Genoprotective Effect of Melatonin Against to the Genotoxicity of Glyphosate on Human Blood Lymphocytes

PURPOSE: Glyphosate is a widely used non-selective herbicide. Previous studies have shown that glyphosate has genotoxicity, and that even low-doses of glyphosate can cause DNA damage. Melatonin is a hormone produced and secreted by the pineal gland that is known to be a potent anti-carcinogen, anti-oxidant, and genetic protector. This study was conducted to investigate the genoprotective effect of melatonin against glyphosate in human blood lymphocytes. METHODS: Human peripheral blood was obtained from 15 young, healthy volunteers and cultured under four different toxicologic conditions. The four groups consisted of a control group, glyphosate only group (300 ng/mL), glyphosate with low level of melatonin group (50 µM), and glyphosate with high level of melatonin group (200 µM). The mean Sister Chromatid Exchange (SCE) frequency of each group was then analyzed. RESULTS: Glyphosate exposed groups had a higher mean SCE frequency (10.33±2.50) than the control group (6.78±2.31, p<0.001). Interestingly, the group that received a low-level of melatonin had a lower mean SCE frequency (8.67±2.58) than the glyphosate-only group, while the group that received a high level of melatonin had a much lower mean SCE frequency (8.06±2.50) than the glyphosate-only group. There was statistical significance. CONCLUSION: Melatonin exerted a potent gene protective effect against the genotoxicity of glyphosate on human blood lymphocytes in a dose-dependent fashion.

In vitro Effects of Epigallocatechin Gallate on Sister Chromatid Exchange in the Lymphocytes Exposed to Glyphosate

PURPOSE: Green tea is known as a potent anti-oxidant, anti-carcinogen, and genetic protector. Glyphosate (N-phosphonomethyl glycine) is a widely used non-selective herbicide that causes DNA damage. The present study was conducted to investigate the protective effects of green tea in human blood lymphocytes exposed to glyphosate using the Sister Chromatid Exchange (SCE) frequency method. METHODS: Peripheral blood was obtained from 10 volunteers and cultured through four different conditions. Four groups were divided into control, glyphosate only (300 ng/mL), glyphosate and low (20 µm) concentrations of epigallocatechin gallate (EGCG) and glyphosate and high (100 µm) concentrations of EGCG. RESULTS: The glyphosate exposed groups had a higher mean SCE frequency (10.33±2.50) than the control group (6.38±2.28, p<0.001). The low concentrations of EGCG groups had a lower mean SCE frequency (9.91±1.93) than the glyphosate-only group, although this difference was not significant (p=0.219). However, the high concentration group (9.49±1.85) had a significantly lower SCE frequency than the glyphosate-only group (p=0.001). CONCLUSION: EGCG has a gene protective effect in human lymphocytes exposed to the genotoxicity of glyphosate in the case of high concentrations.

A study of sister chromatid exchange in patients with dental amalgam restorations.

Study Background: Dental amalgam is still widely used as a restorative material in developing countries due to its low cost and ease of manipulation. The health risks associated with the components of this restorative material has always been a matter of concern. Our study was designed to address this question regarding dental amalgam. Objective: To study sister chromatid exchange (SCE) as an indicator of systemic genotoxicity, due to the exposure from the components of amalgam restorations during its placement and chronic use. Materials and Methods: Systemic genotoxicity in subjects exposed to amalgam during its placement (Group II; n = 5) and subjects with chronic exposure to amalgam (Group III; n = 5) were compared with controls (Group I; n = 5) by SCE assay in cultured peripheral blood lymphocytes. Result: Subjects exposed to amalgam during its placement and subjects having chronic exposure to amalgam showed an increase in the frequency of SCE, but the change was not statistically significant (P = 0.84, P = 0.123 respectively). Conclusion: Systemic genotoxicity was not observed due to the components of amalgam restorations released during its placement and chronic use. The findings of this study can be considered as preliminary information on the systemic toxicity due to the components of amalgam restorations.

