This testimony concerned the efforts of NIOSH in a study of worker exposure to polychlorinated-biphenyls (1336363) (PCBs) at selected General Services Administration (GSA) facilities in the area of metropolitan Washington. The GSA employees being studied were exposed to transformer fluids containing PCBs in the National Capital Region. NIOSH was to review work practices, recommend appropriate PCB handling procedures, and measure airborne levels of PCBs and certain other chemicals. An internal audit at the site had revealed that the PCB material was being improperly stored at the Switch Gear Shop; 43 employees reported various health problems such as sterility, headaches, nausea, skin rashes and loss of appetite. Nearly this entire workforce had been employed in transformer maintenance for at least 3 years. The health of these 43 workers will be compared with a comparison group of unexposed GSA employees. The workers will be given complete medical examinations, including special tests to determine if they suffer from infertility, liver damage, nerve damage, or impairment of lung function. This study was one of 23 requests received by NIOSH for technical assistance from other Federal agencies during the preceding year.