Risk of cancer in an occupationally exposed cohort with increased level of chromosomal aberrations.

We used cytogenetic analysis to carry out a cohort study in which the major objective was to test the association between frequency of chromosomal aberrations and subsequent risk of cancer. In spite of the extensive use of the cytogenetic analysis of human peripheral blood lymphocytes in biomonitoring of exposure to various mutagens and carcinogens on an ecologic level, the long-term effects of an increased frequency of chromosomal aberrations in individuals are still uncertain. Few epidemiologic studies have addressed this issue, and a moderate risk of cancer in individuals with an elevated frequency of chromosomal aberrations has been observed. In the present study, we analyzed data on 8,962 cytogenetic tests and 3,973 subjects. We found a significant and strong association between the frequency of chromosomal aberrations and cancer incidence in a group of miners exposed to radon, where a 1% increase in frequency of chromosomal aberrations was followed by a 64% increase in risk of cancer (p < 0.000). In contrast, the collected data are inadequate for a critical evaluation of the association with exposure to other chemicals.

Semen quality and reproductive health of young Czech men exposed to seasonal air pollution.

This study of male reproductive health in the Czech Republic resulted from community concern about potential adverse effects of air pollution. We compared young men (18 years of age) living in Teplice, a highly industrialized district with seasonally elevated levels of air pollution, to those from Prachatice, a rural district with relatively clean air. Surveys were scheduled for either late winter, after the season of higher air pollution, or at the end of summer, when pollution was low. Participation included a physical examination, donation of a semen sample, and completion of a questionnaire on health, personal habits, and exposure to solvents and metals through work or hobby. Analysis of data from 408 volunteers showed that the men from Teplice and Prachatice were similar in physical characteristics, personal habits, and work- or hobby-related exposures. Sixty-six percent (272) of these men donated a single semen sample for routine semen analysis, computer-aided sperm motion analysis, and sperm chromatin structure assay. The mean (median) sperm concentration and sperm count were 61. 2 (44.0) million/mL semen and 113.3 (81.5) million, respectively, and were not associated with district of residence or period of elevated air pollution. However, periods of elevated air pollution in Teplice were significantly associated with decrements in other semen measures including proportionately fewer motile sperm, proportionately fewer sperm with normal morphology or normal head shape, and proportionately more sperm with abnormal chromatin. These results suggest that young men may experience alterations in sperm quality after exposure to periods of elevated air pollution, without changes in sperm numbers.

[Air pollution and sperm quality]. / Znecistení ovzdusí a kvalita spermií.

BACKGROUND: It has been described that an exposition of males to chemical substances may significantly impoverish quality and quantity of produced spermatozoa. The aim of our study was to test whether the polluted air in the Teplice district has negative effects on the quality of sperm of males living in this district. METHODS AND RESULTS: 325 males 18-year-old living in the Teplice district and in the control district of Prachatice were tested. Samples were taken in 1992 and 1994, always at the end of winter and in autumn. According to WHO laboratory manual for investigation of the human sperm, basic parameters were determined: volume of the semen, pH, motility, number and morphology of spermatozoa. In selected groups of males the frequency of aneuploidia of spermatozoa was also examined. Examination of aneuploidia was done using three color fluorescence in situ hybridisation with satellite DNA proves specific for X, Z and 8 chromosomes. Logistic regression was used for the data analysis and Odd's Ratio was estimated (OR's). OR's was found for the morphology of spermatozoa (4.1 and 10.1 for medium and high exposition respectively), for the head morphology (6.1 and 4.1) and in the percentage of motile spermatozoa (9.8 and 3.5). More intensively exposed males had higher frequency of disomy in chromosomes X (p = 0.012), XY (p = 0.01), and Y (p < 0.001). CONCLUSIONS: Bio-indicators of toxic and genetic impairment have shown lower quality of sperm in males in Teplice district.

Cytogenetic analysis of peripheral lymphocytes in medical personnel by means of FISH.

Genotoxic effects of occupational exposure to cytostatics were investigated in 20 nurses and physicians working in various departments of one hospital. The group was divided into two equal subgroups one of which was involved in the administration of cytostatics (exposed subgroup) and the other was not (unexposed subgroup). The whole group and the two subgroups were compared with a control group of 11 healthy blood donors. Two differently labeled whole chromosome painting (WCP) probes specific for the chromosomes 1 and 4 were used simultaneously. Chromosome aberrations were classified in terms of the Protocol for Aberration Identification and Nomenclature (PAINT) nomenclature. The results obtained by the painting method were compared with findings of conventional unbanded chromosome analysis. Significant differences in the numbers of translocations (FG/100 = 2.25 +/- 1.50 vs. 0.66 +/- 0.21, p < 0.01) and unstable chromosome aberrations determined by the conventional method (AB.C/100 = 2.70 +/- 2.31 vs. 1.63 +/- 1.59, p < 0.05) were found between the exposed subgroup and controls. The unexposed subgroup differed from the controls only in the number of translocations (FG/100 = 2.93 +/- 2.79 vs. 0.66 +/- 0.51, p < 0.05). No significant differences in the number of stable and unstable aberrations were found between the exposed and the unexposed subgroups. On the other hand, highly significant differences (p < 0.01) were demonstrated by the two methods between the whole group (all medical personnel) and the controls. All differences which were found to be significant when translocations were compared were also found to be significant when total stable chromosome exchanges, i.e., the sum of translocations and insertions, were considered. Multicolour chromosome painting is apparently a more sensitive method than the conventional metaphase-based analysis.

