Changes of lead levels in 24-h urine from 1985 to 1998 in Japanese adults

To determine whether current environmental lead (Pb) levels are causing any progressive changes in urinary Pb levels, 24-h urine samples were collecte d from 277 subjects (159 men and 118 women) in 1985, 312 subjects (155 men and 157 women) in 1993, and 311 subjects (156 men and 155 women) in 1998. A ll of the subjects worked in the same factory. The urinary Pb concentration was analyzed by flameless atomic absorption spectrophotometry. The geometr ic means for men were 4.74, 2.67 and 1.31 mu g/day; 3.17, 1.78 and 1.04 mu g/g creatinine; and 3.18, 1.99 and 0.98 mu g/l urine in 1985, 1993 and 1998 , respectively. The values for women were 3.22, 2.14 and 0.97 mu g/day; 3.3 5, 2.26 and 1.15 mu g/g creatinine; and 2.49, 1.86 and 0.83 mu g/l urine, r espectively. These results demonstrated that Pb levels in 24-h urine decrea sed significantly in the 13-year period (P < 0.01). (C) 2000 Elsevier Scien ce Ireland Ltd. All rights reserved.