ULTRASONIC ASSESSMENT OF CALCANEUS IN INHABITANTS IN A CADMIUM-POLLUTED AREA

We used ultrasound (US) transmission to evaluate the speed of sound (S OS) and broadband ultrasonic attenuation (BUA) in the calcaneus in 17 male and 18 female inhabitants oi a Cd-polluted area and 23 men and 45 women living in a nonpolluted area. Significant decreases in SOS and stiffness (Stiff), which was an index empirically derived from SOS and BUA, were found in Cd-exposed women. To evaluate the usefulness of th e US measurements for detecting bone abnormality in Cd-exposed people, we examined the associations with the bone measurements of metacarpus by the previously used microdensitometry (MD) method and the grade of renal tubular damage due to Cd exposure. Bone density estimated by MD , Sigma GS/D, was significantly correlated with BUA, SOS, and Stiff in the Cd-exposed men and with BUA and Stiff in the Cd-exposed women. Fu rther, in the Cd-exposed women, the decreases in BUA and Stiff correla ted significantly with the increases in urinary beta(2)-microglobulin, while Sigma GS/D by the MD method did not. These results suggest that the measurement of the calcaneus using US is not only radiation free but also can be used as a tool for population surveys aiming to evalua te bone dam age in people, especially women, showing renal tubular dam age due to environmental Cd exposure.