Effects of Anticoagulants and Duration of Storage on Blood Lead Levels

Abstract

To explore the influence of different blood sample collecting tubes and the length of storage times on the measurement of blood lead levels (BLLs). Methods: A total of 57 blood specimens were collected from 47 lead-exposed workers and 10 workers not exposed to lead. For each subject, 8 blood samples were drawn with tubes containing different anticoagulants. All specimens were kept in a freezer at a temperature of 4℃ until analyzed. By treating tubes containing lead-free sodium heparin as the reference group, the effects of container types and storage times were analyzed by the generalized estimating equation (GEE) model. Results: For subjects with high BLLs, the blood lead measurements obtained from the blood sample tubes containing the other 7 types of anticoagulants were lower than those of the reference group. Among blood samples from both the high BLL and low BLL groups, higher BLLs existed in tubes containing the anticoagulants, Na2 EDTA and K3 EDTA. On average, the BLLs from tubes using the anticoagulants, buffered Cit, Na 9:1, and Cit, and Na-0.129M Silic were lower than those in the reference group by 1.616μg/dL and 3.182μg/dL, respectively. No significant differences existed in the blood lead concentrations obtained from the blood samples stored in a 4℃ environment and in different types of blood containers for 12 months, whether from the high BLL or the low BLL groups. Conclusions: When collecting blood samples for high BLL analyses, the two anticoagulants (i.e, buffered Cit, Na 9:1, and Cit, and Na-0.129M Silic) are not recommended. However, blood lead concentrations remain stable, even when blood samples have been stored for a period of 12 months.