Improvement in conditions at an amalgamation plant after an industrial hygiene survey

After receipt of urine samples which showed higher than normal levels of mercury (Hg) from workers at a large goldmine, air samples were taken at the mine's amalgamation plant. These showed not only values higher than the threshold limit for Hg in air but also significant quantities of Hg on the worker's overalls. Recommendations were made for improvements and when these were completed samples were again taken at the plant. The mean Hg level in urine samples had dropped to one-third of its original value and concentrations in air were very much reduced.