Hair Zinc and Lead : Relationship to Nutrient Intake and Height and Body Weight in Korean Preschool Children

Park, Hyun Suh; Shin, Kyung Ok

Abstract

The objective was to evaluate the factors influencing on the growth of children aged 3 - 6 years by mini dietary assessment and anthropometric indices in 556 children and by analyzing mineral contents of hair from 273 children by inductively coupled plasma mass spectrometry (ICP-MS). The mean concentration of zinc (Zn) in hair was 68.9 +/- 31.1 ppm and the zinc level of 91% children was less than 60% of the reference value of 180 ppm. The mean content of lead (Pb) in hair was 1.76 +/- 1.20 ppm, but only 67% of 273 children was within the reference value of 2 ppm and the lead level of 33% of children was 2 - 4 times higher than the reference value. The level of Zn was negatively correlated with Pb content (r = -0.305, p < 0.01). Hair Zn content, regardless of age, was significantly positively correlated with height (r = 0.214) and body weight (r = 0.159). The height of 95.3% children was belonged to the normal range of 90 - 109.9% of standard value and the body weight of 49.8% children was in the range of 90 - 109.9% of standard value. However, 8.1% children was overweighted (110 - 119.9% of standard) and 9.4% children was obese (120 - 149.9% of standard) and 0.9% children was severe obese (> 150%) which resulted in total 10.3% obese. Contrary to our expectation 32.8% children was underweight (70 - 89.9% of standard) and 36% of the underweight children showed the low content of zinc (10 - 49 ppm) in hair. There was no significant correlation between dietary intake of Zn and hair Zn content. Hair Zn content was low even though children consumed greater than 75% of their requirement for zinc. Regardless of dietary intake of Zn, hair Zn level was rather negatively correlated to the content of Pb in hair. 38.8% children had an unbalanced diet which resulted in lower intake of calorie, Ca, Zn, vitamin B2 compared with those consuming variety of foods. Therefore, it would be needed that new approach for nutrition education to improve eating habit having the unbalanced diet in preschool children. It might be also suggested to develop new food products to complement the nutrients of Zn, Ca, Fe as snacks or dietary supplement for Korean preschool children.