Effect of environmental lead pollution on blood lead levels in traffic police constables in Islamabad, Pakistan.

OBJECTIVE To determine the blood lead levels and trace elements (copper and manganese) in traffic police constables in Islamabad in order to assess the effects of environmental pollution on the levels of metals in body fluids. METHODS Blood samples were collected from 47 male traffic police constables, 21 to 45 years of age, posted in different areas of Islamabad and controlling traffic from 3 months to 18 years, 8 hours/day, 6 days/week. Adolescent males (13-19 years), residing in comparatively clean and very low traffic areas were included as controls. Blood lead, copper, and manganese concentrations were estimated by atomic absorption spectrophotometry. RESULTS The mean blood lead level among constables (27.27 microg/dl) was significantly (p<0.0001) high as compared to controls (3.22 microg/dl). Twenty one percent constables had elevated blood lead levels (over 25 microg/dl) and 13% had levels above the safety limit (40 microg/dl). No correlation was found between blood lead levels and length of service. No significant difference was found in the mean values for copper between traffic constables (93.49 microg/dl) and controls (71.15 microg/dl). The mean blood manganese levels in traffic constables (21.94 microg/dl) were significantly (p<0.0001) higher than in controls (1.70 microg/dl). The mean blood lead levels were significantly high in traffic constables of Karachi (47.7 microg/dl) as compared to Islamabad (27.2 microg/dl), which shows direct relation of rise in blood lead levels with vehicle exhaust. CONCLUSION Environmental lead pollution is associated with an increased blood lead concentration in those who are regularly exposed to vehicle exhaust in high traffic areas. The degree of lead pollution arising from vehicle exhaust differs in Karachi and Islamabad. Exposure to air containing dust particles rich in manganese may affect blood manganese levels.