Tissue distribution and elimination of selected chlorinated naphthalenes.

Objectives: Polychlorinated naphthalenes are widespread, persistent environmental pollutants. Commercial products are generally mixtures of several congeners and range from thin liquids to hard waxes of high melting point. The higher chlorinated naphthalene products are used as impregnants for condensers and capacitors and dipping encapsulating compounds in electronics. The aim of this study was to investigate the disposition of penta- and tetrachloronaphthalene in rats following a single intraperitoneal administration.

Materials And Methods: Experiments were performed on male Outbred Wist rats with body weight of 200-250 g. Both compounds labeled with tritium, were given intraperitoneally in a single dose of 10 mg/kg body weight. Blood and selected tissues distribution of 3H-radioactivity as well as urine and feces excretion from 0 to 336 h were traced following the administration.

Results: After 120 h about 70% of the given dose was excreted in feces. Feces proved to be the main route of tritium excretion; only about 6% were excreted in urine within 120 h. In all the examined tissues, the highest 3H concentrations were found in the fat tissue, liver, kidneys and adrenals.

Conclusions: Following calculations of the balance of total tritium excreted and stored, it was found out that both chloronaphthalenes belong to compounds of slow turnover rate in the rat body, and especially in the case of repeated exposure they might accumulate in the body.