In vivo cytogenetic effects of natural humic acid.

As humic compounds are naturally widespread in the environment and present in surface water, studies on their genotoxicity are justified. Humic acid (HA) has not been demonstrated to be genotoxic either in vitro or in vivo. In the present paper we investigated its activity both in intestinal and bone marrow cells following a single dose (100 mg/kg b.

Mutagenic activity of some coal-derived humic compounds evaluated by the Ames test.

Two coal-derived humic substances (Sulcis and South Africa, Eniricerche, Italy) have been evaluated for their mutagenic activity on TA98 and TA100 Salmonella typhimurium strains, either in presence or in absence of metabolic activation (S9). Both compounds showed no effect on the two strains, as observed with natural humic acid (Fluka). After chlorination, coal-derived humic acids induced a strong dose-related increase in the number of revertants on TA100 without S9, whose extent was directly proportional to the chlorination ratios.

Cytogenetic monitoring of a group of Italian floriculturists: no evidence of DNA damage related to pesticide exposure.

The induction of sister chromatid exchanges (SCE), structural chromosome aberrations (CA) or micronuclei (MN) was investigated in peripheral lymphocytes of a group of Italian floriculturists exposed to a mixture of pesticides. No statistically significant difference in the frequencies of cytogenetic damage was detected between exposed and control subjects. Assessment of the effect of confounding factors indicated that smoking affected both SCE and CA frequencies.

Alternatives in cosmetics testing.

This paper represents a summary of presentations made during a round-table discussion at the ECVAM Opening Symposium. After introductory comments on the cosmetic industry's use of alternative methods in the safety assessment process, the use of alternative methods by L'Oréal and by the Japanese cosmetic industry is outlined, current validation studies in Japan are noted, and the involvement of COLIPA, the European Cosmetic, Toiletry and Perfumery Association, in promoting the use of alternative methods is discussed. Two final sections deal with the effect of data variability on the performance of alternative methods in validation studies and on the integrated use of quantitative structure-activity relationship (QSAR) analysis with other approaches in the safety assessment process.

Comparative studies by comet test and SCE analysis in human lymphocytes from 200 healthy subjects.

The comet test (single cell gel electrophoresis, SCGE) appears to be a promising tool to estimate DNA damage at the single cell level and it provides information on the presence of damage among individual cells. Previously, we analyzed the degree of DNA damage in peripheral human lymphocytes from 100 healthy subjects living in Pisa (Italy) taking into account age, gender and smoking habit, and we also reported some results aiming at the assessment of the comet test (Betti el al., 1994).

In vivo genotoxic interactions among three phenolic benzene metabolites.

Three benzene metabolites, hydroquinone (HQ), cathecol (CAT) and phenol (PHE) were studied to define their possible interaction in inducing micronuclei (Mn) in mouse bone marrow polychromatic erythrocytes (PCEs). HQ and CAT, administered separately, induced Mn while PHE showed no genotoxic effects. Binary and ternary mixtures of two or three metabolites gave different results, causing considerable increase or decrease in Mn induction.

Microgel electrophoresis assay (comet test) and SCE analysis in human lymphocytes from 100 normal subjects.

Microscopic examination of individual human lymphocytes embedded in agarose, subjected to electrophoresis and stained with a fluorescent DNA-binding dye, provides a novel way of measuring DNA damage as extent of migration of DNA fragments, mainly single-strand breaks. With this relatively simple method, DNA damage arising as a consequence of smoking, age and other factors was examined in peripheral human lymphocytes from 100 healthy individuals living in Pisa (Italy). The extent of DNA migration was found to be significantly increased by smoking.

Two years' air mutagenesis monitoring in a northwestern rural area of Italy with an industrial plant.

The mutagenicity of organic extracts from inhalable airborne particles, collected in a northwestern rural area of Italy in which an industrial plant producing chemical intermediates is present, was assessed during the years 1989 and 1990. The Ames plate test with Salmonella strains TA98 and TA100 with and without metabolic activation was used. Eight sites in the first and three sites in the second year were monitored once and twice a month respectively.

Cytogenetic effects of benzimidazoles in mouse bone marrow.

The cytogenetic effects of three benzimidazoles, i.e., benomyl, methyl thiophanate and methyl 2-benzimidazolecarbamate (MBC), were studied in mouse bone marrow cells by analyzing three genetic endpoints: micronuclei, structural chromosome aberrations plus or minus gaps, and aneugenic effects (hyperdiploidy or polyploidy).

Guidelines for safety evaluation of cosmetics ingredients in the EC countries.

The Scientific Committee on Cosmetology (SCC) of the Commission of the European Communities was established in 1978 to assist the Commission in the application of the 76/768 Directive, which regulates the production and marketing of cosmetics products. The Committee has been asked to update the general guidelines, defined in 1982, for testing cosmetics ingredients with the aim of ensuring consumers' safety. In the present paper the full document approved by the SCC in October 1990 is reported.

Genotoxicity studies in vitro and in vivo on carminic acid (natural red 4).

The potential genotoxic activity of carminic acid (CAS no. 1260-17-9; EINECS no. 215-023-3; C.

Skin cytogenetic assay for the detection of clastogens-carcinogens topically administered to mice.

