Frequency Of Total Chromosomal Aberrations Research Articles

Evaluation of cytogenetic effect of pesticides in onion root meristem

Farmers use chemical insecticides, fungicides and herbicides to control insect pests, diseases and weeds. Extensive use of chemical pesticides is becoming hazardous to the environment and human and animal health. Biopesticides have been used as a safer alternative. Cytogenetic analysis is needed to determine the effects of chemical and biopesticides in plants if these are used frequently in an improper concentration. This investigation assessed the effects of a chemical systemic insecticide ‘Actara 25WG’ and a bioinsecticide ‘Bio Sona’ for seed germination and on root mitosis of five onion varieties. Three concentrations of Actara 25WG were used as seed treatment, viz., 25 g, 50g (recommended) and 75 g/kg seed. Similarly, Bio Sona was applied @ 2 %, 5 % (recommended) and 8 % concentrations. Depressing effects of the two pesticides were recorded in seed germination percentage except for Bio Sona 2% in variety Bhima Shakti. Actara 25WG and Bio Sona showed either mitoenhancing or cytotoxic effects depending on dose and variety. These pesticides also induced genotoxicity at recommended and higher doses on root tip cells as indicated by the frequency of total chromosomal aberrations like binucleate cells, clumps, stickiness, disturbed stage, laggards, bridges and fragments. Bio Sona at higher concentrations showed more aberrations than Actara 25WG. There were differential responses of the varieties to the pesticide treatment. More research must be done on the effects of chemicals and biopesticides in plants to assess their cytogenotoxicity.

Chromosomal Aberrations Due to Acrylamide Exposure and The Protective Role of L-arginine in Bone Marrow Cells of Male Albino Rats.

Acrylamide (Acr) is a human carcinogen which generated in foodstuffs rich with carbohydrates during overheating. It has been recorded to induce carcinogenic and genotoxic effects in experimental animals. So, the present work aimed to evaluate the genotoxic effect of Acr and the possible protective role of L-arginine (amino acid) against Acr genotoxicity using the chromosomal aberration assay in male albino rats (Rattus norvegicus). In the current investigation, 20 male albino rats were equally divided into four main groups (n = 5); Group1 (control): Animals were received the ordinary water and diet. Group2 (L- arginine): Animals were given L- arginine at a dose of 200mg/kg/day for a month by oral gavage. Group3 (acrylamide): Animals were given Acr at a dose of 50mg/kg/day for a month by oral gavage. Group4 (Acrylymide+ L-arginine): Animals were given Arc (50mg/kg/day) together with L-arginine (200mg/kg/day) for a month by oral gavage. The results of the present work concluded that Acr is a genotoxic agent, it induced a significant increase in the frequency of total chromosomal aberrations (numerical and structural). L-arginine provides a protective potential against genotoxicity induced by Acr and this was supported by a significant reduction in the frequency of chromosomal aberrations although, the value remained higher and significant as compared with control group.

Sorption technique as a tool for reduction of genotoxicity.

In the present study, the Allium cepa root chromosomal aberration assay was used to determine the genotoxic effects of copper and cadmium ions solutions before and after sorption processes. The sorption process was carried out using unmodified Dendrocalamus strictus charcoal powder, nitrilotriacetic acid (NTA)-modified D. strictus charcoal powder, and Saccharomyces cerevisiae. The frequency of total chromosomal aberrations was observed to be 24.30-45.13% for copper and 13.16-45.14% for cadmium at different concentrations (1-500 mg/l) before the sorption process. Both metal ions solutions resulted in significant reduction of chromosomal aberrations after all the modes of the sorption processes. However, the order of reduction of percentage chromosomal aberrations for copper and cadmium solutions was found to be 45.29-70.04% and 47.80-84.57%, respectively (NTA-modified D. strictus charcoal powder); >44.53-54.32% and 37.10-79.40%, respectively (unmodified D. strictus charcoal powder); >15.59-48.51% and 13.63-21.50%, respectively (S. cerevisiae).

