Fritz Schweinsberg

Herbicide use on railway tracks for safety reasons in Germany

A short overview on the occurrence of herbicides in groundwater and drinking water located in the vicinity of railway tracks in Germany is presented. The study has been conducted using the experience of various water supply companies and includes a literature research on the subject. It has been documented that in Germany only 1% of the total area treated with pesticides was under management of the former Deutsche Bundesbahn before 1990. The specific amount applied on the railway tracks was, however, a factor of 6 higher than that used in agriculture, although it must be borne in mind that the retaining capacity of railway tracks for pesticides is much lower. The herbicides applied ranged from 2,4-D and 2,4,5-T, triazine derivatives, e.g. atrazine and urea derivatives such as diuron. Traces of almost all of the herbicides applied could be detected in samples of groundwater and drinking water in the vicinity of railway tracks. Since 1997 only glyphosate has been used.

Risk estimation of mercury intake from different sources

Biological monitoring of mercury (Hg) in blood, urine and hair was performed in volunteers with amalgam fillings, in subjects who consumed fish and in Hg-exposed workers. It was found that both amalgam fillings and the consumption of fish burden the organism with Hg in the same order of magnitude. The Hg concentrations in urine in the occupationally exposed group were higher by a factor of about 100 compared to the group with amalgam fillings. No pathological changes were found in the exposed workers. It seems safe to conclude that no health-related problems from Hg are to be expected from amalgam fillings.

Heavy metal concentrations in humans

Etude des differentes concentrations en cadmium, mercure et plomb dans les fluides et les organes du corps humain ainsi que les modifications fonctionnelles que peuvent engendrer ces metaux lourds

Selenium status in fibromyalgia

Fibromyalgia (FM) is a chronic musculoskeletal pain syndrome of unknown etiology. The serum concentration of selenium (Se) was measured in 68 consecutive patients (nine male, mean age: 47 years; 59 female, mean age 49 years) with FM. The age- and sex-matched control group included 97 female healthy blood donors (mean age 46 years). The method is based on high-performance liquid chromatography (HPLC) involving detection of the fluorescent diaminonaphthalene (DAN) derivate of selenite. There was a statistical significant difference (P < 0.05) in serum Se between control (median 77 microg/l; range: 50-118 microg/l) and patients (median 71 microg/l; range: 39-154 microg/l) groups in the region of Tübingen, Germany.

DNA Modification and Repair in Vivo: Towards a Biochemical Basis of Organ-Specific Carcinogenesis by Methylating Agents

The elucidation of the biological basis of organ-specific tumor induction by chemicals is a major objective of cancer research. For many carcinogens, the principal site of tumor induction has been shown to vary with species, dose, route of administration, and age or developmental stage. Some species also exhibit marked differences in their overall susceptibility to certain classes of chemical carcinogens. Accordingly, to accurately predict the adverse effects of genotoxic agents in humans, the basic mechanisms underlying organ and species specificity must first be understood.

Pentachlorophenol in the indoor environment: evidence for a correlation between pentachlorophenol in passively deposited suspended particulate and in urine of exposed persons

Analysis of passively deposited suspended particulate (PDSP) proved to be a reliable and easily applicable method for the investigation of pentachlorophenol (PCP) exposure from indoor air. PDSP was analyzed after manual collection of samples in 78 rooms with wooden paneling, where earlier treatment with wood preservatives was suspected. Pentachlorophenol was quantitatively determined by gas chromatography with an electron capture detector following derivatization with acetic anhydride. For biological monitoring of PCP, morning urine specimens were collected from 135 persons living in the rooms investigated. After acidic hydrolysis, these samples were analyzed for PCP. The urine samples from 9% of the test-persons exceeded a PCP level of 10 micrograms/g creatinine. From this urine level, a corresponding PCP level of approximately 40 micrograms/g in PDSP could be calculated. These results show that there is still a considerable risk of exposure to PCP, even after a long period following treatment of wood with PCP-containing preservatives.

Modifying effects of disulfiram on DNA adduct formation and persistence of benzaldehyde in N-nitroso-N-methyl-benzylamine-induced carcinogenesis in rats

