Reference value of macro elements of Mongolian children’s hair

Abstract

Background: Recently, international researchers have conducted a variety of studies on macro-element changes, including a number of recommendations on how to use macro-elements in prophylactic and therapeutic doses, how to fortify foods with bio-elements, and how to maintain balance in the body. There is currently no study to determine the average amount of macronutrients in the body of a Mongolian child. Compared to the other bio-indicators such as blood, nail, urine, and saliva, human hair has attractive advantages, such as finer stability, easy collection and transportation, convenient storage, and reflects long-time exposure to heavy metals and higher metal concentrations than in other bio-indicators. Aim: Children are more susceptible to environmental pollution than adults, whose organ systems are not fully developed. The amount of trace elements in children’s hair has not been studied in our country, so we are using this study. Objective: To study the content of some toxic elements in the children’s hair aged 8-17 in Ulaanbaatar city depending on anthropometry and some factors. Materials and Methods: A total of 538 (257 male and 281 female) healthy children aged 8 to 17 in Ulaanbaatar secondary schools participated in the study as part of the Science and Technology Foundation’s project called “reference for bio-element concentrations in Mongolian children’s body and detection of changes in its body”. The survey was conducted in 2018, using a cross-sectional model. Moreover, participants were interviewed, examined by a general practitioner (height, weight, blood pressure, pulse), hair samples were taken, and analyzed in the Geological Laboratory by ICP-MS (Induction-coupled plasma mass spectrometer). Results: Reference amounts of macronutrients in the body of Mongolian children expressed in 25 and 75 percentiles and medians (μg/g) Average and reference amounts of macronutrients: Ca-953 (707-1228), K-120 (76.74-239.71), Mg-118.5 (83.39-162.81), Na-417.18 (272-617.2), P-166.2 (106-212.78). By sex, Ca element was 138.96 μg/g higher in girls than boys, K -66.96 μg/g higher in boys, and Na-74.95 μg/g higher in girls(p <0.001). Conclusion: 1. The average level of toxic elements in the hair of children aged 8-17 years was determined. Average concentrations of lead, toxic elements and tin are higher than in some countries. The content of toxic elements in the hair of boys was higher than in girls. 2. Lead, aluminum, arsenic are negatively correlated to children’s age and height, and cadmium is positively correlated; Overweight and obese children had higher levels of cadmium, and underweight and thin children had higher levels of aluminum. There was a weak positive correlation between aluminum, arsenic, cadmium, and systolic pressure.