Micronuclei in peripheral blood lymphocytes and buccal epithelial cells of Polish farmers exposed to pesticides

Genetic instability in farmers using pesticides: A study in Brazil with analysis combining alkaline comet and micronucleus assays

The use of pesticides to prevent and control pests also increases food production. Pesticides are widely used by contemporary farmers, especially in Brazil, where the economy is based on agriculture. The objective of this study was to evaluate the genotoxic potential of pesticide use in rural workers in Maringá, Paraná, Brazil. DNA damage in whole blood cells was measured by the comet assay, while the frequency of cell types, abnormalities, and nuclear damage was estimated using the buccal micronucleus cytome assay. Samples of buccal mucosa were collected from 50 male volunteers (27 not exposed to pesticides and 23 occupationally exposed to pesticides). Among them, 44 volunteered for blood sampling (24 unexposed and 20 exposed). In the comet assay, the exposed farmers had a higher damage index than non-exposed ones. There were also statistically significant differences between the groups in the buccal micronucleus cytome assay. Farmers exhibited an increase in basal cell numbers, and cytogenetic alterations, represented by condensed chromatin and karyolitic cells. Comparisons between cell morphologies and epidemiological factors indicated an increased number of condensed chromatin and karyolitic cells in individuals who were responsible for preparation and transportation of pesticides to agricultural machines. Thus, the participants in this study who were exposed to pesticides were more sensitive to genetic damage, and thereby, more susceptible to diseases resulting from such damage. These results demonstrated that health policies should be developed for pesticide-exposed farmers to better mitigate risks and damage to their health.

Effect of Pesticide Exposure over DNA Damage in Farmers from Los Reyes, Michoacan in Mexico

In the municipality of Los Reyes, Michoacán, in Mexico, several economic activities coexist; however, the most relevant is agriculture. It stands out as an agro-industrial center and commercial enclave in the region, suitable for the cultivation of sugar cane; however, currently fruit growing takes first place with blackberry, raspberry and blueberry, followed by avocado, peach, strawberry and other crops. A large quantity and variety of pesticides are applied to crops, consequently the population is at constant risk. This study aimed to evaluate whether pesticides are a factor in genetic damage to agricultural workers from Los Reyes, Michoacán, using alkaline comet assay. Fifty-nine residents participated (41 workers and 18 controls). Results included confounding factors (alcohol consumption, smoking habit, gender, age, BMI, etc.) indicated a non-significant statistical difference between two groups, with higher DNA damage values in workers that was higher than the values expected in a normal healthy unexposed population. It seems that the control measures, safe handling of pesticides and quality standards, required by the producers so that their products can be exported, have resulted in less damage, despite workers' activity, but higher damage than the reference values still requires regular surveillance of those exposed. The use of protective equipment or measures can reduce the risk of damage, so it is also necessary to promote their service and comply with labor regulations for agricultural workers.

Is micronucleus assay in oral exfoliated cells a useful biomarker for biomonitoring populations exposed to pesticides? A systematic review with meta-analysis

The systematic review (SR) with meta-analysis aimed to infer if micronucleus assay using oral mucosal cells a useful biomarker for biomonitoring populations continuously exposed to pesticides (EP). The SR has been made in accordance with the PRISMA-P guidelines. The PICOS strategy has focused to answer the following question: "Does exposure to pesticides cause genetic damage in oral cells?" The literature search was made in the following scientific databases: Web of Science, PubMed/Medline, and Scopus. The approach was defined as follows: standardized mean difference (SMD) and 95% confidence intervals (CI). The quality assessment of manuscripts was obtained by the EPHPP (Effective Public Health Practice Project). The GRADE tool was chosen for assessing the quality of evidence. A total of 108 articles were selected in this setting. After screening abstracts and titles, 23 manuscripts were evaluated for eligibility. After reviewing the studies, two were considered weak and 22 were classified as moderate or strong. The meta-analysis data pointed out statistically significant differences in volunteers exposed to EP (SMD = 1.23, 95% CI, 0.69 to 1.77, p < 0.001), with a Tau2 = 1.44; Chi2 = 566.38, and p < 0.001, so that the selected manuscripts were considered heterogeneous and the I2 of 97% indicated high heterogeneity. Taken together, this review was able to validate the micronucleus assay in oral exfoliated cells as a useful biomarker in individuals continuously exposed to EP because the studies categorized as moderate and strong have demonstrated positive response related to mutagenesis.

Ameliorative potential of vitamin C and E against Roundup-glyphosate induced genotoxicity triggering apoptosis in caprine granulosa cells

The present study was aimed to investigate the genotoxic and apoptotic effects of glyphosate (GLP) in Roundup formulation along with mitigation of two potent antioxidants that is, vitamin C and E in caprine granulosa cells in vitro. The entire work was done in a dose and time dependent manner where different concentrations of GLP (0.1, 2.0, and 4.0 mg/ml) in Roundup and antioxidants (0.5 and 1.0 mM) were employed to culture of granulosa cells for exposure durations of 24, 48, and 72 h. Analysis of GLP-induced geno-toxicity was accomplished by using single cell gel electrophoresis (comet assay) assay. Results have shown increased incidences of DNA fragmentation, evidenced by presence of different types of comets (Type 1-Type 4) in Roundup-GLP- exposed groups in contrast to the control group (Type 0 comet). However, mitigation by both vitamin C and E was significant (p < .05) in combating the GLP-induced genotoxicity in granulosa cells in a concentration- and time-dependent manner. The results of our study provide a clear indication of the ameliorative actions of vitamin C and E against Roundup-GLP-induced genotoxicity that instigate apoptosis in ovarian granulosa cells of caprine.

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.

Genotoxicity and cytotoxicity of cone beam computed tomography in children

BACKGROUND

Dental radiographs are essential tools for diagnosis. However, there are significant concerns about the dangerous effect of radiation especially on children. The aim of this study was to evaluate genotoxicity and cytotoxicity in the exfoliated cells of buccal mucosa of children subjected to Cone Beam Computed Tomography (CBCT).

