Mean Micronucleus Frequency Research Articles

Genotoxic and Cytotoxic Effects of Cone Beam Computed Tomography and Multidetector Computed Tomography on Exfoliated Buccal Epithelial Cells.

Cone beam computed tomography (CBCT) and multidetector computed tomography (MDCT) are frequently used in dental and maxillofacial problems. This study aimed to assess the genotoxicity and cytotoxicity effects of CBCT and MDCT radiographies on exfoliated buccal epithelial cells during dental examinations. This prospective experimental study was conducted at Babol University of Medical Sciences (Babol, Iran) from March 2021 to April 2021. Buccal mucosa smears were collected bilaterally pre-exposure and 12 days after CBCT or MDCT examinations. To compare the frequency of micronuclei and other cytotoxic cellular changes such as pyknosis, karyolysis, and karyorrhexis, the paired sample t test and Wilcoxon test were used. In addition, independent sample t test, Mann-Whitney, and Chi square tests were used to investigate the differences between the imaging methods and between men and women. All statistical analyses were performed using the SPSS software, and P≤0.05 was considered statistically significant. The current study included 60 adult patients (30 patients in each group), ranging in age from 21 to 50 years. The micronuclei and the other cytotoxic cellular changes increased significantly after CBCT and MDCT radiographic examinations on the 12th day compared to the pre-exposure results (P<0.001). MDCT had statistically higher cytotoxic and genotoxic effects than CBCT (9.4%, 23.1%, and 40% higher values in micronucleus frequency, the mean frequency of micronuclei, and other cytotoxic changes, respectively). There were no significant differences between men and women in the two examination methods (P=0.46 and P=0.49, respectively). Dental examinations with CBCT and MDCT can increase cytotoxicity and chromosomal damage in both men and women. Due to its lower radiation toxicities, CBCT can be recommended as an alternative to MDCT for dental examinations.

Formalin Induced Micronucleus Formation in the Buccal Mucosa of Pathology Laboratory Workers.

Formaldehyde is an irritating substance that is categorized as a definite carcinogen (Group A1), according to the International Agency for Research on Cancer (IARC). This study was conducted to determine the role of this substance in the frequency of micronuclei (MN) in the buccal mucosal cells due to long-term exposure of the pathology staff to formaldehyde. In this case-control study, 32 pathology laboratory staff members were assigned to the case group, and 32 staff members who were not exposed to formaldehyde were assigned to the control group. Buccal mucosa cells were collected with a wet spatula and stained with Papanicolaou stain. In each sample, 500 cells were counted; then, the frequency of MN and the average number of MN in the micronucleated cells were assessed and compared between the 2 groups using the independent t test. Furthermore, the relationship between gender and MN was evaluated using the independent t test. The relationship between years of exposure and time of exposure during the day (in hours) for the case group, as well as the relationship between age and frequency of MN was analyzed using the Pearson correlation coefficient. The mean frequency of MN in exfoliated buccal cells was 18.33±12.36 in the case group, which was significantly higher than the control group (10.55±6.22; P=0.003). The difference in the mean number of total MN in the micronucleated cells was not significant between the case and control groups (P=0.11). The relationship between sex, age, and years of exposure with the mean frequency of MN and the total number of MN in the micronucleated cells was not significant. The relationship between exposure time during the day and both the mean frequency of MN and the total number of MN in the micronucleated cells was significant (P=0.03). Formaldehyde exposure and extended time of exposure during the day can increase the frequency of MN, which can prognosticate the incidence of precancerous and cancerous lesions. Therefore, continuous exposure to formaldehyde can be considered an occupational health hazard, though further studies are needed to confirm this result.

EVALUATION OF CYTOGENIC DAMAGE IN ORAL EXFOLIATED BUCCAL CELLS OF TOBACCO USERS AND PATIENTS WITH POTENTIALLY MALIGNANT DISORDERS USING MICRONUCLEUS ASSAY - A PROSPECTIVE STUDY