Cáncer oral en Santiago de Cali, Colombia: análisis poblacional de la tendencia de incidencia y mortalidad / Oral cancer in Cali, Colombia: a population-based analysis of incidence and mortality trends

Objetivo. Describir la tendencia de las tasas de incidencia y mortalidad por cáncer oral (CaO) en Cali, Colombia durante el periodo 1962-2007. Material y métodos. Se obtuvieron las tasas estandarizadas por edad (población mundial) de incidencia (TIEE) y mortalidad (TMEE) por CaO con información del Registro Poblacional de Cáncer en Cali-Colombia (RPCC) y de la Secretaría de Salud Pública Municipal de Cali (SSPM), respectivamente. Se utilizó el porcentaje de cambio anual (APC) para describir la tendencia de las mismas. Resultados. Se registraron 1637 casos nuevos de CaO y la edad promedio al diagnóstico fue de 60 años. Las TIEE disminuyeron entre 1962-2007 en hombres APC= -1.3 (IC95%:-2.0; -0.6) y mujeres, APC= -1.0 (IC95%: -1.7; -0.4). Las TMEE disminuyeron entre 1984-2001 sólo en los hombres, APC= -2.8 (IC95%: -4.1; -1.5). Conclusión. La morbilidad y mortalidad por CaO ha disminuido de manera significativa en Cali, Colombia. El tipo de tumor asociado con estos cambios fue el carcinoma de células escamosas.

Objective. To describe the time trends of the incidence and mortality rates of oral cancer (OC) in Cali, Colombia between 1962-2007. Materials and methods. Age-standardized (Segi's world population) incidence (ASIR) and mortality (ASMR) rates for oral cancer were estimated using data from the Population-based Cancer Registry of Cali, Colombia and from the database of the Municipal Secretary of Public Health (MSPH) respectively. Annual percentage change (APC) was used to measure the changes in rates over time. Results. 1637 new cases of oral cancer were registered in the CPCR and the mean age upon diagnosis was 60 years. The ASIR decreased from 1962-2007 in men APC= 1.3 (IC95%:-2.0; -0.6) and women APC= -1.0 (IC95%: -1.7; -0.4).The ASMR decreased from 1984-2001 only in men, APC=2.8 (IC95%: -4.1; -1.5). Conclusions. There was a significant decrease in the incidence and mortality rates for OC in Cali, Colombia. The type of tumor associated to these changes was the squamous cell carcinoma.

Genotoxicity of low-dose Glyphosate by Sister Chromatid Exchange

PURPOSE: Glyphosate (N-phosphonomethyl glycine) is widely used as an herbicide for weed control in rural areas. It is also readily available for suicide attempts. Glyphosate has high toxicity and negatively affects the human body. The aim of this investigation was to study the genotoxicity of a low-concentration of glyphosate through sister chromatid exchange (SCE) in human blood lymphocytes in vitro. METHODS: Primary lymphocyte cultures were obtained from blood samples of 11 males and seven females who had been exposed to glyphosate (0, 100, 200, and 300 ng/mL). The frequency of SCEs was examined and statistical analysis was performed. RESULTS: All doses of glyphosate induced a significant dose-dependent increase in SCE frequency compared with the control group (P<0.001). In particular, the SCE frequency for exposure to low-dose glyphosate was significantly higher in females than in males. CONCLUSION: According to the result of this study, even a low-dose of glyphosate may damage DNA and females are more vulnerable to glyphosate.

Genotoxicity of low-dose Glyphosate by Sister Chromatid Exchange

PURPOSE: Glyphosate (N-phosphonomethyl glycine) is widely used as an herbicide for weed control in rural areas. It is also readily available for suicide attempts. Glyphosate has high toxicity and negatively affects the human body. The aim of this investigation was to study the genotoxicity of a low-concentration of glyphosate through sister chromatid exchange (SCE) in human blood lymphocytes in vitro. METHODS: Primary lymphocyte cultures were obtained from blood samples of 11 males and seven females who had been exposed to glyphosate (0, 100, 200, and 300 ng/mL). The frequency of SCEs was examined and statistical analysis was performed. RESULTS: All doses of glyphosate induced a significant dose-dependent increase in SCE frequency compared with the control group (P<0.001). In particular, the SCE frequency for exposure to low-dose glyphosate was significantly higher in females than in males. CONCLUSION: According to the result of this study, even a low-dose of glyphosate may damage DNA and females are more vulnerable to glyphosate.

