent an implementation of remote-sensing inversion models based on hyperspectral imagery to reconstruct soil heavy metal contents within an experimental farmland located in Mianzhu city, Sichuan, China. We collected soil samples at the pre-defined sites, and measured soil heavy metal contents and soil spectrum in the laboratory condition. Meanwhile, we obtained Orbita Hyperspectral Satellites (OHS) imagery and quantified the associated vegetation indexes. The measured soil spectrum, bands of OHS, and the generated vegetation indexes were mathematically transformed to better represent their relations with soil heavy metal contents. Consequently, the most sensitive variables were selected as potent predictors of soil heavy metal contents in the inversion models. After evaluating the optimal inversion models for each heavy metal element, we implemented them to reconstruct the spatial patterns of soil heavy metal contents over the study landscape. We found obvious benefits of the remote sensing inversion model in predicting the spatial heterogeneity of heavy metal content within this small landscape patch. Specifically, the inversion model unraveled a normal distribution of heavy metal contents within the landscape, while the traditional spatial interpolation based on field measurements may suggest a largely skewed distribution. Compared with airborne-based studies, this study represents an application of spaceborne satellite data, which can be easily applied to a large spatial scale and long-term monitoring.

TOXICOLOGICAL ASSESSMENT OF FOOD ADDITIVES BY BIOASSAY

The paper is devoted to the study of the toxicity levels of food additives by bioassay using Daphnia magna as model organisms. The directions and methods of research have been described. The toxicity of most food additives has been determined for the maximum permissible concentrations. The following widely used food additives have been tested: tartrazine (E102), sunset yellow (E110), azorubine (E122), Ponceau 4R (E124), indigo carmine (E132), brilliant blue (E133), sorbic acid (E200), potassium sorbate (E202), benzoic acid (E210), sodium benzoate (E211), formaldehyde (E240), sodium nitrite (E250), boric acid (E284), sodium isoscorbate (E316), citric acid (E330), phosphate Biophos 90 (E339), guar gum (E412), glycerol (E422), copper sulphate (E519), aspartame (E951), saccharin (E954). It has been proposed that the concentrations present in food products be used for bioassay of the additives Sodium Isoascorbate E316, Citric acid E330, Guar gum E412, Glycerol E422, the maximum concentrations of which are not prescribed in the Sanitary Rules and Regulations. The paper determines the acute and chronic toxic effects that each food additive under study produces on Daphnia magna. For tartrazine E102, sunset yellow E110, Ponceau 4R E124, and copper sulphate E519, no acute toxic impact was recorded, since the mortality of the model organisms did not exceed 25%. A synergistic effect of the use of popular combinations of food additives in various products has been revealed, namely that of: benzoic acid E210 and sorbic acid E200, sodium benzoate E211 and potassium sorbate E202, sodium nitrite E250 and sodium phosphate E339. The combination that caused the greatest lethality (more than 75%) during the bioassay was that of the additives E211 and E202. It has been established that all combinations of these food additives produce the greatest toxic effect, as compared with the toxic effect of individual additives. Further research in this direction has been proposed. The research results determine the need to reduce the maximum permissible levels of food additives that are currently in effect.

Based on 16 S rRNA sequencing and metabonomics to reveal the new mechanism of aluminum potassium sulfate induced inflammation and abnormal lipid metabolism in mice

More and more discoveries have been made about the chronic toxic effects of aluminum, but the specific mechanism of action remains unclear. In this study, we explored the perturbation of aluminum on intestinal microflora and its effects on host and microbial metabolites through a more realistic nutrient absorption model. The microorganisms Turicibacter, Lactobacillus murinus, Lactobacillus_reuteri and Bifidobacterium pseudolongum may be the main targets of the aluminum affecting microbiota. Lysine, proline, putrescine, serotonin and cholesterol may be important metabolites affected by aluminum ions after the interference of intestinal flora composition, leading to abnormal metabolism pathways of amino acids and lipids in the body, and thus promoting inflammation and lesion. The possible mechanisms of aluminum action on the body: (1) Affecting immune cell response, ROS generation and production of a series of pro-inflammatory factors to promote inflammation; (2) Through the disturbance of intestinal microbiota composition structure, change the abundance of metabolites, and then affect amino acid metabolism, lipid metabolism pathways. The joint analysis of multiple omics showed significant difference in microbiome abundance and metabolomics expression between high dose group and the control group.

