Illustration showing the resolution of severe burning of a soldier's eye from gas poisoning. The top image shows the stage of resolution after severe burning and the bottom image shows the late stage of resolution. Exposure to mustard gas, an irritant used as a chemical warfare agent, causes damage to the eyes, skin and respiratory tract. Short term effects of mustard gas include coughing and shortness of breath. Mustard gas also has long term effects such as mouth, throat and skin cancer as well as leukaemia. Illustration published in An Atlas of Gas Poisoning, 1918.