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The aim of this study was to investigate the genotoxic potential of low doses of chlorpyrifos (CPF) on blood and bone marrow cells in adult male Wistar rats. CPF was administered by oral gavage at daily doses of 0.010, 0.015, and 0.160 mg/kg of body weight (bw) for 28 consecutive days. Positive control (PC) was administered 300 mg/kg bw/day of ethyl methane sulphonate (EMS) for the final three days of the experiment. Toxic outcomes of exposure were determined with the in vivo micronucleus (MN) assay and alkaline comet assay. The 28-day exposure to the 0.015 mg/kg CPF dose, which was three times higher than the current value of acute reference dose (ARfD), reduced body weight gain in rats the most. The in vivo MN assay showed significant differences in number of reticulocytes per 1000 erythrocytes between PC and negative control (NC) and between all control groups and the groups exposed to 0.015 and 0.160 mg/kg bw/day of CPF. The number of micronucleated polychromatic erythrocytes per 2000 erythrocytes was significantly higher in the PC than the NC group or group exposed to 0.015 mg/kg bw/day of CPF. CPF treatment did not significantly increase primary DNA damage in bone marrow cells compared to the NC group. However, the damage in bone marrow cells of CPF-exposed rats was much higher than the one recorded in leukocytes, established in the previous research. Both assays proved to be successful for the assessment of CPFinduced genome instability in Wistar rats. However, the exact mechanisms of damage have to be further investigated and confirmed by other, more sensitive methods.

Ochratoxin A (OTA) and citrinin (CTN) are nephrotoxic mycotoxins often found together in grain. The aim of this study was to measure their accumulation in the kidney and liver of adult male Wistar rats, see how it would be affected by combined treatment, and to determine if resveratrol (RSV) would decrease their levels in these organs. The rats received 125 or 250 mg/kg bw of OTA by gavage every day for 21 days and/or 20 mg/kg bw of CTN a day for two days. Two groups of rats treated with OTA+CTN were also receiving 20 mg/kg bw of RSV a day for 21 days. In animals receiving OTA alone, its accumulation in both organs was dose-dependent. OTA+CTN treatment resulted in lower OTA but higher CTN accumulation in both organs at both OTA doses. RSV treatment increased OTA levels in the kidney and liver and decreased CTN levels in the kidney. Our findings point to the competition between CTN and OTA for organic anion transporters 1 and 3.

Manufacture of lead-containing products has long been associated with various health risks. To get an insight into the related genotoxic risks, we conducted a biomonitoring study in 50 exposed workers and 48 matched controls using a battery of endpoints that sensitively detect the extent of genome instability in peripheral blood lymphocytes. The levels of primary DNA damage were estimated with the alkaline comet assay, while cytogenetic abnormalities were determined with the cytokinesis-block micronucleus (CBMN) cytome assay. Additionally, CBMN slides of 20 exposed and 16 control participants were subjected to fluorescence in situ hybridisation (FISH), coupled with pancentromeric probes to establish the incidence of centromere-positive micronuclei, nuclear buds, and nucleoplasmic bridges. Blood lead levels (B-Pb) were measured with atomic absorption spectrometry. To further characterise cumulative effects of occupational exposure, we measured erythrocyte protoporphyrin (EP) concentrations and delta-aminolevulinic acid dehydratase (ALAD) activity in blood. We also assessed the influence of serum folate (S-folate) and vitamin B12 (S-B12) on genome stability. Compared to controls, occupationally exposed workers demonstrated significantly higher B-Pb (298.36±162.07 vs 41.58±23.02), MN frequency (18.71±11.06 vs 8.98±7.50), centromere positive MN (C+ MN) (8.15±1.8 vs 3.69±0.47), and centromere negative MN (C- MN) (14.55±1.80 vs 4.56±0.89). Exposed women had significantly higher comet tail intensity (TI) and length (TL) than control women. Furthermore, workers showed a positive correlation between age and nuclear buds and MN, between MN and years of exposure, and between S-B12 levels and TI and ALAD activity, while a negative correlation was found between TI and B-Pb. These findings suggest that occupational settings in the manufacture of lead-containing products pose significant genotoxic risks, which calls for developing more effective work safety programmes, including periodical monitoring of B-Pb and genetic endpoints.

Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety of a feed additive consisting of vitamin B 2 /riboflavin produced with Eremothecium ashbyi CCTCCM 2019833 intended for use as a nutritional additive (functional group: vitamins, pro-vitamins and chemically well-defined substances having similar effects) for all animal species. The characterisation, safety and efficacy of the additive have been already assessed previously; however, the FEEDAP Panel could not conclude on the safety of the additive for the target species, consumers and the users due to lack of reliable toxicological data. In the present assessment, the applicant submitted new genotoxicity and repeated dose oral toxicity studies. After the assessment of the data newly submitted, the FEEDAP Panel concluded that the use of the feed additive in animal nutrition under the conditions of use proposed is of no safety concern for the target species and the consumer. The additive is not a skin/eye irritant nor a skin sensitiser, but it is considered a respiratory sensitiser., (© 2024 European Food Safety Authority. EFSA Journal published by Wiley‐VCH GmbH on behalf of European Food Safety Authority.)

Green agronomy promotes the implementation of natural and naturally derived substances in crop protection. In the present study, we evaluated the endocrine-disrupting potential of the allelopathic herbicide tembotrione in Wistar rats by studying the hormone status of offspring from the treated dams. Three doses of tembotrione (0.0004, 0.0007, and 4.0 mg/kg b.w./day) have been administered to dams during gestation and/or lactation. In the serum of newborn, weaning, and pubertal female and male offspring, 17β-estradiol and testosterone were determined using enzyme-linked immunosorbent assay. A decrease in 17β-estradiol and testosterone was observed in female and male weaning and pubertal offspring exposed to all doses of tembotrione during gestation and lactation. In weaning offspring exposed only during lactation, 17β-estradiol dropped significantly after exposure to the two lower doses and testosterone after exposure to the lowest dose of tembotrione. The greatest effect was observed at the lowest dose of tembotrione. In newborns, we observed increased 17β-estradiol after exposure to two lower doses of tembotrione and significantly increased testosterone after exposure to the lowest dose. The highest dose of tembotrione decreased 17β-estradiol significantly in newborn females. The obtained results suggest that tembotrione might be considered a pro-estrogenic or estrogen agonistic compound under the exposure conditions applied in this investigation.

The aim of this paper was to evaluate whether symbiotic cooperation between green hydra (Hydra viridissima) and photoautotrophic alga gives higher resistance of the preservation of DNA integrity compared to brown hydra (Hydra oligactis). Norflurazon concentrations were 0.061 or 0.61 mg/L and UV-B light 254 nm, 0.023mWcm - 2 applied separately or simultaneously. By alkaline comet assay primary DNA damage was assessed and cytotoxicity by fluorescent staining. Norflurazon at 0.61 mg L - 1 significantly increased DNA damage in brown hydras compared to the control (6.17 ± 0.6 μm, 5.2 ± 1.7% vs. 2.9 ± 0.2 μm, 1.2 ± 0.2%). Cytotoxicity was significantly elevated, being higher in brown hydras (25.7 ± 3.5% vs. 8.2 ± 0.2%). UV-B irradiation induced significant DNA damage in brown hydras (13.5 ± 1.0 μm, 4.1 ± 1.0%). Simultaneous exposure to UV-B and norflurazon led to a synergistic DNA damaging. The frequency of cytotoxicity and hedgehog nucleoids was more pronounced in brown (78.3 ± 9.4%; 56.4 ± 6.0%) than in green hydras (34.7 ± 2.5%; 24.2 ± 0.6%). Evolutionary established symbiotic cooperation proved to provide resistance against cyto/genotoxicity., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