METHODS

The study included 18 healthy children aged (9-12 years) who were exposed to CBCT. All CBCT scans were performed with the i-CAT CBCT. Exfoliated buccal cells were scraped from the left and right cheek immediately before the exposure, after 10 ± 2 days, and after 1 month. Cells were stained using Feulgen/fast green stain and examined under light microscopy. Genotoxicity (Micronuclei) and cytotoxicity (condensed chromatin, karyorrhexis, pyknosis, and karyolysis) were scored. Statistical analysis was performed using the McNemar test, Wilcoxon Signed-Rank test, and Mann-Whitney U test at a significance level of p < 0.05.

RESULTS

There were statistically significant differences in the mean percentages of micronuclei, condensed chromatin, karyorrhexis, pyknosis, and karyolysis before and 10 ± 2 days after the CBCT scan (p < 0.05). There were no statistically significant differences in the frequency of micronuclei, condensed chromatin, karyorrhexis, or pyknosis before and 1 month after the exposure (p > 0.05) except for karyolysis (p < 0.05).

CONCLUSIONS

CBCT may induce genotoxicity and cytotoxicity in buccal mucosa cells of children. Therefore, CBCT should not be prescribed unless necessary as it cannot be considered a risk-free procedure.

Genotoxic effect of meat consumption: A mini review

In 2015, the International Agency for Research on Cancer classified the consumption of processed meat as carcinogenic to humans (Group 1) and red meat as probably carcinogenic to humans (Group 2A) based on sufficient data from animal models and epidemiological studies. However, research characterising the mechanisms underlying this carcinogenic process in humans are limited, particularly with respect to measures of direct DNA damage. The current review sought to evaluate and summarize the recent literature, published since 2000, regarding the associations of meat consumption and three biomarkers of genotoxicity in humans: DNA strand breaks (measured using the comet assay), DNA adducts, and micronucleus formation. After screening 230 potential articles, 35 were included, and then were classified as experimental or observational in design, the latter of which were further categorized according to their dietary assessment approach. Among the 30 observational studies, 4 of which used two different assays, 3 of 5 comet assay studies, 13 of 20 DNA adduct studies, and 7 of 9 micronucleus studies reported a positive association between meat consumption and DNA damage. Among the 5 experimental studies, 1 of 1 using the comet assay, 3 of 3 measuring DNA adducts and 0 of 1 measuring micronuclei reported significant positive associations with meat consumption. Nevertheless, common limitations among the selected publications included small sample size, and poor methodological reporting of both exposure and outcome measures. Moreover, the vast majority of studies only measured DNA damage in one biological sample using a single assay and we cannot exclude the possibility of publication bias. Ultimately, our review of the literature, published since 2000, revealed a preponderance of studies that support mechanisms of genotoxicity in playing an important role in the meat-cancer association.

Synthetic Pesticides and Health in Vulnerable Populations: Agricultural Workers

PURPOSE OF REVIEW

This review aims to summarize epidemiological literature published between May 15, 2018, and May 14, 2019, that examines the relationship between exposure to synthetic pesticides and health of agricultural workers.

RECENT FINDINGS

Current research suggests that exposure to synthetic pesticides may be associated with adverse health outcomes. Agricultural workers represent a potentially vulnerable population, due to a combination of unique social and cultural risk factors as well as exposure to hazards inherent in agricultural work. Pesticide exposure among agricultural workers has been linked to certain cancers, DNA damage, oxidative stress, neurological disorders, and respiratory, metabolic, and thyroid effects. This review describes literature suggesting that agricultural workers exposed to synthetic pesticides are at an increased risk of certain cancers and neurological disorders. Recent research on respiratory effects is sparse, and more research is warranted regarding DNA damage, oxidative stress, metabolic outcomes, and thyroid effects.

Different working conditions shift the genetic damage levels of pesticide-exposed agriculture workers

In the current study, we had two main purposes. Firstly, we aimed to compare genetic damages in the agricultural workers of two different types of environmental conditions including the greenhouse and open fields. Secondly, we aimed to compare genetic damages in the total agricultural workers as the exposed group (greenhouse and open field workers) (n = 114) and the non-exposed control group (n = 98) living in the same area in Canakkale, Turkey. For these purposes, we investigated the incidence of micronucleus (MN), nucleoplasmic bridges (NPBs), and nuclear buds (NBUDs) in peripheral blood lymphocytes. We observed that the frequencies of MN, NPB, and NBUD obtained for the greenhouse workers were statistically significantly higher than those obtained for the open field workers. When the results of the control group were compared with those of the total workers, there were statistically significant differences in terms of MN and NBUD frequencies. We found that age and MN were correlated at a significant level in both the agricultural workers and the control group. The MN frequency of the female workers was 1.5 times greater than that of the male workers, and it was a significant level in the agricultural workers.

Herbicide biomonitoring in agricultural workers in Valle del Mayo, Sonora Mexico

Valle del Mayo is an important agricultural area at the northwest of Mexico where up to 20,000 L of a mix composed of glyphosate and tordon is used in drains and canals. This study was carried out in order to evaluate the cellular damage caused by glyphosate, aminomethylphosphonic acid (AMPA), and picloram in agricultural workers. Biomonitoring was performed through the quantification of herbicides in urine using HPLC (high-performance liquid chromatography) to then evaluate the cellular damage in exposed people by means of an evaluation of micronuclei and cellular proliferation in lymphocyte cultures. The urine samples (n = 30) have shown a concentration of up to 10.25 μg/L of picloram and 2.23 μg/L of AMPA; no positive samples for glyphosate were reported. The calculation of the external dose reveals that agricultural workers ingest up to 146 mg/kg/day; however, this concentration does not surpass the limits that are allowed internationally. As for the results for the micronuclei test, 53% of the workers showed cellular damage, and the nuclear division index test reported that there was a significant difference (P < 0.05) between the exposed and the control population, which indicated that the exposure time to pesticides in the people of Valle del Mayo can induce alterations which can cause chronic damage.

