Estimating rice intake rate from average daily cadmium dose associated with urinary cadmium of cadmium contaminated area in Northwestern Thailand.
Published online November 30, 1999
© 1999 .

Aroon La-Up 1, 4, Phongtape Wiwatanadate 1*, Sakda Pruenglampoo 2, Sureeporn Uthaikhup 3

1Department of Community Medicine, Faculty of Medicine, Chiang Mai University, 2Research Institute for Health Sciences, Chiang Mai University, 3Department of Physical Therapy, Faculty of Associated Medical Sciences, Chiang Mai University
Received: March 20, 2017; Revised: June 7, 2017
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
This study investigates the dose-response relationship between average daily cadmium dose (ADCD) in rice and the occurrence of urinary cadmium (U-Cd) in individuals eating that rice. This was a retrospective cohort study. The study was designed to compare the populations in two areas which different in terms of cadmium contamination. Five hundred and sixty-seven participants aged 18 and above were interviewed to estimate their rice intake and assessed for U-Cd. Rice consumption source was sampled for cadmium measurement, from which the ADCD was estimated. Binary logistic regression was used to examine the association between ADCD and U-Cd. A relationship was established between ADCD and U-Cd was found to exist. The lowest estimate was ADCD = 0.5 ug/kg bw/day [odds ratio (OR) = 1.71; with a 95% confidence interval (CI) 1.02– 2.87]. By comparison, the relationship in contaminated area is expressed by ADCD = 0.7 ug/kg bw/day, OR = 1.84; [95% CI, 1.06 – 3.19] while no relationship was found in otherwise area, meaning that the highest level is ADCD = 0.6 µg/kg bw/day [95% CI, 0.99 – 2.95] for the no relationship to prevail. Rice, as a main dietary staple, is the most likely source of dietary cadmium intake. The abstention or limitation of rice consumption, therefore, will increase the chance of keeping U-Cd at the level not exceeding the standard. As the recommended maximum ADCD is not to exceed 0.6 µg/kg bw/day, the consumption of rice grown in cadmium contaminated area should not be more than 246.8 g/day. However, the exclusion of many edible plants grown well in contaminated area from the analysis might results in an estimated ADCD that does not reflect the true level of cadmium exposure among local people.
Keywords : dose-response, average daily cadmium dose, urinary cadmium, binary logistic regression