Individual mercury exposure of chloralkali workers and its relation to blood and urinary mercury levels.

Abstract

On 2 occasions, chloralkali workers were investigated with regard to personal air Hg exposure, blood Hg and urinary Hg. The 1st investigation (13 workers, 2 wk) was made at an exposure above the threshold limit value (64 .mu.g/m3, range 36-112), the second (16 workers, 8 wk) at a lower exposure (23 .mu.g/m3, range 15-43). At the higher level of exposure, good correlations were found between air exposure and blood or urinary Hg for the group, but not for individuals. At the lower level, the correlations were less pronounced for the group. For individuals, the best correlation was found between mean air exposure during 1 wk and blood Hg about half a wk later. Other individuals, mainly the least exposed showed no such correlation. Corresponding correlations were not found for urinary Hg. The urinary excretion rate was determined only for the last few hours of the workday, but the results agreed with earlier investigations of 24 h excretion on a group basis. The threshold limit value for Hg in air (50 .mu.g/m3) corresponded to 150-175 nmol Hg/l blood (= 30-35 .mu.g/l) for the group, with large individual variation.