Monitoring human genotoxicity risk associated to urban and industrial Buenos Aires air pollution exposure

The quality of life in large megacities is directly affected by its air quality. In urban environments, suspended particles from anthropogenic origin is one of the main air contaminants identified as highly genotoxic, mutagenic, or carcinogenic. Atmospheric monitoring is therefore imperative, and bioassays to detect the effects of genotoxic agents give usually excellent results. Analysis of micronucleus (MN) in exfoliated oral mucosa cells is a sensitive non-invasive method for monitoring genetic damage in human populations. The first aim of this study was to analyze and characterize levels of volatile organic compounds (VOCs), particulate matter (PM), and polycyclic aromatic hydrocarbons (PAHs) in two areas from Buenos Aires: La Plata city, an urban (U) area and Ensenada, an industrial (I) area. Secondly, we evaluated the possible health risk of its inhabitants through a simple genotoxic assay on exfoliated oral mucosa cells. Whole blood cell count and nuclear abnormalities frequencies were evaluated in the exfoliated oral mucosa cells from urban and industrial inhabitants. Smoking habit represented a significant factor increasing MN percentage while, age did not increase the production of any of the nuclear aberrations assayed (micronuclei, binucleated, karyorrhexis) when the inhabitants from the urban and the industrial areas were compared. In addition, changes in MN and binucleated cell percentages in males and females were found to be area-dependent. We suggest that regardless PM concentration, PM-specific characteristics (size, shape, chemical elements, etc.) and VOCs levels could be responsible for the different harmful genotoxic effects seen in the two areas. Although this is a preliminary study, our results allowed to recognize that individuals living in both the urban and the industrial areas could be considered susceptible groups and should periodically undergo biological monitoring and appropriate care.

Results of buccal micronucleus cytome assay in pesticide-exposed and non-exposed group

Since many different pesticides have been used occupationally, there have been inconsistent results regarding DNA damages among greenhouse workers. Thus, the aim of the study is to evaluate DNA damages, cell death, and chromosomal instability by using the buccal micronucleus cytome (BMcyt) assay in greenhouse workers and to compare those with a non-exposed group. The BMcyt assay was applied to the exfoliated buccal cell samples collected from 66 pesticide-exposed and 50 non-exposed individuals. We evaluated the frequency of micronucleus (MN), nuclear bud (NBUD), binucleated (BN) cells, and karyolitic (KL), pyknotic (PY), and karyorrhectic (KH) cells. The results showed that the MN, BN, PY, and KH frequencies of the pesticide-exposed group were significantly higher than those of the controls (P ˂ 0.05, P ˂ 0.05, P ˂ 0.01, and P ˂ 0.05, respectively). We observed that the MN, BN, PY, and KH frequencies in the autumn were statistically different compared with those in the control group (P = 0.037 for MN, P = 0.001 for BN, P = 0.016 for PY, and P = 0.033 for KH). The same comparison was done in the spring for the control, and there was a statistically significant difference for MN (P = 0.046) and PY (P = 0.014). We can conclude that pesticide exposure in greenhouse workers was one of the factors that altered DNA damages, cell death, and chromosomal instability in oral mucosa cells.

Comet assay for assessment of DNA damage in greenhouse workers exposed to pesticides

Purpose: The main goal of the present study was to determine DNA damage in pesticide-exposed greenhouse workers and pesticides non-exposed controls. Materials and methods: The DNA damage was measured by alkaline comet assay method (pH > 13) in 41 greenhouse workers and 45 non-exposed individuals as the control. Pesticide exposure was assessed by duration of working in the greenhouse and pesticide application in the greenhouse time. DNA damage was estimated by arbitrary unit and damage frequency. Results: Arbitrary unit and damage frequency were consistently significantly higher in greenhouse workers than those of the controls (p = 0.001). In terms of gender in greenhouse, DNA damage of female workers was significantly higher than those in male workers (p < 0.05). We found significant correlation between DNA damage and working hours spent. Multiple linear regression analysis showed that working hours in the greenhouse as an indication of pesticide exposure were significantly associated with the DNA damage, which can be attributed to the genotoxic potential of the pesticide mixture. Conclusions: The comet assay is sensitive to detect the damage exposed to chronic effect of pesticides in greenhouse workers. Significant DNA damage was obtained for the exposed group, which was associated with the pesticide exposure.

Cytotoxic and Genotoxic Effects of Pesticide Exposure in Male Coffee Farmworkers of the Jarabacoa Region, Dominican Republic

Intensive agrochemical use in coffee production in the Global South has been documented. The aim of this study was to investigate cytotoxic and genotoxic effects of pesticide exposure in male farmworkers in the Dominican Republic comparing conventional farming using pesticides to organic farming. Furthermore, feasibility of the buccal micronucleus cytome assay (BMCA) for field studies under difficult local conditions was tested. In a cross-sectional field study, pesticide exposed (sprayers) and non-exposed male workers on coffee plantations were interviewed about exposure history, and pesticide application practices. Buccal cells were sampled, and BMCA was applied to assess potential effects on cell integrity. In total, 38 pesticide-exposed and 33 non-exposed workers participated. Eighty-four and 87%, respectively, of the pesticide-exposed respondents did not use masks or gloves at all. All biomarkers from the BMCA were significantly more frequent among exposed workers—odds ratio for micronucleated cells: 3.1 (95% confidence interval: 1.3–7.4) or karyolysis: 1.3 (1.1–1.5). Buccal cells as sensitive markers of toxic oral or respiratory exposures proved feasible for challenging field studies. Our findings indicate that the impact of pesticide use is not restricted to acute effects on health and wellbeing, but also points to long-term health risks. Therefore, occupational safety measures including training and protective clothing are needed, as well as encouragement towards minimal application of pesticides and more widespread use of organic farming.