Cytogenetic Finding of Breast Cancer Cases and in Their First-Degree Relatives / 한국유방암학회지

PURPOSE: The aim of this study was to evaluate and compare the rate of sister chromatid exchange (SCE), the occurrence of micronuclei, and the lymphocyte proliferation rate index (PRI) in patients with breast cancer, their first-degree relatives, and healthy volunteers. METHODS: We analyzed the frequency of SCE and micronuclei, and the PRI in the peripheral blood lymphocytes of 30 women with breast cancer, 22 of their female family members, and 20 age-matched healthy female volunteers. RESULTS: SCE occurred significantly more often in the lymphocytes of breast cancer patients (10.84+/-0.4 per metaphase), compared with their first-degree relatives (7.45+/-0.54) and controls (5.94+/-0.2) (p<0.001 for both). The mean SCE frequency was not statistically different between first-degree relatives and controls (p=0.071). Similarly, micronuclei occurred at a significantly higher rate in breast cancer patients (9.6+/-0.72), and in their first-degree relatives (7+/-0.64), compared to controls (3.85+/-0.4) (p<0.001 and p=0.001, respectively). There was also a significant difference between the occurrence of micronuclei in patients compared to their family members (p=0.021). The PRI was significantly lower in patients (1.61+/-0.1), compared with both their first-degree relatives (1.75+/-0.1), and controls (1.74+/-0.1) (p=0.001 and p=0.002, respectively). CONCLUSION: Increased SCE and the occurrence of micronuclei, as well as a reduced PRI are associated with breast cancer. Furthermore, increased SCE and the frequency of micronuclei in a first-degree relative suggest that they exhibit greater genetic instability than women of the same age.

Short-term comparative study of the cyclophosphamide genotoxicity administered free and liposome-encapsulated in mice

Cyclophosphamide [CYP] is used to treat a wide range of human tumors. However, the mutagenic effect of CYP is still the primary limitation for wider applications to treat a variety of human malignancies. It has been reported that CYP entrapped in liposomes reduces non-specific toxicity and enhances anticancer effects in animal systems. In the present experiment, mice were injected with 50 mg/kg free CYP or encapsulated in liposomes to compare their ability to induce mutagenic damages including chromosomal aberrations, changes in Sister Chromatid Exchange [SCEs] frequencies, and in Mitotic Index [MI], as well as in cell cycle kinetics. Both forms of CYP induced an increase in chromosomal aberrations and SCEs at the different sampling time. On the contrary, a decrease in mitotic index and delay in cell cycle kinetics was observed at all stages of the experiment. Encapsulation of CYP increased its mutagenicity, especially at a longer sampling time. This may due to interaction of liposomes with cells which is mainly through endocytosis or fusion resulting in accumulation of drug inside the cell causing chromosomal damage. Further evaluation of possible toxicity of encapsulation drugs in healthy tissue is needed

Induction of SCEs and DNA fragmentation in bovine peripheral lymphocytes by in vitro exposure to tolylfluanid-based fungicide

The potential for genotoxic and cytotoxic effects of tolylfluanid-based fungicide (50 percent active agent) was evaluated using sister chromatid exchange (SCE) and proliferation indices (PI) in cultured bovine peripheral lymphocytes. For the detection of possible genetic damage, DNA fragmentation assay was also applied. Bovine lymphocytes cultured for 72 h were treated with the fungicide at the final concentrations of 1.75, 3.5, 8.75, and 17.5 µg/mL for the last 24 and 48 h of culture without S9 metabolic activation, and during the last 2 h of culture with S9 metabolic activation. In the SCE assays no evidence for genotoxic activity of the fungicide was found in treatments of 24 h without and 2 h with S9. After the 24 h exposure to tolylfluanid, a weak decrease in the PI was observed. With the prolonged exposure time (48 h), dose dependence in the increase of SCE frequencies was observed. Moreover, after 48 h exposure slight fragmentation of DNA at the concentrations of 3.5 and 8.75 µg/mL was demonstrated. SCE quantification is the most widely used approach for the assessment of genotoxic/cytogenetic effects of chemical compounds. Positive results in the assay at 48 h exposure indicated a potential of the fungicide to increase frequency of chromosomal damage (replication injuries) that is the confirmation of early effect of exposure.