To contribute new information to the pyrethroid pesticide α-cypermethrin toxicity profile, we evaluated its effects after oral administration to Wistar rats at daily doses of 2.186, 0.015, 0.157, and 0.786 mg/kg bw for 28 days. Evaluations were performed using markers of oxidative stress, cholinesterase (ChE) activities, and levels of primary DNA damage in plasma/whole blood and liver, kidney, and brain tissue. Consecutive exposure to α-cypermethrin affected the kidney, liver, and brain weight of rats. A significant increase in concentration of the thiobarbituric acid reactive species was observed in the brain, accompanied by a significant increase in glutathione peroxidase (GPx) activity. An increase in GPx activity was also observed in the liver of all α-cypermethrin-treated groups, while GPx activity in the blood was significantly lower than in controls. A decrease in ChE activities was observed in the kidney and liver. Treatment with α-cypermethrin induced DNA damage in the studied cell types at almost all of the applied doses, indicating the highest susceptibility in the brain. The present study showed that, even at very low doses, exposure to α-cypermethrin exerts genotoxic effects and sets in motion the antioxidative mechanisms of cell defense, indicating the potential hazards posed by this insecticide.

This paper assessed the potential of trans-placental and -lactational genotoxicity and oxidative stress induction of tembotrione, a naturally derived allelopathic herbicide. Several treatment protocols were applied to measure primary DNA damage by alkaline comet assay in leucocytes and liver. To address the oxidative stress induction, TBARS, ROS, SOD, CA, GSH-Px activity were recorded. The dams were treated from the first gestation day and pups sacrificed after birth. The second treatment protocol comprised treating the dams during gestation and lactation and sacrificing the pups at weaning. The third group of pups comprised offspring of dams that were treated in gestation and lactation and sacrificed in puberty. To address translactational genotoxicity, dams were treated in lactation only. Dams treated in gestation and lactation were sacrificed after reentering the estrous cycle and analyzed for DNA damage and oxidative stress. Tembotrione doses encountered in everyday human exposure, as estimated by the EFSA, were applied in dam treatment in consecutive days (ADI: 0.0004 mg/kg b.w./day, AOEL: 0.0007 mg/kg b.w./day, 1/500 LD 50 4.0 mg/kg b.w./day). Although we observed mitigated DNA integrity at the dose of 4.0 mg/kg/b.w./day in female pubertal rats, we can conclude that at the conditions employed in the study low doses of tembotrione do not pose a risk for DNA damage of the offspring of treated dams. Contrary to this, the highest dose significantly affected all the oxidative stress parameters in the liver and plasma of pubertal females, CAT and GSH-Px in the liver of males and ROS and CAT of dams., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The aim of this cross-sectional study was to investigate the occurrence of chromosomal abnormalities through the frequency of micronuclei and other genomic damage markers in patients with chronic generalized periodontitis and without periodontal disease. Micronucleus assay was performed in exfoliated gingival epithelial cells of 35 patients with generalized chronic periodontitis and 30 control subjects with healthy periodontium. Full mouth clinical examination was performed to define periodontal condition. The mean number of cells with micronuclei observed in chronic periodontitis and control groups was 1.8 (±1.49) and 2.0 (±1.34), respectively. Differences between the groups were not significant (p=0.574). Compared to control subjects, patients with chronic periodontitis showed a significant increase in the number of binucleated cells (p≤0.001) and number of cells with nucleoplasmic bridges (p=0.042). Study results indicated that chronic periodontitis was not associated with higher occurrence of chromosomal damage in gingival cells compared to individuals with healthy periodontium.

