Lead levels in urine of never-smoking adult women in non-polluted areas in Japan, with references to cadmium levels in urine.

The present study was initiated to assess current level of general population exposure to lead (Pb) in terms of Pb in urine (Pb-U). For this purpose, spot urine samples were collected from 2,332 never-smoking adult women in 10 areas all-over Japan, and were subjected to analysis for Pb-U by graphite furnace atomic absorption (GFAA). Data on cadmium in urine (Cd-U) as measured by GFAA were cited from a previous publication). The grand geometric means (GM) for Pb-U as observed, as corrected for creatinine (cr) and as corrected for a specific gravity of 1.016 were 1.06 microg/l, 1.28 microg/g cr and 1.14 microg/l, respectively, with small intra- and inter-variations with geometric standard deviations of about 2 or less. Arithmetic means of the 10 GMs (one each for the 10 areas) were 1.05 microg/l, 1.19 microg/g cr and 1.18 microg/l, respectively. The levels observed appeared to be lower than levels reported for other populations in the world. Chronological comparison within Japan suggested a gradual decrease in Pb-U in past over 20 yr. No close correlation was detected between Pb-U and Cd-U.