Genotoxicity Biomarkers Research Articles

Environmental exposure of humans to bromide in the Dead Sea area: Measurement of genotoxicy and apoptosis biomarkers

Bromide (Br−) is a bromine atom with a negative charge which is released mainly in the production of pesticides and flame retardants. It is also found naturally in seawater. Br¯ has been associated with many detrimental effects such as respiratory problems, gastric hemorrhages, and dermal burns. The aim of the study was to monitor serum bromide in humans and to correlate its level with genotoxicity and apoptosis in human. The study utilized comet assay, to measure DNA damage in peripheral leukocytes (i.e. T%DNA), enzyme-linked immunosorbent assay were used to determine fortilin level as an apoptosis marker, and spectrophotometry to measure serum Br¯ in two populations at the Dead Sea area, which are located close to and far from a local bromine factory: Ghor As-safi and Deir Alla, respectively. The biomarkers were compared with the correlating serum Br¯. A total of 397 individuals were involved in the study. The serum Br− and the genotoxicity biomarker were significantly higher (p < 0.001) in Ghor As-safi than in Deir Alla. In contrast, serum fortilin did not differ significantly between the two regions (p > 0.05). T%DNA was significantly correlated (r = 0.867, p < 0.01) to serum Br¯. In conclusion, residing near a bromide source site is increasing the bromide body burden, and enhancing genotoxicity with no detectible apoptosis. Furthermore, the selected biomarkers could serve as tools to assess the toxicity of bromide as a consequence of environmental exposure.

Hair straightening products and the risk of occupational formaldehyde exposure in hairstylists

Hair straitening products are widely used by hairstylists. Many keratin-based hair smoothing products contain formaldehyde. This study aimed to investigate occupational formaldehyde exposure among hairstylists dealing with hair straightening products and the relation between genotoxicity biomarkers and the short-term formaldehyde exposure concentrations and the working years. The study was carried out in Cairo, Egypt on 60 hairstylists use hair straightening products divided into two groups according to the working years. All hairstylists were subjected to micronucleus (MN) frequencies in both epithelial buccal cells (EBC) and peripheral blood lymphocytes (PBL). Fifteen-minute (min) formaldehyde exposure concentrations were measured at workplace during hair straightening procedure. Fifteen-minute formaldehyde concentrations in both groups exceeded the National Institute for Occupational Safety and Health and the American Conference of Governmental Industrial Hygienist thresholds levels. The MN frequencies in EBC and PBL showed a significant increase in group II in comparison to control and group I, which in turn showed a significant increase in MN frequency in PBL and a nonsignificant increase in the MN frequency in EBC when compared to control. A positive correlation was found between genotoxicity biomarkers and working years. Occupational exposures to hair straightening products in the studied hairstylist were found to expose them to formaldehyde concentrations that exceeded the standard limits. All selected genotoxicity biomarkers showed a significant increase in exposed workers and were positively correlated to the duration of exposure.

Ecotoxicological evaluation of gilthead seabream (Sparus aurata) exposed to the antibiotic oxytetracycline using a multibiomarker approach

Oxytetracycline (OTC) is an antibiotic widely used in human and veterinary medicines. Since the primary toxicity occurs mainly at molecular/biochemical levels, the study of different biological responses corresponds to a sensitive and crucial approach. The aim of the present study was to assess the toxic effects of OTC in gilthead seabream (Sparus aurata) through the use of multibiomarkers and elucidate about the possible toxicological mechanisms involved. S. aurata were acutely (96 h: 0.04–400 μg/L) and chronically (28 days: 0.0004–4 μg/L) exposed to OTC. Detoxification, antioxidant defense, lipid peroxidation, genotoxicity, neurotransmission and energy metabolism biomarkers were evaluated. OTC impaired the detoxification pathways and caused peroxidative damage and genotoxicity. The relevance of the here-obtained data is high, since significant effects were recorded for levels already reported to occur in the wild, meaning that environmentally-exposed marine organisms (including those cultured at fish farms) are not completely exempt of risks posed by OTC.