Imidacloprid is a neonicotinoid insecticide that acts selectively as an agonist on insect nicotinic acetylcholine receptors. It is used for crop protection worldwide, as well as for non-agricultural uses. Imidacloprid systemic accumulation in food is an important source of imidacloprid exposure. Due to the undisputable need for investigations of imidacloprid toxicity in non-target species, we evaluated the effects of a 28-day oral exposure to low doses of imidacloprid (0.06 mg/kg b. w./day, 0.8 mg/kg b. w./day and 2.25 mg/kg b. w./day) on cholinesterase activity, oxidative stress responses and primary DNA damage in the blood and brain tissue of male Wistar rats. Exposure to imidacloprid did not cause significant changes in total cholinesterase, acetylcholinesterase and butyrylcholinesterase activities in plasma and brain tissue. Reactive oxygen species levels and lipid peroxidation increased significantly in the plasma of rats treated with the lowest dose of imidacloprid. Activities of glutathione-peroxidase in plasma and brain and superoxide dismutase in erythrocytes increased significantly at the highest applied dose. High performance liquid chromatography with UV diode array detector revealed the presence of imidacloprid in the plasma of all the treated animals and in the brain of the animals treated with the two higher doses. The alkaline comet assay results showed significant peripheral blood leukocyte damage at the lowest dose of imidacloprid and dose-dependent brain cell DNA damage. Oral 28-day exposure to low doses of imidacloprid in rats resulted in detectable levels of imidacloprid in plasma and brain tissue that directly induced DNA damage, particularly in brain tissue, with slight changes in plasma oxidative stress parameters., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Aim: The main purpose of this study was to assess the genotoxic and cytotoxic effect of fissure sealants on buccal epithelial cells., Material and Methods: The study was conducted on 45 patients (27 girls and 18 boys), seven to 16 years of age (age mean 12.09 ± 2.20). Buccal swabs were collected before (T0), seven (T1), 30 (T2) and 90 days (T3) consequently after fissure sealant placement (Helioseal F®, Equia Fil®, Constic®). Patients or legal guardians filled in the questionnaire regarding the demographic data (age, gender), dietary habits, health status, medication usage, and recent X-ray exposure. DNA damage was analyzed using the micronucleus test., Results: Statistically significant difference in the number of buccal cells with condensed chromatin was found between T0 (time before fissure sealant placement) and T3 (90 days after fissure sealant placement) period for Helioseal F® (P = 0.025). For the other two analyzed materials, no difference was observed during the tested period. There was no difference between materials in the same sampling time., Conclusion: Apart from an increase in cells with condensed chromatin 90 days after the placement of Helioseal F®, no other nuclear abnormalities were observed for tested fissure sealants. Although these sealants have now largely been used, it is of high importance that their biocompatibility is checked continuously, especially in in vivo clinical studies., Competing Interests: Conflict of interest: The authors declare no conflict of interest.

Tembotrione is a rather novel pesticide, usually used for post-emergence weed control. Even though its use is rapidly growing, it is not followed by an adequate flow of scientific evidence regarding its toxicity towards non-target organisms. We evaluated the potential of low doses of tembotrione to induce oxidative stress and cytogenetic damage in blood and brain cells of adult male Wistar rats. Parameters of lipid peroxidation, glutathione levels, activities of antioxidant enzymes and primary DNA damage were assessed following 28-day repeated oral exposure to doses comparable with the currently proposed health-based reference values. The results of the alkaline comet assay showed that such low doses of tembotrione have the potency to inflict primary DNA damage in both peripheral blood leukocytes and brain of treated rats, even with only slight changes in the oxidative biomarker levels. The DNA damage in blood and brain cells of Wistar rats significantly increased at all applied doses, suggesting that tembotrione genotoxicity is mainly a result of direct interaction with DNA while the induction of oxidative stress responses contributes to DNA instability in a lesser extent. The findings of the present study call for further research using other sensitive biomarkers of effect and different exposure scenarios., Competing Interests: Declaration of competing interest None to declare., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The food enzyme is a d-xylose aldose-ketose-isomerase (EC 5.3.1.5) produced with the genetically modified Streptomyces rubiginosus strain DP-Pzn37 by Danisco US Inc. Although the production strain contains antibiotic resistance genes, the food enzyme was shown to be free from viable cells of the production organism and its DNA. The food enzyme is intended to be used in an immobilised form for the isomerisation of glucose for the production of high fructose syrups. Residual amounts of total organic solids (TOS) are eliminated by the use of an immobilised food enzyme and further removed by the purification steps applied during the production of high fructose syrups using the immobilised enzyme; consequently, dietary exposure was not calculated. Genotoxicity tests did not raise safety concerns. The systemic toxicity was assessed by a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 85.2 mg TOS/kg body weight (bw) per day, the highest dose tested. Similarity of the amino acid sequence to those of known allergens was searched and no match was found. The Panel considered that, under the intended conditions of use, the risk of allergic sensitisation and elicitation reactions by dietary exposure cannot be excluded, but the likelihood is considered to be low. Based on the data provided, the immobilisation process and the removal of total organic solids during the production of high fructose syrups, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use., (© 2020 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority.)

