Health professionals who had been working in different health care units and who were chronically exposed to cytostatic drugs were examined during the last 25 years. In their working area of the oncology outpatient and hospital units cytostatic drug exposure regularly exceeded safety limits due to the lack of proper safety devices. Their health condition was annually investigated by clinics, and it was found that they developed more hematological, immunological and reproductive alterations. In the present study we assessed changes in immune phenotypes based on the CD4/CD8 T-cells ratio, B and NK cell percentages measured by FACS methodology. The investigations were carried out in 550 subjects exposed to different cytostatic agents in oncology departments. Data were compared to age matched 83 healthy and non-exposed female controls. Biomarkers were measured by routine clinical laboratory tests, completed with immune phenotyping and measured in peripheral blood lymphocytes (PBL). Health personnel exposed to different agents showed increased ratio of CD4/CD8 T-cell and a decrease in activated T-cells. Beside these parameters we found an elevation of B-cells and a decrease in NK-cells. Within the exposed groups smokers showed even stronger decreased NK-cell counts compared to non-smokers. These changes in immune-phenotypes may give us a new biomarker immune suppression of PBL-cells among nurses after toxic exposures in their working environment.

Background: Health professionals chronically exposed to anesthetic gases in the operating rooms are at higher risk of lung diseases, hematological, immunological and reproductive alterations. Anesthetic gas exposure often exceeds the safety limits, especially in the case of pediatric anesthetists, or when no proper ventilation has been installed in operating theaters. In the present study we assessed the health risk among anesthetics exposed nurses and measured genotoxicological parameters in the presence or absence of confounding factors such as smoking. Methods: The investigations were carried out in 128 subjects exposed to anesthetic gases from health services. The data were compared to 137 healthy, non-exposed controls. The measured biomarkers were: clinical laboratory routine tests, completed with genotoxicological (chromosome aberrations and sisterchromatid exchange, DNA repair and apoptosis) monitoring system. The exposed group was divided into Halothane and Non-Halothane exposed subgroups to compare the differences within exposures. Results: In the group of health personnel exposed to anesthetic gases, we did not find significant changes in the frequency of chromosome aberrations. Sister-chromatide exchange rates in Halothane exposed and control smokers was increased, compared to nonsmokers. We also found a decrease of apoptosis and inhibition of UV induced DNA repair capacity compared to controls. The exposed individuals had high incidences of malignant diseases (9.3%) mainly breast, skin, and colon cancers. Conclusion: Low level of cytogenetic changes may be related to the decreased apoptotic rate of peripheral blood lymphocytes due to the low risk of misrepair from a decreased DNA-repair capacity. Our results suggest that our biomarkers can be useful in tracking occupational/environmental genotoxic effects among anesthetic gases exposed personnel.

Introduction: More than half of the Hungarian population is overweight or obese, therefore, non-alcoholic fatty liver is a common problem. According to clinical experience, 20–30% of fatty liver cases is not related to alcohol, but can be linked to diabetes, obesity or metabolic syndrome. Aim: The authors studied the correlation between genotoxicity, immuntoxicity and non-alcoholic fatty liver among oil refinery workers. Method: During this genotoxicological monitoring study the data of 107 exposed were compared to 67 controls. Results: 36% of oil refinery workers had non-alcoholic fatty liver, while none of the selected, non-exposed controls had this abnormality. Chromosomal aberrations were elevated from 1.6% to 3.75% in the exposed group, immunotoxicological parameters were also changed, and CD71 positive B-cell ratio increased especially among subjects having non-alcoholic fatty liver. Conclusions: Non-alcoholic fatty liver can negatively influence the genotoxic effects of environmental hazards in workplaces. In the future this condition should be considered during risk assessment. Orv. Hetil., 2016, 157(35), 1394–1402.