Stress oxidative and genotoxicity in Prochilodus lineatus (Valenciennes, 1836) exposed to commercial formulation of insecticide cypermethrin

The use of toxic pesticides has become a world problem because they can contaminate streams and rivers, producing an adverse impact on non-target aquatic biota, including fishes. Cypermethrin is one of the most important insecticides to control ectoparasites in wide-scale. The aim of this study was to evaluate the effect of commercial formulations of cypermethrin, SHERPA O (0.0, 0.075, 0.15, and 0.3 µg/L of cypermethrin) in fish Prochilodus lineatus for 96 h in semi-static condition, using biomarkers of genotoxicity: micronucleus frequency (MNF) in erythrocytes and biomarkers of oxidative damage: lipid peroxidation (TBARS) and antioxidant defenses, catalase (CAT) and glutathione (GSH) in liver tissue. Our results showed a significant decrease (p < 0.05) of CAT at pesticide concentrations of 0.150 and 0.300 μg/L, but no significant difference was observed in TBARS or GSH in any exposed group (p > 0.05) in comparison to the control. A significant increase was observed in the MNF in the group exposed to 0.3 μg/L of cypermethrin compared to negative control (p < 0.05). Finally, P. lineatus proved to be a sensitive species to the commercial formulations of cypermethrin and that CAT and MNF are effective indicators of these toxic effects.

Strongly heated carbohydrate-rich food is an overlooked problem in cancer risk evaluation

A cascade of compounds is produced when foodstuffs are heated at high temperatures but only a few of these compounds have been identified and quantified. In this study data are evaluated regarding differences in the micronucleus frequency of human erythrocytes (fMNs) in peripheral blood (a known biomarker of genotoxicity) in individuals that consumed either high- or low-heated food during a 4-day period. Concomitantly, acrylamide (aa) levels were measured in the food that the participants consumed. The obtained fMNs in this human study are compared with the fMNs in mice after comparable exposure levels of pure aa. The results of this comparison showed several hundred times higher fMNs in humans compared with mice. With an assumed linear correlation between an increased genotoxic effect and cancer, our data suggest that aa only represents a fraction of all carcinogenic compounds produced in heated carbohydrate-rich food. Consequently, our daily intake of carbohydrate-rich food heated at high temperatures might be responsible for one-fifth of the rate of the total cancer risk. One sentence summaryA biomarker of genotoxicity indicates the risk of cancer to be some hundred-fold greater in heated carbohydrate-rich food than the risk calculated from animal studies on pure acrylamide.

Adverse outcome pathway-driven identification of rat liver tumorigens in short-term assays

Chemicals induce liver cancer in rodents through well characterized adverse outcome pathways (AOPs). We hypothesized that measurement of molecular initiating events (MIEs) and downstream key events (KEs) in liver cancer AOPs in short-term assays will allow early identification of chemicals and their associated doses that are likely to be tumorigenic in the liver in two-year bioassays. We tested this hypothesis using the rat in vivo TG-GATES study data to measure MIEs (genotoxicity, cytotoxicity, AhR, CAR, ER, PPARα) and associated KEs (oxidative stress, cell proliferation, liver to body weights) across 77 chemicals that could be linked to doses with previously established effects on rat liver tumor induction. Gene expression biomarkers for MIEs generally considered to be rodent specific and human irrelevant (CAR, PPARα) and for MIEs that would be considered of greater risk at human relevant exposures (ER, AhR) were built using microarray comparisons from the livers of rats treated with prototypical activators of the receptors. The genotoxicity biomarker, also a potentially human relevant MIE, was comprised of 7 p53-responsive genes known to be induced upon DNA damage. The ability of the biomarkers to accurately predict MIE activation ranged from 91% to 98%. The Toxicological Priority Index (ToxPi) was used to rank chemicals based on their ability to activate MIEs/KEs. Chemicals administered at tumorigenic doses clearly gave the highest ranked scores. Our AOP-directed approach could be used in short term assays to identify chemicals and their doses that would be predicted to cause liver tumors in rats.