DNA damage in the liver and kidney cells of adult male Wistar rats was studied using the comet assay after a 28-day oral administration of tembotrione at doses of 0.0007, 0.0013 and 0.7 mg/kg b.w./day [AOEL (acceptable operator exposure level), REL (residual exposure level) and 1000× AOEL]. As a descriptor of DNA damage, tail intensity was used. Antioxidant status was assessed by activity of glutathione peroxidase (GPx). Significant DNA damage was recorded in the kidney cells at all three doses as compared to negative control. In parenchymal liver cells, significant DNA damage was observed in AOEL and 1000× AOEL doses, while in non-parenchymal liver cells, only AOEL-treated group was significantly different compared to negative control. In both types of liver cells, REL and 1000× AOEL doses were significantly different from the AOEL dose. No significant changes in GPx activity compared to control were observed at any exposure level. The results of the present study suggest that repeated in vivo exposure to tembotrione led to low-level DNA instability in kidney and liver cells. Exposure to the highest tembotrione dose showed a relatively weak response with the alkaline comet assay. Further research should focus on the effects of this herbicide in other models along with different exposure scenarios.

The food enzyme glucan 1,4-α-maltotetraohydrolase (EC 3.2.1.8) is produced with the genetically modified Bacillus licheniformis strain DP-Dzf24 by Danisco US Inc. The production strain contains multiple copies of a known antimicrobial resistance gene. However, based on the absence of viable cells and DNA in the food enzyme, this is not considered to be a risk. The food enzyme is intended to be used in baking processes and starch processing for the production of glucose syrups. The residual amounts of the Total Organic Solids (TOS) in glucose syrups are removed by filtration and purification during starch processing. Consequently, dietary exposure was not calculated for this use. Based on the maximum use levels recommended for the baking processes and individual data from the EFSA Comprehensive European Food Consumption Database, dietary exposure to the food enzyme-TOS was estimated to be up to 0.271 mg TOS/kg body weight per day in European populations. Toxicological tests with the food enzyme indicated that there was no concern with respect to genotoxicity or systemic toxicity. A no-observed-adverse-effect level (NOAEL) was identified in rats, which, compared with the dietary exposure, results in a margin of exposure of at least 347. The allergenicity was evaluated by searching for similarity of the amino acid sequence to those of known allergens; no match was found. The Panel considers that, under the intended conditions of use, the risk for allergic sensitisation and elicitation reactions by dietary exposure cannot be excluded, but the likelihood is considered low. Based on the microbial source, genetic modifications, the manufacturing process, the compositional and biochemical data, the dietary exposure assessment and the findings in the toxicological studies, the Panel concludes that this food enzyme does not give rise to safety concerns under the intended conditions of use., (© 2019 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority.)