Absztrakt Bevezetes: A magyarorszagi felnőtt lakossag tobb mint fele tulsulyos vagy elhizott, amelynek hatranyos kovetkezmenye a zsirmaj kialakulasa lehet. Az esetek 20–30%-aban nem alkoholos eredetű, hanem az elhizassal, cukorbajjal vagy metabolikus szindromaval fugghet ossze. Celkitűzes: Jelen dolgozatban az olajipari munkasok koreben fellelhető, nem alkoholos zsirmaj eseteit hasonlitottak ossze a kontrollokkal a gen- es immuntoxikologiai karosodasok fuggvenyeben. Modszer: 107 olajipari munkas adatait hasonlitottak ossze 67 felnőtt ferfi kontrollal. Eredmenyek: Az olajipari dolgozoknal az esetek 36%-aban volt jelen zsirmaj. A kontrollok csoportjaban sem zsirmaj, sem gentoxikologiai elteres nem volt. Az exponaltak koreben a citogenetikai parameterek pozitivitasa a kontrollhoz kepest szignifikansan emelkedett, amit a zsirmaj jelenlete tovabb fokozott. Az immunologiai parameterek kozul a zsirmajban szenvedő exponaltaknal a CD71-pozitiv, vagyis transzferrinreceptort hordozo B-sejtek aranya nőtt. Kovetkeztetesek: A nem alkoholos zsirmaj az ipari vegyi expozicioval egyutt kepes a gentoxikus es az immuntoxikus hatasok fokozasara, amit a munkaalkalmassag megallapitasaban es a kockazatbecslesben a jovőben figyelembe kell venni. Orv. Hetil., 2016, 157(35), 1394–1402. | Abstract Introduction: More than half of the Hungarian population is overweight or obese, therefore, non-alcoholic fatty liver is a common problem. According to clinical experience, 20–30% of fatty liver cases is not related to alcohol, but can be linked to diabetes, obesity or metabolic syndrome. Aim: The authors studied the correlation between genotoxicity, immuntoxicity and non-alcoholic fatty liver among oil refinery workers. Method: During this genotoxicological monitoring study the data of 107 exposed were compared to 67 controls. Results: 36% of oil refinery workers had non-alcoholic fatty liver, while none of the selected, non-exposed controls had this abnormality. Chromosomal aberrations were elevated from 1.6% to 3.75% in the exposed group, immunotoxicological parameters were also changed, and CD71 positive B-cell ratio increased especially among subjects having non-alcoholic fatty liver. Conclusions: Non-alcoholic fatty liver can negatively influence the genotoxic effects of environmental hazards in workplaces. In the future this condition should be considered during risk assessment. Orv. Hetil., 2016, 157(35), 1394–1402.

OBJECTIVE:Several biomarkers may be used to detect harmful exposure and individual susceptibility to cancer. Monitoring of biomarkers related to exposure may have a significant effect on early detection of cell transformation, thereby aiding the primary prevention of various chronic and malignant diseases. Nurses who handle cytotoxic drugs are exposed to carcinogenic agents, which have the potential to interrupt the cell cycle and to induce chromosomal aberrations. The presence of high chromosomal aberrations indicates the need for intervention even when exposure to these carcinogens is low.METHODS:Nationally representative samples of 552 nurses were investigated by a follow-up monitoring system. The measured biomarkers were clinical laboratory routine tests, completed with genotoxicological (chromosome aberrations [CAs] and sister chromatid exchanges [SCEs]) and immunotoxicological monitoring (ratio of lymphocyte subpopulations and lymphocyte activation markers) measured on peripheral blood lymphocytes. Results were compared to the data of 140 healthy, age-matched controls.RESULTS:In nurses exposed to cytostatics, we observed a significantly increased frequency of CAs and SCEs compared with those in the controls. Cytostatic drug exposure also manifested itself in an increased frequency of helper T lymphocytes. Genotoxicological and immunotoxicological changes, as well as negative health effects (i.e., iron deficiency, anemia, and thyroid diseases), increased among cytostatic exposed subjects.CONCLUSIONS:These results raised concerns about the protection of nursing staff from chemical carcinogens in the working environment.