A method for assessing the effect of clastogens on mouse skin epidermal cells was devised and applied. Toxic and mutagenic responses in epidermal cells were tested using two known mutagens and carcinogens, urethane (URE) and 7,12-dimethylbenz[a]anthracene (DMBA). Cell generation time, sister-chromatid exchanges (SCE) and chromosomal aberrations (CA) after topical and intraperitoneal (i.

The analysis of the joint effect of substances on reversion systems and the assessment of antimutagenicity.

The statistical methods for the analysis of mutagenicity and carcinogenicity underwent considerable theoretical-practical development following the need for assessing the mutagenic and carcinogenic potential of substances. Antimutagenicity is investigated through the analysis of respondents in dose-response assays, when two different molecules are administered separately and as a mixture to a respondent system. When the number of respondent units is high, and doses are orthogonal, it is possible to apply simple models such as analysis of variance.

Data selection and treatment of chemicals tested for genotoxicity and carcinogenicity.

A database containing qualitative and quantitative results of experimental studies in the fields of genotoxicity and carcinogenicity has been developed. By analyzing results of the studies performed by the U.S.

Development of assays for the detection of photomutagenicity of chemicals during exposure to UV light--I. Assay development.

Two complementary assay systems have been adapted for the detection of compounds which may form mutagenic photoproducts during exposure to UV light from an Osram Ultra-Vitalux sunlamp as used in the evaluation of the effectiveness of sun filters. The effects of UVA and of UVB were evaluated. A bacterial plate test using Escherichia coli strain WP2 allowed the bacteria, co-plated with test chemical in soft agar, to be irradiated with various doses of UV light.

Correlations between 15 polycyclic aromatic hydrocarbons (PAH) and the mutagenicity of the total PAH fraction in ambient air particles in La Spezia (Italy).

Airborne particulate matter has been monitored 4 times a month for 1 year (1988) in the city of La Spezia (Italy). The polycyclic aromatic hydrocarbon (PAH) fractions were extracted, purified and characterized for the content of 15 individual PAH. In general when concentrations of individual PAH were compared statistical correlation was obtained.

An experimental approach to identifying the genotoxic risk from cooked meat mutagens.

In order to define the toxicological risk to the human population from the chemical compounds formed during the process of cooking animal meat, which have been described as possessing mutagenic, genotoxic and carcinogenic activities, an extensive study was undertaken of cooked meat extract and two cooked meat mutagens, 2-amino-3-methylimidazo(4,5-f)quinoline (IQ) and 2-amino-3,8-dimethylimidazo(4,5-f)quinoxaline (MeIQx). The study involved toxicokinetics and mouse-tissue distribution studies of the two chemicals, in vitro and in vivo mutagenicity/genotoxicity analyses (i.e.

Induction of chromosomal aberrations and SCE by chloramphenicol.

The induction of chromosomal aberrations and sister-chromatid exchanges (SCE) was studied in human lymphocyte cultures treated with chloramphenicol (CAP), an antimicrobial agent acting by inhibiting protein synthesis. Moreover chromosomal aberrations and sister-chromatid exchanges were studied in bone marrow cells of treated mice and in Chinese hamster cell cultures (V79) respectively. While no aberrations were induced by short treatments in human lymphocytes exposed in G1 and G2 phases, high frequencies of aberrations, exclusively of the chromatid type, were induced when the drug was administered during a whole cell cycle.

Correlation between mutagenicity of airborne particles and air pollution parameters in eleven Italian towns.

Organic extracts from airborne particles collected in 11 Italian towns between February and April, 1988, were tested for mutagenicity on TA98 and TA100 (± S9), and their nitroreductase (NR) deficient Salmonella strains, by the use of the Ames plate incorporation assay. Mutagenic responses were fitted by an equation which takes into account toxic effects on tester organisms. Generally parallel responses were obtained with the two Salmonella strains, but the TA98 gave, mostly, higher increases of revertants over the control level.

Micronucleated lymphocytes in people occupationally exposed to potential environmental contaminants: the age effect.

This work is part of a research project on 2 groups of tannery workers (i.e., workers employed in the tanning process and those employed in the finishing department), and 2 control groups consisting of individuals paired with each exposed person according to sex, age and smoking habit.

An experimental approach to identifying the genotoxic risk by cooked meat mutagens.

In order to define the toxicological risk for the human population derived from the chemical compounds formed during the process of cooking animal meat, which have been described to possess a mutagenic, genotoxic, and carcinogenic activity, an extensive study has been developed on cooked meat extract and two cooked meat mutagens, IQ and MeIQx. The study has been based on toxicokinetics and mouse tissue distribution of the two chemicals, on in vitro and in vivo mutagenicity/genotoxicity analyses (gene mutation, chromosome aberration, micronuclea in mouse bone marrow cells, mice urine and faeces mutagenicity test), as well as in vivo protein and DNA binding. The two chemicals have been found positive for the induction of gene mutation on Salmonella, but not in V-79 Chinese hamster cells; IQ only has been found positive for the induction of chromosome aberrations on CHO cells and cultured human lymphocytes.

Chromosomal monitoring of chromium-exposed workers.

A cytogenetic analysis was carried out on peripheral blood lymphocytes of workers exposed to chromite in a ferrochromium plant, to evaluate the possible existence of genetic damage. A quantitatively limited increase in aberrant cell frequencies was detected in subjects working in the furnace sector. The data were analyzed by several statistical approaches.