The pyrethroid λ-cyhalothrin induces biochemical, genotoxic, and physiological alterations in the teleost Prochilodus lineatus

The λ-cyhalothrin (CL) is a globally used pyrethroid insecticide that has been detected in different water bodies worldwide. However, studies on the effects of CL on freshwater fishes are still incipient. In this context, we evaluated the acute effects of a commercial formulation containing CL (Karate Zeon® CS 50) in juveniles of the teleost Prochilodus lineatus exposed for 96 h to four concentrations of the active ingredient (5, 50, 250 and 500 ng.L−1). Biochemical, physiological, and genotoxic biomarkers were evaluated in different organs of the fish. Exposure to CL induced significant changes in the enzymatic profiles of P. lineatus, with specific alterations in biotransformation enzymes and antioxidant defence in different tissues. Lipid peroxidation was observed in fish gills and kidney. Increases in esterases were observed in the liver of fish exposed to all CL concentrations evaluated, whereas acetylcholinesterase activity decreased in the muscles of fish at all concentrations. CL also promoted osmoregulatory disorders, with decreases in calcium and magnesium gill ATPases, with consequent hypocalcaemia, in addition an increase in sodium-potassium ATPase activity was observed in the gills of fish exposed to the highest CL concentration, probably in order to compensate a reduction in plasma sodium. Besides, increases in DNA damage were observed in the erythrocytes of fish exposed to all CL concentrations. Thus, despite the low CL concentrations and the short exposure time, this pyrethroid caused hematological adjustments, oxidative stress, osmoregulatory disorders, and DNA damage in P. lineatus, showing that the species is highly sensitive to the deleterious effects of CL.

Depuration time and sublethal effects of microcystins in a freshwater fish from water supply reservoir

Microcystins (MCs) are hepatotoxins that have been considered to be a worldwide problem due the effects that they can cause to environmental and human health systems. The Iraí Reservoir, located in the South of Brazil, is used as a water supply and MCs concentrations have been reported in this ecosystem. This study aimed to determine the MCs concentrations in the Iraí Reservoir and to evaluate the MCs depuration time and the health of Geophagus brasiliensis using biomarkers. Water and fish samples were collected in the Iraí Reservoir from August 2015 to May 2016. Phytoplankton and chemical analyses were conducted using water samples and the fish were divided into two groups; the Immediate Group (IMM) and the Depuration Group (DEP). In the IMM group, the blood, liver, muscle, brain and gills were collected, in order to evaluate the genotoxic, biochemical and chemical biomarkers. The DEP group was used in the depuration experiment for 90 days, and after this period the fish were submitted to the same procedure as the IMM group. Our results suggested that fish accumulated MCs and it may have caused oxidative stress, neurotoxicity and molecular damage. Furthermore, MCs concentrations increased during the depuration time and it resulted in molecular damage over the first 30 days. After 90 days, the recovery of the antioxidant system occurred. The depuration started on the 15th day, however, the toxins were still present in the samples. Therefore, the effects and the persistence of MCs are a risk to environmental systems and human health.

Cytotoxicity and genotoxicity of CuO nanoparticles in sea urchin spermatozoa through oxidative stress

Copper oxide nanoparticles (CuO NPs) are extensively used in various industrial and commercial applications. Despite their wide application may lead to the contamination of marine ecosystem, their potential environmental effects remain to be determined. Toxicity assessment studies have primarily focused on investigating the effects of CuO NPs on fertilization success and embryo development of different sea urchin species while the impact on sperm quality have never been assessed. In this line, this study aims to assess the effects of CuO NPs on the spermatozoa of the sea urchin Paracentrotus lividus.After sperm exposure to CuO NPs, biomarkers of sperm viability, cytotoxicity, oxidative stress, and genotoxicity as well as morphology were evaluated. Results showed that CuO NPs exposure decreased sperm viability, impaired mitochondrial activity and increased the production of reactive oxygen species (ROS) and lipid peroxidation. Furthermore, CuO NPs exposure caused DNA damage and morphological alterations. Together with the antioxidant rescue experiments, these results suggest that oxidative stress is the main driver of CuO NP spermiotoxic effects. The mechanism of toxicity is here proposed: the spontaneous generation of ROS induced by CuO NPs and the disruption of the mitochondrial respiratory chain lead to production of ROS that, in turn, induce lipid peroxidation and DNA damage, and result in defective spermatozoa up to induce sperm cytotoxicity. Investigating the effects of CuO NPs on sea urchin spermatozoa, this study provides valuable insights into the mechanism of reproductive toxicity induced by CuO NPs.

