CO2,CO, greenhouse gases etc. They deplet ozone layer. They do harm to our body and lungs.if these are in excess upon air then we can get killed

SO2, CO2, CO, NO2 and water. Sulphurdioxide and nitrogen dioxide are poisionous gases which causes acid rain and also bronchitis, CO2 is the green house gas which increases the temperature of the earth, CO is poisionous gas which binds the heamoglobin and prevent it from carrying oxygen and cause breathing problems