The objectives of the present study are to examine if there exists a quantitative relationship between lead in urine (Pb-U) and that in blood (Pb-B), and also between cadmium in urine (Cd-U) and that in blood (Cd-B) among the general populations who are environmentally (and not occupationally) exposed to these elements at various levels. For this purpose, peripheral blood and morning spot urine samples were collected in 1991-1998 from approximately 50 non-smoking adult women each in four cities in south-east Asia and five cities in mainland China, and two cities each in Japan and Korea. The samples were wet-ashed and then analyzed by inductively-coupled plasma mass spectrometry for Pb-B, Cd-B, Pb-U and Cd-U. Measured values were subjected to analysis to detect possible correlation between the pairs of parameters. A significant correlation between Pb-B and Pb-U was observed when the intensity of Pb exposure (as expressed by Pb-B) was relatively high so that the correlation was significant in all cases studied when Pb-B level was, e.g. 50 microg/l or above. It was also observed that the correlation between Cd-B and Cd-U was significant when Cd-B was, e.g. > 1 microg/l. Thus, it is possible to deduce that, in environmental health, Pb-B and Cd-U levels can be estimated on a group basis from Pb-U and Cd-B, respectively, when Pb and Cd exposure levels are relatively high, e.g. with Pb-B and Cd-B of > 50 microg/l and > 1 microg/l.