The interactions of fullerene C60 and Benzo(α)pyrene influence their bioavailability and toxicity to zebrafish embryos

This study aimed to assess the toxicological consequences related to the interaction of fullerene nanoparticles (C60) and Benzo(α)pyrene (B(α)P) on zebrafish embryos, which were exposed to C60 and B(α)P alone and to C60 doped with B(α)P. The uptake of pollutants into their tissues and intra-cellular localization were investigated by immunofluorescence and electron microscopy. A set of biomarkers of genotoxicity and oxidative stress, as well as functional proteomics analysis were applied to assess the toxic effects due to C60 interaction with B(α)P. The carrier role of C60 for B(α)P was observed, however adsorption on C60 did not affect the accumulation and localization of B(α)P in the embryos. Instead, C60 doped with B(α)P resulted more prone to sedimentation and less bioavailable for the embryos compared to C60 alone. As for toxicity, our results suggested that C60 alone elicited oxidative stress in embryos and a down-regulation of proteins involved in energetic metabolism. The C60 + B(α)P induced cellular response mechanisms similar to B(α)P alone, but generating greater cellular damages in the exposed embryos.

Genotoxicity and Cytotoxicity Evaluation Applied to Environmental Health, Research of Polycyclic Aromatic Hydrocarbons

Environmental toxicology contributes for the evaluation of chemical exposures, proposing interventions based in preventive actions promoting a risk decrease. The industrial development, agriculture activities, the increase of the number of automobiles, among others, lead to a constant increase in the concentrations of air pollutants that are hazardous to health, therefore becoming a public health problem. Besides many chronic and acute respiratory diseases, related to environmental chemical exposures, the consequences related to genotoxic effects are poorly evidenced. Biomarkers of genotoxicity such as the comet assay, micronucleus assay, Salmonella/microsome assay and chromosomal aberration assay are reliable techniques for the early detection of the damage and for the evaluation of the chemical exposure aiming the prevention, mainly in environmental exposures, in which there is a really short window between the exposure to the chemical and the appearance of the damage. This paper aims to identify potential biomarkers of genotoxicity as reference to environmental chemical exposure, its usage and contributions to the decrease of this public health problem, especially for the Polycyclic Aromatic Hydrocarbons (PAHs). Keywords: biomarkers of genotoxicity; environmental health; PAHs;

Biomarkers of early genotoxicity and oxidative stress for occupational risk assessment of exposure to styrene in the fibreglass reinforced plastic industry

This study aimed to identify sensitive and not-invasive biomarkers of early genotoxic/oxidative effect for exposure to styrene in the fibreglass reinforced plastic manufacture. We studied 11 workers of a plastic manufacture using open molding process (A), 16 workers of a manufacture using closed process (B) and 12 controls. We evaluated geno/cytotoxic effects on buccal cells by Buccal Micronucleus Cytome (BMCyt) assay and genotoxic/oxidative effects on lymphocytes by Fpg-comet test. On A workers we also evaluated urinary 8oxoGua, 8oxodGuo and 8oxoGuo to investigate oxidative stress. Personal inhalation exposure to styrene was monitored by passive air sampling and GC/MS. Biological monitoring included urinary metabolites mandelic acid (MA) and phenylglyoxylic acid (PGA). The findings show higher styrene exposure, urinary MA + PGA levels and micronucleus frequency in manufacture A. Higher buccal karyolytic cell frequency vs controls were found in both exposed populations. We found in exposed workers, no induction of direct DNA damage but oxidative DNA damage. Fpg-comet assay and urinary oxidized guanine seem to be sensitive biomarkers of oxidative stress and BMCyt assay a good-not invasive biomarker of cyto-genotoxicity at target organ. The study, although limited by the small number of studied subjects, shows the usefulness of used biomarkers in risk assessment of styrene-exposed workers.

