8-Hydroxydeoxyguanosine in leukocyte DNA and urine of quartz-exposed workers and patients with silicosis.

OBJECTIVE: To examine radical-induced DNA damage and its elimination in workers exposed to quartz and in patients with silicosis, and to assess the relationship of these effects to lung function. METHODS: Blood and spontaneous urine samples were obtained from active, quartz-exposed workers without silicosis (n = 63), and from retired workers with silicosis (n = 42). Levels of 8-hydroxydeoxyguanosine (8-OHdG) were determined in peripheral blood leukocyte DNA and urine, by the use of high-performance liquid chromatography coupled with ultra violet- (UV) and electrochemical detection. RESULTS: No significant differences in the mean levels of 8-OHdG in leukocyte DNA and of urinary excretion of 8-OHdG were found between silicosis patients and quartz-exposed healthy workers. However, in the group of silicosis patients with increased oxidative DNA damage the urinary excretion of 8-OHdG was lower than in the corresponding group of active workers without silicosis. In the case of silicosis, urinary 8-OHdG correlated positively, and 8-OHdG in DNA correlated negatively, with forced expiratory volume in one second (FEV1) and forced vital capacity (FVC). Healthy workers with a personally estimated high dust exposure in the workplace showed higher levels of 8-OHdG in DNA than did workers with moderate dust exposure. No association of 8-OHdG formation and/or elimination with duration of employment, field of activity, smoking or age was found. CONCLUSION: Our findings suggest that a less effective repair of 8-OHdG is associated with a higher degree of pulmonary airway obstruction in patients with silicosis.

Occupational exposure to static, ELF, VF and VLF magnetic fields and immune parameters.

Despite the important role of the immune system in defending the body against infections and cancer, very few investigations have been undertaken to study possible effects of electromagnetic fields on human immunity. The aim of the present study was to examine the effect of occupational exposure on hospital personnel operating magnetic resonance tomographs and on industrial workers at induction heaters. In both categories of workplaces, magnetic flux densities exceeding Austrian exposure standards have been registered. Because of the complexity and high redundancy of the immune system, an extensive range of assay systems was applied: relative and absolute numbers of lymphocytic subsets were counted, the proliferative activity of T and B cells determined, the production of interleukin 2, interferon gamma and tumour necrosis factor alpha analysed, serum immunoglobulins evaluated, as well as non-specific immunity of monocytes and granulocytes measured by their oxidative burst. The number of natural killer cells and oxidative burst in monocytes showed statistically significant differences in workers at induction heaters and controls. The observed effect on oxidative burst was counteracted by a higher number of active cells in the exposed group, indicating normal non-specific immunity. The high number of natural killer cells, observed in some of the study subjects working at induction heaters, was reconfirmed in another investigation and deserves a further follow-up.

Occupational exposure to high frequency electromagnetic fields and its effect on human immune parameters.

The present study recorded a considerable excess of recommended exposure limits in the vicinity of shortwave diathermy devices used for medical treatment of patients. Different kinds of field probes were used to measure electric and magnetic field strength and the whole body exposure of medical personnel operating shortwave, decimeter wave and microwave units was calculated. To investigate the influence of chronic exposure on the immune system of operators, blood was sampled from physiotherapists working at the above mentioned devices. Eighteen exposed and thirteen control persons, matched by sex and age, were examined. Total leucocyte and lymphocyte counts were performed and leucocytic subpopulations determined by flow cytometry and monoclonal antibodies against surface antigens. In addition, to quantify subpopulations of immunocompetent cells, the activity of lymphocytes was measured. Lymphocytes were stimulated by mitogen phytohemagglutinin and their proliferation measured by a flow cytometric method. No statistically significant differences between the control and exposed persons were found. In both study groups all immune parameters were within normal ranges.

Immunological investigations in a group of workers exposed to various levels of polycyclic aromatic hydrocarbons.

To evaluate a possible immunotoxic effect of chronic exposure to polycyclic aromatic hydrocarbons (PAHs), several immune parameters were investigated in two groups of coke-oven workers. Exposure levels were different for both groups, one group being employed in a new coking facility of sophisticated technical standard, and the other in a facility with rather high emission of PAH-containing dust, built during the late 1960s. Immunomodulating effects of exposure were found on three levels of immunity: a reduced mitogenic response of T cells to phytohaemagglutinin observed by a reduced rate of DNA synthesis and a retardation in the expression of interleukin 2 receptor; an impairment of B cell activity, observed by a reduced proliferation of B cells and a low synthesis of immunoglobulin M after Staphylococcus aureus stimulation; a reduced oxidative burst in monocytes after challenge with E. coli. The differences in numbers of lymphocytic subpopulations in peripheral blood and in immunoglobulin levels of serum were statistically insignificant. The data of the present investigations point to significant, albeit slight, changes in immune function by PAH exposure. But these changes could not yet be related to health impacts of the exposure.

Detection of polycyclic aromatic hydrocarbon exposure damage using different methods in laboratory animals.

Benzo[a]pyrene, benzo[b]fluoroanthene and dibenzo[a,h]anthracene dissolved in a 1:2 mixture of dimethylsulphoxide (DMSO) and water were administered to two groups of female mice, each group containing 15 mice. The doses were administered orally (via gavage) at the respective rates of 1 and 100 micrograms kg-1 body weight five times per week for a period of 9 weeks. The influence of the polycyclic aromatic hydrocarbons (PAHs) was determined using the following methods: determination of DNA-PAH adducts, of chromosome injuries (micronucleus test), of induction of repair using the unscheduled DNA synthesis (UDS) test, and by examination of the DNA structure after nucleoid sedimentation. All the methods investigated provided evidence of a significant effect resulting from exposure to PAHs on the parameters examined. Following chronic exposure to PAHs, the formation of DNA-PAH adducts and injury to the genetic material, as well as the appearance of micronuclei (micronucleus test), the induction of unscheduled DNA synthesis (UDS test) and mutation of the DNA structure (nucleoid sedimentation), were demonstrated. The described methods therefore provide a means for the detection of genetic damage caused by PAH exposure in humans.