Background: Cytogenic methods acts with complex type mutations, known as structural mutations (aberrations)and a special type of chromosomal damage, known as micronucleus. So, micronucleus (MN) assay has been used as a biomarker of genetic damage in buccal mucosa cells. Aim and Objectives: To evaluate micronucleus in the exfoliated cells of buccal mucosa of individuals with potentially malignant disorders and different tobacco related habits and in control group. To observe the incidence of micronucleus count based on duration, frequency and type of tobacco usage and also auto immune condition of Lichen planus. Materials and Method: The study population is divided into 3 groups. Group I : 15 healthy subjects (control), Group II : 15 smokers or chewers with habits andno evidence of lesion Group III : 30 Patients clinically diagnosed as having PMD of the oral cavity. Smears stained with DNA specific Feulgen stain. Association of micronucleus between all groups and its mean and standard deviation was assessed with ANOVA with p&lt;0.05 was considered as significant level. Results: The mean MN revealed that individuals with potentially malignant disorders had 26.8±5.1, individuals with tobacco habit (smokers/chewers) had 11.0±5.5 and controls had 0.2±0.5. The ANOVA test for association and mean frequency of micronucleus between all groups revealed significant value of &lt;0.001. Conclusion: Hence, MN assay in oral exfoliated buccal cells can be conveniently used as a biomarker for screening of potentially malignant disorders of oral cavity. And also provides an insight into the importance of early detection and prevention of OPMDs.

Micronucleus assay in the exfoliated cells of buccal mucosa of gasoline station workers in Tehran.

One of the most critical landmarks of DNA damage is the micronucleus assay. Enumeration of micronuclei contributes to the early diagnosis of precancerous lesions and cancers; however, there are few studies on the frequency of micronucleus in gasoline station workers. To the best of our knowledge, no study has addressed this issue in Iran. The present study aimed to determine the role of working in the gasoline stations of Tehran city on micronucleus frequency in buccal mucosa. In this historical cohort study, buccal mucosa samples were collected from 110 individuals working at gasoline stations and 100 unemployed persons using wet tongue depressors. After Papanicolaou staining, the percentage of cells containing micronucleus as well as the mean number of micronucleus in the micronucleated cells was reported. Student's t-test, Mann-Whitney test, and regression analyses were used to specify the effect of other variables on the frequency and mean number of micronucleus per cell. The mean frequency of micronucleus in the case and control group was 29.8 ± 8.2 and 9.3 ± 3.2, respectively, which was statistically significant (P = 0.0001). Furthermore, the mean number of micronucleus in the micronucleated cells of buccal mucosa was significantly higher in individuals who were exposed to gasoline than the control group (P = 0.0001). The results indicated that exposure to gasoline could increase the frequency of micronucleus. It was also revealed that cigarette and hookah smoking and alcohol consumption, together with working in gasoline stations, increase micronucleus abundance, implying the cumulative carcinogenic effect of these factors.

Sublethal effects of acrylamide on thyroid hormones, complete blood count and micronucleus frequency of vertebrate model organism (Cyprinus carpio)

Abstract Objectives Acrylamide, a widely used chemical in industry, clinical laboratory and waste treatment plants, is considered a carcinogen in humans. The present study examined the hormonal, hematologic, and genotoxic responses in the invertebrate model common carp Cyprinus carpio after exposure to sublethal acrylamide. Methods Fish were exposed to acrylamide at 10 and 50 mg/L for 96 h, along with the respective control group. Serum levels of cortisol and thyroid hormones were measured using diagnostic ELISA direct immunoenzymatic kits. For micronucleus (MN) frequency assay, thin smears of the peripheral blood of fish were prepared. Results Serum levels of cortisol in both treatment groups considerably increased, which proposed that acrylamide caused a stress reaction of acrylamide exposed fish (p&lt;0.05). Fish demonstrated significant decreases in triiodothyronine (T3), free thyroxine (FT4), and free triiodothyronine (FT3) concentrations in a dose-dependent manner after acrylamide exposure (p&lt;0.05). However, serum thyroxine (T4) concentrations did not alter significantly in the treatment groups. Mean MN frequencies of fish erythrocytes increased significantly in acrylamide exposed groups suggesting that acrylamide is genotoxic in common carp (p&lt;0.05). The hematocrit, hemoglobin, and erythrocyte numbers of carp increased significantly in exposure groups (p&lt;0.05). Conclusions These results suggested that acrylamide can significantly affect the hemopoietic system. Furthermore, this study confirmed that the widespread use of acrylamide, even in sublethal concentrations, could affect the survival of non-target organisms, especially fish, in aquatic environments.