The food enzyme glucose oxidase (β-d-glucose:oxygen 1-oxidoreductase; EC 1.1.3.4) is produced with a genetically modified Aspergillus niger strain ZGL by DSM Food Specialties B.V.. The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism and recombinant DNA. The glucose oxidase is intended to be used in baking processes. Based on the maximum use levels, dietary exposure to the food enzyme-total organic solids (TOS) was estimated to be up to 0.004 mg TOS/kg body weight (bw) per day. The toxicity studies were carried out with an asparaginase from A. niger (strain ASP). The Panel considered this enzyme as a suitable substitute to be used in the toxicological studies, because they derive from the same recipient strain, the location of the inserts are comparable, no partial inserts were present and the production methods are essentially the same. Genotoxicity tests did not raise a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level (NOAEL) at the highest dose of 1,038 and 1,194 mg TOS/kg bw per day (for males and females, respectively) that, compared with the estimated dietary exposure, results in a sufficiently high margin of exposure (MoE) (of at least 260,000). Similarity of the amino acid sequence to those of known allergens was searched and one match was found. The Panel considered that, under the intended conditions of use, the risk of allergic sensitisation and elicitation reactions by dietary exposure cannot be excluded, but the likelihood to occur is considered to be low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use., (© 2019 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority.)

Chlorpyrifos, imidacloprid, and α-cypermethrin are some of the most widely used insecticides in contemporary agriculture. However, their low-dose, nontarget genotoxic effects have not been extensively assayed. As one of the most relevant cancer biomarkers, we aimed to assess the aneuploidy due to chromosome missegregation during mitosis. To aim it we treated human lymphocytes in vitro with three concentrations of insecticides equivalents relevant for real scenario exposure assessed by regulatory agencies. We focused on chlorpyrifos as conventional and imidacloprid and α-cypermethrin as sustainable use insecticides. Cytokinesis-blocked micronucleus assay was performed coupled with fluorescence in situ hybridization (FISH) with directly labeled pancentromeric probes for chromosomes 9, 18, X and Y. None of the insecticides induced significant secondary DNA damage in terms of micronuclei (MN), nuclear buds (NB), or nucleoplasmic bridges (NPB). However, significant disbalances in chromosomes 9, 18, X and Y, and in insecticide-treated cells has been observed. According to recent studies, these disbalances in chromosome numbers may be atributted to defect sister chromatid cohesion which contribute to the increase of chromosome missegregation but not to micronuclei incidence. We conclude that tested insecticidal active substances exert chromosome missegregation effects at low concentrations, possibly by mechanism of sister chromatid cohesion. These findings may contribute to future risk assesments and understanding of insecticide mode of action on human genome. Environ. Mol. Mutagen. 60:72-84, 2019. © 2018 Wiley Periodicals, Inc., (© 2018 Wiley Periodicals, Inc.)

Objective: The aim of this study was to evaluate cytotoxic potencies of two light cured composite materials after heating on different temperatures and cured directly and through CAD/CAM overlay., Materials and Methods: Composite materials (microfilled-hybrid Gradia Direct Posterior and Beautifil II) were heated in a Calset warming unit at three different temperatures (T1:37°C, T2:54°C, T3:68°C). A small amount of heated composite material was placed in a round mold (diameter 6mm; 0.65mm thick), covered with Mylar sheet, pressed and polymerized with Bluephase LED unit. One group of samples were polymerized directly, and the other group through 2mm thick CAD/CAM ceramic-reinforced polymer (CRP) and CAD/CAM lithium disilicate ceramic (LDC) overlay for 20 and 40 seconds. The polymerized samples were placed immediately after curing in a lymphocyte cell culture. The viability of peripheral blood lymphocytes was evaluated using a dye exclusion technique by simultaneous staining with ethidium bromide and acridine orange. Quantitative assessments were made by determination of the percentage of viable, apoptotic and necrotic cells. The Pearson chi-square test was used for statistical analysis., Results: In case of 20 seconds polymerization, the highest number of viable cells polymerization were recorded when materials were heated at 37°C (T1), while in case of 40 seconds polymerization, the highest number of viable cells were recorded when the materials were heated at 54°C (T2). The samples polymerized through CAD/CAM overlays showed less cytotoxicity than samples polymerized directly., Conclusion: Apart from composite material composition, the cell viability was also influenced by curing time, temperature of pre-heating and polymerization pattern., Competing Interests: Conflict of interest: None declared

