On December 2, 2009, EPA Region 4's Phone Duty Officer received a call from an Alabama Department of Public Health social worker pertaining to a 14 month old child that was admitted to the hospital due to mercury poisoning. The child was admitted to the hospital on two separate occasions, October 22 and November 13, 2009. The child's 24-hr urine mercury levels were up to 4 times higher than the permissible level. The 14 month old is undergoing treatment. The child's mother is 6-7 months pregnant. The social worker reported that another family lives in the apartment and have two children. Their 9 year old, had been admitted to the hospital with an unrelated illness but was discovered to have mercury poisoning as well. He has a 2 year old sister. The social worker did not have details of the source of mercury. Because of the extreme circumstances, Phone Duty Officer dispatched R2 OSC Karen Buerki and START contractor OTIE to investigate the source. Air monitoring conducted inside the apartment with a Lumex Mercury Vapor Analyzer indicated elevated mercury levels in the living room of 5000-6000 ng/m3 and up to 137,000 ng/m3 in the back bedroom upon opening the door. OSC Buerki requested ATSDR assistance and Bob Safay was dispatched to assist with health consultations. OSC Buerki will continue to locate the possible source of mercury and will coordinate the response with the apartment complex, local, and State health officials, and nearby residents.