Biological monitoring of urinary lead: Preshift and postshift sampling detects efficiently recent lead exposure and signals the need to review and possibly improve controls at work

Abstract

The objective of this study is to highlight the effectiveness of urinary lead as an index of recent lead exposure. In the past scientific literature urinary lead has been studied as a parameter for recent lead exposure. It is a reliable indicator for occupational lead exposure. But, strangely enough, nowadays is scarcely used in the Netherlands and worldwide. We performed six field biological monitoring studies of preshift and postshift urinary lead tests during tank maintenance and bridge repair work. Highest values occurred during bridge repair. Mean urinary values were postshift 1,6−5 times higher than preshift values, indicating clearly recent lead exposure and failing protective measures. This is so far we know the first study combining preshift and postshift sampling of urinary lead. We compared our studies with crossectional and follow-up studies in occupational medicine. Our conclusion is that preshift and postshift urinary lead testing is a worker friendly test, ideally for detecting recent lead exposures in the field. It signals the need to review or possibly improve controls at work.There are no safe lead levels, so we recommend to use a target value for urinary lead of <3 μg/g creatinine for all lead workers in the Netherlands.