Low Concentration of Rotenone Impairs Membrane Function of Spodoptera litura Cells by Promoting Their Aggregation

Rotenone is a widely used botanical insecticide, which can inhibit the mitochondrial respiratory chain of various insect cells, while the mechanism of its toxicity to insect cells needs further investigation. The purpose of this study was to understand the toxicity level of low (0.2 µg/mL) and high (20 µg/mL) concentrations of rotenone in Spodoptera litura cells (SL-1) using trypan blue and Coomassie brilliant blue staining assays. Our study found that rotenone possessed cytotoxicity against SL-1 cells with varying effects of action between high and low concentrations. After low-concentration rotenone treatment, the SL-1 cells showed obvious aggregation time-dependently, with the fastest aggregation rate observed under the first 8 h of treatment time, but no such phenomenon was observed at high concentration. Furthermore, this aggregation phenomenon caused SL-1 cells to squeeze each other and led to the destruction of the cell membrane structure and function. Taken together, the results suggested that treatment with a low concentration of rotenone exhibited a chronic toxic effect that was significantly different from treatment with a high concentration of rotenone, which provides new insight into the cytotoxic mechanism of rotenone.

Chronic toxic effects of isoflucypram on reproduction and intestinal energy metabolism in zebrafish (Danio rerio)

The intestine is a vital organ involved in chemical and nutrient uptake and biotransformation. Intestinal dysfunction can impair energy and material supply for reproduction. Isoflucypram, a new succinate dehydrogenase inhibitor fungicide, is highly toxic to aquatic systems. However, the chronic toxic effects of isoflucypram on intestinal differentiation in aquatic organisms remain unknown. In this study, zebrafish (F0, 4-month-old) were exposed to 0, 0.008, or 0.08 μM isoflucypram for 120 days. After 90 days of exposure, F0 generations of adult zebrafish were paired, and the corresponding F1 generation embryos were obtained and observed. After 120 days of exposure, the gut of F0 generation zebrafish was collected, and intestinal histopathology and mitochondrial morphology were analyzed. Exposure to 0.08 μM isoflucypram resulted in significant death, hatching delay, and malformation (blood clot clustering, pericardial edema, and microphthalmia) of F1 embryos and larvae. Exposure to isoflucypram caused irregular and swollen villi in the zebrafish gut, accompanied by alterations in the intestinal mitochondrial ultrastructure. In addition, the differentially expressed genes involved in mitochondrial energy metabolism were significantly enriched. Overall, our data suggest that chronic exposure to isoflucypram is associated with reproductive and intestinal dysfunction in adult zebrafish.

Influence of acid-base equilibria on the rate of the chemical reaction in the advanced oxidation processes: Coumarin derivatives and hydroxyl radical

