Hair zinc of young children from rural and urban areas in North Rhine-Westphalia, Federal Republic of Germany

Abstract

Hair zinc levels were estimated by atomic absorption spectrophotometry in 474 children, aged 3-7 years, from 11 kindergartens in a highly industrialized and polluted area (Duisburg) and 8 kindergartens in a rural area of North Rhine-Westphalia. The mean hair zinc level amounted to 118 micrograms/g, increasing between the 4th and 7th year of life. At all ages the values from the urban toddlers were lower than from rural toddlers, and in both regions they were higher in winter than in summer. Children with frequent upper respiratory tract infections (greater than 6 infections/year) showed significantly lower zinc hair values, independent of their age. Low hair zinc values (below 70 micrograms/g) were frequently found, raising the question as to whether this is a normal, age-related phenomenon, or whether it indicates a suboptimal zinc status of young children from North Rhine-Westphalia.

Associations of Socio-demographic and Behavioral Variables with Hair Zinc of Vancouver Preschoolers

“…The study findings indicated that the average hair zinc in this population, together with the occurrence of low hair zinc (<70 μg/g), were comparable to the only available report for a smaller group of apparently healthy Canadian preschoolers [3], as well as with reports on children of other industrialized societies [20,21]. Among our study participants, we observed that the two sexes had comparable mean hair zinc, while girls had a significantly higher occurrence of low hair zinc.…”

“…Among our study participants, we observed that the two sexes had comparable mean hair zinc, while girls had a significantly higher occurrence of low hair zinc. We could not explain this finding given that the majority of evidence in the zinc literature suggests male children are more vulnerable to low hair zinc [3,21] and show a better response to zinc supplementation [22][23][24][25][26]. We have discussed the relationship between hair zinc in our sample and gender and age elsewhere [5].…”

Age-Based Differences in Hair Zinc of Vancouver Preschoolers

“…The study findings indicated that the average hair zinc in this population was comparable to previous reports for Canadian [5,6], American [19] and other industrialized societies' [20] children. The rate of low hair zinc (17%) in our study was also comparable with 16% reported for a group of preschoolers from Eastern Canada [5].…”

Zinc

“…In infants, the plasma level decreases to less than half of the birth level during the first 3 months of life, rising rapidly from the third to the sixth month, then slowly up to an age of 3 years to the level at adults. In preschool children, zinc in the hair increased significantly from 98 to 137 mg kg À1 with age (3 -7 years) (Lombeck et al 1988). …”