Blood and Urine Lead Levels in Adults Attending Harare Polyclinics

Abstract

Lead is a toxic environmental pollutant and exposure to it can produce serious adverse health effects in adults and children. There is no safe exposure to lead, however the CDC recommends adult blood lead level (BLL) of < 20μg/dl to be safe and <5 μg/dl for children. However evidence suggests subclinical toxicity at lower levels. In Harare, people are exposed to lead from exhaust fumes from leaded petrol, old leaching lead plumbing and flaking leaded paint. The main objective of the study was to evaluate the level of lead exposure of ordinary residents in Harare. The secondary objective was to determine if lead levels were affected by serum protein levels. Three urban areas were chosen for their potential of increased risk of environmental exposure. One rural area was chosen to act as a control. Water lead levels were also measured from the different study areas. The lead levels were measured using the inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Protein levels were determined using the Lowry method. The mean blood lead levels that were obtained for the urban areas were 0.80±0.69μg/dl and 0.96±0.98μg/dl for the rural clinic. The urine lead levels for the urban areas were 0.57±0.67 μg/dl and 0.51±0.13μg/dl for the rural clinic. The water lead levels from the different study populations were 1.1μg/dl for Mbare, 1.6μg/dl for Highfield, 0μg/dl for Goromonzi and 0.4μg/dl, for Mabvuku/Tafara respectively. The mean serum protein levels were 24.45±3.76g/l for the study population. The Pearson correlation coefficient for the serum protein levels and blood lead levels was 0.225 at a p-value of 0.124. The ordinary residents in Harare urban have minimal environmental exposure to lead. There was no significant correlation between serum protein levels and blood lead levels.