Lots of waste are produced from cities and embeded at the depository. The waste produces chemicals and organic matters. Those toxicants contaminate air and water. The pollution causes the increase of insects thereby to spray pesticide on the depository as well as its outskirts. Chemicals and pesticide ingredients are accumulated on the depository and released into outskirts. Those toxic agents are assumed to generate DNA damage to animals exposed to the water and air pollutions. To prove the possibility of DNA damage to pollution, comet assay was conducted on lymphocytes of animals exposed to the pollution of a depository at Southern part of Seoul. Peripheral lymphocytes of animals were treated with endonuclease III and electrophoresed. Broken DNA was released and measured under fluorescence microscope. The measurement showed no statistically significant DNA damage but some individuals showed higher DNA damage than in that of control group. These experiments were carried out on rabbits and dogs, the most and the least contaminated, respectively. The rate of DNA damage of cows was in between that of rabbits and dogs.