Trends in occupational lead exposure since the 1978 OSHA lead standard.

BACKGROUND The purpose of the study was to evaluate trends in occupational lead exposures throughout U.S. industry after the establishment of the general industry lead standard in 1978 and the construction industry standard in 1993. METHODS Lead exposure measurements collected by the Occupational Safety and Health Administration (OSHA) under their compliance and consultation programs were analyzed. Time trends in the distributions of exposure levels were evaluated graphically. Trends in the proportion of exposures above the OSHA permissible exposure limit (PEL) were analyzed using logistic regression models. RESULTS The distribution of lead exposure levels declined over the study time period for general industry, but not for construction. The median exposure levels for general industry facilities decreased five- to tenfold. Logistic regression models reveal statistically significant declines in the odds of a lead exposure exceeding the PEL. CONCLUSIONS This study provides evidence for relatively large decreases in lead exposure levels in general industry facilities over time. The study does not provide similar evidence for the construction industry. Given the limited number of years of data available since the implementation of the revised construction standard for lead, re-analysis of lead exposure levels within this industry would be worthwhile when more data become available.