Micronuclei and other nuclear anomalies in exfoliated buccal cells of urban solid waste collectors and recyclers in southern Brazil

Workers involved in urban solid waste collection may be exposed to various environmental contaminants, including chemical pollutants, which might be mutagenic and increase the risk of diseases such as cancer. Evaluation of DNA damage in workers in this field are still scarce. This study aims to evaluate mutagenic and cytotoxic effects in workers involved in the collection and segregation of urban solid waste generated in southern Brazil. Municipal solid waste collectors were recruited in two municipalities of the state of Rio Grande do Sul. The control group was composed of workers of the education and commerce areas, with no exposure to known genotoxic agents. Slides of exfoliated buccal cells were analyzed to estimate the frequency of micronuclei (MN) as well as other nuclear abnormalities, such as broken-egg/bud, binucleation and karyorrhexis. The analyses of 44 workers and 45 control subjects have shown that the frequencies of MN, binucleated cells and karyorrhexis in the exposed workers were significantly higher than in the control group. In the exposed group, frequencies of MN and binucleated cells showed a significant positive correlation. The other cytogenetic parameters were not correlated among each other or with age and exposure time. These results indicate that the workers involved in urban solid waste collection are exposed to mutagenic and cytotoxic agents.

Modulatory role of GSTM1 null genotype on the frequency of micronuclei in pesticide-exposed agricultural workers

In this study, we aimed to investigate the extent of genotoxic risk and the association between null GSTM1/GSTT1 and GSTP1 Ile105Val variants and cellular DNA damage, as measured by micronucleus (MN) assay in a group of agricultural workers from Denizli, Turkey. Peripheral blood samples were collected from 116 subjects, including 58 workers who were occupationally exposed to pesticides and 58 healthy unexposed controls. The MN frequencies of each individual were assessed by cytokinesis-blocked micronuclei assays on lymphocytes. Genotypes for different GST variants were determined using polymerase chain reaction-based methods. A significant 3.4-fold increase in MN frequency was observed in workers compared with the controls ( p < 0.001). Among the GST genotypes, only the GSTM1 null genotype was found to be significantly associated with an increased MN frequency in workers ( p = 0.01). Individuals with a concomitant null GSTM1/GSTT1 genotype demonstrated a significant ( p = 0.01) increase in MN frequency compared with those with functional isozymes in the exposed worker group. The association of the GSTM1 null genotype with higher MN frequency suggests that it may be a modifier of genotoxic risk in individuals exposed to pesticides and may thus be a candidate susceptibility biomarker for human biomonitoring studies.

The use of the lymphocyte cytokinesis-block micronucleus assay for monitoring pesticide-exposed populations

Pesticides are widely used around the world, and hundreds of millions of people are exposed annually in occupational and environmental settings. Numerous studies have demonstrated relationships between pesticide exposure and increased risk of cancers, neurodegenerative and neurodevelopmental disorders, respiratory diseases and diabetes. Assessment of genotoxicity of pesticides and biomonitoring their effect in exposed populations is critical for a better regulation and protection, but it can be complicated because pesticides are often used as complex mixtures. The cytokinesis-block micronucleus assay in human lymphocytes (L-CBMN) is a validated method of assessment of DNA damage induced by clastogenic and aneuploidogenic mechanisms. The goal of this review is to provide an updated summary of publications on biomonitoring studies using this assay in people exposed to pesticides in different settings, and to identify gaps in knowledge, and future directions. A literature search was conducted through MedLine/PubMed and TOXLINE electronic databases up to December 2015. A total of 55 full-text articles, related to 49 studies, excluding reviews, were selected for in depth analysis, divided by the settings where exposures occurred, such as chemical plant workers, pesticide sprayers, floriculturists, agricultural workers and non-occupationally exposed groups. Majority of studies (36 out of 49) reported positive findings with L-CBMN assay. However, most of the studies of professional applicators that used single pesticide or few compounds in the framework of specific programs did not show significant increases in MN frequency. A decreased level of pesticide-induced genotoxicity was associated with the proper use of personal protection. In contrast, subjects working in greenhouses or during intensive spraying season and having acute exposure, showed consistent increases in MN frequency. Overall, this analysis confirmed that L-CBMN is an excellent tool for pesticide biomonitoring, and can validate the effects of educational and intervention programs on reducing exposure and genetic damage.

The association of nuclear abnormalities in exfoliated buccal epithelial cells with the health status of different agricultural activities farmers in Peninsular Malaysia

BACKGROUND

Pesticide exposure possesses risk of genotoxicity to humans, particularly farmers. Despite accumulating evidences linking genotoxicity to pesticide exposure, epidemiological studies to address pesticide toxicity in occupationally exposed farmers in Malaysia remain underreported. Thus, this study was aimed to determine the presence of nuclear abnormalities through the assessment of micronucleus (MN) and binucleus (BNu) frequencies in exfoliated buccal epithelial cells from farmers who were exposed to pesticides. A cross-sectional study of farmers among different agricultural activities farmers in Bachok and Pasir Puteh, Kelantan, North East of Peninsular Malaysia was done to evaluate the presence of nuclear abnormalities and its correlation with their health status and farming activities.

RESULTS

Analysis of buccal cells revealed that the frequency of MN was significantly higher (p < 0.05) in farmers as compared to controls. In contrast, no significant difference (p > 0.05) was observed for BNu frequency in between groups. Correlation analysis showed that apart from a significant (p < 0.05) and positive correlation between the duration of fertilizers exposure and frequencies of MN (r = 0.42, P = 0.001) and BNu (r = 0.37, P = 0.02), no other correlation of various confounding factors on the formation of MN and BNu were observed.

CONCLUSION

In conclusion, pesticide and fertilizers exposure may contribute to the promotion of nuclear anomalies among Malaysian farmers who are engaged in mixed plantation activities. Further assessment of larger populations is important to address and overcome the potential risk of pesticide-induced genotoxicity.

Dose-dependent micronuclei formation in normal human fibroblasts exposed to proton radiation

Micronuclei are small extranuclear bodies resulting from chromosome fragments or the whole chromosomes secluded from daughter nuclei during mitosis. The number of radiation-induced micronuclei reflects the level of chromosomal damage and relates to an absorbed dose and quality of incident ionizing radiation. The aim of the present study was to determine the micronucleus formation as a specific biological marker for acute radiation-induced DNA damage in normal human fibroblasts exposed to 30-MeV protons and Co-60 gamma radiation. We found a linear increase in binuclear cells containing micronuclei for absorbed doses from 1 to 5 Gy for both radiation modalities. However, the total number of micronuclei in binuclear cells follows a linear-quadratic dose dependence. In case of human exposure to mixed radiation fields or high LET radiation, the proportion of binuclear cells containing micronuclei from all binuclear cells can thus serve as a good biomarker of radiation-induced DNA damage.