The decomposition and chemical manipulation of stable aromatic pollutants into less toxic products is an important topic for wastewater management and natural water remediation. The mechanism of the Advanced Oxidation Process (AOPs) of 4,7-dihydroxycoumarin (4,7-DHC) and 7-hydroxycoumarin (7-HC), as examples of stable naturally-occurring industrially-important compounds, in the presence of hydroxyl radical (HO) in the aqueous solution has been analyzed using Electron Paramagnetic Resonance spectroscopy (EPR) and Quantum Mechanics-based test for Overall Free Radical Scavenging Activity (QM-ORSA). The effect of pH values of the medium on the investigated reaction mechanisms has been fully investigated. The rate constants were estimated by the conventional transition state theory (TST) and Eckart's method (ZCT_0). Estimated values of the overall rate constant (koverall) higher than >4.06 × 109 M−1 s−1 at all pH values showed that both compounds undergo a chemical transformation when exposed to HO. When pH increased in the range of 0–14, the koverall increased from 4.06 × 109 to 1.11 × 1010 (4.7-DHC) and 2.09 × 109 to 1.76 × 1010 M−1s−1 (7-HC). At physiological pH = 7.4 value, 7-HC was ∼1.5 times more prone to radical action, as shown by EPR and QM-ORSA, due to the dominant anionic form. Both compounds were more reactive towards HO than Trolox at this pH value. The ecotoxicity assessment of the starting compounds, intermediates and oxidation products indicated that the formed products show lower acute and chronic toxicity effects on aquatic organisms than starting compounds, which is a prerequisite for the development of novel AOPs procedures.

Countrywide Spatial Variation of Potentially Toxic Element Contamination in Soils of Turkey and Assessment of Population Health Risks for Nondietary Ingestion.

Countrywide surface soil concentrations of potentially toxic elements (PTEs) in Turkey were reviewed in the Web of Science database. A total of 93 papers were investigated to compose a PTE dataset for determining spatial variations and estimating exposure and health risks. Al, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn were selected as PTEs in surface soil. A compiled PTE concentration dataset was used to estimate chronic toxic risks (CTRs) and carcinogenic risks (CRs) according to the deterministic and probabilistic approaches. While the CTR and CR levels of age and sex groups were estimated using a deterministic approach, population risks were estimated using a probabilistic approach. CTR and CR levels in lower age groups and female sex groups were estimated to be higher than those in higher age groups and associated male sex groups. The average CTR levels of the nondietary ingestion of As-containing soil in <11 year age groups were near/just above the threshold level, while As-associated average CR levels of adults and other age groups were estimated to be in the acceptable risk range (10–6 < CR < 10–5) and low priority risk range (10–5 < CR < 10–4), respectively. As-, Cr(VI)-, and Pb-associated upper-bound CR levels of the Turkish population were simulated to be 5.14 × 10–4, 6.23 × 10–5, and 2.34 × 10–6, respectively. Health risk models show the significance of As in both chronic toxic and carcinogenic effects.

The effect of temperature on toxicokinetics and the chronic toxicity of insecticides towards Gammarus pulex

A comprehensive understanding of chemical toxicity and temperature interaction is essential to improve ecological risk assessment under climate change. However, there is only limited knowledge about the effect of temperature on the toxicity of chemicals. To fill this knowledge gap and to improve our mechanistic understanding of the influence of temperature, the current study explored toxicokinetics and the chronic toxicity effects of two insecticides, imidacloprid (IMI) and flupyradifurone (FPF), on Gammarus pulex at different temperatures (7–24 °C). In the toxicokinetics tests, organisms were exposed to IMI or FPF for 2 days and then transferred to clean water for 3 days of elimination at 7, 18, or 24 °C. In the chronic tests, organisms were exposed to the individual insecticides for 28 days at 7, 11, or 15 °C. Our research found that temperature impacted the toxicokinetics and the chronic toxicity of both IMI and FPF, while the extent of such impact differed for each insecticide. For IMI, the uptake rate and biotransformation rate increased with temperature, and mortality and food consumption inhibition was enhanced by temperature. While for FPF, the elimination rate increased with temperature at a higher rate than the increasing uptake rate, resulting in a smaller pronounced effect of temperature on mortality compared to IMI. In addition, the adverse effects of the insecticides on sublethal endpoints (food consumption and dry weight) were exacerbated by elevated temperatures. Our results highlight the importance of including temperature in the ecological risk assessment of insecticides in light of global climate change.

Transfer of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) from oral exposure into cow's milk - Part I: state of knowledge and uncertainties.

