The blood lead level was measured with 23 workers at the assembly section before occupational health education and with 26 workers 2 months after occupational health education. It was performed under NIOSH 80033). Blood sampling was conducted by trained examiners. Samples were analyzed at the Department of Occupational Health Laboratory, Ministry of Public Health, Thailand. To minimized measurement errors, we selected the same laboratory that we had asked to analyze the blood samples since 1998.