Investigations of the frequency of DNA strand breakage and cross-linking and of sister chromatid exchange frequency in the lymphocytes of female workers exposed to benzene and toluene.

Peripheral lymphocyte DNA damage as measured by the method of alkaline filter elution and the frequency of sister chromatid exchange (SCE) in lymphocytes was investigated for a group of 20 female workers of a shoemaking plant who were exposed to benzene and toluene, primarily below the German threshold limit value of 5 and 100 p.p.m. respectively; the results were compared with those from a control group. In the female workers significantly raised (P less than 0.05) SCE values were found. The relative DNA elution rate through polycarbonate filters was significantly increased (P less than 0.001). The elution rate through polyvinylidene fluoride (HVLP) filters showed a tendency to increase (P = 0.052), which must be interpreted as indicating increased DNA strand breakage. The SCE rates of the female workers were significantly correlated (P less than 0.01) with the relative DNA elution rate through HVLP filters. There was no correlation with the actual benzene and toluene uptake measured by personal air monitoring. Four months after cessation of work, DNA strand breakage decreased significantly (P less than 0.05) in blood samples of six reinvestigated female workers.

[Pharmacokinetics of tetrachloroethylene in steady stage conditions]. / Pharmakokinetik von Tetrachlorethen unter Steady-state-Bedingungen.

Pharmacokinetic behaviour of tetrachloroethylene (clearance, pool, elimination kinetics, metabolic capacity) was studied by intravenous and inhalative long term administration. Concentrations of tetrachloroethylene in blood can be calculated from the concentration in the external air, as to be predicted for a substance, practically not metabolizable and eliminated totally by exhalation. The advantages of steady state techniques and their applicability to problems of industrial pharmacology are discussed.

[Development of a rational monitoring strategy for workers exposed to tetrachloroethylene]. / Gestaltung einer rationellen Uberwachungsstrategie exponierter Werktätiger gegenüber Tetrachlorethen.

A 5 year follow-up of 130 workers exposed to tetrachlorethylene (dry cleaning) was performed, including measuring of exposure conditions (personal dosimetry, exposure tests) and clinical investigations. No signs of hepatoxicity of tetrachlorethylene could be detected, but slight derangements of nerval functions may develop in long-term exposed workers. Nerve motor and sensory conduction velocity shows a tendency to diminution. Recommendations are derived for biological monitoring and health surveillance of workers exposed to tetrachlorethylene.