Protective effects of pomegranate peel against hematotoxicity, chromosomal aberrations, and genotoxicity induced by barium chloride in adult rats

Context Pomegranate peel (PP) has health benefits including antibacterial, antioxidant, anti-inflammatory, and antimutagenic properties. Objective This study investigated the biochemical composition and protective effects of PP against hematotoxicity and genotoxicity induced by barium chloride (BaCl2) in adult rats. Materials and methods Adult Wistar rats were divided into four groups of six each: control, barium (67 ppm via drinking water), PP (5% via diet), and their combination during 21 d. Oxidative stress was determined by MDA, AOPP, and antioxidant status: CAT, GPx, GSH, Vit C. Osmotic fragility (OF), chromosomal aberrations (CAs), and micronucleus (MN) assays were also studied. Results PP showed a rich composition of antioxidant compounds. DPPH test found IC50 value= 5.3 μg/mL and a high polysaccharides content (315 ± 5 mg/g of extract). In vivo study showed a decrease in red blood cells (70%) and platelet counts (46%), hemoglobin content (8%), hematocrit percent (7%), and an 80% increase of white blood cells in Ba-treated rats. A reduction in antioxidant status: catalase, glutathione peroxidase activities, glutathione, and vitamin C levels by 31, 21, 28, and 29%, respectively, and an increase in MDA (46%) and AOPP levels (72%) were also observed compared with controls. BaCl2-treatment showed a significant increase in the frequencies of total chromosomal aberrations with abnormal metaphases and micronucleus in bone-marrow cells. Oxidative stress induced by BaCl2 might be the major cause for chromosomal abnormalities leading to DNA damage. Discussion and conclusion A decrease in hematotoxic and genotoxic effects induced by PP is due to its powerful antioxidant capacity.

Analysis of Chromosomal Aberrations in PBL of Chrome Tanning Industrial Workers

In order to monitor the geno-toxic effects of chromium compound, 160 chrome tanning industrial workers (80 each of smoker and non-smoker) were selected from a leather tanning industry to perform the cytogenetic protocol of chromosomal aberrations in the peripheral blood lymphocytes. The workers were further classified into two groups on the basis of their personnel habit (Smoker and Non-Smokers) and on the duration of their employment (1-5, 6-10 and 11-15 years). Even 120 individuals (62 smokers and 58 non-smokers) were also selected as controls for the purpose of comparison. A statistically significant increased frequency of total chromosomal aberrations was observed in the chrome tannery workers (6.20 ± 0.12) as against the control (1.61 ± 0.09). The increased frequencies of aberrations were duration dependent. Even higher incidence of chromosome aberrations was reported among the smoker group of both control and exposed workers. The results clearly establish the mutagenic nature of the chromium compound in human beings.

Hyparrhenia hirta: A potential protective agent against hematotoxicity and genotoxicity of sodium nitrate in adult rats.

The present study was carried out to examine the adverse hematotoxic and genotoxic effects of water nitrate pollution on male adult rats and the use of hyparrhenia hirta methanolic extract in alleviating these effects. Sodium nitrate (NaNO3 ) was administered to adult rats by oral gavage at a dose of 400 mg kg(-1) bw daily for 50 days, while hyparrhenia hirta methanolic extract was given by drinking water at a dose of 1.5 mg mL(-1) (200 mg kg(-1) bw). The NaNO3 -treated group showed a significant decrease in red blood cell count, hemoglobin and hematocrit and a significant increase in total white blood cell, in neutrophil and eosinophil counts. Platelet count, mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration remained unchanged in treated groups compared to those of controls. Meanwhile, the results showed a marked reduction in the antioxidant enzyme activities, such as superoxide dismutase, catalase, and glutathione peroxidase, along with an elevation in the level of lipid peroxidation and a reduction in the total glutathione content, indicating the induction of oxidative stress in the erythrocytes of NaNO3 -treated group. Interestingly, NaNO3 treatment showed a significant increase in the frequencies of total chromosomal aberrations, aberrant metaphases and micronucleus in bone-marrow cells. The oxidative stress induced by nitrate treatment might be the major cause for chromosomal rearrangements as free radicals leading to DNA damage. Hyparrhenia hirta methanolic extract appeared to be effective against hematotoxic and genotoxic changes induced by nitrate, as evidenced by the improvement of the markers cited above.

