Mercury exposure from the repair of blood pressure machines in medical facilities

Hospital employees who repair broken blood pressure machines or who work in areas where such machines are repaired are potentially at risk for mercury poisoning. To assess this risk, the extent of exposure and related health effects from this source were investigated in 13 hospitals. Ninety-three employees who repaired blood pressure machines, who cleaned the repair area, or who worked in the repair room participated in the project. A comprehensive industrial hygiene survey was conducted to assess mercury contamination. Occupational histories and symptoms of mercury poisoning was elicited from employee interviews, and mercury absorption were assessed via urine samples. The investigation showed that repair and cleanup of broken blood pressure machines were carried out with little programmatic attention having been paid to providing a safe environment. Employees were not trained in the hazards associated with mercury nor in proper handling of this material. In 6 of 13 facilities, the level of airborne mercury, measured over 10-second intervals with a real-time instrument, exceeded 50 Jlg/m3. The Permissible Exposure Limit (PEL) set by the Occupational Safety and Health Administration is 50 pg/m3 as an 8-hour time-weighted average (TWA). Eleven of 86 employees who submitted urine samples had levels consistent with excess mercury absorption (> 19 μg/L). Of these, eight never or rarely repaired the blood pressure machines but worked in the repair room. To prevent future mercury exposure in this setting, a comprehensive health and safety program for the repair work was developed.