Noninvasive effects measurements for air pollution human studies: methods, analysis, and implications

Human exposure studies, compared with cell and animal models, are heavily relied upon to study the associations between health effects in humans and air pollutant inhalation. Human studies vary in exposure methodology, with some work conducted in controlled settings, whereas other studies are conducted in ambient environments. Human studies can also vary in the health metrics explored, as there exists a myriad of health effect end points commonly measured. In this review, we compiled mini reviews of the most commonly used noninvasive health effect end points that are suitable for panel studies of air pollution, broken into cardiovascular end points, respiratory end points, and biomarkers of effect from biological specimens. Pertinent information regarding each health end point and the suggested methods for mobile collection in the field are assessed. In addition, the clinical implications for each health end point are summarized, along with the factors identified that can modify each measurement. Finally, the important research findings regarding each health end point and air pollutant exposures were reviewed. It appeared that most of the adverse health effects end points explored were found to positively correlate with pollutant levels, although differences in study design, pollutants measured, and study population were found to influence the magnitude of these effects. Thus, this review is intended to act as a guide for researchers interested in conducting human exposure studies of air pollutants while in the field, although there can be a wider application for using these end points in many epidemiological study designs.

Increased cytogenetic abnormalities in exfoliated oral mucosal cells of South Indian foundry workers

Biomonitoring offers a valuable tool to estimate the genetic risk as of exposure to genotoxic agents. Here, we intend to assess the potential cytogenetic damage related with occupational exposure to polycyclic aromatic hydrocarbons by evaluating the genetic damages in exfoliated buccal epithelial cells of foundry workers via counting micronucleus (MNs) and other nuclear abnormalities (NAs). This was a cross-sectional study and all study subjects were male . Exfoliated buccal mucosal cells were obtained from 100 subjects involved in either foundry molding or melting processes, and 100 controls matched for sex, age, and smoking from the area of Coimbatore city, Southern India. For each individual, 2000 exfoliated buccal cells were analyzed. Significantly, there was a higher frequency of MN in the exposed workers than in the controls (P < 0.05). Smoking was associated with the increased frequencies of micronuclei and NAs in the buccal epithelium of both the control and the exposed groups. Smoking represented significant factors in terms of increasing the production of MN when the control and the exposed groups were compared (P < 0.05). The results specify that buccal cells of foundry workers display increased levels of genotoxicity and these biomarker responses may be related to the increased cancer risk. These results conclude that the studied individuals are at a risk group and they require periodical biological monitoring and proper care which is essential for them.

Cytogenetic damage in the oral mucosa cells of bladder cancer patients exposed to tobacco in Southern Tunisia

Bladder cancer was associated to exposure to several pollutants which can be absorbed, inhaled, or possibly ingested. We analyzed the frequency of micronuclei (MNC) and binucleated cells (BNC) in exfoliated cells of the oral mucosa of 24 bladder cancer (BC) patients and 48 controls residing in Southern Tunisia. An assessment was carried out on the incidence of MNC and BNC in 1,000 cells per individual. The data were analyzed with SPSS, using the chi-square and the Mann-Whitney U test, α = 0.05. The frequency of MN cells in BC cases was 2.5-fold higher, than in the control group (P < 0.001), while the difference for BNC between both groups was not significant. The smoking habits, age, and gender significantly influenced the MN but not the BNC alterations. The results of our study showed significantly increased frequencies of MN but not of BNC in exfoliated oral cells of BC patients associated with the smoking status, sex, and age. This study provides preliminary evidence that the frequency of MN in oral mucosa could be a predictive biomarker for cancers in parts of the body other than the upper aerodigestive tract, such as BC. Further scrupulous investigations are certainly warranted in order to implement this assay as a routine test in the planning and validation of cancer surveillance and prevention programs.

Assessment of cytotoxic and genotoxic potential of pyracarbolid by Allium test and micronucleus assay

The present study evaluates the cytotoxic and genotoxic potential of pyracarbolid using both micronuleus (MN) assay, in human lymphocytes, and Allium cepa assay, in the root meristem cells. In Allium test, EC50 value was determined in order to selecting the test concentrations for the assay and the root tips were treated with 25 ppm (EC50/2), 50 ppm (EC50) and 100 ppm (EC50 × 2) concentrations of pyracarbolid. One percent of dimethyl sulphoxide (DMSO) and methyl methane sulfonate (MMS) were used as negative and positive controls, respectively. In the micronucleus assay, the cultures were treated with four concentrations (250, 500, 750 and 1000 µg/ml) of pyracarbolid for 24 and 48 h, negative and positive controls were also used in the experiment parallely. The results showed that mitotic index (MI) significantly reduced with increasing the pyracarbolid concentration at each exposure time. It was also obtained that prophase and metaphase index decreased significantly in all concentration at each exposure time. Anaphase index decreased as well and results were found to be statistically significant, except 24 h. A significant increase was observed in MN frequency in all concentrations and both treatment periods when compared with the controls. Pyracarbolid also caused a significant reduction in the cytokinesis block proliferation index (CBPI) in all concentration and both exposure time.

Assessment of the genotoxic effects of organophosphorus insecticides phorate and trichlorfon in human lymphocytes

In vitro genotoxic effects of organophosphorus insecticides Phorate (PHR) and Trichlorfon (TCF) were investigated using four genotoxicity endpoints. Different concentration ranges between 0.25-2.00 μg mL(-1) of PHR and 2.34-37.50 μg mL(-1) of TCF were applied to lymphocytes. PHR and TCF significantly increased the frequency of chromosomal aberrations (except 2.34 μg mL(-1) for TCF) and sister chromatid exchanges at all treatment times and concentrations. Most of the used concentrations induced a significant increase in the frequency of micronuclei. Furthermore, PHR and TCF significantly decreased the mitotic index at the higher concentrations after 24- and 48-h treatments. In the comet assay, PHR and TCF significantly increased the comet tail at all concentrations. However, the comet tail intensity was significantly increased at only the highest concentration of PHR and at all concentrations of TCF. According to these results, PHR and TCF possess clastogenic, mutagenic, and DNA damaging effects in human lymphocytes in vitro.