G2 chromosomal radiosensitivity and background frequency of sister chromatid exchanges of peripheral blood lymphocytes of breast cancer patients

Chromosomal alterations play an important role in carcinogenesis. Enhanced chromosomal radiosensitivity is shown for many cancer predisposition conditions including breast cancer. In this study chromosomal radiosensitivity and the frequency of background sister chromnatid exchanges [SCE] in lymphocytes of normal individuals and breast cancer patients was compared. G2 assay was performed on peripheral blood lymphocytes obtained from 60 breast cancer patients and 50 normal control. Blood culture was initiated and cells were irradiated with 1 Gy gammarays 4 h prior to harvesting. After metaphase preparations and slide making, chromatid aberrations were scored. For SCE studies, blood samples from 30 breast cancer patients and 30 normal control were studied. 24 hours after culture initiation, 5-bromodeoxy uridine [BrdU] was added and cells were harvested 48 hours after addition of BrdU. Slides were stained in Hoechst 33258 and exposed to UVA source, then stained in Giemsa. Results indicated that the frequency of radiation induced chromatid breaks was significantly higher in breast cancer patients compared to normal control [p<0.01]. From radiosensitivity point of view, 12% of normal control and 47% of breast cancer patients showed elevated chromatid radiosensitivity. Frequency of background SCE was significantly higher in lymphocytes of breast cancer patients compared to lymphocytes of control [p<0.05]. Elevated chromosomal radiosensitivity and higher frequency of SCE in lymphocytes of breast cancer patients might be indicative of genomic instability of these cells. Increased radiosensitivity could also be due to defects in DNA repair genes involved in breast cancer formation

Change of structural maintenance of chromosome (SMC)1, SMC3, Separase and Securin expression in BEAS-2B malignant transformation cell induced by coal tar pitch smoke extracts / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>to study the role of structural maintenance of chromosome (SMC)1, SMC3, Separase and Securin in tumorgenesis that contact with coal tar pitch.</p><p><b>METHODS</b>the BEAS-2B cells was induced by coal tar pitch smoke extracts to form malignant transformation cell model in vitro. The gene expression levels of mRNA were assessed by real-time quantitative RT-PCR, and the protein expression variation were determined by cell culture overslip of immunohistochemical methods.</p><p><b>RESULTS</b>in malignant transformation cells, the mRNA and the protein expression level of SMC1 gene was not statistically significantly different compared with the BEAS-2B group and DMSO group (P > 0.05); SMC3 and Separase was increased and Securin was decreased (P < 0.05), while the difference between other two control groups was not significant (P > 0.05).</p><p><b>CONCLUSIONS</b>the up expression level of SMC3 and Separase and the down expression level of Securin are involved in the process that evolves into malignant transformation in bronchial epithelial cells BEAS-2B induced by coal tar pitch smoke extracts.</p>

Health Effects of Chemicals used in hospitals among Healthcare Workers

Healthcare workers are exposed to a variety of chemical agents used in many different areas and purposes. The chemicals could cause health problems to healthcare workers using them. Glutaraldehyde is a kind of disinfectant and used for endoscopes, catheters, and many kinds of operating apparatus. It may cause allergic contact dermatitis. Formaldehyde is another disinfectant and can be used for fixing tissues. Formaldehyde was classified to a Group 1 carcinogen by IARC and it may cause lung or nasal cancer. Ethylene Oxide gas is the most popular disinfectant these days and may be applied to many health care sets or linens. EO gas may cause allergic contact dermatitis and breast cancer or leukemia. It is also classified as Group 1 carcinogen despite limited evidence for human cancers. Anesthetics are related to genotoxicities, sister chromatid exchange, and might be related to spontaneous abortion, stillbirth or birth defects. Some of the anti-neoplastic drugs such as Busulfan, Chlorambucil, cyclophosphamide, melphalan are Group 1 carcinogens. They could cause nausea, pruritus, or decreasing leukocytes or platelets. Other miscellaneous chemical agents are heavy metals such as elementary mercury or lead and organic solvents such as toluene, xylene and acetone. Although some of these chemical agents including EO gas have occasionally exceeded to permissible level, air levels of most above chemicals in Korean hospitals were relatively low. However, we have to make every effort to reduce the exposure level of these chemicals.

Cytogenetic study of Ascaris trypsin inhibitor in cultured human lymphocytes with metabolic activation.

