The micronucleus assays have emerged as one of the preferred methods for assessing chromosome damages because they enable both chromosome loss and chromosome breakage to be measured reliably. The cytokinesis block MN assay deals with most frequently used in hazard identification and risk assessment process. Cytokinesis block MN assay using mononuclear lymphocytes in Traffic Police Population in Tiruchirappalli. The overall view present by the experiment was that as age increase the damage, namely, single stranded breaks and their mis repair resulting in double strand breaks leading to MN, increase in a directly proportional way and reached a peak value of damage at the age group of > 51. Air pollutants enhanced MN in mononuclear lymphocytes in Traffic police population.