Chronic biological effects of methyl methacrylate vapor: I. Body and tissue weights, blood chemistries, and intestinal transit in the rat

The effects upon body and tissue weights, various blood parameters, and intestinal transit time associated with chronic exposures of rats to monomeric methyl methacrylate (MMA) vapor concentrations are summarized in this report. The most remarkable and readily apparent phenomenon was the obvious lack of body fat in the group which had been exposed for 3 months to an MMA vapor concentration of 116 ppm in air. It was determined that rats which have received a daily 8-hour exposure to 116 ppm of MMA vapor for 6 months have significantly lower adiposity, as measured by the popliteal fat pad, than those of a similar group which have received sham exposures. It was also determined that protracted exposures to MMA vapor in this concentration were associated with a significant decrease in intestinal transit performance.