In vivo antigenotoxic activity of Diplotaxis tenuifolia against cyclophosphamide-induced DNA damage: Relevance of modulation of hepatic ABC efflux transporters

Several epidemiological studies have demonstrated that a diet with high contents of cruciferous vegetables (which belong to the Brassicaceae family) may reduce the incidence of cancer and neurodegenerative diseases. However, some authors have postulated that they might bring about toxic effects. Therefore, the aim of this study was to assess the effects of chronic administration of Diplotaxis tenuifolia (wild rocket), a species found in Argentina, concerning its putative genotoxicity or antigenotoxicity against the DNA damage inducer cyclophosphamide, and its ability to modulate the hepatic expression of ABC efflux transporters on mice. The alkaline comet assay and the micronucleus test were used as genotoxicity biomarkers, and the ABC transporter expression was analyzed by Western-blotting. D. tenuifolia juice exhibited no genotoxicity in any of the three tested doses (p > 0.05), showing instead a protective effect against genotoxic damage induced by cyclophosphamide (p < 0.001) in a dose-dependent behavior. Furthermore, hepatic expression of ABCB1 remained unchanged in both sexes at every dose, whereas ABCG2 expression increased in females (p < 0.05) and males (p < 0.01) at the highest dose. Regarding ABCC2, sex-related differences were observed (p < 0.05), its expression decreasing in females (p < 0.05) and increasing in males (p < 0.05). The modulation of these transporters may contribute to the antigenotoxic effects of D. tenuifolia since they act as universal detoxifiers, excreting xenobiotics to the cellular exterior. Phytochemicals present in the juice such as glucosinolates, quercetin and kaempherol may be responsible for these beneficial effects.

Development of a classification scheme for evaluating water quality in marine environment receiving treated municipal effluent by an integrated biomarker approach in Meretrix meretrix

To evaluate the pollution level of marine environment received treated municipal effluent (TME), the water quality classification index (WQCI) capable of integrating biomarker results into a four-level pollution for effluent assessment was proposed and applied. The WQCI calculation was that of the integrated biomarker responses vesion 2 (IBRv2) index based on the expert system classification scale. In this research, mussels of Meretrix meretrix were treated with different effluent volume ratios (EVRs, 0–40%, v/v) for 12 days, six biomarkers of oxidative stress, metal exposure and neurotoxicity in both gills and digestive glands as well as the other two biomarkers of general health and genotoxicity in hemocytes were measured. Then based on the correlation analysis between the response of biomarkers and EVRs, the lysosomal membrane stability (LMS) and micronucleus frequency (MF) in hemocytes, glutathione (GSH) and acetylcholinesterase (AChE) in gills were chosen to calculate the IBRv2 and WQCI. The results showed that the control (EVR = 0%) was defined as Level I, EVR of 1–5% as Level II, EVR of 10–30% as Level III, and EVR of 40% as Level IV. In addition, two other sets of data of biomarkers in previous studies were used to test the applicability of the classification scheme established. The WQCI values and the evaluation results based on them were almost identical to those obtained by using the first set of data. This study is the first attempt to develop an index on water quality assessment of marine environment received discharged effluent from a biological perspective. The findings confirm that WQCI offers a potential measurement of water quality evaluation of marine environment and possible to be a water quality standard.

