Interaction between Aeroallergens and Airborne Particulate Matter.

The in situ interaction between pollen and airborne particulate matter (APM) as well as the effect of extracts of APM on grass pollen (Dactylis glomerata) was studied. The samples were processed for structural analysis using scanning and transmission electron microscopy as well as for determination of protein content and release using immunoblot techniques. The results indicate a direct in situ interaction between pollen surfaces and APM. This effect is prominent in industrialized regions with high emission of organic pollutants. It is also found to occur near roads with heavy traffic. There is morphological evidence for preactivation of pollen by organic extracts of APM. Aqueous extracts, however, directly induce the release of allergens with altered antigenicity. It is concluded that the generation and release of allergenic aerosols in a humidified air is initiated and mediated by substances adsorbed to APM.

Inhalation hazards from airborne particulates evaluated by in vitro cyto- and genotoxicity testing: a long-term study over a period of 14 years (1975-1988) from a highly industrialized area.

26 samples of airborne particulates collected between 1975 and 1988 in the highly industrialized Rhine-Ruhr region were analyzed for cytotoxic and genotoxic activity. Samples were extracted by organic solvents and quantitatively transferred to dimethyl sulfoxide for tissue culture experiments. Cytotoxicity testing of samples revealed a dose related loss of cell viability of mouse and human macrophages as well as an impairment of phagocytosis. We observed a reduction of "plating efficiency" of rodent and human lung cell lines induced by extracts. In the presence of extracts we found an inhibition of DNA synthesis, alterations of cell cycle progression and diminished cell growth of rodent, primate and human tissue culture cells. Genotoxic potency of extracts caused dose dependently an induction of "sister chromatid exchanges" in human lymphocyte cultures, Chinese hamster cell line V 79 and human type II pneumocytes of line A 549. Furthermore, we observed by extracts "chromosomal aberrations" in human lymphocyte cultures and a strong "enhancement" of malignant cell transformation of SV40-infected Syrian hamster kidney cells.

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.

The effect of automobile exhaust particulates on cell viability, plating efficiency and cell division of mammalian tissue culture cells.

Extract of particulate matter (EPM) of gasoline engine exhaust induced only a slight loss of cell viability of mouse macrophages (line IC-21) in vitro, while a strong dose-dependent reduction of plating efficiency of human cell line A-549 and of Syrian hamster line 14-1b occurred. Cytological investigations of exposed macrophages of line IC-21 revealed an increase in the mitotic index from 1.5% of control values up to 14.6% at the highest tested concentration of EPM. Mitotic arrest is based almost exclusively on C-type mitoses occurring dose-dependently in the presence of EPM. Results indicate disturbances of the spindle apparatus in the presence of EPM.

Mutagenic and carcinogenic effects of airborne particulate matter from polluted areas on human and rodent tissue cultures.

Global extract of airborne particulate matter from an industrialized area contains chemical substances which exert a dose-dependent mutagenic and carcinogenic activity on mammalian cells in vitro. Mutagenic activity was demonstrated by induction of "sister chromatid exchanges" in human lymphocyte cultures and in Chinese hamster lung cell line V 79. Furthermore, "point mutations" at the HGPRT-locus were induced in V 79 cells. Carcinogenicity was shown by "enhancement" of malignant cell transformation of Syrian hamster kidney cultures exposed to global extract and thereafter infected with Simian virus 40. When considering a human respiratory volume of 12-14 cbm of air per day we have to emphasize that amounts of global extract equivalent to particulates from 0.5-1 cbm clearly showed mutagenic and carcinogenic activity. This relationship is visualized on Fig. 1.

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.

[Comparative study of the behavior of particulate emissions from diesel and gasoline engines in animal lungs: elimination rate and induction of benzo(a)pyrene hydroxylase and ethoxycoumarin de-ethylase]. / Vergleichende Untersuchung zum Verhalten von partikulären Diesel- und Ottomotoremissionen in Tierlungen: Eliminationsrate und Induktion der Benzo(a)pyren Hydroxylase und Ethoxycumarin Deethylase.

The emitted particulates of five diesel-engined and two gasoline-engined passenger cars were investigated for the elimination rate from hamster lungs after intratracheal instillation. In addition extracts of these particulates were studied for their influence on the mixed function oxidase activity (MFO; Benzo(a)pyrene Hydroxylase, Ethoxycoumarine Deethylase). Differences in the elimination rates of diesel soot and particulates from gasoline engines were not found. Compared with the blanc the extracts of diesel soot from two vehicles proved to give a moderate increase of the MFO activity, but a significant difference to the blanc was observed with the extracts of the gasoline engines. It should be mentioned that the effects were studied without taking into account the quantitative relations of the emissions in the ambient air. However, the amounts of particulates were extremely high in relation to the natural conditions. In the limits of our test model there is no indication of a higher toxicity of diesel-emissions.