Cytogenetic abnormality in exfoliated cells of buccal mucosa in head and neck cancer patients in the Tunisian population: impact of different exposure sources

Chromosome/DNA instability could be one of the primary causes of malignant cell transformation. The objective of the present study was to evaluate the spontaneous genetic damages in exfoliated cells of buccal mucosa of head and neck cancer (HNC) by counting micronucleus (MN) and binucleated (BN) cells frequencies. MN and BN frequencies were significantly increased in HNC patients compared with controls (5.53 ± 3.09/1000 cells, 5.63 ± 2.99/1000 cells versus 2.36 ± 2.11/1000 cells, 3.09 ± 1.82/1000 cells, P < 0.001). Regarding the gender and the age, the frequencies of the MN and BN were significantly higher than those of controls (P < 0.01). The evaluation of the MN and BN frequencies revealed a significant increase (P < 0.001) in the cases in relation to the control group after controlling the risk factors (tobacco smoking and chewing and occupational exposure) of HNC. Moreover, MN and BN frequencies were significantly increased in smokers and chewers compared with nonsmokers and nonchewers among patients (P < 0.05). MN frequency was significantly (P = 0.014) different between patients occupationally exposed (6.99 ± 3.40/1000 cells) and nonexposed (4.70 ± 2.48/1000 cells) among HNC group. The logistic regression model illustrated that HNC was significantly associated with frequencies of MN (OR = 8.63, P < 0.0001) and BN (OR = 5.62, P = 0.001). Our results suggest that increased chromosome/DNA instabilities may be associated with HNC.

Bio-monitoring for the genotoxic assessment in road construction workers as determined by the buccal micronucleus cytome assay

Buccal micronucleus cytome (BMCyt) assay monitors genetic damage, cell proliferation and cell death in humans exposed to occupational and environmental agents. BMCyt is used as an indicator of genotoxic exposure, since it is associated with chromosomal instability. There is little research on the occupational exposure among road construction workers for genotoxicity testing. In the present study, we evaluated MN frequencies and other nuclear changes, karyorrhexis (KR), karyolysis (KL), broken egg (BE), binucleate (BN), condensed chromatin cell (CCC), and picnotic cell (PC) in buccal mucosa cells of 40 road construction workers (twenty smokers and twenty non-smokers) and 40 control groups consisting of healthy persons (twenty smokers and twenty non-smokers). Microscopic observation was performed of 2000 cells per individual in both road construction workers and control group. In control and worker groups, for each person repair index (RI) was calculated via formula KR+L/BE+MN. The results showed a statistically significant increase in the frequency of MN in buccal epithelial cells of exposed group compared with control group (p<0.001). There is no significant difference between smokers and non-smokers for incidence of MN or nuclear changes and value of RI in exposed group. In road construction workers, RI is lower than the control group. There is a significant difference between workers and control group (p<0.001) for RI. Our data reveal that asphalt fumes during road paving operations are absorbed by workers and that asphalt fume exposure is able to significantly induce cytogenetic damage in buccal mucosa cells of workers after controlling some possible confounding factors, such as age, sex and smoking habits. In addition to determination of nuclear changes and the micronucleus, the determination of RI value presents a new approach to genotoxic bio-monitoring assessment studies of occupationally exposed population.

Micronucleus assay as a biomarker of genotoxicity in the occupational exposure to agrochemicals in rural workers

This paper aims to evaluate the genotoxic effect of agrochemicals in rural workers occupationally exposed by the micronucleus assay in peripheral blood lymphocytes and to promote the development of health and environmental preventive and protective practices. A total of 30 blood samples from 20 individuals occupationally exposed to different agrochemicals and 10 unexposed persons, who formed the reference group, were analyzed. We found statistically significant differences (p < 0.0005, Student's t Test) in the frequency of micronuclei between the two groups (7.20 ± 1.55 and 15.15 ± 5.10 CBMN for reference and exposed groups respectively). The analysis of age showed a positive correlation (Pearson Correlation Test) with the frequency of micronuclei in exposed population (p < 0.05; r(2) = 0.47), in contrast with smoking habits and years of exposure. Micronucleus assay allows an early detection of populations at higher risk of having genetic damage, allowing us to implement strategies of intervention for the purpose of contributing to reduce that risk.

Adapting the buccal micronucleus cytome assay for use in wild birds: age and sex affect background frequency in pigeons

Micronucleus (MN) formation has been used extensively as a biomarker of damage from genotoxic exposures. The Buccal MN Cytome (BMCyt) assay provides a noninvasive means of quantifying MN frequency in humans, but it has not been developed for use in wildlife. We adapted the BMCyt assay for use in wild birds, with a focus on feral pigeons (Columba livia) as a potential indicator species. Five of six urban bird species sampled using oral cavity swabs produced sufficient buccal cells for the BMCyt assay. The body size of species sampled ranged almost 100-fold (~60 to 5,000 g), but was a not major factor influencing the number of buccal cells collected. Pigeon cells were stained and scored following published BMCyt assay protocols for humans, but with a modified fixation approach using heat and methanol. Pigeons had the same common nuclear abnormalities reported in human studies, and a similar background MN formation frequency of 0.88 MN/1,000 cells. Adult pigeons had on average a threefold higher rate of MN formation than juveniles, and males had a 1.4- to 2.2-fold higher frequency than females. Domestic and feral pigeons did not differ in overall MN frequency. Our results indicate that the BMCyt assay can be used on wild birds, and could provide a means of assessing environmental genotoxicity in pigeons, a useful indicator species. However, bird age and sex are important factors affecting background MN frequency, and thereby the design of environmental studies.