Management by Erythropoietin and Nerve Growth Factor on Healing of Spinal Cord Injury in Rats

Research on the pathology of spinal cord injury (SCI) has been recently focused on oxidative radical-induced stress and inflammation associated neuronal apoptosis. However, the study of neurorepair and the underlying mechanism in SCI model has been limited. In this study, we investigated the effects of erythropoietin plus nerve growth factor (EPO + NGF) on neurologic and histopathologic changes after SCI and explored its anti-apoptotic role after SCI. Intravenous injection four times a week over a period of 4 weeks of EPO plus NGF (5000 & 2000 U /kg respectively) in male rats following SCI by whole body gamma irradiation caused significant decrease in 8 hydroxyguanosine (8-HDG) and heat shock protein 70 (HSP70). To investigate the possible mechanism, anti-oxidant effect of EPO plus NGF was assessed by measuring superoxide dismutase (SOD), malondialdehyde (MDA), catalase (CAT) and GSH levels after SCI. EPO plus NGF treatment reversed the decrease of SOD activity and increase of MDA level caused by SCI, suggesting its anti-oxidant role in response to the injury. In addition, EPO plus NGF treatment, after SCI, restored the concentration of neurotransmitters to near normal values seen in control rats after 4 weeks of treatment. Assays for DNA damage in bone marrow cells as well as in spinal cord of rats by chromosomal aberrations, and micronucleus assay and DNA fragmentation techniques were performed in this study. Data showed that the frequency of total chromosomal aberrations and number of micronucleated polychromatic erythrocytes (MNPCE) in animals that received erythropoietin and nerve growth factor after radiation were lower than that in radiated animals that had not been treated with erythropoietin and nerve growth factor. Also, the percentage of DNA fragmentation was reduced after treatment of radiated animals with erythropoietin and nerve growth factor. Further, histopathological alternations were evaluated with H.E. staining that showed a restored SC histology after EPO plus NGF administration.

Chromosomal damage among medical staff occupationally exposed to volatile anesthetics, antineoplastic drugs, and formaldehyde

Structural chromosomal aberrations in blood lymphocytes represent a biomarker for cellular damage caused by genotoxic carcinogens and are an indicator of increased cancer risk. We evaluated the association between frequencies of total chromosomal aberrations, chromatid- and chromosome-type aberrations, and occupational exposures to volatile anesthetics, antineoplastic agents, and formaldehyde among 601 medical professionals. Chromosomal damage among exposed individuals and unexposed controls was determined by conventional cytogenetic analysis. We used binary logistic regression to evaluate the effects of workplace exposures and major confounders on chromosomal damage. Significantly higher frequencies of total chromosomal, chromatid-type and chromosome-type aberrations were observed among subjects occupationally exposed to volatile anesthetics, antineoplastic agents, and formaldehyde compared to age- and sex-matched controls (P<0.0001). The risk of an increased frequency of chromosomal aberrations was associated with exposure to anesthetics [odds ratio (OR) 3.9, 95% confidence interval (95% CI) 2.7-5.8], cytostatics (OR 2.7, 95% CI 1.9-3.9), and formaldehyde (OR 1.7, 95% CI 1.1-2.7). No other covariate contributed significantly to the model. Chromatid- and chromosome-type aberrations were associated with exposure to anesthetics and cytostatics without any contribution of other variables. Stratified data analysis showed the risk of increased chromosomal aberrations among non-smoking female nurses and physicians exposed to anesthetics, cytostatics and, partially, formaldehyde. Chromatid and chromosome exchanges were significantly higher in the exposed groups than among controls. Our findings indicate that the presence of genotoxic compounds in operating rooms, oncological units, and pathological departments results in a significant increase of chromosomal damage (impair of chromosomal integrity) among medical workers employed in these facilities.

Telomere length and LINE1 methylation is associated with chromosomal aberrations in peripheral blood