Introduction: More than half of the Hungarian population is overweight or obese, therefore, non-alcoholic fatty liver is a common problem. According to clinical experience, 20-30% of fatty liver cases is not related to alcohol, but can be linked to diabetes, obesity or metabolic syndrome. Aim: The authors studied the correlation between genotoxicity, immuntoxicity and non-alcoholic fatty liver among oil refinery workers. Method: During this genotoxicological monitoring study the data of 107 exposed were compared to 67 controls. Results: 36% of oil refinery workers had non-alcoholic fatty liver, while none of the selected, non-exposed controls had this abnormality. Chromosomal aberrations were elevated from 1.6% to 3.75% in the exposed group, immunotoxicological parameters were also changed, and CD71 positive B-cell ratio increased especially among subjects having non-alcoholic fatty liver. Conclusions: Non-alcoholic fatty liver can negatively influence the genotoxic effects of environmental hazards in workplaces. In the future this condition should be considered during risk assessment.

INTRODUCTION:Environmental exposure to harmful chemicals may produce severe consequences.AIM:The aim of the authors was to perform geno- and immune-toxicological monitoring in female employees occupationally exposed to cytostatic agents in hospitals and compare the findings to those obtained from controls.METHOD:Altogether 642 women working in hospital who were occupationally exposed to cytostatic drugs and 262 control women participated in the study. Frequency of chromosome aberrations, immune phenotype and activation of lymphocytes, and the production of reactive oxygen-species in neutrophil granulocytes were determined.RESULTS:Markedly higher number (n=39) of thyroid alterations was observed among exposed subjects as compared to controls (n=3). In persons with abnormal thyroid functions, the frequency of chromosome aberrations (3.69%) was significantly higher (3.69%) than in exposed subjects without thyroid alterations (2.43%) and in controls (1.70% and 1.60% in control subjects with and without thyroid alterations, respectively). Significantly increased ratio of helper T lymphocytes and decreased ratio of cytotoxic T cells and transferrin-receptor (CD71) expressing B cells were observed in exposed subjects having abnormal thyroid functions as compared to controls. In addition, the ratio of B cells, CD71 expressing T cells and production of reactive oxygen-intermediates was significantly decreased in exposed subjects with thyroid alterations in comparison to exposed subjects without thyroid alterations.CONCLUSIONS:The results indicate increased geno- and immune-toxic effects among exposed subjects having thyroid alterations. Further data are needed to clearly establish the underlying pathophysiological mechanism of this finding.

INTRODUCTION:Kaqun-water contains a high amount of stable oxygen, which absorbed through the skin and intestinal tract, increases tissue oxygenation.AIM:The aim of the authors was to evaluate the effect of 21 days of Kaqun-water treatment on the immune parameters of healthy volunteers.METHOD:Subpopulations of lymphocytes were determined by immune phenotyping, and CD25 and CD71 activation antigens were used to assess lymphocyte activation. Production of reactive oxygen intermediates was measured to determine the killing capacity of neutrophil granulocytes. Data was analysed with repeated measures ANOVA.RESULTS:The reactive oxygen intermediate production of neutrophils increased significantly in stimulated samples during three weeks of Kaqun-water treatment. The percent of activated, CD25 positive T and helper T cells, and the ratio of NK cells increased.CONCLUSIONS:The increase in oxygen concentration caused by Kaqun-water treatment affects several immune functions: the killing potential of neurophil granulocytes is enhanced, the activation of lymphocytes shows an increased activity of immune function, and the elevated ratio of NK cells may help combat virally infected and tumorous cells.