Polychlorinated dibenzo-para-dioxins (PCDDs) and dibenzofurans (PCDFs) (collectively and colloquially referred to as 'dioxins') as well as polychlorinated biphenyls (PCBs) are persistent and ubiquitous environmental contaminants that may unintentionally enter and accumulate along the food chain. Owing to their chronic toxic effects in humans and bioaccumulative properties, their presence in feed and food requires particular attention. One important exposure pathway for consumers is consumption of milk and dairy products. Their transfer from feed to milk has been studied for the past 50 years to quantify the uptake and elimination kinetics. We extracted transfer parameters (transfer rate, transfer factor, biotransfer factor and elimination half-lives) in a machine-readable format from seventy-six primary and twenty-nine secondary literature items. Kinetic data for some toxicologically relevant dioxin congeners and the elimination half-lives of dioxin-like PCBs are still not available. A well-defined selection of transfer parameters from literature was statistically analysed and shown to display high variability. To understand this variability, we discuss the data with an emphasis on influencing factors, such as experimental conditions, cow performance parameters and metabolic state. While no universal interpretation could be derived, a tendency for increased transfer into milk is apparently connected to an increase in milk yield and milk fat yield as well as during times of body fat mobilisation, for example during the negative energy balance after calving. Over the past decades, milk yield has increased to over 40 kg/d during high lactation, so more research is needed on how this impacts feed to food transfer for PCDD/Fs and PCBs.

Polystyrene microplastic particles in combination with pesticides and antiviral drugs: Toxicity and genotoxicity in Ceriodaphnia dubia

Freshwater ecosystems are recognized as non-negligible sources of plastic contamination for the marine environment that is the final acceptor of 53 thousand tons of plastic per year.In this context, microplastic particles are well known to directly pose a great threat to freshwater organisms, they also indirectly affect the aquatic ecosystem by adsorbing and acting as a vector for the transport of other pollutants (“Trojan horse effect”). Polystyrene is one of the most widely produced plastics on a global scale, and it is among the most abundant microplastic particles found in freshwaters. Nevertheless, to date few studies have focused on the eco-genotoxic effects on freshwater organisms caused by polystyrene microplastic particles (PS-MPs) in combination with other pollutants such as pharmaceuticals and pesticides.The aim of this study is to investigate chronic and sub-chronic effects of the microplastic polystyrene beads (PS-MP, 1.0 μm) both as individual xenobiotic and in combination (binary/ternary mixtures) with the acicloguanosine antiviral drug acyclovir (AC), and the neonicotinoid broad-spectrum insecticide imidacloprid (IMD) in one of the most sensitive non-target organisms of the freshwater food chain: the cladoceran crustacean Ceriodaphnia dubia. Considering that the individually selected xenobiotics have different modes of action and/or different biological sites, the Bliss independence was used as reference model for this research. Basically, when C. dubia neonates were exposed for 24 h to the mixtures during Comet assay, mostly an antagonistic genotoxic effect was observed. When neonates were exposed to the mixtures for 7 days, mostly an additive chronic toxic effect occurred at concentrations very close or even overlapping to the environmental ones ranging from units to tens of ng/L for PS-MPs, from tenths/hundredths to units of μg/L for AC and from units to hundreds of μg/L for IMD, revealing great environmental concern.

Real-time PCR, and Recombinase Polymerase Amplification combined with SYBR Green I for naked-eye detection, along with Propidium Monoazide (PMA) for the detection of viable patulin-producing fungi in apples and by-products

