[Evaluation of inhalation toxicity of organic solvent xylene in pregnant rats]

The objective of the present experimental study was the assessment of organism susceptibility to the toxic xylene effect during gestation period, with a view to elaborating recommendations for female work protection. The experiments were carried out in a comparative aspect in 60 pregnant and 60 virgin, sexually matured female albino rats, exposed to 1850 and 467.8 mg/m3 technical xylene in inhalation chambers--levels 40 and 10 times higher than MAC of the solvent, in the course of 21 days (period of gestation of rats), 5 hours daily, 5 times a week. The assessment of inhalation toxicity of xylene is based on the data from the complex biochemical investigations in serum, liver, brain, myocardium and aorta, supported by pathomorphological studies. Xylene disturbs the balance of serum lipid fractions with both levels of inhalation effect and has a manifested hepatotoxic and cardiovascular effect to pregnant animals. Less manifested disorders in serum lipid profile, liver and the brain of the female, non-pregnant rats, were established with the administration of high xylene concentrations only, suggesting the higher vulnerability of the pregnant organism to the toxic xylene effect. Recommendations for early labour readjustment of pregnant women engaged in xylene production are presented on the base of the data obtained about the disorders of vital functions of organism during gestation period, supported by epidemiological observations and the presence of experimentally established specific embryotoxic effect of xylene at MAC levels.