2017 年 28 巻 1 号 p. 18-27
Objectives: Cadmium (Cd) and lead (Pb) are two toxic environmental pollutants. As foods are leading sources for Cd and Pb, concerns persist on health of people, particularly, children. This survey was initiated in 2004-5, i.e., early this century to investigate dietary Cd and Pb intakes (Cd-D and Pb-D) of children in China.
Methods: Children studied were in kindergartens in Beijing, 2 provincial capitals and 2 rural villages. Guardians of 167 children (5 to 6 years-old) in 8 kindergartens offered 24-hours food duplicate samples. Cd and Pb were analyzed by ICP-MS. The results were expressed in terms of geometric means (GMs) after correction for body weight (BW).
Results and Discussion: Children consumed 1542 g of foods/day on an average. GMs for Cd-D and Pb-D in total 167 samples were 0.54 and 0.64 μg/kg BW/day, respectively. Both Cd-D and Pb-D were significantly (p<0.05) higher in rural areas than in urban areas. Comparison with JECFA-established PTMI (provisional tolerable monthly intake) for Cd-D (25 μg/kg/month, or about 0.83 μg/kg BW/day when calculated for a daily basis) and PTWI (provisional tolerable weekly intake) for Pb-D (25μg/kg BW/week, or about 3.57μg/kg BW/day) disclosed that the observed Cd-D and Pb-D accounted for 65 and 18% of tolerable intakes, respectively.
Conclusions: The observed dietary Cd intake was about 2/3 of the tolerable limit, which suggests that the safety margin was rather narrow. The value for Pb intake was well below 20% of the tolerable limit, suggesting a wide margin of safety.
