Blood lead in hemodialysis patients

Blood lead corrected for hematocrit (PbC) was measured in 115 hemodialysis (HD) patients. Information was collected with a questionnaire about personal and environmental factors thought to influence blood Pb levels. HD patients had significantly higher mean blood Pb than healthy subjects (p < 0.001). A non-negligible percentage of the HD population (13%) had values over 30 micrograms/dl, the threshold for risk in occupational exposure, and 4% over 40 micrograms/dl which reflects Pb intoxication. No association was found between sex, age, duration of HD and PbC. The prevalence of high diastolic blood pressure was associated with PbC over 30 micrograms/dl (p < 0.01). Also, at blood Pb levels generally considered as 'nontoxic' (less than 40 micrograms/dl), we found a low correlation with diastolic blood pressure (r = 0.19, p = 0.049). A correlation was found between PbC and parathyroid hormone (r = 0.22, p = 0.01) and between PbC and mean corpuscular volume (r = -0.21, p = 0.02). The patients with individual risk factors (smoke, alcohol consumption and alkyl Pb from air contamination) had PbC levels higher than patients without (p = 0.001). The patients with environmental risk factors (professional exposure, tap water consumption and older houses) had PbC levels higher than patients without (p = 0.01). Patients with past occupational exposure had the highest mean PbC levels (34.1 micrograms/dl = 1.65 nM/ml).