Expression of cyp1a induced by benzo(A)pyrene and related biochemical and genotoxic biomarkers in the neotropical freshwater fish Prochilodus lineatus

The goal of this work was to design specific cyp1a primers for the fish Prochilodus lineatus to study the expression of this gene and its relation to the activity of biotransformation phase I enzyme (ethoxyresorufin O-deethylase - EROD) and genotoxic damage after 6 and 24 h of benzo(a)pyrene (B(a)P) intraperitoneal injection. In comparison to fish injected only with canola oil (vehicle), the expression of cyp1a and EROD activity both in the liver and gills were significantly higher after 6 and 24 h of B(a)P injection. A significant increase in DNA damage was detected in liver and blood cells after 6 h of B(a)P injection and in the gill cells after both times, probably caused by intermediate metabolites of B(a)P. Thus, the expression of cyp1a and its relationship with the corresponding enzyme activity is a potential biomarker for evaluation P. lineatus exposure to organic compounds.

Morphotoxicity and cytogenotoxicity of pendimethalin in the test plant Allium cepa L. - A biomarker based study

Pesticides have brought tremendous benefits to mankind by increasing food production and controlling various crop diseases. But their prolonged and extensive use has been reported to induce toxicity. Biological markers used for the evaluation of toxic effects of pesticides have increased these days. The aim of this study was to determine the morphotoxic and cytogenotoxic effects of pesticide pendimethalin applied to the soil by using morphological and genotoxic biomarkers in the test plant Allium cepa L. A pot experiment was set up in which pendimethalin was added to soil at the rate of 0, 0.033, 0.044, 0.055 and 0.066 g kg−1 soil. Similar sized onion bulbs were planted in each pot and 3 replicates were maintained for each dose of pendimethalin at 1, 7, 15, 30 and 45 days after treatment. Average root number (ARN) and average length of roots (ALR) of onion bulbs were recorded and on the day 3 of sowing roots were harvested and fixed for cytological analysis. Morphological biomarkers revealed significant concentration and duration dependent inhibition of ARN and ALR as compared to control which shows the morphotoxicity of pendimethalin. The results also showed inhibitory effect on the mitotic index (%) of A. cepa while relative abnormality rate (%) increased. Further, we observed aberrations in both the dividing and non-dividing cells along with spotting of few ring chromosomes. Reduced mitotic index, increased relative abnormality rate; various chromosomal and interphase nuclear aberrations all being mitosis endpoint markers reflect the cytogenotoxicity of pendimethalin, even at lower concentrations.

Genotoxicity and physiological effects of CeO2 NPs on a freshwater bivalve (Corbicula fluminea)

The rapid development of nanotechnology and the increased use of nanomaterials in products used in everyday life have raised the question of the potential release of nanoparticles into the aquatic environment. Their fate and effects in natural ecosystems are not currently well understood but harmful effects of nanoparticles have been demonstrated at low concentrations on some freshwater and marine species. Cerium dioxide nanoparticles (CeO2 NPs) are produced in large quantities and used in products in many different fields, such as automotives or optics. Because of their widespread use in daily products, CeO2 NPs are included in the OECD priority list of manufactured nanomaterials for human and environmental assessment. Indeed some studies have been conducted to assay various enzymatic biomarkers, which showed the CeO2 NPs potential to modify anti-oxidative defenses and cellular membrane stability. Nevertheless, only a few studies were performed on their genotoxic potential. The aim of this work was to evaluate the genotoxic and physiological effects of CeO2 NPs on a widespread freshwater bivalve Corbicula fluminea by using comet assay and a multi-enzymatic biomarker approach. Exposure to two CeO2 NP concentrations during a short term experiment (6 days) was set up. The first one (10 μg/L) was chosen in order to work with low but measurable concentrations whereas the second one was ten times higher (100 μg CeO2 NPs/L). DNA damage was significantly more pronounced compared with control for both concentrations tested as early as two days of exposure and seemed to increase with time. Some enzymatic biomarkers of anti-oxidative defenses (total antioxidant capacity, catalase activity), anti-toxic mechanisms (glutathione-S-transferase activity, caspase-3 activity) or metabolism (lactate dehydrogenase activity) tended to increase after 6 days of exposure but only the induction of caspase pathway and DNA damages appeared significant for exposed organisms. In this study, time and concentration effects of CeO2 NPs were highlighted by coupling genotoxic and cellular biomarker assessments.