In this study, the influence of anthropogenic pollution on the aquatic environment of Plitvice Lakes National Park (PLNP) was investigated during 2011-2012 using a combination of chemical and cytogenetic analyses. Four groups of major contaminants [(volatile organic compounds: benzene, toluene, ethylbenzene, and xylenes (BTEX); persistent organochlorine pollutants: organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs); major and trace elements; anthropogenic radionuclides ( 90 Sr, 134 Cs, and 137 Cs)] were determined in three aquatic compartments (water, sediment, fish). Mass fractions of inorganic constituents in different compartments reflected the geological background of the area, indicating their origin from predominantly natural sources. Levels of volatile and persistent organic compounds in water and fish, respectively, were very low, at levels typical for remote pristine areas. Analysis of anthropogenic radionuclides in water and sediment revealed elevated activity concentrations of 137 Cs in water, and measurable 134 Cs in the upper sediment layers from April 2011, possibly as a consequence of the Fukushima nuclear accident in March 2011. The potential genotoxicity of river and lake water and lake sediment was assessed under laboratory conditions using the alkaline comet assay on human peripheral blood lymphocytes, and measured levels of primary DNA damage were within acceptable boundaries. The results showed that despite the protected status of the park, anthropogenic impact exists in both its terrestrial and aquatic components. Although contaminant levels were low, further monitoring is recommended to make sure that they will not rise and cause potentially hazardous anthropogenic impacts.

The food enzyme endo-1,4-β-xylanase (EC 3.2.1.8) is produced with the genetically modified Bacillus subtilis strain LMG S-24584 by Puratos N. V. The genetic modifications do not give rise to safety concerns. The Panel noted that, although the production strain was not detected in the food enzyme, recombinant DNA was present in all batches of the food enzyme tested. The food enzyme is intended to be used in baking processes. Based on the maximum use levels recommended for the baking processes and individual consumption data from the EFSA Comprehensive European Food Consumption Database, dietary exposure to the food enzyme-Total Organic Solids (TOS) was estimated to be up to 0.017 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not raise a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rodents. A comparison of the no observed adverse effect level of 37 mg TOS/kg bw per day from this study with the dietary exposure results in a sufficiently high margin of exposure. The amino acid sequence of the food enzyme did not match those of known allergens. The Panel considered that, under the intended condition of use, the risk of allergic sensitisation and elicitation reactions upon dietary exposure to this food enzyme cannot be excluded, but the likelihood of such reactions occurring is considered to be low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use., (© 2018 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority.)

The food enzyme is an α-amylase (4-α-d-glucan glucanohydrolase; EC 3.2.1.1), produced with the genetically modified Aspergillus niger strain NZYM-SB by Novozymes A/S. The food enzyme does not contain the production organism or its DNA; therefore, there is no safety concern for the environment. The α-amylase is intended for use in starch processing, beverage alcohol (distilling) processes and baking processes. Residual amounts of total organic solids (TOS) are removed by distillation and by the purification steps applied during the production of glucose syrups (by > 99%). Consequently, dietary exposure was not calculated for these two uses. Based on the maximum use levels recommended for the baking processes and individual consumption data from the EFSA Comprehensive European Food Consumption Database, dietary exposure to the food enzyme-TOS was estimated to be up to 3.075 mg TOS/kg body weight per day in European populations. The food enzyme did not induce gene mutations in bacteria or micronuclei in human lymphocytes. Subchronic toxicity was assessed by means of a repeated-dose 90-day oral toxicity study in rodents. A no observed adverse effect level (NOAEL) was derived that, compared with the dietary exposure, resulted in a sufficiently high margin of exposure (MOE). Similarity of the amino acid sequence to those of known allergens was searched and two matches were found. The Panel considered that the risk of allergic sensitisation and elicitation reactions by dietary exposure cannot be excluded, but the likelihood is considered low. Based on the genetic modifications, the manufacturing process, the compositional and biochemical data, the findings in the toxicological and genotoxicity studies, as well as the estimated dietary exposure, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use., (© 2018 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority.)