Mutagenicity of feeds and bovine milk in districts with different levels of environmental pollution.

Mutagenic activities of feedstuffs and bovine milk were investigated by the Ames test in two districts of the Czech Republic (Teplice and Prachatice), differing in the levels of industrial pollution. Salmonella typhimurium strains TA 98 and TA 100 with or without metabolic activation were used in the tests. Samples of currently fed feedstuffs and milk were collected in both districts in the spring 1992, autumn 1992, spring 1993, and autumn 1993. The Teplice and Prachatice sets included 12 and 11 representative samples, respectively. The samples were rinsed and extracted with acetone and methanol. Thus each sample was divided into four separate samples. The total number of revertants obtained in the industrial district Teplice was significantly higher than the corresponding value for the Prachatice district. Some between-the-seasons differences were also found within each of the two districts. The strain TA 98 proved to be more sensitive in the mutagenicity tests than the strain TA 100. Thirty-eight and thirty-one milk samples were collected in the districts Teplice and Prachatice, respectively. The overall evaluation demonstrated a significant between-the-districts difference in the total number of revertants induced by the milk samples in the strains TA 98 and TA 100.

Environmental genotoxicity monitoring using Salmonella typhimurium strains as indicator system.

Screening for mutagens in environmental complex mixtures is gradually accepted as a routine methodology in the monitoring processes. Examination of 70 drinking water samples showed that the variations in the degree of mutagenicity was dependent on the location of the water source and the type of drinking water tested. Analogous screening for mutagens in river and waste waters may help better assess the potential genotoxic hazard from various types of industrial technology. The recommended methods are routinely used for monitoring the mutagenicity and for checking the effectiveness of preventive measures.

[Environmental monitoring and biological monitoring of young people exposed to nonoccupational levels of formaldehyde, toluene and other hydrocarbons]. / Monitorování prostredí a biologické monitorování mladistvých, neprofesionálne exponovaných nízkým koncentracím formaldehydu, toluenu a jiných uhlovodíkû.

During the period of 1983-1985, in two of apprentice schools of P. town the health disorders were investigated in the total of 82 apprentices 15-18 years old from the environment with elevated concentrations of formaldehyde and toluene. The study was contrasted with a control total of 42 apprentices. Cytogenetical examination has been performed, and selected immunological parameters in both blood serum and saliva have been assessed with red and white blood cells counts including differential formula of white blood cells. In addition, the atmospheric toxicity of formaldehyde and vapours of organic solvents (toluene, xylene, varnish naphtha) was measured. A single biological exposure test has been performed for the detection toluene. Statistically significant were differences in occurrence of cell chromosomal aberrations between the group of long term formaldehyde and toluene exposure (averagely 3.53% ABB) and controls (2.21% ABB) as obtained in 1983 and 1984, and so were differences between the long term-to-toluene exposed group (3.30% ABB) and the above mentioned control group as obtained in 1984. No similar results were stated between the long term-to-formaldehyde exposed (3.07% ABB) and control (2.55% ABB) groups in 1985. The main evidence consisted in finding the genotoxical/clastogenic effect of observed agents associated with mainly chromosomal abnormalities of chromatide type. It outflowed from the determination of selected serum proteins (Ig and acute phase proteins) and salivary lysozyme that the group under the combined influence of formaldehyde and toluene showed significantly lower IgG and higher alpha-1-antitrypsin (A1AT). The group at risk of toluene was characteristical in elevated concentrations of alpha-2-macroglobulin (A2M) and A1AT. Most pronounced changes in first year had been revealed through the evaluation of the influence of the duration at risk (significant decrease in IgA and prealbumin, and the increase in A2M and A1AT). The infectious disease as experienced 2 month prior the collection resulted in a significant decrease of IgM, A2M and A1AT in risky groups in individuals with infection in anamnesis. Salivary lysozyme concentration of apprentice environmentally exposed to formaldehyde in the noon showed the decrease, whereas its increase occurred in controls with the difference on 5% significancy level. Blood count assessements showed no significant differences between the investigated values as well as any were assessed between the incidence of health disorders of apprentices and their correspondance to the given group.

Spontaneous abortions and twinning.

The relation between spontaneous abortions and twinning was studied in the years 1980-1981 in 22 towns of the South Moravian Region, Czechoslovakia. Each town has more than 10,000 inhabitants and less than 750 births per year. The number of spontaneous abortions and the number of twin births were evaluated separately for each town and for a time unit of three months. The comparison indicated that the group with a higher number of spontaneous abortions also had a lower number of twin births. The relation between spontaneous abortions and twinning is discussed.

Cytogenetic analysis of peripheral lymphocytes in workers occupationally exposed to epichlorohydrin.

Peripheral lymphocytes of 3 groups of adult subject (28 workers occupationally exposed for 4 years to epichlorohydrin [ECHH], 34 matching controls and 21 subjects of the general population (control group) were cytogenetically analysed. In total, 11 806 metaphases were scored. The following frequencies of aberrant cells (bearing mostly chromatid and chromosome breaks) were detected in individual groups: ECHH-exposed group 3.12%; matching controls 2.06%; general population control group 1.33%. The results seem to indicate that even the concentration of 1 mg ECHH/m3 was capable of increasing the frequency of aberrant cells in the occupationally exposed group of workers.