Evaluation of caffeine effects on biochemical and genotoxic biomarkers in the neotropical freshwater teleost Prochilodus lineatus

Caffeine is often found in aquatic environments, leading to concerns regarding its adverse consequences for aquatic biota. Biochemical and genotoxic biomarkers were analysed in juveniles of Prochilodus lineatus to evaluate the effects of caffeine. Fish were exposed to caffeine (0.3, 3 and 30 μg L−1) for either 24 h or 168 h. Longer exposure to caffeine resulted in a significant reduction in the activity of the phase I biotransformation enzyme ethoxyresorufin-O-deethylase (EROD) in the brain but a significant increase in the liver. Changes in glutathione content (GSH), glutathione S-transferase (GST) activity, and lipid peroxidation were not found in the liver and brain of fish exposed to caffeine. DNA damage in erythrocytes were also not found. These results show that caffeine may interfere with the biotransformation mechanism of P. lineatus after 168 h exposure, but it does not generate sufficient changes to trigger a state of oxidative stress.

Micronuclei in Exfoliated Oral Epithelial Cells in Tobacco Users and Controls with Various Oral Lesions: A Study from Gujarat, India.

To assess and compare cytogenic damage in the form of micronuclei in various oral lesions according to duration and frequency of tobacco use. The present cross sectional study was carried out from October 2015 to October 2016. We included total 420 cases with 60 cases in each of the following subgroups, no tobacco habit with no obvious oral lesion (control) and tobacco habit with no obvious oral lesion, oral sub mucous fibrosis, leukoplakia, melanoplakia, erythroplakia, oral squamous cell carcinoma. Oral mucosal cells were collected from both sides of cheek; slides were prepared and examined for cells with micronuclei. The mean micronuclei index distribution in control group, potentially malignant group, and malignancy group was 1.14, 2.63, and 4.88 respectively and was statistically significant. The mean micronuclei index in control group, smoking tobacco and smokeless tobacco group was 1.14, 2.64, and 2.76 and was statistically significant. The mean micronuclei index was significantly higher in those using tobacco, for longer duration and with frequent tobacco use. The mean micronuclei index can be used as a potential screening tool of genotoxic damage and biomarker for epithelial carcinogenesis. The method has practical utility for warning tobacco users that higher than range has a danger of malignant event and therefore this in future can be used as reinforcement to advice of avoiding tobacco before malignancy develops.

ENSAYO DE MICRONÚCLEOS DE CITOMA BUCAL EN TRABAJADORES DE FINCAS FRUTÍCOLAS QUE HAN APLICADO PLAGUICIDAS ALREDEDOR DE QUINCE AÑOS

The application of pesticides is a common practice in agriculture. Many of these chemicals are associated with the induction of genetic damage. The chemical groups used and the methods of application vary from one region to another, what makes it difficult to transfer the evidence of genotoxicity detected in other geographical zones. In this research, the level of genetic damage was evaluated in people that have applied pesticides in fruit plantations of Mendoza, Argentina, for 15 ± 3.15 years. Buccal micronucleus cytome assay was used to determine the frequency of micronuclei and other nuclear alterations. Forty people participated in the study (field workers and a control group). Genetic damage in exposed workers showed an increase in micronucleated cells (p ≤ 0.01), nuclear buds and binucleated cells (p ≤ 0.05) compared to the control group. Sixty five per cent of workers have used between one and three personal protection elements, and 70 % have applied pesticides through a turbo disperser. The type and amount of personal protection elements, as well as the machinery used by these groups should be registered systematically in order to compare the results obtained elsewhere. The detected anomalies did not show statistical associations between the confounder factors and the types of agricultural practices. Biomarkers of genotoxicity that showed statistically significant increases in the exposed group can help to understand the current and future problems of health in the human group studied.