Josef Warkany, 90, a pediatrician who showed that birth defects can be caused by environmental factors and helped eliminate a sometimes fatal disease in young children. In 1940, Warkany demonstrated in animals that birth defects can be caused by dietary deficiencies in the mother during pregnancy. That broke the hold of traditional views that all birth defects were genetic. He also helped eradicate pink disease, which caused the loss of hair and teeth, high blood pressure, weight loss and sometimes death in infants. He proved in 1948 that the disease was caused by mercury poisoning. His findings resulted in mercury being removed from teething powders, ointments and other medications. Between 1939 and 1948, 585 children under 3 died of pink disease in England and Wales. About 10% of the children who contracted the disease died. In 1956, Warkany founded the Hamilton County Diagnostic Clinic for the Mentally Retarded, which evolved into the Cincinnati Center for Developmental Disorders. The center has been affiliated with Children’s Hospital Medical Center since 1973. He was also an artist whose drawings and etchings have been shown in galleries in Cincinnati as well as in the Library of Congress. In Cincinnati on Monday.