Comparative study of the genotoxic activity of Artemisia vulgaris L. and Artemisia alba Turra extracts in vitro

In this study, the genotoxic activity of acetone and aqueous extracts of two species of genus Artemisia (Artemisia vulgaris L. and Artemisia alba Turra), and possible role of their polyphenolic composition in the observed activities were investigated. Polyphenolic contents were evaluated by high-performance liquid chromatography (HPLC-PDA), while the genotoxic activity was tested using cytokinesis block micronucleus (CBMN) assay on human peripheral blood lymphocytes (PBLs) in vitro. HPLC-PDA showed that both A. alba extracts were richer in polyphenolic contents than A. vulgaris extracts. The acetone A. alba extract was the richest of polyphenolic content where we detected six phenolic acids and two flavonoids. CBMN assay showed that aqueous extract of A. vulgaris significantly increased micronucleus (MN) frequency in the PBLs treated with all tested concentrations (10, 50, 100, and 250 µg/mL), while A. alba did not significantly affect the mean MN frequency. Further, both acetone extracts were genotoxic in all tested concentrations, except the lowest tested (10 µg/mL) of A. alba. All tested extracts affected the nuclear division index (NDI) except the aqueous A. alba extract (p < 0.05). Based on our results, we can conclude that both acetone and aqueous A. vulgaris extracts and A. alba acetone extract were genotoxic in PBLs in vitro. A. alba aqueous extract was not genotoxic and cytotoxic in tested concentrations. We suggest that the aqueous extract of A. alba can be used in treatment, which has been confirmed by traditional medicine, but with a high dose of caution and not in high concentrations.

Buccal micronucleus cytome assay in children living in an area with low anthropogenic pressure: The EFFE.BI.P. study

The study aimed to evaluate the micronucleus (MN) frequency in exfoliated buccal cells (EBCs) of 256 6-8-years-old schoolchildren living in a rural area of Salento peninsula (Southern Italy) with low anthropogenic pressure and with a normal rate of chronic diseases in order to determine the basal level of MN and identify which factors are able to influence it. Information about the personal data, lifestyles and dietary habits of the children were obtained by the administration of a questionnaire to their parents. The buccal micronucleus cytome assay was performed to evaluate the presence of early genotoxic effects among the children. In addition, the level of environmental exposure was assessed by sampling atmospheric particulate fractions near the schools attended by participants. The association between MN frequency and individual or environmental factors was also assessed. The children had a mean MN frequency of 0.27 ± 0.43‰ (95%CI = 0.22−0.33). This frequency was positively associated with vehicular traffic (OR = 2.99; 95%CI = 1.15−7.74) and negatively associated with a high educational level of the mother (OR = 0.41; 95%CI = 0.18−0.95) and physical exercise (OR = 0.56; 95%CI = 0.32−0.57). Data on genotoxic effects in buccal cells found in this study could be considered as the MN level in a pediatric population not exposed to environmental pollution.

Winter Air Pollution and Genotoxic Effects in Children Living in a Highly Polluted Urban Area

Air pollutants, especially PM, have been found to determine various effects on human health, including genotoxic effects. The aim of this study was to assess DNA damage with micronuclei (MN) and comet tests on buccal cells of 6–8 years old children living in an area with high air pollution. Both tests were repeated in the same children in two consecutive winters to compare the levels of DNA damage under different pollution conditions. A complete data set including lifestyle, air pollutants levels and biological sampling was available for 180 children in the two winters. A high mean MN frequency was found in both seasons, with higher value in the first (0.51 ± 0.59) than the second winter (0.40 ± 0.52), whereas DNA damage measured with comet test showed higher damage in the second versus the first winter (visual score 208.8 ± 67.1 vs. 173.2 ± 50.8). The associations between air pollutant levels (CO, NO2, SO2, benzene, O3, PM10, and PM2.5; PM0.5 and PAHs) and DNA damage were investigated at different lag times, and mainly, no significant association was found. This study on repeated measure of MN frequency and DNA damage in children’s buccal did not show an association with various air pollutants evaluated in an area with high levels of air pollution.

Global and gene-specific promoter methylation, and micronuclei induction in lead-exposed workers: A cross-sectional study.

