Quality assurance in the biological monitoring of lead exposure in China.

Based on the statistical data of the nationwide occupational diseases reporting in 1986-1988, lead poisoning stood the first place of chronic occupational poisonings in China. Biological monitoring of lead exposure is of paramount importance in both occupational and environmental health. In order to ensure lead testing data valid enough for taking actions of prevention and control, a quality assurance scheme including selection of reliable analytical techniques, establishing reference laboratory, application of standard reference materials, and conducting internal and external quality control program was implemented in China. Since the rigid assurance procedure was conducted during studies on "background levels of lead in non-exposure population" and "revision of the diagnostic criteria for lead", compatible and reliable results were obtained.