The frequency of chromosomal aberrations in peripheral blood predicts a probable cancer risk. The individual telomere length and methylation of repetitive elements may be susceptibility factors for chromosomal aberrations. A cohort of healthy Norwegian men (N = 364) recruited during 1980-1999 were analyzed for chromosomal aberrations in phytohemagglutinin-stimulated lymphocytes from peripheral blood. Chromosome-type or chromatid-type aberrations were scored. DNA was extracted from slides cytogenetically analyzed and relative average telomere length and methylation of LINE1 repeats were determined by quantitative polymerase chain reaction and bisulfite pyrosequencing, respectively. Information about individuals with malignant tumors (N = 49) diagnosed after chromosomal aberrations testing until end of 2008 was obtained and two matched controls per case were used in a nested case-control analysis. Shorter relative telomere length and higher methylation of LINE1 were associated with higher frequency of total chromosomal aberrations (β = -0.76, P = 0.022; and β = 0.042, P = 0.048, respectively; age-adjusted ordinal regression). The telomere length was stronger associated with chromosome-type (β = -1.00, P = 0.006) than with chromatid-type aberrations (β = -0.49, P = 0.115). The LINE1 methylation was stronger associated with chromatid-type (β = 0.062, P = 0.003) than with chromosome-type aberrations (β = 0.018, P = 0.41). Telomere length [individuals with short telomeres odds ratio (OR) = 0.87, 95% confidence interval (CI) 0.38-2.0], LINE1 (individuals with high methylation OR = 1.04, 95% CI 0.43-2.5) and chromosomal aberrations (individuals with high frequency OR = 1.6, 95% CI 0.63-3.9) at baseline did not predict cancer risk, but the conclusions were hampered by low statistical precision. The results suggest that shorter telomere length and higher LINE1 methylation in peripheral blood lymphocytes are predisposition factors for increased frequency of chromosomal aberrations.

Chromosomal Aberrations (CA), Sister Chromatid Exchanges (SCE), and High-Frequency Cells (HFC) Frequencies in Peripheral Blood Lymphocytes of Tunisian Gasoline Truck Loaders

ABSTRACT Gasoline constitutes a mixture of chemicals that contain well-known genotoxicants. Thus, chronic occupational exposure to gasoline may be considered to possess genotoxic risk. In this study, the frequencies of total chromosomal aberrations (TCA), aberrant cells (Ab.c.), sister chromatid exchanges (SCE), high-frequency cells (HFC), and high-frequency cell individual (HFI) were investigated in peripheral blood lymphocytes from 17 gasoline-exposed workers (10 smokers and 7 non-smokers) and 22 unexposed reference subjects (12 smokers and 10 non-smokers). The exposed subjects were gasoline truck loaders at a gasoline company from Tunis City, north of Tunisia. The results indicate multiple CA, such as dicentrics (DIC), chromatid breaks (SB), and chromosome breaks (DB). A significant difference was observed in TCA and Ab.c. frequencies between exposed and unexposed groups (p < 0.01). A significant difference was found in frequencies of SCE (p < 0.01) and HFI (p < 0.05) between exposed and unexposed groups. SCE and TCA frequencies of smokers were found to be significantly higher than those of non-smokers in both groups. There was an interaction between gasoline exposure and smoking habit for TCA (p = 0.020), but not for SCE. Our findings indicate that gasoline truck loaders were under risk of significant cytogenetic damage that was enhanced by their smoking habit.

Androgenic profile and genotoxicity evaluation of testosterone propionate and novel synthesized heterocyclic steroids

In this study, we tested the androgenic activity of three structurally promising novel synthesized heterocyclic steroids compared with testosterone propionate in male mice. Additionally, the possible genotoxic effects of the novel synthesized heterocyclic steroids in comparison with testosterone propionate on male mice using chromosomal analysis of somatic and germ cells as well as RAPD–PCR were investigated. Male mice were administered with two doses of testosterone propionate, pyridoandrostene derivative 4b, pyrimidinoandrostene derivative 9a and thienoandrostene derivative 12 (200 and 400 mg/kg b.w.) daily for 2 weeks. Results indicated that compounds 4b and 12 have androgenic activity as well as testosterone propionate. There were no significant differences in the frequencies of total chromosomal aberrations in both somatic and germ cells as well as no alteration in the DNA bands patterns between control, testosterone propionate and pyridoandrostene 4b treated animals. However, the pyrimidinoandrostene derivative 9a caused significant increase in the mean value of total chromosomal aberrations of both somatic and germ cells ( P ≤ 0.01) as well as enhanced the polymorphic bands patterns as compared to the control and the other tested compounds. On the other hand, thienoandrostene derivative 12 induced significant decrease in the mean values of chromosomal aberrations in both somatic and germ cells, decreased sperm morphological abnormalities, increased the sperm count and motility than control. Our data indicate that testosterone propionate; pyridoandrostene 4b and thienoandrostene derivative 12 have no genotoxic activity. However, pyrimidinoandrostene derivative 9a has genotoxic activity possibly due to a modulation of the different expression of the catalyzing enzyme systems which will be investigated in the nearly future.