Genotoxicity in vinyl chloride-exposed workers and its implication for occupational exposure limit

BACKGROUND

Vinyl chloride monomer (VCM) is a colorless gas under room temperature and has been mostly used to produce polyvinyl chloride (PVC) since the 1970s. It is classified by the International Agency of Research on Cancer (IARC) as a known human carcinogen (Group 1). In this study, genetic damage in VCM workers was evaluated in relation to their occupational cumulative exposure to VCM.

METHODS

Cytokinesis-block micronucleus assay was conducted in 229 VCM workers and 138 controls to detect chromosome damage in peripheral blood lymphocytes. The cumulative exposure dose (CED) of VCM was calculated based on the job type and duration of each worker and the workplace VCM concentration. Dose-response relationships between VCM CED and micronucleus frequency or chromosomal damage were evaluated, and benchmark doses (BMDs) estimated.

RESULTS

Dose-response relationships between VCM CED and chromosomal damage were obtained. The 95% lower confidence bound of BMD of VCM CED was 2.86 mg/m(3) -year for both genders combined, leading to an estimated exposure limit of 0.072 mg/m(3) assuming a work life of 40 years.

CONCLUSIONS

VCM exposure may induce chromosomal damage at occupational exposure levels below the Chinese national occupational health standard. Further research is needed to better understand micronuclei as biomarker of VCM genotoxicity. Better dose-response assessment and BMD estimation are desirable in order to improve the quantification of occupational exposure limits for VCM with respect to non-cancer risk.

Cytotoxic effects of permethrin on mouse liver and spleen cells

This study analyzed the histopathological and histochemical effects of different dosages of permethrin on liver and spleen cells of mice, in order to evaluate the toxic potential of this substance and the possible impairments that this chemical causes in different tissues of nontarget organisms (laboratorial conditions). The results showed that permethrin caused severe alterations in the liver cells, reducing the size of the nuclei and causing hydropic degeneration of the hepatocytes, in addition to stimulating the proliferation of Kupffer cells, altered the amount of proteins, polysaccharides, lipids, and vacuoles in the cytoplasm of the hepatocytes and congested the hepatic capillaries. As for the spleen of the treated mice, no alterations were observed in the morphology in relation to the control group, what would suggest that the spleen would continue performing its functions, without suffering morphological alterations even in the presence of the toxic agent.

Micronuclei and pesticide exposure

Micronucleus (MN) is a biomarker widely used in biomonitoring studies carried out to determine the genetic risk associated to pesticide exposure. Many in vitro and in vivo studies, as well as epidemiological approaches, have demonstrated the ability of certain chemical pesticides to produce genetic effects including cancer and other chronic pathologies in humans; thus, biomonitoring studies have been carried out to characterise the genetic risk associated to pesticide exposure. It must be noted that 'pesticide exposure' is a broad term covering complex mixtures of chemicals and many variables that can reduce or potentiate their risk. In addition, there are large differences in pesticides used in the different parts of the world. Although pesticides constitute a wide group of environmental pollutants, the main focus on their risk has been addressed to people using pesticides in their working places, at the chemical industry or in the crop fields. Here, we present a brief review of biomonitoring studies carried out in people occupationally exposed to pesticides and that use MN in lymphocytes or buccal cells as a target to determine the induction of genotoxic damage. Thus, people working in the chemical industry producing pesticides, people spraying pesticides and people dedicated to floriculture or agricultural works in general are the subject of specific sections. MN is a valuable genotoxic end point when clear exposure conditions exist like in pesticide production workers; nevertheless, better study designs are needed to overcome the uncertainty in exposure, genetic susceptibility and statistical power in the studies of sprayers and floriculture or agricultural workers.

Frequencies of micronuclei (MNi), nucleoplasmic bridges (NPBs), and nuclear buds (NBUDs) in farmers exposed to pesticides in Çanakkale, Turkey

This study aimed to determine the incidence of micronuclei (MNi), nucleoplasmic bridges (NPBs), and nuclear buds (NBUDs) in peripheral blood lymphocytes due to direct exposure to pesticides among 46 farmers in Çanakkale, Turkey. 48 non-exposed individuals living in the same socioeconomic conditions were chosen as control. In addition, a cytokinesis-block proliferation index (CBPI) was calculated. MNi and NBUDs frequencies were significantly higher among the farmers (p < 0.05). Although the NPB frequency of the farmers was higher than the controls, there was no statistical difference. Multiple linear regression analysis showed that apart from gender, no significant effects of various confounding factors were observed. Regarding CBPI, data obtained for the controls were higher than that of the farmers; however, there was no statistically significant difference.

Chromosome damage and cytotoxicity in oral mucosa cells after 2 months of exposure to anabolic steroids (decadurabolin and winstrol) in weight lifting

The aim of the present study was to evaluate DNA damage (micronucleus) and cellular death (pyknosis, karyolysis and karyorrhexis) in exfoliated buccal mucosa cells from anabolic steroid users after 2 months of exposure. Two experimental groups consisting of 15 adult males who practise weight lifting and are anabolic steroid users or 15 adult males who practise weight lifting, but are non-anabolic steroid users, were recruited. In addition, 20 sedentary males, who do not practise any physical activity regularly, were matched by age with experimental groups. No significant statistical differences (p>0.05) were noticed in individuals who practise physical activity only. On the other hand, an increase of micronucleated cells (MNCs) in anabolic steroid (decadurabulin and Winstrol) users was observed. Regarding cytotoxic parameters, the same observation has occurred, that is, significant statistical differences (p<0.05) were noticed in the group exposed to anabolic steroids when compared with other controls, as depicted by high frequencies of pyknosis, karyolysis and karyorrhexis. Taken together, our results suggest that genomic instability and cytotoxicity are induced by anabolic steroid administration in oral mucosa cells as assessed by the micronucleus test.