The trypsin inhibitor (ATI) isolated from gastrointestinal nematode Ascaris suum was tested in vitro for induction of chromosome aberrations and sister chromatid exchanges (SCE). Genotoxicity assessment of purified ATI was carried out on metaphase plates received from peripheral blood lymphocyte macroculture (48 h test of structural chromosome aberrations and 72 h test of SCE) with exogenous metabolic activation. ATI was tested in dose of 25, 50 and 100 mu g per ml of culture. Kinetics of cell divisions were determined by the replication index (RI). The mitotic index (MI) was expressed as a number of metaphases per 1000 nuclei analysed. Analysis of chromosome aberrations showed that higher doses of ATI (50 and 100 mu g-ml) significantly increased the frequency of chromosome aberrations (mainly of chromatid gaps and breaks) compared to the negative control. All concentrations of ATI caused a statistically significant reduction in the MI and RI. In comparison with the negative control, a significant increase in the SCE frequency was observed in all applied doses of ATI. Thus, in the presence of S9 activation, the Ascaris trypsin inhibitor showed potential clastogenic activity and inhibition of the dynamics of lymphocyte divisions.

Sister chromatid exchange in peripheral blood lymphocytes as a possible breast cancer risk biomarker: a study of Iranian patients with breast cancer

Sister chromatid exchanges [SCEs] can be induced by various genotoxic treatments, suggesting that SCEs reflect a DNA repair process and it may be a good index for assessment of genomic instability. However, the occurrence of genetic instability and in particular, of spontaneous SCEs has been strongly linked to cancer. Several chromosomal regions and many genes have been implicated in breast cancer. Blood samples were obtained from 31 Iranian breast cancer patients and 11 healthy women. SCE was measured in peripheral blood lymphocytes by adding to Ham'sF10 medium in presence of PHA, BrdU [5-bromo-deoxy Uridine] fluorochrome Hoechst 33258, exposure to UV light and Giemsa staining. Then, SCE frequencies of patient and control groups were compared by the Mann-Withney U-test. Significantly difference was observed between two groups [p < 0.001]. This study indicates that SCE can be used as a risk biomarker for breast cancer

Possible modulating action of plant infusion of Ocimum sanctum L. on chromosomal aberrations and sister chromatid exchanges induced by chlormadinone acetate in human lymphocytes in vitro.

Chlormadinone acetate (CMA) is a synthetic progesterone analogue. It has its usage in oral contraceptives formulations and also for estrous synchronization of animals. The aim of the present study is to study the anti- genotoxic activity of the plant infusion against the CMA induced genotoxic damage on cultured human lymphocytes, using chromosomal aberrations and sister chromatid exchanges (SCFs) as parameters. For chromosomal aberration analysis, the treatment of 40 microM of CMA was associated with 4.33% abnormal metaphases. The treatment of 40 microM of CMA, separately with 1.075 x 10(-4), 2.125 x 10(-4) and 3.15 x 10(-4) gm l(-1) of plant infusion results in the reduction of the number of abnormal metaphases i.e. 2.67%, 2.00% and 1.67% respectively. For sister chromatid exchange analysis, the frequency of sister chromatid exchange per cell (SCE(S)/Cell) for the treatment of 40 microM of CMA was 6.43. The treatment of 40 microM of CMA, separately with 1.075 x 10(-4), 2.125 x 10(-4) and 3.15 x 10(-4) gm l(-1) of plant infusion results in the significant reduction of the frequency of SCE(S)/Cell i.e. 3.76, 3.01 and 2.94, respectively, as compared to the CMA (40 microM) treatment alone (6.43). The used dosages of plant infusion did not increase chromosomal aberrations and sister chromatid exchanges at significant level as compared to the untreated. The results of the present study suggest that the plant infusion per se does not have genotoxic potential, but can modulate the genotoxicity of chlormadinone acetate in human lymphocytes in vitro.