Perturbation of epigenetic regulation is a well-established mechanism for cancer but its role for lead (Pb)-associated toxicity has not been adequately investigated. We aimed to investigate whether occupational Pb exposure is associated with micronuclei (MN) frequency and to further explored the mediating roles of epigenetic gene regulation. All the Pb-exposed workers recruited from a Chinese acid battery factory, blood lead levels (BLLs) and MN frequency in lymphocytes were measured. In addition, methylation levels of seven genes (Line-1, RASSF1A, RUNX3, p16, CYP26C1, hMLH1, p15) were examined among 230 workers. Robust Poisson regression model was used to investigate the association between BLLs and MN frequency. Mediation analysis was used to explore the mediating role of specific DNA methylation. Among total 677 participants, 71% were male, median BLLs was 229.1μg/L (P25 = 155.5, P75 = 319.3; ranged from 8.9 to 647.7μg/L), mean MN frequency was 2.5‰ (SD = 1.8‰; ranged from 0 to 9‰). Results from base model, adjusted for age, sex, and body mass index, showed that MN frequency would increase 1.38 (95%confidential interval: 1.34, 1.43) per 100 μg/L increment in BLLs. Using categorized exposure variable analyses, a BLLs dose-response increase in MN frequency was observed: 2.74 (2.13, 3.51), 3.43 (2.73, 4.32), 4.41 (3.89, 5.01) to 6.86 (6.02, 7.81). Mediation analysis indicated that Line-1 methylation significantly mediated 3.6% of the association of BLLs with MN frequency. Occupational Pb exposure induces MN frequency in a dose-response relationship. Part of this association was mediated by Line-1 promotor methylation.

Genotoxic effect of exposure to polycyclic aromatic hydrocarbons (PAHs) in asphalt workers

Asphalt workers are at risk due to exposure to asphalt fumes containing polycyclic aromatic hydrocarbons (PAHs). The main purpose of this study was to measure the urinary metabolite of PAHs and to determine its effect on micronucleus (MN) formation as an indicator of genotoxic damage. In this cross-sectional study, the MN frequency in 48 male asphalt workers exposed to PAHs was measured and compared with 48 male non-exposed employees. PAHs exposure was evaluated by determining urinary 1-Hydroxypyrene (1-OHP). The mean concentrations of 1-OHP in the exposed and non-exposed groups were 0.58 ± 0.41 μmol/mol creatinine and 0.38 ± 0.25 μmol/mol creatinine, respectively. 1-OHP concentration was significantly higher in smokers compared with non-smokers in both exposed and non-exposed groups. Moreover, the mean MN frequency in the exposed group was significantly higher than in the non-exposed group. The MN frequency was significantly higher in asphalt workers with a work history of ≥ 15 years compared to workers with lower work history. In a fully adjusted model, there was a statistically significant association between exposure to PAHs, with MN and 1-OHP concentration, and between smoking status with 1-OHP. The findings of the present study indicated that occupational exposure to PAHs was associated with increased urinary 1-OHP as well as DNA damage in the asphalt workers.

The micronucleus cytome assay – A fast tool for DNA damage screening in human conjunctival epithelial cells

PurposeTo assess whether the micronucleus cytome assay (MCyt) reliably detects DNA damage occurring in control and pathological superficial epithelial cells from human conjunctiva. MethodsImpression cytology samples from the bulbar conjunctiva of 33 healthy controls, eight patients with conjunctival intraepithelial neoplasia (CIN) and eight with mucous membrane pemphigoid (MMP) were examined using the MCyt modified for the ocular surface. ResultsThe mean number of micronuclei (MNi) in control samples was 0.94 MNi/1000 epithelial cells, with no significant difference between conjunctival quadrants and independent of sex and age. The MCyt assay applied to CIN-affected eyes showed a significantly higher frequency of MNi (18.63/1000 cells), apoptotic cells, nuclear enlargement, multinucleated cells, and keratolysis compared with the corresponding unaffected paired eyes and with the control value. Although the mean MNi frequency in MMP eyes was also higher (1.73 MNi/1000 cells), it did not prove to be statistically different from the control samples. On the other hand, the MMP-affected eyes revealed significantly elevated percentages of cells with snake-like chromatin, multinucleated cells, apoptotic cells, and nuclear buds compared with controls. ConclusionsMicronucleus cytome assay was adapted as a rapid screening test for genomic instability on the ocular surface. We have determined reference levels for MNi and other nuclear alterations on healthy conjunctiva and demonstrated that particularly frequencies of MNi are significantly elevated in conjunctiva affected by CIN. We demonstrate that MNi are more specific than other nuclear abnormalities and thus can be used for screening of ocular surface neoplasia.

Is duration of exposure a determinant factor for genotoxicity and clinical manifestations induced by Formaldehyde?

