The present systematic review (SR) aims to evaluate manuscripts in order to help further elucidate the following question: is the micronucleus assay (MA) also a useful marker in gingiva, tongue, and palate for evaluating cytogenetic damage in vivo? A search was performed through the electronic databases PubMed/Medline, Scopus, and Web of Science, all studies published up to December 2023. The comparisons were defined as standardized mean difference (SMD), and 95% confidence intervals (CIs) were established. Full manuscripts from 34 studies were carefully selected and reviewed in this setting. Our results demonstrate that the MA may be a useful biomarker of gingival tissue damage in vivo, and this tissue could be a useful alternative to the buccal mucosa. The meta-analysis analyzing the different sites regardless of the deleterious factor studied, the buccal mucosa (SMD = 0.69, 95% CI, - 0.49 to 1.88, p = 0.25) and gingiva (SMD = 0.31, 95% CI, - 0.11 to 0.72, p = 0.15), showed similar results and different outcome for the tongue (SMD = 1.19, 95% CI, 0.47 to 1.91, p = 0.001). In summary, our conclusion suggests that the MA can be a useful marker for detecting DNA damage in gingiva in vivo and that this tissue could be effective site for smearing.

Indoor air pollution is becoming a rising public health problem and is largely resulting from the burning of solid fuels and heating in households. Burning these fuels produces harmful compounds, such as particulate matter regarded as a major health risk, particularly affecting the onset and exacerbation of respiratory diseases. As exposure to polluted indoor air can cause DNA damage including DNA sd breaks as well as chromosomal damage, in this paper, we aim to provide an overview of the impact of indoor air pollution on DNA damage and genome stability by reviewing the scientific papers that have used the comet, micronucleus, and γ-H2AX assays. These methods are valuable tools in human biomonitoring and for studying the mechanisms of action of various pollutants, and are readily used for the assessment of primary DNA damage and genome instability induced by air pollutants by measuring different aspects of DNA and chromosomal damage. Based on our search, in selected studies (in vitro, animal models, and human biomonitoring), we found generally higher levels of DNA strand breaks and chromosomal damage due to indoor air pollutants compared to matched control or unexposed groups. In summary, our systematic review reveals the importance of the comet, micronucleus, and γ-H2AX assays as sensitive tools for the evaluation of DNA and genome damaging potential of different indoor air pollutants. Additionally, research in this particular direction is warranted since little is still known about the level of indoor air pollution in households or public buildings and its impact on genetic material. Future studies should focus on research investigating the possible impact of indoor air pollutants in complex mixtures on the genome and relate pollutants to possible health outcomes.

Humans ingest particles and fibers on daily basis. Non-digestible carbohydrates are beneficial to health and food additives are considered safe. However, titanium dioxide (E171) has been banned in the European Union because the European Food Safety Authority no longer considers it non-genotoxic. Ingestion of microplastics and nanoplastics are novel exposures; their potential hazardous effects to humans have been under the radar for many years. In this review, we have assessed the association between oral exposure to man-made particles/fibers and genotoxicity in gastrointestinal tract cells and secondary tissues. We identified a total of 137 studies on oral exposure to particles and fibers. This was reduced to 49 papers with sufficient quality and relevance, including exposures to asbestos, diesel exhaust particles, titanium dioxide, silver nanoparticles, zinc oxide, synthetic amorphous silica and certain other nanomaterials. Nineteen studies show positive results, 25 studies show null results, and 5 papers show equivocal results on genotoxicity. Recent studies seem to show null effects, whereas there is a higher proportion of positive genotoxicity results in early studies. Genotoxic effects seem to cluster in studies on diesel exhaust particles and titanium dioxide, whereas studies on silver nanoparticles, zinc oxide and synthetic amorphous silica seem to show mainly null effects. The most widely used genotoxic tests are the alkaline comet assay and micronucleus assay. There are relatively few results on genotoxicity using reliable measurements of oxidatively damaged DNA, DNA double strand breaks (γH2AX assay) and mutations. In general, evidence suggest that oral exposure to particles and fibers is associated with genotoxicity in animals.

This study aimed to evaluate the scientific literature on the micronucleus assay in nasal mucosa as an appropriate method for evaluating genotoxicity caused by chemical agents. According to the PRISMA guidelines, only in vivo human studies with micronucleus assays using nasal cells were considered. Reviews, case reports, editorials, letters to the editor, and articles not written in English were excluded. The following scientific databases/search engines were used: PubMed/MEDLINE, Scopus, and Web of Science. Results: This review included 13 studies. Four articles detected no statistical significance regarding the frequency of micronuclei while nine articles showed an increase in micronuclei in nasal cells. In the qualitative analysis, two articles were considered strong, eight were moderate and three were weak. The micronucleus assay using nasal mucosa cells is a sensitive and effective technique for assessing DNA damage and an appropriate method for monitoring humans continuously exposed to chemicals.

The aim of this study was to evaluate if the micronucleus test using oral epithelial cells is a suitable biomarker for biomonitoring children exposed to X-ray.
A search was performed through the electronic databases PubMed/Medline, Scopus, and Web of Science, all studies published up to February 2022 that examined the relationship between exposure of children to radiographic examinations and micronucleus.
A total of 17 full-text manuscripts were screened for eligibility. Only two studies found a difference in micronucleus labeling. On the other hand, all studies showed that X-ray was able to induce cellular death in oral mucosa cells. Following the parameters of the Effective Practices in Public Health Project (EPHPP), five manuscripts reached moderate and strong scores, and four studies were categorized as weak at final rating. In the meta-analysis, statistically significant difference was detected in micronucleated cells in children before and after radiographic examinations (SMD = 0.96, 95% CI, 0.07-1.84, p = .04), with τ2=1.09; χ2=53.37, and p < .001.
Radiographic examinations in children can cause genotoxic and cytotoxic damage in the oral epithelium with a large effect size.

