[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.

Mutagenicity of some substituted 1-phenyl-3,3-dimethyltriazenes. I. The salmonella/mammalian microsome assay and repair test.

The mutagenic activity and related biological properties of Br-, Cl-, NO2- and CH3-derivatives of 1-(phenyl)-3,3-dimethyltriazene were investigated in Salmonella/microsome assays with standard and preincubation metabolic activation and in the repair test using Salmonella and E. coli B/r. In the repair test, the CH3-derivative was slightly positive in the E. coli recA and uvrA repair system, the NO2-derivative had a killing effect on Salmonella typhimurium uvrB-deficient strains. In Salmonella mutagenicity assays, all tested triazene derivatives reverted frameshift tester strains, especially TA1537. The highest number of frameshift mutations was induced by the CH3-derivative in the presence of a standard metabolic activation system; direct mutagenicity of this derivative was weak, reaching about the same level of activity as seen after preincubation. The only test compound that induced mutations of the base-substitution type was the NO2-derivative; this derivative showed the highest mutagenicity when activated by preincubation.

Mutagenicity of some substituted 1-phenyl-3,3-dimethyltriazenes. II. Chromosomal aberrations in human peripheral lymphocytes in vitro.

The chromosome-breaking activity of four 1-(phenyl)-3,3-dimethyltriazenes was tested in vitro on human peripheral blood lymphocytes using S9 mix as a metabolic activation system. 1-(4-Nitrophenyl)-3,3-dimethyltriazene was the most active compound. The difference in the frequency of chromosomal aberrations in a test with and without metabolic activation was significant at the 1% level of significance. The lowest frequency of chromosomal aberrations was induced by 1-(4-methylphenyl)-3,3-dimethyltriazene which, under the conditions of this experiment, is the least stable and probably rapidly degraded to non-active compounds. The chromosomal aberrations were also induced by 1-(4-chlorophenyl)-3,3-dimethyltriazene and 1-(4-bromophenyl)-3,3-dimethyltriazene, this activity was unrelated to metabolic activation.

Chromosomal aberrations, SCE and urine mutagenicity in workers occupationally exposed to cytostatic drugs.

The genetic risk run by workers occupationally exposed to chemicals, including the newly developed cytostatics, was assessed in large chemical laboratories. The exposed group comprising 38 people consisted of chemists, laboratory assistants and pilot plant workers. The average rate of aberrant cells in peripheral blood lymphocytes (AB.C). was 3.9% and the value of break/cell ratio was 0.046. The group of matched controls (N = 18) was found to have 1.5% of AB.C. and 0.020 breaks/cell. In the exposed group, there were, on average, 8.94 SCEs/cell, and in controls, 5.81. Urine mutagenicity tests on Salmonella typhimurium tester strain TA98 revealed a significant increase of activity in 23 (64%) out of 36 urine samples tested as compared to the control group (N = 19) with 4 (21%) positive urine samples. Strain TA100 showed only a weak response to urine mutagens.

Indirect mutagen assay in human lymphocyte in the presence of a metabolic activation system.

Chromosome aberrations in cultured human lymphocytes were examined after exposures to various concentrations (from 1 X 10(-6) to 1 X 10(-3) mol X l-1) of cyclophosphamide (CP) in the presence or absence of a metabolic activation system (S9 mix). With metabolic activation, increases in the frequency of aberrant cells (AB. C.) produced by CP were significant and dose-dependent. At a concentration of 5 X 10(-4) mol X l-1, activated CP induced 29% AB. C. versus 6% AB. C. detected after exposures to CP without metabolic activation. The freshly prepared S9 mix did not virtually differ in its activation potency from the S9 mix stored for 3 weeks at -20 degrees C. CP preincubated for 100 min with S9 mix caused little or no increase in AB. C. frequency above the control level.

Cytogenetic analysis of peripheral blood lymphocytes of workers occupationally exposed to styrene.

The genetic risk run by workers occupationally exposed to styrene vapors was assessed in two different plants A and B, using the cytogenetic analysis of peripheral blood lymphocytes. In plant A engaged in the manufacture of polystyrene vessels the mean styrene exposure level was found to range between 70 and 150 mg . m-3, in plant B manufacturing sports boats, plastic slides for children and plastic guard-stones it reached the level of about 200 mg . m-3. The rate of aberrant cells (AB.C.) found in plant A workers (N = 36) at the time of first sampling was 1.38% and the value of break/cell (B/C) ratio was 0.015; at the second sampling the rate of AB.C. was 1.41% and the B/C ratio was 0.014. The group of matched controls (N = 19) was found to have 1.26% of AB.C. and 0.014 breaks per cell. Plant B workers (N = 22) exhibited at the first sampling 1.72% of AB.C. and their value of B/C ratio was 0.018, the group of matched controls (N = 22) had 1.36% of AB.C and the B/C ratio 0.015; the respective values at the time of second sampling were 2.81% for AB.C. rate and 0.029 for B/C ratio in the exposed and 1.89% for AB.C. rate and 0.021 for B/C ratio in the control group. It is concluded that styrene exposure levels below 100 mg . m-3 do not pose any serious genetic risk for the exposed population groups. The variations found in the degree of chromosome injury by smoking habits, drug intake pattern, or sex were not statistically significant.

Cytogenetic analysis of human peripheral blood lymphocytes in culture exposed in vitro to styrene and styrene oxide.

Styrene and styrene oxide mutagenicity was tested in cultured human lymphocytes treated in vitro with various concentrations of test agents. Styrene alone was found mutagenic at the highest concentration used (5 X 10(-4) mol. l-1, combined with the alkylating agent THIO-TEPA it did not affect the chromosome aberration yield. Exposure to styrene oxide gave a positive result showing a clear-cut dose-effect relationship within the concentration range 5 X 10(-6) to 1 X 10(-3) mol. l-1. In combination with THIO-TEPA its effect on chromosome aberration yields was additive. Styrene oxide proved also to be a very potent inducer of sister chromatid exchanges (SCE) within the concentration range 5 X 10(-6) to 1 X 10(-3) mol. l-1 tested. Combined with THIO-TEPA it exhibited a distinct additive effect in the production of SCEs.