The myth of blood-sucking vampires has a basis in misunderstood science and a University of Northern Iowa researcher is working to explain fiction with facts. Catherine Zemen, a professor of preventative medicine at U-N-I, has been studying blood disorders in Romania the past several summers — yes — in the region of Transylvania. Dr. Zemen says there’s a long history of mythology in rural Romania involving werewolves and various types of night spirits that may cause people to go mad or steal their vitality. According to the myths, the various creatures had increased activity during the spring and winter — the same times when people are more susceptible to infectious diseases and poor water quality. Zemen is studying a blood disorder caused by high levels of nitrate in the blood.Nitrate can occur naturally in the soil but can also be derived from human and animal waste, for example, if a well is located near a barn. Zemen says too much nitrate in the system can cause red blood cells to malfunction, making a person short of breath, fall into a stupor and even turn blue around the mouth and sternum. Some of the symptoms match up with western tales of vampires. Zemen hopes to publish her study of Romanian mythology and blood disorders in an international journal of global health next spring.