Antimutagenic Activity of Some Natural supplements on Ivermectin ge- notoxicity in Lymphocytes of Buffalo

Ivermectin is a veterinary anthelminthic drug, highly effective against a number of arthropod and nematode infestations in vertebrates. The literature reported that ivermectin have mutagenic activities. The extensive use of ivermectin in food producing animals can cause potential hazard to humanity by causing gene mutation or chromosomal aberrations. Recently, there have been considerable efforts to search for naturally occurring substances that can inhibit, reverse, retard or prevent mutagenicity. A wide array of substances derived from edibles and medicinal plants reported to possess anticarcinogenic and antimutagenic activities. Therefore, the aim of this study was to evaluate the modulator role of each of garlic, L-carnitine and wheat germ oil (WGO) against genotoxicity of ivermectin in buffalo lymphocyte cultures by using the cytokinesis block micronucleus assay and chromosomal aberrations test as cytogenetic end-points. Results showed that ivermectin induced dose dependent increase in the frequencies of the binucleated lymphocytes with micronuclei as well as the number of micronuclei in lymphocytes of river buffalo, while the number of binucleated lymphocytes significantly decreased. In addition, ivermectin low dose caused nonsignificant increase in the frequency of total chromosomal aberrations in lymphocytes of river buffalo as compared to control. Whereas, in medium and high doses the frequencies of aberrant cells increased at a significant level (P ≤ 0.001) than control. Meanwhile, the treatment with the three natural supplements (garlic, L-carnitine, wheat germ oil) in continuous with ivermectin significantly reduced the frequencies of binucleated lymphocytes with micronuclei, the number of micronuclei and the frequencies of total chromosomal aberrations induced by ivermectin tested doses, and increase the number of binucleated lymphocytes. In addition, the results indicated that there were non-significant differences between the modulator role of garlic, L-carnitine or wheat germ oil against the mutagenicity of ivermectin in blood lymphocytes. Finally, we can concluded that regular consumption of natural antioxidants, antimutagenic compounds is inversely related to the risk of cancer, since the free radicals scavenger activities of antioxidants are very important due to the de

Antimutagenic Activity of Some Natural supplements on Ivermectin ge- notoxicity in Lymphocytes of Buffalo

Ivermectin is a veterinary anthelminthic drug, highly effective against a number of arthropod and nematode infestations in vertebrates. The literature reported that ivermectin have mutagenic activities. The extensive use of ivermectin in food producing animals can cause potential hazard to humanity by causing gene mutation or chromosomal aberrations. Recently, there have been considerable efforts to search for naturally occurring substances that can inhibit, reverse, retard or prevent mutagenicity. A wide array of substances derived from edibles and medicinal plants reported to possess anticarcinogenic and antimutagenic activities. Therefore, the aim of this study was to evaluate the modulator role of each of garlic, L-carnitine and wheat germ oil (WGO) against genotoxicity of ivermectin in buffalo lymphocyte cultures by using the cytokinesis block micronucleus assay and chromosomal aberrations test as cytogenetic end-points. Results showed that ivermectin induced dose dependent increase in the frequencies of the binucleated lymphocytes with micronuclei as well as the number of micronuclei in lymphocytes of river buffalo, while the number of binucleated lymphocytes significantly decreased. In addition, ivermectin low dose caused nonsignificant increase in the frequency of total chromosomal aberrations in lymphocytes of river buffalo as compared to control. Whereas, in medium and high doses the frequencies of aberrant cells increased at a significant level (P ≤ 0.001) than control. Meanwhile, the treatment with the three natural supplements (garlic, L-carnitine, wheat germ oil) in continuous with ivermectin significantly reduced the frequencies of binucleated lymphocytes with micronuclei, the number of micronuclei and the frequencies of total chromosomal aberrations induced by ivermectin tested doses, and increase the number of binucleated lymphocytes. In addition, the results indicated that there were non-significant differences between the modulator role of garlic, L-carnitine or wheat germ oil against the mutagenicity of ivermectin in blood lymphocytes. Finally, we can concluded that regular consumption of natural antioxidants, antimutagenic compounds is inversely related to the risk of cancer, since the free radicals scavenger activities of antioxidants are very important due to the de

