Cytokinesis blocked micronucleus assay of peripheral lymphocytes revealing the genotoxic effect of formaldehyde exposure

Formaldehyde (FA), which is said to be a carcinogenic agent, is commonly used in anatomy laboratories. This study used the cytokinesis blocked micronucleus assay (CBMN) to assess DNA damage due to FA exposure by measuring the frequency of micronuclei (MN) in lymphocytes. The extent of DNA damage was assessed with respect to the duration of exposure. Thirty male anatomy laboratory workers from various medical colleges involved with storing specimens and embalming were included in the study. Thirty males who were not exposed to FA were included as a comparison group. Blood samples were collected after informed consent was given. Information regarding age, duration of FA exposure and smoking habits was obtained by a questionnaire. The CBMN assay was conducted on cultured isolated lymphocytes stained with Giemsa. MN were counted in a total of 1000 binucleated lymphocytes. The effect of smoking was assessed using appropriate statistical tests. The frequency of MN in lymphocytes was significantly higher in the exposed group (P < 0.001). The duration of exposure correlated positively with the frequency of MN (r = 0.5, P = 0.02). Neither aging nor smoking correlated significantly with the formation of MN. The present study highlights significant DNA damage in people exposed to FA. The extent of damage was directly proportional to the duration of exposure.