Low-level lead exposure among South Korean lead workers, and estimates of associated risk of cardiovascular diseases.

This study investigated the distribution of blood lead (PbB) levels, especially low levels, among Korean lead workers. The authors also estimated the potential effects of PbB on the blood pressure (BP) and cardiovascular diseases using models taken from the published meta-analyses. The PbB data from a total of 13,043 lead workers in 1217 companies throughout Korea were used. The geometric mean PbB level was 6.08 microg/dL (geometric standard deviation was 2.53), and 56.6% of the workers showed PbB levels greater than 5 microg/dL. Females accounted for 31.3% of all Korean lead workers in 2003. Considering two factors, such as PbB levels and the number of lead workers, the relatively important industry subclasses were identified as Manufacture of Accumulators; Manufacture of Other Electronic Valves, Tubes, Electronic Components n.e.c.; and Manufacture of Other Parts and Accessories for Motor Vehicles. The industrial processes of relative importance included battery assembly, acid treatment, and other soldering. Although uncertainties exist in the prediction model and associated model parameters, the authors attempted to estimate potential adverse health effects related to the lead exposure. It was estimated that 7383 South Korean lead workers might have increased blood pressure and the health risks due to the lead exposures in 2003. The highest estimated risk of BP increases due to lead exposures was expected in workers of industrial subclasses and processes, such as Other Basic Nonferrous Metal Industries and Maintenance. If the models in this study were applied to the South Korean population, the impact fractions for cardiac disease among lead workers would be estimated at 4.9-12.8 times those of the general population.