N.H. Seemayer

Comparative study of sister-chromatid exchanges and chromosomal aberrations induced by airborne particulates from an urban and a highly industrialized location in human lymphocyte cultures

Cytogenetic effects induced by extracts of airborne particulates in human lymphocyte cultures were studied with regard to local and seasonal variations. Samples of airborne particulates were collected from an urban and a highly industrialized area in March and October, respectively. All extracts of particulates induced a significant increase of sister-chromatid exchanges (SCE) in a dose-dependent manner. Referring to the induction of sister-chromatid exchanges, local and seasonal differences were observed. Samples from the industrialized area revealed the highest activities. In addition, SCE rates found for March samples were always higher than those for October for both locations. Furthermore, a remarkable, significant induction of chromosomal aberrations occurred with all samples from both locations and sampling periods. Aspects of health risk evaluation for exposed human populations are discussed with respect to the observed cytogenetic effects of airborne particulates in human lymphocyte cultures.

Cytogenetic effects of airborne particulate matter in human lymphocytes in vitro.

City smog was collected in a heavily industrialized area and investigated for its ability to induce cytogenetic effects in human lymphocytes in vitro. Total extract of city smog was found to produce sister-chromatid exchanges and chromosomal aberrations in a dose-dependent manner. In addition cell-cycle delay was observed at higher concentrations of city smog extract. Results of cytogenetic testing are discussed with respect to cell-cycle kinetics.

Evaluation of health risks by airborne particulates from in vitro cyto- and genotoxicity testing on human and rodent tissue culture cells: A longitudinal study from 1975 until now

Abstract Airborne particulate matter or city smog from heavily industrialized regions contains more than 600 mostly organic chemical substances, among them also potential carcinogens and mutagens. 41 samples of airborne particulate matter were collected between 1975 and 1990 at various locations of the highly industrialized Rhine-Ruhr region in F.R.Germany. Extracts of airborne particulates were prepared by organic solvents. Results demonstrate pronounced cytotoxic, mutagenic and carcinogenic activities of various samples of airborne particulates. Cytotoxicity testing of samples revealed a gradual dose-related impairment of phagocytosis of human and rodent macrophages leading at higher concentrations to a loss of cell viability. We observed a dose-dependent reduction of “plating efficiency” of human and rodent cell lines. Genotoxic activity of extracts was demonstrated by a dose-related induction of “sister chromatid exchanges” in human lymphocyte cultures. Furthermore, we found a pronounced dose-dependent “enhancement” of neoplastic cell transformation of Syrian hamster kidney cultures infected with Simian virus (SV-) 40.

Comparison of cytotoxicity of airborne particulates to rat and human macrophages

In this study we report the effect of extract of airborne particulates collected in the Rhine-Ruhr region on alveolar macrophages of the rat and on human macrophages in culture

Inhalation Studies with Airborne Particulates in Rodents: Cytotoxic and Genotoxic Effects on Alveolar Macrophages and Bone Marrow Cells

Industrialization, traffic, and urbanization are the most important factors causing contamination of the atmosphere with particulate and gaseous pollutants. These represent a very complex chemical mixture composed of several hundreds of mostly organic compounds (Helmes et al. 1982; Schlipkoter 1983). In previous studies it has been repeatedly reported that organic extracts are cytotoxic, mutagenic, and carcinogenic in a number of short-term bioassays using rodent and human tissue culture cells (Hadnagy et al. 1986, 1989; Motykiewiecz et al. 1991; Seemayer et al. 1984, 1988, 1989). Airborne particulates with a diameter of less than 5 μm are of special importance as they can reach the bronchoalveolar space in human lung by respiration. Macrophages in alveoli come into direct contact with noxious particles and gases as well as with diverse pathogenic microorganisms.

Comparative Investigation of Genotoxic and Nongenotoxic Mechanisms and Their Relevance in Carcinogenesis Induced by Airborne Particulates and Automobile Exhaust Particulates

The most important sources of air pollutants are industrial processes, power generation, traffic, waste incineration, and fuel or coal combustion for space heating (Fishbein 1990). Nearly 700 mostly organic compounds have been detected as air pollutants, among them potential and proven mutagens and carcinogens (Helmes et al. 1982; Schlipkoter 1983). In addition to gaseous pollutants, airborne particulates are of special importance. Most organic substances are found in fine dust particles, which as respirable particulate matter with a particle diameter smaller than 3.5 pm can reach the bronchoalveolar space of the human lung (Hileman 1981). Genotoxic activity and rodent-derived airborne allergens are mostly associated with this fraction of fine particles (Talcott and Harger 1980; Corn et al. 1988). Genotoxic activity of airborne particulates leading to mutation and cancer has been well documented (Chrisp and Fisher 1980; Epstein et al. 1979; Hughes et al. 1980). Nongenotoxic or epigenetic effects have not been investigated thoroughly. To avoid an underestimation of the mutagenic and carcinogenic potential of airborne particulates, nongenotoxic or epigenetic effects leading to mutation and cancer must be considered (Williams 1983; ICPEMC 1984; Tennant 1988). In this study we report the genotoxic and nongenotoxic effects of two samples of airborne particulates collected in the highly industrialized Rhine-Ruhr district (FRG) and of two samples of exhaust particles from automobiles driven with leaded and unleaded gasoline, utilizing human and rodent tissue culture cells.

Dust Induced Alterations of Human Macrophages

Alveolar macrophages are the first and most important cells in the defense line against airborne particles. The cells eliminate respirable foreign material by their ability to phagocytize, to store and to degradate it. During this process alveolar macrophages are known to generate and release a variety of mediators of inflammation as well as enzymes. Depending on the chemical composition of a particle, it will be either stored within phagolysosomes without further degradation (i.e. inert particles, or some heavy metals), or it will undergo subsequent degradation and may thereby develop cytotoxic acitivity (i.e. silica particles). In addition, internalized particles may alter and impair the function of macrophages to other stimuli (i.e. latex beads, zymosan or bacteria).