Terbuthylazine belongs to the chloro-s-triazine group of herbicides and acts primarily as a photosynthesis inhibitor. The mechanisms of action related to its exposure, relevant both in animals and humans, are still insufficiently investigated. This comprehensive study focused on the outcomes of terbuthylazine exposure at cell level in vitro, and a mice model in vivo. Experiments in vitro were conducted on whole human peripheral blood, isolated lymphocytes, and HepG2 cells exposed for 4 h to terbuthylazine at 8.00, 0.80, and 0.58 ng/mL, which is comparable with current reference values set by the European Commission in 2011. Terbuthylazine cytotoxicity was evaluated using dual fluorescent staining with ethidium bromide and acridine orange on lymphocytes, and CCK-8 colorimetric assay on HepG2 cells. The levels of DNA damage were measured using alkaline and hOGG1-modified comet assays. The potency of terbuthlyazine regarding induction of oxidative stress in vitro was studied using a battery of standard oxidative stress biomarkers. The in vivo experiment was conducted on Swiss albino mice exposed to terbuthlyazine in the form of an active substance and its formulated commercial product Radazin TZ-50 at a daily dose of 0.0035 mg/kg bw for 14 days. Following exposure, the DNA damage levels in leukocytes, bone marrow, liver, and kidney cells of the treated mice were measured using an alkaline comet assay. In vitro results suggested low terbuthylazine cytotoxicity in non-target cells. The highest tested concentration (8.00 ng/mL) reduced lymphocyte viability by 15%, mostly due to apoptosis, while cytotoxic effects in HepG2 cells at the same concentration were negligible. Acute in vitro exposure of human lymphocytes and HepG2 cells to terbuthylazine resulted in low-level DNA instability, as detected by the alkaline comet assay. Further characterization of the mechanisms behind the DNA damage obtained using the hOGG1-modified comet assay indicated that oxidative DNA damage did not prevail in the overall damage. This was further confirmed by the measured levels of oxidative stress markers, which were mostly comparable to control. Results obtained in mice indicate that both the active substance and formulated commercial product of terbuthylazine produced DNA instability in all of the studied cell types. We found that DNA in liver and kidney cells was more prone to direct toxic effects of the parent compound and its metabolites than DNA in leukocytes and bone marrow cells. The overall findings suggest the formation of reactive terbuthylazine metabolites capable of inducing DNA cross-links, which hinder DNA migration. These effects were most pronounced in liver cells in vivo and HepG2 cells in vitro. To provide a more accurate explanation of the observed effects, additional research is needed. Nevertheless, the present study provides evidence that terbuthylazine at concentrations comparable with current reference values possesses toxicological risk because it caused low-level DNA instability, both at cellular and animal organism level, which should be further established in forthcoming studies.

Pesticides are a highly diverse group of compounds and the most important chemical stressors in the environment. Mechanisms that could explain pesticide toxicity are constantly being studied and their interactions at the cellular level are often observed in well-controlled in vitro studies. Several pesticide groups have been found to impair the redox balance in the cell, but the mechanisms leading to oxidative stress for certain pesticides are only partly understood. As our scientific project "Organic pollutants in environment - markers and biomarkers of toxicity (OPENTOX)" is dedicated to studying toxic effects of selected insecticides and herbicides, this review is focused on reporting the knowledge regarding oxidative stress-related phenomena at the cellular level. We wanted to single out the most important facts relevant to the evaluation of our own findings from studies conducted on in vitro cell models.