Mutagenicity and cytotoxicity assessment in patients undergoing orthodontic radiographs

OBJECTIVES

The aim of the present study was to evaluate DNA damage (micronucleus) and cellular death (pyknosis, karyolysis and karyorrhexis) in exfoliated buccal mucosa cells from individuals following radiography.

METHODS

Lateral and frontal cephalometric X-ray and panoramic dental X-rays were taken of a total of 18 healthy patients (6 male and 12 female) referred for orthodontic therapy. Exfoliated oral mucosa cells were collected immediately before X-ray exposure and after 10 days.

RESULTS

The results revealed no statistically significant difference (P > 0.05) in the frequency micronucleated oral mucosa cells after X-ray exposure. However, X-ray was able to increase other nuclear alterations closely related to cytotoxicity, such as karyorrhexis, pyknosis and karyolysis.

CONCLUSIONS

Data indicated that exposure to certain radiography may not be a factor in inducing chromosomal damage, but it does promote cytotoxicity.

Biomonitoring of DNA damage and cytotoxicity in individuals exposed to cone beam computed tomography

OBJECTIVES

The aim of the present study was to evaluate DNA damage (micronucleus) and cellular death (pyknosis, karyolysis and karyorrhexis) in exfoliated buccal mucosa cells from adults following cone beam CT exposure.

METHODS

A total of 19 healthy adults (10 men and 9 women) submitted to cone beam CT were included.

RESULTS

No significant statistically differences (P > 0.05) in micronucleus frequency were seen before and after cone beam CT exposure. In contrast, the tomography was able to increase other nuclear alterations closely related to cytotoxicity such as karyorrhexis, pyknosis and karyolysis (P < 0.05).

CONCLUSION

In summary, these data indicate that cone beam CT may not be a factor that induces chromosomal damage, but it is able to promote cytotoxicity.

Genotoxic effects of a particular mixture of acetamiprid and alpha-cypermethrin on chromosome aberration, sister chromatid exchange, and micronucleus formation in human peripheral blood lymphocytes

The genotoxic effects of a particular mixture of acetamiprid (Acm, neonicotinoid insecticide) and alpha-cypermethrin (alpha-cyp, pyrethroid insecticide) on human peripheral lymphocytes were examined in vitro by chromosomal aberrations (CAs), sister chromatid exchange (SCE), and micronucleus (MN) tests. The human peripheral lymphocytes were treated with 12.5 + 2.5, 15 + 5, 17.5 + 7.5, and 20 + 10 microg/mL of Acm+alpha-cyp, respectively, for 24 and 48 h. The mixture of Acm+alpha-cyp induced the CAs and SCEs at all concentrations and treatment times when compared with both the control and solvent control and these increases were concentration-dependent in both treatment times. MN formation was significantly induced at 12.5 + 2.5, 15 + 5, 17.5 + 7.5, microg/mL of Acm+alpha-cyp when compared with both controls although these increases were not concentration-dependent. Binuclear cells could not be detected sufficiently in the highest concentration of the mixture (20 + 10 microg/mL) for both the 24- and 48-h treatment times. Mitotic index (MI), proliferation index (PI) and nuclear division index (NDI) significantly decreased because of the cytotoxic and cytostatic effects of the mixture, at all concentrations for two treatment periods. Significant decreases in MI and PI were concentration dependent at both treatment times. The decrease in NDI was also concentration-dependent at 48-h treatment period. In general, Acm+alpha-cyp inhibited nuclear division more than positive control, mitomycin C (MMC) and showed a higher cytostatic effect than MMC. Furthermore, in this article, the results of combined effects of Acm+alpha-cyp were compared with the results of single effects of Acm or alpha-cyp (Kocaman and Topaktas,2007,2009, respectively). In conclusion, the particular mixture of Acm+alpha-cyp synergistically induced the genotoxicity/cytotoxicity in human peripheral blood lymphocytes.

Cellular death but not genetic damage in oral mucosa cells after exposure to digital lateral radiography

The aim of the present study was to evaluate DNA damage (micronucleus) and cellular death (pyknosis, karyolysis, and karyorrhexis) in exfoliated buccal mucosa cells from individuals following digital lateral radiography. A total of 30 healthy patients (15 men and 15 women) indicated to the orthodontic therapy were submitted to digital lateral X-ray. Exfoliated oral mucosa cells were collected immediately before the X-ray exposure and after 10 days. The results pointed out no significant statistically differences (p > 0.05) of micronucleated oral mucosa cells. On the other hand, X-ray was able to increase other nuclear alterations closely related to cytotoxicity such as karyorrhexis, pyknosis, and karyolysis. In summary, these data indicate that exposure to digital lateral radiography may not be a factor that induced chromosomal damage, but it is able to promote cytotoxicity.

Biomonitoring of oral epithelial cells in petrol station attendants: comparison between buccal mucosa and lateral border of the tongue

Owing to the influence of geno- and cytotoxicity on chemical carcinogenesis, studies have demonstrated that petroleum derivatives are able to induce genetic damage and cellular death with conflicting results so far. The aim of the present study was to comparatively evaluate DNA damage (micronucleus) and cellular death (pyknosis, karyolysis and karyorrhexis) in exfoliated oral mucosa cells from gas petrol attendants using two different anatomic buccal sites: cheek mucosa and lateral border of the tongue. A total of 23 gas petrol attendants and 23 health controls (non-exposed individuals) were included in this setting. Individuals had epithelial cells from cheek and lateral border of the tongue mechanically exfoliated, placed in fixative and dropped in clean slides which were checked for the above nuclear phenotypes. The results pointed out significant statistical differences (p<0.05) of micronucleated oral mucosa cells from gas petrol attendants for both oral sites evaluated. In the same way, petroleum derivate exposure was able to increase other nuclear alterations closely related to cytotoxicity such as karyorrhexis, pyknosis and karyolysis, being the most pronunciated effects as those found in the lateral border of the tongue. No interaction was observed between smoking and petroleum exposure. In summary, these data indicate that gas petrol attendants comprise a high risk group for DNA damage and cellular death. It seems that the lateral border of the tongue is a more sensitive site to geno- and cytotoxic insult induced by petroleum derivates.