Introduction: The comet assay is a fluorescent microscopic method that is able to detect DNA strand-breaks even in non-proliferative cells in samples with low cell counts. Aim: The aim of the authors was to measure genotoxic DNA damage and assess oxidative DNA damage caused by occupational exposure in groups exposed to benzene, polycyclic aromatic carbohydrates and styrene at the workplace in order to clarify whether the comet assay can be used as an effect marker tool in genotoxicology monitoring. Method: In addition to the basic steps of the comet assay, one sample was treated with formamido-pirimidine-DNA-glycolase restriction-enzyme that measures oxidative DNA damage. Results: An increase was observed in tail moments in each group of untreated and Fpg-treated samples compared to the control. Conclusions: It can be concluded that occupational exposure can be detected with the method. The comet assay may prove to be an excellent effect marker and a supplementary technique for monitoring the presence or absence of genotoxic effects.

In this study, changes in the immune phenotype of 127 subjects exposed to anesthetic gases from health services were measured by flow cytometry. The data was compared to healthy, non-exposed controls. We supposed that there is a relationship between health risk for the personnel exposed to anesthetic gases and the alteration of the measured immune parameters in the presence or absence of confounding factors such as smoking and alcohol consumption.In the group of health personnel exposed to anesthetic gases, we found a statistically significant increase in the ratio of CD25+/CD8+ cells - activated cytotoxic T cells - compared to the control. In those workplaces, where protective measures were strictly adhered to (with quality assurance) the activation of lymphocytes was at control level, however, where there was no quality assurance, activation of lymphocytes increased significantly compared to the control. In the anesthetic gas exposed smokers, there was a statistically significant shift in the T cell subpopulations: the percentage of helper T cells increased, while the percentage of cytotoxic T cell decreased, leading to an elevated Th/Tc ratio compared to the nonsmokers. Our results suggest that our biomarkers can be useful in tracking occupational/environmental immunotoxic effects. Smoking as a confounding factor has to be taken into account when assessing occupational exposures.

The aim of our study was to investigate the immunotoxicity of occupational cytostatic drug exposure, and to assess the possible effect of confounding factors, such as age and smoking. In this human study, the immunotoxic effect of antineoplastic drugs was investigated among 306 nurses working in oncology chemotherapy units. Results were compared to 98 non-exposed women. The immune status of the subjects was characterized by immune phenotyping of peripheral blood lymphocytes by flow cytometry, using monoclonal antibodies against surface antigens (CD3, CD4, CD8, CD19, CD25, CD45, CD56 and CD71). The killing ability of neutrophil leukocytes was assessed by the measurement of reactive oxygen intermediate production. Occupational exposure to antineoplastic drugs caused shifts in the major lymphocyte subpopulations, resulting in a statistically significant increase in the ratio of B cells. Cytostatic drug exposure also manifested itself in a decreased frequency of CD25 positive, activated T lymphocytes, and increased oxidative burst of neutrophil granulocytes, both of which may have a functional impact on the immune system of exposed subjects. In the younger subjects exposure also caused a shift in T cell subpopulations: a reduction in the cytotoxic T cell population lead to an elevated Th/Tc ratio. In the exposed group, smoking increased activation of T lymphocyte subpopulations. In conclusion, we have demonstrated that low dose occupational cytostatic drug exposure is immunotoxic, and age and smoking modify the effect of exposure.