[Studies on the mutagenic effect of extracts derived from airborne particulates within one year in differently burdened areas using the Ames test (author's transl)]. / Untersuchungen zur mutagenen Wirkung von Schwebstoffextrakten unterschiedlich belasteter Gebiete im Ames-Test während eines Jahres.

Suspended matter was collected at three sampling sites with different air pollution levels (DU = Duisburg, mining, iron and steel industry; D = Düsseldorf, residential city; K = Krahm, rural district) in 1978. The seasonal variations of the mutagenicity of extracts from samples collected monthly were assayed by the Ames-test. Th results are presented as the number of revertants related to air volume, weight of the suspended matter, weight of the dried extract and to the amount of benzo(a)pyrene in the extract. The mutagenicity varies according to the benzo(a)pyrene concentration in the atmosphere: the highest values are found during the winter, the lowest during the summer. When the mutagenicity is based on the benzo(a)pyrene content, it remains nearly constant throughout the year (sampling site DU) or rises in the summer (sampling sites D and K). These results indicate that at least in heavily polluted areas the larger part of the mutagens may originate from the same sources as benzo(a)pyrene (e.g. incomplete combustion). The direct (assayed without activating system) mutagenicity of the extracts is somewhat higher in winter than in summer. However, these differences are low or missing, when the mutagenicity is expressed as number of revertants per weight of suspended matter or dried extract. The mutagenicity reaches a maximum in summer, provided, the number of revertants is related to the benzo(a)pyrene concentration. These results indicate that the direct acting mutagens present in the air originate from other sources than that of benzo(a)pyrene (e.g. automobile exhaust). The mean values of the mutagenicity related to the number of revertants per dry-weight and weight of suspended matter do not differ among the three sampling sites. It can be assumed that the composition of the particulate matter may be similar with respect to mutagens regardless the level of pollution.

[Studies on the tumourigenicity of extracts and their fractions of airborne particulates with the subcutaneous test in the mouse (author's transl)]. / Untersuchungen zur tumorerzeugenden Wirkung von Extrakten und Extraktfraktionen aus atmosphärischen Schwebstoffen im Subkutantest bei der Maus.

Airborne particulate matter was collected on filters at various times in Duisburg, Duesseldorf, Muenster and in 2 rural areas. After extraction with organic solvents the extract was partly fractionated and analyzed for BaP and 7 other polycyclic aromatic hydrocarbons (PAH). The carcinogenicity was examined with the subcutaneous test using 7000 mice in total. The amount of extract required was relatively small. Extracts from suspended matter with a BaP content of 0.37 to 1.1 microgram BaP brought about tumour rates in the range of 30%. On account of the results the following can be concluded: 1. The total extract of atmospheric particulates results in definite dose-response relationship, when the part of the compounds not belonging to the PAH is rather low. 2. The PAH fractions derived from the suspended matter collected in different cities show the same carcinogenic potency, when they are adjusted to the same BaP level by means of concentration or dilution. 3. The PAH bear the most important share with respect to the carcinogenic potency of an extract from suspended matter. 4. Numerous compounds (polar substances) which are not classed with the PAH are carcinogenic to some extent, partly they are able to inhibit the carcinogenic effect. 5. The dose-response relationship of BaP is strongly leveled off in general when all the substances of an extract are present. That means when the dose of an extract is low, the importance of BaP becomes less. Therefore a fixed ratio concerning the effect of BaP within an extract cannot be given. It has to be examined in particular, which PAH and non-PAH are necessary to analyse in order to describe the carcinogenic effect due to an extract from airborne particulates. Much more attention is to be payed to the polar substances.

[Analysis of the biological effect of city smog extract IV. Growth inhibition of kidney cell cultures (cercopithecus aethiops) under the influence of a city smog extract and its polyaromatic fractions (author's transl)]. / Untersuchung der biologischen Wirkung von atmosphärischen Feinstaubextrakten IV. Wachstumshemmung von Nierenzellkulturen (Cercopithecus aethiops) unter Einwirkung eines atmosphärischen Feinstaubextraktes und seiner Polyaromatenfraktionen.

The cell growth of exponentially growing kidney cell cultures of Cercopithecus aethiops was determined by estimation of protein content. The effect of city smog extracts and its polyaromatic fractions on cell growth was examined. Based on the benzo(a)pyren-content the crude extract of city smog exerted the strongest inhibition of cell growth, followed by non purified and purified fraction of polyaromates. The inhibition of cell growth was dose dependent. Results indicate, that for cell growth inhibition are of importance concentrations of toxic substances and exposition time.