Cytogenetic Studies on Two Drugs for Natural Relief of Prostatic Disorders

Pepon and prostoplex, new drugs containing natural substances, are used in the treatment of prostatic disorders. The cytogenetic effects of these drugs were tested in mice's bone marrow and spermatocytes cells at two doses comparable to propose human therapeutic and double therapeutic doses.The results revealed that the total numbers of structural chromosomal aberrations in mice's bone marrow, with or without gap, were significantly increased at p<0.01 for pepon and at p<0.05 for prostoplex at therapeutic doses. Whereas at double therapeutic doses, the two drugs showed highly significant increases in the total numbers of structural chromosomal aberrations compared with controls.The frequency of total chromosomal aberrations in mice's spermatocytes was increased at significant level p<0.01 for both drugs at therapeutic doses. At double therapeutic doses, pepon and postoplex increased the total chromosomal aberrations in spermatocyte cells at highly significant level p<0.001.In conclusion, the cytogenetic analysis of pepon and prostoplex revealed that the two drugs have adverse effect on somatic and germinal materials at therapeutic dose. Also, our results are considered as a caution for the treatment with these two drugs at double therapeutic doses, which have mutagenic effect on somatic and germinal materials.

Cytogenetic Damage and the Radiation-Induced G 1 -Phase Checkpoint

It is proposed that genomic integrity is preserved after DNA damage in a variety of ways. X irradiation induces a p53-dependent G1-phase cell cycle checkpoint which putatively allows time for repair of DNA damage. The p53 protein is also involved in the initiation of apoptosis after radiation-induced DNA damage, presumably leading to the elimination of lethally damaged cells from the irradiated population. To test the hypothesis that repair occurs in the additional time provided by the activation of the G1-phase checkpoint, we investigated whether the presence of a G1-phase arrest modified the frequency and type of chromosomal rearrangements at the first mitosis after irradiation. Isogenic cell lines derived from the same human glioma cell line, but differing in p53 status, were used. Purified G1-phase cells, isolated by centrifugal elutriation and X-irradiated, were studied. The wild-type p53 cell line demonstrated a dose-dependent arrest during G1 phase, as determined by flow cytometry. These cells remained in G1-phase as long as 48 h after irradiation. Cells expressing a dominant-negative p53 mutation accumulated to a much lesser extent in G1 phase after irradiation. Cells lacking the G1-phase checkpoint showed increased survival at all radiation doses. There were no significant differences in the type or frequency of total chromosomal aberrations in mitotic cells from either cell line after 1,2,4 or 6 Gy X rays, as measured by conventional cytogenetic analysis. There was an increase, however, in the number of reciprocal translocations in mitotic cells with mutant p53 (lacking a G1-phase checkpoint), as measured by fluorescence in situ hybridization with a chromosome 4-specific DNA library, but only after 6 Gy. The results suggest that the presence of a well-defined p53-dependent G1-phase arrest does not reduce chromosomal aberrations caused by low doses of ionizing radiation markedly, but may reduce the overall degree of survival by triggering other G1-phase events.

High spontaneous chromosomal damage in lymphocytes from patients with hereditary megaduodenum

Chromosomal aberration and micronucleus assays were used to investigate the extent of cytogenetic damage in peripheral blood lymphocytes from four patients in two unrelated families with hereditary megaduodenum. The frequencies of total chromosomal aberrations, which significantly correlated with those of micronuclei, were higher in the patients than in sex- and age-matched controls, with no overlapping between the two groups. The considerable chromosomal fragility in patients which hereditary megaduodenum may be a genotypic marker for preclinical diagnosis predictive of increased cancer risk.

Clastogenic effect of pesticides in peripheral lymphocytes of cotton-field workers

We studied clastogenic effects in peripheral lymphocytes of cotton-field workers who were exposed to different pesticides. All the cells were grown in RPMI 1640 medium for 48 and 72 h. The type of aberrations observed in the exposed group are gaps, breaks, dicentrics, exchanges, rings and polyploidy. The frequency of total chromosomal aberrations increased significantly in male pesticide applicators when compared to controls. A significant decrease in mitotic index was observed in the exposed group as compared to the control group. The 48-h cultures showed high incidence of chromosomal aberrations and low mitotic index when compared to 72-h cultures. The difference in chromosomal aberrations between 48- and 72-h cultures was not significant. 24 out of 26 individuals showed ill health effects such as severe giddiness and nervous disorders.