Introduction: Formaldehyde is a naturally occurring compound extensively used as cadavers' preservative in medical schools anatomy departments. The International Agency for Research on Cancer (IARC) classifies formaldehyde as carcinogenic to humans (group 1). Aim of the work: To examine duration of exposure as a determining factor in genotoxicity of formaldehyde exposure using the micronucleus test, correlate clinical manifestations with genotoxic effects, and measure formaldehyde air levels in dissecting rooms of Alexandria Faculty of Medicine, Egypt. Materials and methods: A pre-designed questionnaire was filled for each subject to assess clinical signs and symptoms of exposure and to screen for exclusion criteria. Buccal epithelial cells were collected; twice from 40 undergraduate students before and after one month of exposure, and once from 10 staff members who had participated in anatomy classes. Cells of both groups were stained using Feulgen method and micronucleus test (MN) was applied. The air levels were measured in 3 anatomy labs using MIRAN-IR. Results: Mean frequency of micronuclei was significantly higher in staff group (2.60 ±1.26)/1000 cells than the control and student groups (0.80±0.76)/1000 cells, (1.05 ±1.28)/1000 cells respectively with p= 0.001. Significant positive correlation between frequency of MN and skin, eye and respiratory symptoms. The mean level of airborne formaldehyde in 3 dissecting rooms was 7.2 ±6.9 ppm which is above OSHA recommendations. Conclusion: Duration of exposure is an important determinant in genotoxiciy of formaldehyde exposure. Clinical manifestations of formaldehyde exposure were correlated to the MN frequency. Studied participants are exposed to high concentrations of formaldehyde above the standard levels according to time of exposure. Efforts have to be made to improve air quality and reduce exposures during anatomy classes.

Assessment of Chromosomal Damage in Umbilical Blood Lymphocytes of Newborns from Kragujevac in Central Serbia Born 18 Years after Environmental Contamination.

The measurement of micronuclei (MN) in umbilical blood lymphocytes of newborns are increasingly used in cytogenetic epidemiology as one of the preferred methods for assessing chromosomal damage resulted from maternal exposure to mutagen. In the present study, we evaluated the effect of strong environmental contamination (EC) (which occured in the City of Kragujevac, Central Serbia in 1999) on the MN frequency in group of 22 newborns born in Kragujevac 18 years after EC, using cytokinesis-block micronucleus (CBMN) assay. The mean MN frequency in umbilical lymphocytes of these newborns was 5.14 ± 2.17/1,000 binucleated (BN) cells, which is significantly lower than mean MN frequency of newborns born 12 months after contamination (9.36 ± 5.60/1,000 BN cells). Sex of newborns, age of mothers, cigarette smoking, and number of pregnancies did not affect the MN frequency of newborns. Our results showed that in utero exposure to environmental pollution affected genome instability of the fetuses, but that by improving the quality of environmental conditions there was a decrease in mean MN frequency of newborns born 18 years after contamination. In general, genome of umbilical lymphocytes shows a realistic picture of all changes in body and the environment.

Evaluation of Genetic Damage in Persons Occupationally Exposed to Antineoplastic Drugs in Serbian Hospitals.

Although useful in the treatment of malignant cells, antineoplastic drugs (ANPDs) as chemical genotoxic agents, can interfere with normal cell physiology causing genetic damage and unfavourable health effects, especially in occupationally exposed persons. The Cytokinesis-block Micronucleus (CBMN) Cytome assay has been widely used in human biomonitoring studies as a reliable biomarker of chemical genotoxic exposure. Our comprehensive research was conducted in order to evaluate micronuclei as a marker for preventive medical screening purposes for persons occupationally exposed to ANPDs. Using the CBMN Cytome test, peripheral blood lymphocytes of 201 control and 222 exposed subjects were screened for genetic damage. Age and gender influenced micronucleus (MN) frequency, but smoking habit did not. The mean micronuclei frequencies and other parameters of the CBMN Cytome test [numbers of binuclear lymphocytes with one (MN1) or two (MN2) micronuclei] were significantly higher in the group of exposed persons. Positive correlation between duration of occupational exposure and MN frequency was revealed. The results of our study performed on a large sample confirmed the capacity of the CBMN Cytome assay to serve as a reliable biomarker of long-term ANPD exposure.