Evaluation of genetic damage in human lymphocytes of women using oral contraceptives

The genotoxic effect of low dose oral contraceptive pills on the frequency of chromosomal aberrations [CA] and sister chromatid exchange [SCE] was investigated on 43 healthy females classified as; 15 women received pills containing 150 microg desogesterel and 30 microg ethinyl estradiol, 14 women received pills containing 250 microg Norgestamine and 35 microg ethinyl estradiol and 14 women received pills containing 75 microg gestodene and 30 microg ethinyl estradiol. The pills were taken orally as a single daily usage in a monthly cycle of 3 weeks and one week off during twelve consecutive menstrual cycles. Also 15 healthy women with regular menstrual cycle not receiving any hormonal therapy were included as a control. There was no statistically significant difference in CA, SCE when healthy women were compared with women taking oral contraceptive pills [p>0.05]. Also no statistically significant difference was detected when comparing between the 3 different types of oral contraceptives [p>0.05]. Our data suggest that the 3 types of oral contraceptive pills used during twelve consecutive menstrual cycles do not induce chromosomal aberrations or sister chromatid exchange in peripheral blood lymphocytes of women

In vitro antigenotoxicity of Ulva rigida C. Agardh (Chlorophyceae) extract against induction of chromosome aberration, sister chromatid exchange and micronuclei by mutagenic agent MMC / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To determine the in vitro possible clastogenic and cytotoxic activities of Ulva rigida crude extracts (URE), and identify their antigenotoxic and protective effects on chemotherapeutic agent mitomycine-C (MMC).</p><p><b>METHODS</b>Anti-clastogenic and anti-genotoxic activities of Ulva rigida crude extracts (URE) were studied using chromosome aberration (CA), sister chromatid exchange (SCE), and micronuclei (MN) tests in human lymphocytes cultured in vitro.</p><p><b>RESULTS</b>The chromosome aberration, sister chromatid exchange or micronuclei tests showed that URE at concentrations of 10, 20, and 40 microg/mL had no clastogenic activity in human lymphocyte cell culture. Three doses of URE significantly decreased the number of chromosomal aberrations and the frequencies of SCE and MN when compared with the culture treated with MMC (P < 0.0001).</p><p><b>CONCLUSION</b>Although URE itself is not a clastogenic or cytotoxic substance, it possesses strong antigenotoxic, anti-clastogenic, and protective effects on MMC in vitro.</p>

The Effects of Etodolac, Nimesulid and Naproxen Sodium on the Frequency of Sister Chromatid Exchange after Enclused Third Molars Surgery

PURPOSE: Non-steroidal anti-inflammatory drugs (NSAID) are frequently used in oral surgical procedures in dentistry. The evaluation of the frequency of sister chromatid exchange (SCE) is accepted as a reliable cytogenetic method to assess the genotoxic effects of environmental factors. MATERIALS AND METHODS: In this study, the genotoxic effects of various NSAIDs were assessed in 30 patients to who they were administered following encluosed third molar surgery using SCE analysis before and after the operation. The frequency of SCE was evaluated before the operation and after 3 days of etodolac, nimesulid and naproxen use. RESULTS: There was no statistically significant difference in the frequency of SCE between the preoperative and postoperative states in patients given etodolac, nimesulid or naproxen sodium. CONCLUSION: Short term use of selective and non-selective NSAIDs was not associated with a significant genotoxic effect that could be detected using the SCE method in peripheric lymphocytes.

Protective role of nordihydroguaiaretic acid (NDGA) against the genotoxic damage induced by ethynodiol diacetate in human lymphocytes in vitro.

Antioxidants and plant products are reported to reduce the genotoxic damage of steroids. In our present study we have tested different dosages of nordihydroguaiaretic acid (NDGA) against the genotoxic damage induced by ethynodiol diacetate in the presence of S9 mix. Treatments with nordihydroguaiaretic acid (NDGA) results in the reduction of the genotoxic damage. A significant decrease was observed at all the tested doses of NDGA in sister chromatic exchanges of number of abnormal cells. The results suggest a protective role of NDGA against the genotoxic damage.

High sister chromatid exchange among a sample of traffic policemen in Bangkok, Thailand.

There are several volatile substances from the traffic, including benzene, toluene, carbon monoxide, lead and formaldehyde. Most of these substances are considered carcinogens. Police are at occupational risk for toxic fume exposure. This study compared sister chromatid exchange (SCE), a marker for genotoxicity, among a sample of Thai traffic policemen in Bangkok with healthy control subjects. Thirty police officers (all male) and 20 controls were included in this study. The average (mean+/-SD) SCE for policemen and controls were 4.40+/-0.93/cell and 0.24+/-0.12/cell, respectively. A significantly higher SCE among the policemen was observed. Concern for and prevention of toxic substance exposure in traffic police officers should be made a national goal.