In this study, the reference level of cadmium in urine and blood related with bone damage was assessed using benchmark dose in a Chinese female population. Total of 338 women was recruited, and urine and blood samples were collected from each individual for determination of cadmium in urine (UCd) and blood (BCd). Bone mineral density was measured by dual energy X-ray absorptiometry. BMD and BMDL were calculated corresponding to additional risk of 5% and 10%. With benchmark response (BMR) of 5%/10%, the BMD of BCd, UCd related with osteoporosis was 1.88 mu g/L/3.23 mu g/L and 5.30 mu g/g crea/9.06 mu g/g crea, and the BMDL-05 was 1.39 mu g/L/2.38 mu g/L and 3.78 mu g/g crea/6.36 mu g/g crea; the BMD of BCd, UCd related with low bone mass was 0.95 mu g/L/3.12 mu g/L and 3.12 mu g/g crea/5.87 mu g/g crea, and the BMDL-05 was 0.72 mu g/L/1.35 mu g/L and 2.14 mu g/g crea/3.99 mu g/g crea. The BMD of UCd in people over 60 years old was much lower than that of people less than 60 years old. BMD value was related with ages and effects biomarkers. Our data showed that BMD of UCd associated with osteoporosis was lower than that previously estimated. (C) 2013 Elsevier Ltd. All rights reserved.