SummaryWhereas disulfiram (DSF) is known to inhibit tumor formation resulting from a number of chemical carcinogens, such inhibition does not apply to nitrosamines. In the present study, biochemical and morphological findings were examined to elucidate the effect of DSF on long-term application of N-nitroso-N-methylbenzylamine (NMBA). HPLC and fluorescence detection were used to determine O6-methylguanine (O6-MG) in DNA obtained from the respiratory tract of rats subjected to long-term simultaneous application of DSF and NMBA. After 2 days of treatment, more O6-MG was detected in the proximal portion of the respiratory tract, including the trachea and main bronchi, than in the distal portion. The findings were reversed after 10 and 30 days, at which time formation of the DNA adduct was substantially higher in the distal portion of the respiratory tract, despite increases in both portions. The biochemical results corresponded to morphological findings. Initially, mereased numbers of metabolizing goblet cells appeared in mucous cell hyperplasia in the proximal respiratory tract. Subsequently, the hyperplasia migrated to distal regions of the respiratory tract; at this stage, the goblet cells disappeared from the proximal portion, which now revealed toxic degeneration, atrophy and subsequent squamous metaplasia of the mucous lining and squamous papillomas.At various times during a 40-day period, 2 to 7 times more O6-MG in pulmonary DNA was detected in rats treated with DSF and NMBA, than with NMBA alone, whereby distinct amounts of O6-MG were found in the latter animals. In contrast to the above-mentioned morphological findings, no morphological alterations occurred in the respiratory tract of the animals treated with NMBA alone. It is therefore conceivable that the above pathological lesions resulted not merely from the presence of DNA adducts, but also from an additional, previously unspecified effect.As benzaldehyde (BA) is formed in equimolar amounts in NMBA metabolism and DSF has been demonstrated to inhibit aldehyde metabolism, this aldehyde is a possible candidate for such an effect. In the present study, rats were therefore treated with BA, DSF, or NMBA, or combinations thereof. Histomorphological evaluation of these experiments revealed that long-term application of BA alone led to the following alterations in the respiratory tract: goblet cell hyperplasia, hyperplasia of the peribronchial lymphatic system, mucous epithelial atrophy and accompanying peerivasculitis — the same alterations seen under long-term application of NMBA and DSF. Furthermore, these changes were most pronounced in the group with concomitant application of NMBA, DSF, and BA. It is therefore conceivable that BA plays a role in pathological changes observed under the influence of NMBA.

Pustular psoriasis exacerbation under intoxication with mercury

Zusammenfassung. Unter einer 3wöchigen systemischen Therapie mit einem quecksilberhaltigen Präparat exazerbierte eine seit 4 Jahren bestehende Psoriasis pustulosa palmaris. Es entwickelte sich eine Psoriasis pustulosa generalisata ohne Schleimhautbeteiligung. Die Hg-Spiegel in Blut und Urin waren deutlich erhöht. Nach Absetzen des Hg-haltigen Präparates wurden das Quecksilber-Antidot DMPS (2,3-Dimercapto-1-propan-sulfonsäure) sowie kurzzeitig ein aromatisches Retinoid und PUVA angewendet. Innerhalb weniger Tage waren die Hg-Spiegel deutlich rückläufig, die Hauterscheinungen heilten fast vollständig ab.Abstract. A patient suffering from long-standing pustular psoriasis of the palms was treated for 3 weeks with a mercury-containing drug. Exacerbation into generalized pustular psoriasis developed. Mercury levels in blood and urine were increased. After withdrawal of the mercury preparation, therapy with DMPA (2,3-Dimercapto-1-propane-sulfonic acid), a mercury antidote, was initiated, together with short-term treatment with aromatic retinoids and PUVA. Within a few days mercury levels decreased significantly and the skin lesions practically disappeared.

Investigation of the Validity of Quantitative Determination of Cadmium and Lead in Human Hair by Atomic Absorption Spectroscopy

Heavy metals occur in increasing amounts in the human environment. There is growing evidence for their role in the development of several diseases. “Biological monitoring” is an established tool in investigating their significance to human health. As in the case of cadmium and lead, this approach is commonly limited to determination of concentrations in the body fluids blood and urine. It has been shown, however, that these body fluids are best suited to revealing short-term exposure to heavy metals. Because cadmium and lead are known to accumulate in the human body, long-term exposure to even small amounts may also be important in the development of disease. Since cadmium and lead accumulate in human hair, analysis of this compartment has been proposed for investigation of these heavy metals.

19 – TOXIC EFFECTS OF SOLVENT EXPOSURE

Highest exposures can be found in workplace (e.g., evaporation of solvents) or during special processes (e.g., leaks of normally closed systems). Acute and severe solvent accidents often happen in workplaces (high solvent concentrations, intermittent high-level exposures, high duration of exposure). Apart from working sites, various other emission sources of solvents should be considered, e.g., consumer products. The description of exposure parameters (type of solvents, concentrations, duration, routes of exposure) are important for the evaluation of toxicokinetics. Solvents and other chemicals are usually emitted as a mixture of various substances. Therefore, the risk assessment of emitted solvents is difficult to ascertain. Solvent concentrations and duration of exposure vary in most cases (intermittent high-value peaks, periods of low exposure). The exposure is influenced essentially by surrounding occupational and environmental conditions, such as working climate, protective equipment and by individual parameters such as eating habits. The exposure to solvents is regulated by relevant threshold limit values. Exposure and exposure values can be controlled by defined methods (e.g., ambient and biological monitoring).