BACKGROUND:Association between rectal or colon cancer risk and serine hydroxymethyltransferase 1 (SHMT1) C1420T or methylenetetrahydrofolate reductase (MTHFR) C677T polymorphisms was assessed. The serum total homocysteine (HCY), marker of folate metabolism was also investigated.METHODS:The SHMT1 and MTHFR genotypes were determined by real-time PCR and PCR-RFLP, respectively in 476 patients with rectal, 479 patients with colon cancer and in 461 and 478, respective controls matched for age and sex. Homocysteine levels were determined by HPLC kit. The association between polymorphisms and cancer risk was evaluated by logistic regression analysis adjusted for age, sex and body mass index. The population stratification bias was also estimated.RESULTS:There was no association of genotypes or diplotypes with colon cancer. The rectal cancer risk was significantly lower for SHMT1 TT (OR = 0.57, 95% confidence interval (CI) 0.36-0.89) and higher for MTHFR CT genotypes (OR = 1.4, 95%CI 1.06-1.84). A gene-dosage effect was observed for SHMT1 with progressively decreasing risk with increasing number of T allele (p = 0.014). The stratified analysis according to age and sex revealed that the association is mainly present in the younger (< 60 years) or male subgroup. As expected from genotype analysis, the SHMT1 T allele/MTHFR CC diplotype was associated with reduced rectal cancer risk (OR 0.56, 95%CI 0.42-0.77 vs all other diplotypes together). The above results are unlikely to suffer from population stratification bias. In controls HCY was influenced by SHMT1 polymorphism, while in patients it was affected only by Dukes' stage. In patients with Dukes' stage C or D HCY can be considered as a tumor marker only in case of SHMT1 1420CC genotypes.CONCLUSIONS:A protective effect of SHMT1 1420T allele or SHMT1 1420 T allele/MTHFR 677 CC diplotype against rectal but not colon cancer risk was demonstrated. The presence of SHMT1 1420 T allele significantly increases the HCY levels in controls but not in patients. Homocysteine could be considered as a tumor marker in SHMT1 1420 wild-type (CC) CRC patients in Dukes' stage C and D. Further studies need to clarify why SHMT1 and MTHFR polymorphisms are associated only with rectal and not colon cancer risk.

Peripheral blood lymphocytes (PBL) of 37 formaldehyde-exposed women from four pathology departments in Hungary were investigated to collect data on the effects of occupational exposures to formaldehyde and to find a possible relationship between in vivo formaldehyde-induced apoptosis and genotoxic effects. The subjects were divided into two groups: 16 donors exposed to formaldehyde together with various organic solvents, and 21 subjects exposed mainly to formaldehyde. The results were compared with 37 controls (all women) without known occupational exposure. Ambient air concentrations of formaldehyde were measured in three work places, and ranged from 0.23 to 1.21mg/m(3) (mean 0.9mg/m(3)). Measures of genotoxicity included the determination of the frequencies of chromosomal aberrations (CA), sister-chromatid exchange (SCE), HPRT mutations (variant frequency, VF) and the measurement of UV-induced unscheduled DNA-repair synthesis (UDS). The percentages of premature centromere division (PCD) and of cells with a high frequency of SCE (HF/SCE) were also scored. Apoptosis and cell proliferation were determined by flow cytometry. In both formaldehyde-exposed groups, the apoptotic activity and the CA levels in PBLs were significantly higher than in controls. The CA were mostly breaks of the chromatid type. In the second group, which was mainly exposed to formaldehyde, CA were slightly lower in comparison with the group exposed to formaldehyde and solvents, which may be attributed to a different rate of elimination of damaged lymphocytes as a consequence of formaldehyde-induced apoptotic activity. In the second group, a significant decrease of VF and a non-significant increase in HF/SCE were found compared with the control and the other group. In conclusion, the results demonstrate that exposure to formaldehyde induces apoptosis and CA, indicating an excess cancer risk among subjects occupationally exposed to formaldehyde. The results also emphasize the importance of the measurement of occupational air pollutants, such as formaldehyde, in order to avoid genotoxic effects in the workers.