Assessment of Micronuclei Frequency in Individuals with a Habit of Tobacco Chewing by Means of Exfoliated Oral Buccal Cells

INTRODUCTION: Majority of cancers are diagnosed at an advanced stage resulting in poor prognosis and survival rates among patients. Hence early diagnosis of oral cancers seems to be the need of the hour. Analysis of exfoliated buccal cell micronuclei (MN) is a sensitive method of monitoring genetic damage. AIM: The present study has been carried out with an objective to evaluate the genotoxic effects of tobacco chewing by means of micronucleus assay in exfoliated cells of buccal mucosa.MATERIALS AND METHOD: This cross sectional study was carried out in Department of Oral Pathology, Swami Devi Dyal Hospital And Dental College, Golpura, Barwala, Panchkula. The study population comprised of a total of 50 subjects, divided into five groups: Group 1comprising of 10 age and sex matched healthy subjects without any habits as controls, Group 2 comprising of 10 subjects with a history of chewing tobacco. Group 3 comprising of 10 subjects with a history of chewing tobacco and cigarette smoking, Group 4 comprising of 10 subjects with a history of chewing tobacco and drinking and Group 5 comprising of 10 subjects with a history of chewing tobacco, smoking and drinking. Oral exfoliated cells were obtained from buccal mucosa of the subjects, slides were prepared from each subject stained with stain respectively.RESULTS: The mean numbers of micronuclei in group 1 were 7.86±6.7, Group 2 were 63.37±10.01, Group 3 were 65.49±12.32, Group 4 were 68.22±11.11 and Group 5 were 69.43±10.71. On comparison we observed that the difference in Mean micronuclei frequency among all the 5 study groups came to be statistically also highly significant (p&lt;0.0001*)CONCLUSION: Micronuclei assay is an effective tool that reflects severity of disease. Even though tobacco induced cancers are preventable, banning the use of tobacco has not been possible for social and political reasons.

Evaluating the Effect of Working in the Dental Radiology Center on Micronucleus Frequency in Buccal Mucosa

Background: The present study aimed to investigate the effect of working in the dental radiology department on the frequency of micronucleus. Results: The mean frequency of micronucleus per cell in the control and case groups was not statistically significant (P = 0.4). In addition, no statistically significant difference was observed in males and females regarding the mean frequency of micronucleus per cell (P = 0.6). Employment background and age had no significant impact on the percentage of micronucleus-containing cells and the mean frequency of micronucleus per cell. Conclusions: Working in a dental radiology center had no impact on the percentage of micronucleuscontaining cells and the mean frequency of micronucleus per cell.

Evaluation of telomere length and genotoxicity among asphalt associated workers

There are contradictory reports about bitumen exposure and malignancy risk worldwide. Also, the evidence for genotoxicity risk among workers occupationally exposed to asphalt is insufficient. The study intended to evaluate particulate matter 10 (PM10) at the workplace and biomarkers of genotoxicity effects among a group of asphalt workers in and around Bangalore, India. This study involved a total of 107 participants (54 exposed group and 53 unexposed control group). To evaluate the genotoxicity, the urinary 8-OHdG and relative telomere length as oxidative damage while micronucleus (MN) assay for cytogenetic damage was carried out during the study. The majority of workers have reported health complaints and 57.4% of them were not using any personal protective equipments (PPE’s). The level of PM10 detected was 104 ± 9.5 μg/m3 and 619 ± 22.7 μg/m3 in the road paving and asphalt mixing sites respectively. The biomonitoring study observed a highly significant (p = <0.001) increase in the level of 8-hydroxy-2-deoxyguanosine (8-OHdG) in the exposed group (23.17 ± 8.65 ng/mg creatinine) compared to the control (13.6 ± 7.12 ng/mg creatinine), revealed age significant associated and non-smoking borderline significant associated for oxidative stress. The relative telomere length (TL) analysis revealed its highly significant (p = 0.004) reduction in the exposed group, adjusted mean 0.95 (95% CI 0.83–1.07) compared to the control 1.06 (95% CI 0.91–1.26). The job category (p = 0.028), non-smoking (p = 0.026), and tobacco chewing (p = 0.013) were associated with reduced relative TL in the asphalt exposed group. In cytogenotoxicity analysis, the mean micronucleus (MN) frequency per 100 cells in the exposed group (26.46 ± 19.8) was significantly (p = <0.001) increased over the control group (8.56 ± 7.18). Neither smoking habit nor age appeared to influence the MN frequencies in either group. In the present study, we have demonstrated genetic damage in workers occupationally exposed to asphalt and particulate matter, raising concern for an increased risk of malignancy in these workers.

