Objective To explore the potential damage of gaseous formaldehyde on genetic material of cells. Methods SPF-class Kun -Ming male mice were used in the experiment. The mice were exposed to gaseous formaldehyde in different concentrations :0. 5 mg/m3 .1.0 mg/m3 and 3.0 mg/m3 ,the agent was administrated by continuous dynamic inhalation for 72 hours. After the exposure to formaldehyde, micronucleus rate in peripheral lymphocytes and liver cells was measured. Results Gaseous formaldehyde could induce the increase of micronucleus rate in peripheral...