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.

The aim of this systematic review and meta-analysis was to assess the association between exposure to ambient air pollutants and micronuclei (MN) frequency in children. This work was performed according to the Cochrane Collaboration and the PRISMA guidelines and recommendations. Articles published before November 2021 were identified by an advanced search on PubMed/MEDLINE, Scopus and Web of Science databases. A critical appraisal using a specific tool was conducted to assess the quality of each included study. All analyses were carried out by using the Review Manager (RevMan) 5.4 software (The Cochrane Collaboration, London, UK). One hundred and forty-five references were firstly identified, and, at the end of selection process, 13 studies met the inclusion criteria. Six studies carried out a direct evaluation through the use of air samplers, whereas the other ones accessed environmental databases (n = 2) or used other tools (n = 3). In two cases, exposure was not directly investigated, with children sampled in two different areas with well-known different levels of pollution. The overall effect size (ES) was 1.57 ((95% CI = 1.39; 1.78), p-value < 0.00001) (total evaluated subjects: 4162), which highlighted a statistically significant association between outdoor air pollution and MN frequency in children. As a high MN frequency has been associated with a number of pathological states and a higher risk of developing chronic degenerative diseases, our results should be taken into consideration by policy makers to design and implement interventions aimed at reducing the introduction of pollutants in the atmosphere as well as at minimizing the exposure extent, particularly in children.

This systematic review (SR) with meta-analysis aimed to evaluate the scientific data related to cytogenetic damage in oral exfoliated cells of patients diagnosed with oral potentially malignant disorders (OPMDs). The SR was conducted according to the PRISMA-P guidelines. The PICOS (Participants, Intervention, Comparison, Outcome, and Study Design) strategy was used to answer the question: \"Is micronucleus assay in oral exfoliated cells a suitable biomarker for predicting cancer risk in individuals with OPMDs?\" The search strategy was performed in the following electronic databases: PubMed, Medline, Scopus and Web of Science. The comparisons were defined as standardized mean difference (SMD), and 95% confidence intervals (CI). The quality of included studies was assessed using the EPHPP (Effective Public Health Practice Project). The GRADE tool was also utilized to assess the quality of evidence of the SR. A total of 110 potentially relevant studies were selected through the search strategy. After screening titles and abstracts, 20 full-text manuscripts were assessed for eligibility and three observational studies were included in the meta-analysis. After reviewing the 20 studies, 13 were considered weak. The meta-analysis data revealed a statistically significant difference in oral micronucleated cells by patients with OPMDs when compared to control (SMD=1.77, 95% CI, 0.36-3.18, p = 0.01), with a Tau2 = 1.97; Chi2 = 66.64, and p < 0.001. Patients with OPMDs had a positive response related to mutagenicity in oral cells compared to control patients. However, SR was not able to validate the micronucleus assay as a putative biomarker in individuals with oral potentially malignant disorders since the majority of studies were considered weak based on high risk of bias.

Beside partial coverage in three reviews so far (1994, 2009, 2019), there is no review on genotoxic studies dealing with mercury (Hg) and human exposure using the most usual genotoxic assays: sister chromatid exchanges (SCE), chromosomal aberrations (CA), cytochalasin B blocked micronucleus assay (CBMN), and single-cell gel electrophoresis (SCGE or alkaline comet assay). Fifty years from the first Hg genotoxicity study and with the Minamata Convention in force, the genotoxic potential of Hg and its derivatives is still controversial. Considering these antecedents, we present this first systematic literature overview of genotoxic studies dealing with Hg and human exposure that used the standard genotoxic assays. To date, there is not sufficient evidence for Hg human carcinogen classification, so the new data collections can be of great help. A review was made of the studies available (those published before the end of October 2021 on PubMed or Web of Science in English or Spanish language) in the scientific literature dealing with genotoxic assays and human sample exposure ex vivo, in vivo, and in vitro. Results from a total of 66 articles selected are presented. Organic (o)Hg compounds were more toxic than inorganic and/or elemental ones, without ruling out that all represent a risk. The most studied inorganic (i)Hg compounds in populations exposed accidentally, occupationally, or iatrogenically, and/or in human cells, were Hg chloride and Hg nitrate and of the organic compounds, were methylmercury, thimerosal, methylmercury chloride, phenylmercuric acetate, and methylmercury hydroxide.

In agricultural activities, pest control is essential, and the most effective method is the use of chemical agents that also represent an important source of exposure to potentially toxic compounds. Pesticides constitute a heterogeneous group of compounds designed specifically to control different pests. Besides measuring their levels or that of their metabolites in air, plasma, serum, blood, urine, etc., some studies reported increased DNA damage levels after occupational or environmental pesticides exposure, evidenced by several cytogenetic biomarkers such as chromosomal aberrations (CA), sister chromatid exchanges (SCE), micronuclei frequency (MN) together with other nuclear abnormalities (NA), alkaline comet assay, but also changes in oxidative stress parameters and miRNA levels. Single or combined, these techniques have also been used in genotoxic biomonitoring studies of workers occupationally exposed to pesticides in Mexico. Despite being a country with great agricultural activity and reported excessive pesticide use, genotoxic studies have been relatively few and, in some cases, contradictory. A review was made of the studies available (published until the end of 2020 on PubMed, Web of Science, Redalyc and Scielo, both in English and Spanish) in the scientific literature that evaluated occupational exposure of human samples to pesticides assessed with DNA damage and related biomarkers in Mexico.