[Profiles of polycyclic aromatic hydrocarbons in suspended particles of different cities in the Western Federal Republic of Germany (author's transl)]. / Profile von polyzyklischen aromatische Kohlenwasserstoffen in Immissionen verschiedener Schwebstoffsammelstationen in der westlichen Bundesrepublik Deutschland.

The relative proportion of eight polycyclic aromatic hydrocarbons (PAH) in suspended particles from several sampling stations with different level of air pollution (cities and rural districts) was investigated. The PAH-profiles of most samples collected in three winters (1974/75, 1975/76, 1976/77) and in one summer (1975) were very similar. On the other hand the PAH-profiles differ distinctly from those of several exhausts, especially regarding automobiles, coke and oil stoves. It can be presumed, that the mixture of the emissions in the atmosphere leeds to a rather uniform relative proportion of the eight PAH in the immission as much as the difference in stability of the PAH.

The mutagenicity of airborne particulate pollutants.

The mutagenic effect of extracts derived from airborne particulate matter was investigated with the Ames-test. The whole extract proved to be distinctly mutagenic. To find out whether the content of polycyclic aromatic hydrocarbons may be responsible for the mutagenic effect, the extract was split into several fractions. The fraction containing the polycyclic compounds showed the lowest mutagenic rate that was enzymatically mediated. The other fractions required metabolic activation for some of their components, but some components were active without metabolic activation.

Tumours in mice after subcutaneous injection of automobile exhaust condensates.

Automobile exhaust condensate (AEC), either mixed with benzo[a]pyrene (BaP) or suspended or dissolved in tricaprylin, was injected subcutaneously into NMRI mice in a series of experiments. The addition of AEC decreased the incidence of tumours which developed with 30, 90 and 270 microgram BaP. Reduction of tumour incidence was proportional to the amount of AEC added. With an injection of 10 microgram BaP, the latent period was greatly increased when AEC was added, but the occurrence of tumours was the same. Components of AEC appear to inactivate BaP, at least temporarily. In further experiments AEC and nine fractions thereof were injected subcutaneously into mice. The fraction comprising only polycyclic aromatic hydrocarbons (PAH) induced the highest incidence of tumours. In contrast, when it was administered in combination with other fractions the PAH fraction was less active. Application of the products of further fractionation of PAH showed that polycyclic compounds with seven or more rings can also induce tumours in this model.

[An animal experimental study on the retention rate of polycyclic aromatic hydrocarbons in the lung and in the subcutaneous tissue (author's transl)]. / Tierexperimentelle, Untersuchungen zur Retentionsrate von polyzyklischen aromatischen Kohlenwasserstoffen in der Lunge und im subkutanen Gewebe

The retention rate of five polyaromatic hydrocarbons (PAH) (benzo(a)pyrene, dibenz(ah)anthracene, chrysene, pyrene, benz(a) anthracene) was studied after intratracheal instillation into syrian hamsters and subcutanous injection into mice. For subcutanous injection the PAH were solved in 0.5 ml tricaprylin, for intratracheal instillation a suspension in NaCl was used. The results were the following: 1. With respect to the retention rate of the five PAH the largest difference was found comparing the application modes. The ratio of the averaged half-time-values for the intratracheal test to the subcutanous test is about 1:35. 2. The retention rates for each polycyclic hydrocarbon differs significantly. An interrelation of PAH after application of a PAH-mixture was not detectable. 3. The retention rates determined in the lung and in the subcutanous tissue do not give a constant ratio concerning each PAH. Thus DBahA is retained in the lung as well as in the subcutanous tissue definitely longer than BaP. Chrysene and benz(a)anthracene behave - respecting the retention rate - in the subcutanous test like BaP. In lung tissue, however, the different behaviour becomes obvious: while benz(a)anthracene is eliminated most rapidly, chrysene can be detected for a relative long time.

Polycyclic aromatic hydrocarbons in human bronchial carcinoma.

A study was made to determine whether and to what extent polycyclic aromatic hydrocarbons (PAH) are present in human bronchial carcinoma. Twenty-four carcinomas, obtained from surgical operations and autopsies, were examined. The samples were tested for 12 PAH; these were determined by direct fluorescence analysis on thin-layer plates. Only 4 of the 12 PAH were detected in the cancerous tissue: benzo(a)pyrene, fluoranthene, benzo(ghi)perylene. Beno(a)pyrene was found in all carcinomas. The reasons for increased concentration of the detected PAH in cancerous tissue are discussed with respect to deposition and elimination of inhaled particles as well as the metabolism of these compounds.