The association between blood lead levels and cardiovascular diseases among lead-exposed male workers.

Objective We prospectively evaluated the association between blood lead levels (BLL) and increases in hospital admissions for treatment of cardiovascular diseases among lead-exposed workers in Korea. Methods The study cohort was derived from Korea Occupational Safety and Health Agency data, which included lead-exposed male workers who underwent lead-associated medical check-ups at least once between 2000 and 2004. The adjusted hospital admission hazard ratio (AHR) of cardiovascular diseases for each BLL grade (10-20 and ≥20 μg/dL) was compared with that of the reference grade (<10 μg/dL) using Cox's proportional hazard models. The adjusted variables included age and exposure to other metals. Results AHR of ischemic heart disease [IHD; AHR 1.78, 95% confidence interval (95% CI) 1.17-2.72], angina pectoris (AHR 1.93, 95% CI 1.13-3.29) and cerebral infarction (AHR 2.24, 95% CI 1.14-4.39) were significantly higher among workers with a BLL ≥20 μg/dL than those with a BLL ≤10 μg/dL. The AHR (1.52, 95% CI 1.00-2.31) for cerebrovascular disease was significantly higher among workers with a BLL 10-20 μg/dL than those with a BLL ≤10 μg/dL. IHD, cerebrovascular disease, angina pectoris and cerebral infarction all showed a positive linear relationship with BLL. Conclusions Although we were unable to control for other major risk factors such as smoking, socioeconomic status, and antihypertensive medication, we found an association between BLL and increased hospital admission for IHD, cerebrovascular disease, angina pectoris and cerebral infarction treatment. The BLL standard should be lowered to prevent the cardiovascular effects of lead exposure.