Nowadays, the application of rapid molecular-based methods such as PCR/qPCR and isothermal techniques like Recombinase Polymerase Amplification (RPA), has increased in order to overcome some of the drawbacks of traditional culture-based methods due to their high sensitivity and specificity. One of the main limitations of these techniques is their inability to differentiate between live and dead microorganisms. Patulin is a mycotoxin typically produced by fungi belonging to Penicillium spp. that exerts acute and chronic toxic effects to humans and animals. In the present study, one real-time PCR assay, and a RPA coupled with SYBR Green I for naked-eye detection, were developed for the detection of patulin-producing fungi. Primers and a probe were designed based on the idh gene of the patulin metabolic pathway. Furthermore, propidium monoazide was implemented in the DNA extraction protocol for the specific detection of viable fungi. The developed assays were able to detect down to 1.25 pg/μL (qPCR) and 23.8 pg/μL (RPA-SG) of pure P. expansum DNA. Finally, when artificially inoculated apples, and by-products, were analysed the LOD50 of the qPCR was found to be 8.1 × 103 spores/5 g of food sample. In the case of the RPA-SG, the determined LOD50 was 5.8 × 104 spores/5 g.

Acute and Chronic Toxicity Effects of the Heptachlor Pesticide on Tilapia (Oreochromis mossambicus): Impact to Behavioral Patterns and Histopathological Responses

Manimekalai, D.; Srinivasan, A.; Padmavathy, P.; Jawahar, P.; George, R., and Arisekar, U., 2022. Acute and chronic toxicity effects of the heptachlor pesticide on tilapia (Oreochromis mossambicus): Impact to behavioral patterns and histopathological responses. Journal of Coastal Research, 38(5), 999–1010. Coconut Creek (Florida), ISSN 0749-0208. Heptachlor is an organochlorine (cyclodiene) insecticide that enters water bodies and affects aquatic organisms such as fishes and shellfishes. Due to its persistent nature, it spreads from the source of its use and pollutes the area. The toxic effect of heptachlor on histopathological changes in the gill, liver, kidney, and muscles of tilapia Oreochromis mossambicus were studied. The experimental fish were exposed to four concentrations of heptachlor, viz., 0.756, 1.513, 3.025, and 6.050 ppm, for a period of 96 hours during an acute toxicity test. In the current study, the lethal concentration (LC50) value of heptachlor on tilapia at 96 hours was calculated as 4.006 ppm. Fish were subjected to three different concentrations of heptachlor (0.2003, 0.4006, and 0.8012 ppm) based on the LC50 value to study the long-term effect of heptachlor. Histological changes such as lamellar fusion, lamellar cell hyperplasia, degenerated secondary gill lamellae; Bowman's space dilation and renal tubules detachment; hepatic cells death, melanomacrophage formation, and multifocal degeneration of myocytes; and myoepithelium vacuolation were observed in the gill, kidney, liver, and muscles, respectively, during acute and chronic exposure to heptachlor. The toxicity study revealed that the heptachlor pesticide is highly toxic to tilapia even at a minimum concentration of 0.756 ppm. Hence, it is suggested that care must be taken not to allow the entry of pesticides into the habitat of fishes.

Organophosphate-induced inhibition of acetylcholinesterase, oxidative stress and neuroinflammation

Organophosphate (OP) neurotoxicants exert their toxicity by inhibiting acetylcholinesterase. Overstimulation of cholinergic receptors can rapidly lead to neuronal damage, seizures, death, and long-term neurological damage in survivors. This review summarizes the mechanisms by which OP agents inhibit acetylcholinesterase action and lead to pathological acetylcholine overload in vivo, with attention to the effects of chronic and low-dose toxicity. Importantly, the massive accumulation of ROS during oxidative stress caused by OP agents are found to widely present in all toxic reactions. Moreover, OP agents can cause the release of pro-inflammatory cytokines from astrocytes, microglia, and increase the levels of prostaglandins and is prostaglandins, leading to neuroinflammation. A comprehensive understanding of the mechanisms of op-agents could help develop rational therapeutic approaches to treat toxicant exposure. However, current treatment for organophosphorus agent poisoning is relatively limited. Further research on the mechanisms of neurotoxicity is required to find ways to detoxify and treat organophosphorus agents.