Abstract
The purpose of this article is to present extremely low frequency magnetic field exposures to a group of electricians working in a large petroleum refinery. Petroleum refinery workers were classified into groups based on the type of exposure sources and work conducted. Electricians were divided into three categories: high voltage electrical distribution (HVED) workers; low voltage electrical distribution (LVED) workers; and operating unit electrical workers, referred to as maintenance electricians (MNTE). For comparison purposes nonelectrical workers in the refinery and nonoccupational exposures were also determined. The EMDEX-C dosimeter developed by the Electric Power Research Institute was used to determine full-shift magnetic flux density exposure estimates.
A total of 48 individuals, 11 HVED electricians, 12 LVED electricians, 11 MNTE workers, and 14 nonelectrical workers were monitored for an 8-hour shift. Both the HVED and LVED groups were found to have average full-shift mean exposures slightly greater than 10 milligauss (mG). The MNTE group and the CMPR group exhibited lower magnetic flux density exposures, with means between 2 and 3 mG. A special group of high voltage electricians were monitored during a maintenance turn-around on bulk station reactors. Individual full-shift magnetic field means ranged from 0.06 to 2.0 G, with an overall mean of 0.93 gauss (G). Peak exposures ranged from 2.1 to 18 G, with an average of 12.1 G.