UDS-test with freon 11 (R-11).

Trichlorofluoromethane, in concentrations of 80, 400, 2 000, 10 000 and 50 000 ppm, was administered to rats of both sexes (Sprague Dawley) by inhalation exposure.2 000 ppm in air (= 11 200 mg/m(3)) amount to twice the MAK value of 1 000 ppm. At exposure times of 4 hours this corresponds to the MAK value defined for an 8 hour workday.Unscheduled DNA synthesis (UDS) was measured in single-cell suspensions of hepatocytes, pulmonary epithelial cells and lymphocytes of the spleen, respectively.In the pulmonary cells concentrations of 2 000, 10 000 and 50 000 ppm of freon 11 lead to a significantly increased mean silver grain count compared to a negative control group.In spleen and liver cells increasing concentrations of R 11 tend to increase the incorporation of thymidine into the DNA of the cells. These changes of the extent of unscheduled DNA synthesis can, however, not be statistically verified.

[A 2-generation fertility study with 1,4-dichlorobenzene in rats]. / 2-Generationen-Fertilitätsstudie mit 1,4-Dichlorbenzol an Ratten.

1,4-Dichlorobenzene (pDCB), dissolved in olive oil, was administered orally to two generations of rats to detect possible effects of the test substance on reproduction (OECD guideline 416). The doses used for the three test substance groups were 30, 90 and 270 mg pDCB per kg body weight. Olive oil was applied to one negative control group. Dose volume was 1 ml per kg body weight for all groups. In both generations the test substance had no effects on: time between beginning of mating and evidence of copulation, time of gestation, fertility index, gestational index, percentage of dams with only dead pups, total number of pups at birth, percentage of pups with positive ear reflex, grasping reflex and orientation reaction, absolute and relative weights of testes, epididymides and ovaries, absolute and relative weights of female kidneys, spleens and livers. In the mid and/or high-dose groups the test substance had an effect on: number of live pups at birth (reduced), number of pups deceased between days of lactation 1 to 4 and 5 to 21 (increased), mean body weight of pups (reduced), erection of ears and opening of eyes (retarded), percentage of pups with positive draw up test (reduced), alterations of the skin (dry, squamous) and ring tails in pups, absolute and relative organ weights of adult males (livers and kidneys: increased; spleens: reduced). Damages to the kidneys in mid- and high-dose groups of both generations are also probably test substance related. At the low dose of 30mg pDCB per kg body weight--equivalent to the actual MAK-value of 450 mg/m3 (exposure by inhalation)--no effects of the test substance were detected on fertility parameters of rats. The next higher dose of 90 mg/kg already caused massive damage in pups. Therefore, a reduction of the actual MAK value should be taken into consideration.

[Biological monitoring at the work site]. / Biologisches Monitoring am Arbeitsplatz.

To evaluate the standard of industrial hygiene whilst dealing with pathogenic substances, threshold limit values, (TL-Values) have to be observed. This strategically important preventive concept is being supplemented by a secondary preventive measure. This is legally based on Section 8. Workers' Protection Act (physical aptitude of workers), Federal Ordinance Nr. 39/1974 regarding the physical aptitude of workers for specified jobs. The determination of pathogenic substances or their metabolites in body fluids, therefore, constitutes a possibility to evaluate the individual health hazard. In addition, the problems of the test concept to evaluate the effects of exposure to polycyclic aromatic hydrocarbons by means of determining DNA-PAH adducts are discussed.

[Risk of occupational hepatitis B in gynecologic and obstetric units in Austria]. / Das berufliche Hepatitis-B-Risiko auf gynäkologisch-geburtshilflichen Stationen in Osterreich.

Evaluation of the hepatitis-B data of the Austrian Workers' Compensation Board (AWCB), where the results of the serological findings of the markers HBsAg, anti-HBs and anti-HBc are stored, allows the following conclusions to be reached regarding persons employed in gynaecological departments: The average hepatitis-B infection rate in the gynaecological departments amounts to 11.6%, which is slightly above the average figure with in the Austrian health service. This infection rate is approximately 10 times higher than in the Austrian population in general. The following groups are most affected by the infection in the gynaecological wards: medico-technical staff (29.7%), followed by nurses and midwives (12.6%), doctors (12.2%), auxiliary staff (10%) and cleaning staff (5.1%). 22% of all antigen bearers in health-related professions are employed in gynaecological departments. Information on post hepatitis cases is unsatisfactory. This evaluation within one particular field of the Austrian hospitals shows the necessity of epidemiological documentation by registering the hepatitis-B markers before vaccination. Moreover, the fact that nine out of ten persons employed in gynaecological wards need protective vaccination against hepatitis B serves as a proof that the introduction of this prophylactic measure to combat occupational diseases by the Austrian Social Accident Insurance Companies is an absolutely correct step.

[Vitiligo from p-tert. butylphenol; a contribution to the problem of the internal manifestations of this occupational disease]. / Vitiligo durch p-tert. Butylphenol; Beitrag zur Frage interner Manifestationen dieser Berufserkrankung.

10 worker suffering from occupational vitiligo due to p-tert. butyl phenol have been observed in an Austrian resin factory. The dust concentration and its content of p-tert. butyl phenol in the working area were measured. On the basis of these results preventive measures were taken to reduce the exposure of the workers to p-test butyl phenol. In the presented cases an involvement of internal organs--as described by Rodermund et al. (1975)--could not be observed.