Changes in the Radiation Toxicity of Human Lymphoblastic T-cell Line (Jurkat) by a Common Pesticide: Diazinon.

Background: Diazinon is one of the most common pesticides in the world playing a similar role to radiation and it could cause DNA breaks and genetic effects.Objective: In this study, radiosensitivity of a lymphoblastic cell line pretreated by Diazinon was investigated.Material and Methods: In this case-control study, the human lymphoblastic T-cell line was divided into 6 groups based on receiving radiation or/and Diazinon. After that, the DNA damage, in all of the groups, were counted by cytokinesis-block micronuclei assay using different indices. Results: The mean frequency of micronuclei, nuclear bridges and nuclear buds in cell groups exposed by both Diazinon and radiation were remarkably higher than the other groups which just received radiation or Diazinon alone. The interaction between radiation and Diazinon treatment was statistically significant for NBUDS index.Conclusion: The results indicated that the Diazinon contamination could affect the radiosensitivity index of cancerous cells while further molecular and in-vivo studies are needed to investigate genetic and toxic effects of Diazinon on DNA and its repair system.

Chronic exposure to lead and cadmium pollution results in genomic instability in a model biomonitor species (Apodemus flavicollis Melchior, 1834)

Polymetal dust is a common industrial pollutant. While the use of remediation filters and equipment in lead smelters has reduced pollutant emission, surrounding areas remain contaminated due to the long-term transfer of heavy metals along the food chain. Here we assess the mutagenic potential of the lead-zinc smelter near Plovdiv (Bulgaria) situated in an area that has been contaminated with heavy metals for 60 years. We aimed to evaluate the genomic response of the yellow-necked mouse (A. flavicollis), a biomonitor species, in three sampling sites along the pollution gradient. Mice from Strandzha Natural Park were used as a negative control. The bioaccumulation rate of two non-essential heavy metals, lead (Pb) and cadmium (Cd), in liver tissues was determined by atomic absorption spectroscopy. Genetic alterations attributable to chronic exposure to trace levels of heavy metals were assessed in different blood cell populations using two independent methods: a micronucleus test was applied to evaluate the clastogenic and aneugenic alterations in erythrocytes, while a comet assay was used to assess DNA instability, as evidenced by single- and double-stranded breaks and alkali-labile sites, in leucocytes. We observed elevated levels of Pb and Cd in livers derived from mice from the impacted area: the mean Pb concentration (21.38±8.77μg/g) was two-fold higher than the lowest-observed-adverse-effect levels (LOAELs), while the mean Cd concentration (13.95±9.79μg/g) was extremely close to these levels. The mean levels of Pb and Cd in livers derived from mice from the impacted area were 31-fold and 63-fold higher, respectively, than the levels measured in mice from the control area. The mean frequency of micronuclei was significantly higher (four-fold) than that observed in the control animals. Furthermore, parameters measured by the comet assay, % tail DNA, tail length and tail moment, were significantly higher in the impact area, indicating the degree of genetic instability caused by exposure to heavy metals. In conclusion, this study shows that despite the reported reduction in lead and cadmium emissions in Bulgaria in recent years, A. flavicollis individuals inhabiting areas subject to long-term contamination exhibit significant signs of DNA damage.

Micronucleus Frequency in Exfoliated Buccal Cells of Children Living in an Industrialized Area of Apulia (Italy).

Micronuclei (MN) are biomarkers of early biological effect often used for detecting DNA damage in human population exposed to genotoxic agents. The aim of this study was to evaluate the frequency of MN in exfoliated buccal cells of children living in an industrialized (impacted) area compared with that found in children living in a control area without significant anthropogenic impacts. A total of 462 6–8-year-old children (206 in the impacted area, 256 in the control area) attending primary school were enrolled. A questionnaire was administered to the parents of the recruited children to obtain information about personal data, lifestyles, and food habits of their children. Atmospheric particulate fractions were collected near the involved schools to assess the level of environmental exposure of the children. The presence of MN was highlighted in 68.4% of children living in the impacted area with a mean MN frequency of 0.66‰ ± 0.61‰. MN positivity and frequency were significantly lower in the control area (37.1% and 0.27‰ ± 0.43‰, respectively). The frequency of MN was positively associated with quasi-ultrafine particulate matter (PM0.5), traffic near the home, and consuming barbecued food; while adherence to the Mediterranean diet and practicing sport were negatively associated.