Bitumen ( asphalts) used for road pavement in Hungary have a low tar content since the 1960s. However, traditional bitumen, as a substance belongs to the IARC Group 2B of carcinogens, because of its tar content, which was radically reduced in the last decades to develop an environmentally friendly substance. Other carcinogens in the working environment which are used, are solvents such as crude oils ( Group 1), and diesel exhaust gases ( Group 2A). Lifestyle factors also affect the health status of road pavers. The aim of this study was to investigate the changes in health status and geno- and immunotoxicology parameters of asphalt exposed road pavers. Multiple end- point follow- up genotoxicology monitoring was performed in Hungarian road pavers between 1996 - 1999 and 2003 - 2006. The latter set was supplemented with immunotoxicological endpoints. Studied subjects were interviewed by a physician to collect data on age, medication, smoking and drinking habits, medical and work histories, and they took part in a routine clinical laboratory checkup, including hematology, liver and kidney function tests and risk factors. The multiple end- point genotoxicology monitor, developed in our laboratory, includes the determination of chromosome aberration ( CA), sister- chromatid exchange, and HPRT mutation frequencies and the measurement of DNA repair performed in peripheral blood lymphocytes according to the standard methods. Immunotoxicology monitoring includes determination of lymphocyte subpopulations and the measurement of lymphocyte activation. Altogether 89 asphalt-exposed workers ( 23 managers, 23 hand pavers, 28 finishers and 15 mixers) were investigated. The results were compared to 33 non- exposed industrial controls. More than half of the studied subjects were active smokers and more than 80% were regular drinkers. Among the exposed the most frequent clinical symptoms were liver and kidney dysfunctions, hypertension, hyperglycemia, high cholesterol, rheumatoid complaints and high count of white blood cells. However, the low exposed management also suffered from hypertension, hyperglycemia and high cholesterol. For genotoxicology monitoring the most significant changes were in the mean CA yields. At the start ( 1996) CA was increased in exposed subjects. The highest CA was found among mixers, and CA was also elevated among finishers working in closed cabins and pavers cleaning equipment with crude oil. By 1999 the CAs of exposed subjects decreased and remained at the level of industrial controls, except that of mixers still above the control level in 2004. The immunotoxicological tests showed a shift of lymphocyte subpopulations both in the exposed workers and management controls as well as the activation of T and B cells. Alterations found in clinical parameters except rheumatoid complaints can be attributed to the lifestyles of the studied subjects. Data suggest that the main genotoxic agents were exhaust gases in the closed cabins among finishers and crude oil used for cleaning in pavers, as proper ventilation and the use of harmless detergents resulted in the decrease of CA yields.

