Standard methods of culturing human lymphocytes in vitro were used to assess the ability of inducing micronuclei of six polymers (Polymethyl methacrylate polyurethane, ea al).Results showed a significant increasing in microuncleus and a dosage-effect relation of polymethyl methacrylate (PMMA). Dosage of PMMA exceeding certain limit, the growth inhibition or death of cell appeared. Micronucleus rate of human lymphocytes cultured with other materials appeared normal or almost normal, there were no difference ...