Intestinal absorption of trichloroethylene in dogs

In order to examine the intestinal absorption of trichloroethylene (TRI), we developed the intestinal circulation system of dogs and administered TRI solution at three concentrations (0.1, 0.25 and 0.5%) to the three parts of the intestinal tract (jejunum, ileum, and colon) of the operated dogs. We measured TRI and its metabolites, free-trichloroethanol, trichloroacetic acid, and conjugated trichloroethanol, in serum or blood, urine, bile and circulating solutions. The absorption rates of TRI from the intestine were 50-70% of the administered volume of TRI 2 hr after administration in all groups, and all parts of intestine readily absorbed TRI. Moreover, there were no significant differences in the absorption rates of TRI and water between the jejunum and ileum, and ileum and colon, respectively. The excretion rates of TRI and its metabolites in urine and bile were very low (0.1-0.4%) compared with the volume of absorbed TRI from the intestine 2 hr after administration in all groups. The high degree of absorption of TRI should be considered when threshold limits for TRI in the drinking water, the surface water, and the ground water are established.