A Magyar Kórházszövetség legújabb statisztikai adatai szerint a hazai egészségügyi ellátás személyi állo- mánya meglehetôsen leromlott. Fôleg a létszámhiány miatt a jelenleg aktív dolgozók túlterhelése jelen- tôs. 2005-ös adatok szerint az ellátásból 4400 ápoló és 2500 orvos hiányzik. A hazai betegellátásban foglal- koztatottakat az sem vigasztalja, hogy az orvos- és nôvérhiány világjelenség. Annyiban azért hatással van a hazai helyzetre, hogy elôsegíti az orvosok és a nyelvet tudó nôvérek külföldi munkavállalását. Jelenleg 1000 orvos vállal munkát az EU valamelyik államában. És mi a helyzet azokkal, akik nem tudnak, vagy nem akarnak külföldre menni? Milyenek az élet- és munkakörülményeik az itthon dolgozó egészség- ügyieknek? A jelen közleményben az elmúlt 10 évben végzett klinikai, ill. gén- és immuntoxikológiai vizsgálatok eredményeirôl számolunk be 500 onkológiai nôvér komplex prevenciós vizsgálata kapcsán. Megállapítottuk, hogy az országos átlaghoz képest az onkológiai nôvérek általános egészségi állapota jó. A krónikus nem fertôzô betegségek vonatkozásában még jobb is az országos átlagnál (hipertónia, diabe- tes). Ugyanakkor bizonyos klinikai jelek arra utalnak, hogy a citosztatikum-kezelést végzô személyzet a korban és nemben egyeztetett kontrollhoz képest fokozottan veszélyeztetett a vashiányos anémia és a pajzsmirigybetegségek szempontjából. Összefüggést kerestünk a vashiány és a szénhidrát- és lipidanyag- csere vonatkozásában is. Azt az összefüggést találtuk, hogy a vashiány potencírozza az inzulinreziszten- cia mértékét, és azok a donorok, akiknél a vashiány huzamosabb ideig fennáll, hajlamosabbak a vércu- korszint emelkedésére. A kromoszómatörés és testvérkromatid-kicserélôdés gyakorisága, ill. a B-limfoci- ták csoportátlaga a nôvérekben az egyeztetett kontrollhoz képest szignifikánsan emelkedett volt, ami a kezelési módok során alkalmazott személyi védelem hiányosságaira utal. A gén- és immuntoxikológiai paraméterekben talált eltérések szignifikánsan kimutatták, hogy a citosztatikumokkal foglalkozók önma- guk is exponálódnak a gyógyszerrel. Ezért a jelenleg érvényben levô munkavédelmi rendszabályok to- vábbi szigorítása szükséges. Magyar Onkológia 50:153-161, 2006 Statistical data indicate a chronic shortage of work-force due to overwork, ill health state and increased risk of chronic noninfectious diseases in Hungarian health care personnel, which needs investigations in order to decrease the risk. Nurses of oncology units, often exposed to carcinogens when preparing and handling cytostatic drugs, are especially at high risk. In the present publication we report a complex clinical, geno- and immunotoxicology risk assessment of altogether 500 nurses, performed during the last 10 years at various oncology units in Hungary. The obtained results indicate that the health status of nurses at oncology units is better than the Hungarian average, especially of hypertonia and type II diabetes. However, the prevalence of iron deficiency anemia and different thyroid gland diseases is significantly higher than those of the controls matched for sex and age. The results suggest that iron deficiency can potentiate the resistance to insulin, i.e. the persistance of iron deficiency may increase the serum glucose levels and thus the risk of diabetes. Among the studied geno- and immunotoxicology biomarkers, the frequency of chromosome aberrations, sister chromatide exchange and B lymphocytes was significantly increased compared to the matched controls. The obtained alterations demonstrate the occupational exposure of the nurses to cytostatic drugs, thus the introduction of more strict hygienic controls and compliance with the European Union chemical safety regulations is necessary. Tompa A, Magyar B, Tóth F, Bíró A, Fodor Z, Jakab M, Major J. Characterization of the health state of oncology unit nurses by geno- and immunotoxicological biomarkers. Hungarian Oncology 50:153-161, 2006

Abstract: In the present study genotoxicological and immunotoxicological follow-up investigations were made on 811 donors including 94 unexposed controls and 717 nurses with various working conditions from different hospitals (The Hungarian Nurse Study). The nurses were exposed to different chemicals: cytostatic drugs, anesthetic, and sterilizing gases, such as ethylene oxide (ETO) and formaldehyde. The measured biomarkers were: clinical laboratory routine tests, completed with genotoxicological (chromosome aberrations [CA], sister chromatid exchange [SCE]), and immune-toxicological monitoring (ratio of lymphocyte subpopulations, lymphocyte activation markers, and leukocyte oxidative burst). The highest rate of genotoxicologically affected donors (25.4%) was found in the group of cytostatic drug-exposed nurses. Comparing geno- and immunotoxicological effect markers, we found that among genotoxicologically affected donors the frequency of helper T cell (Th) lymphocytes, the ratio of activated T and B cells increased, whereas the oxidative burst of leukocytes decreased. In hospitals with lack of protective measures increased CA yields were observed compared to those with ISO 9001 quality control or equivalent measures. Anemia, serum glucose level, thyroid dysfunctions, benign, and malignant tumors were more frequent in the exposed groups than in controls. The hygienic standard of the working environment is the basic risk factor for the vulnerability of nurses. On the basis of these results, it is suggested, that the used cytogenetic and immunological biomarkers are appropriate to detect early susceptibility to diseases. The Hungarian Nurse Study proved that the use of safety measures could protect against occupational exposure at work sites handling cytostatic drugs, anesthetic, and sterilizing gases.