INAA to Determine Trace Element Concentrations in the Hair of Street Children of Isfahan City, Iran ()
1. Introduction
Approximately ten million children around the world are homeless and 150 million spend much of their time on the streets [1]. Living in street, exposure to the smoke of cars and lack of family and social supports can remarkably affect the health of these children and the society [2, 3]. So far, almost all reports in Iran come from subjects of drugs, poverty, sexual and physical abuse and little information on body health is available, then in this research we focus on this matter.
However, although there are studies which focus on the health status of street children in a specific area of the world [4,5], to date, few studies actually investigate the trace element nutrition status of the street children. In fact, trace elements, as well as vitamins and minerals, play an important role in maintaining metabolic homeostasis in the future of them so it is needed to study the trace elements in order to prevent of many age-associated diseases [6].
The study advantages of biomonitoring of trace elements and organic pollutants using body tissues to investigate health and nutritional status of human have been proved [6-13]. Determination of trace element concentrations and their distribution in body tissues also can be a tool to assess the health status of them [6,14-19].
Unfortunately, up to now, no data for trace element concentrations in the hair of street children are available in the published literature. Within the context of the perspectives mentioned above, the aim of our study was to investigate trace element concentrations in the hair of healthy street children in Isfahan city, which is an industrial and big city in Iran, for providing a data base. So far, awareness especially concerns people living close to industrial sites or in geological areas characterized by anomalous enrichments in metal and metalloids, and also in urban areas affected by traffic-derived air pollution [20]. For this reason, the concentration of heavy metals is also studied on the street children of this area [21]. Simultaneously, body composition tests and 24 hours’ dietary recall and anthropometric measurements and the relation between these parameters and trace element were studied.
2. Material and Methods
The 17 children (5 boys and 12 girls), aged 6 - 15 are selected from the Isfahan city, which is a industrial region and has traffic contamination as it has just 25 clean days last year. Consent of the orphanage mentors was required for study participation. Interviews with their or phanage mentors indicated that all of the children were left in their houses and lived in the streets and none of them were receiving special education or related services for health issues. Also, 3 children (1 boy and 2 girls), aged 8 - 12, living with their family, are selected. Not only the subjects and their orphanage mentors were interviewed via questionnaire in order to identify and control variables affecting health issues (as the food 24 recall forms) but body composition analysis also has been done. Samples were washed according to the procedure recommended by the IAEA and about 100 mg samples were washed [22]. Seven biological standard reference materials, Peach Leaves NIST-1547, Bovine Liver NIST-1577b, Rice Flour NBS-1568a, Coal Fly Ash NIST 1633b, Pine Needles NIST-1575, Apple Leaves NIST-1515 and Trace Elements in Human Hair CRM-397 were chosen as quantity control SRM. Samples or standards were placed in a 5 × 5 cm2 polyethylene film that had been cleaned with C2H5OH with 70˚C temperature and deionized water.
The samples and standards were irradiated with thermal neutrons from a Miniature Neutron Source Reactor, Atomic Energy Organization of Iran. The irradiation, cooling and counting times for the first and second counting of radio activity measurements, and the determined isotopes for each cycle by comparative method are summarized in Table 1. Gamma ray spectra of the irradiated samples were obtained with a well type HPGE detector. This type of detectors was mainly used to minimize the geometry errors arising during gamma ray counting of the hair samples. The resolution of this detector was 2.0 keV for the 1332 keV peak of 60Co. The NAA software SPAN was used for the identification of the radionuclides and the calculation of their activities. The relative method was used to calculate element concentrations. The analytical results of the samples are in good agreement with the certified values.
Nutritional assessment was evaluated by measurement of height, weight and body mass index (BMI) calculation. Body weight was taken to the nearest 0.1 kg. Subjects were asked to be in light clothing, barefoot, standing straight up and looking at the front without any movement at the centre of scale. To measure height, a portable stadiometer was used, with the subjects standing upright, barefoot, legs straight with their heels close together, back straight and arms stretched along the body in Frankfurt horizontal level position. BMI was defined as weight (in kilograms) divided by the square of the height (in meters). Respondents were categorized into five groups: severe thinness, thinness, normal weight, overweight and obese by cut-off points for BMI-for-age [23]. Food intake was assessed using a 24-hour dietary recall. Portion size of food items was estimated based on the household measurements. Then, all were converted to gram based
Table 1. Neutron activation analysis conditions for human hair.
on Iranian food composition table [24,25] to inter in analysis software. Nutritionist IV software program version 3.5.2 was used since there was not any specific analysis software based on Iranian foods in order to analyze the energy and different macronutrients (carbohydrate, protein, fat) intake of the subjects. The energy requirement of patients was calculated using standard equation for each subject with activity factor 1.13 for boys and 1.16 for girls according to DRI [26]. The mean consumption of macronutrient was compared to DRI recommendation since there was no recommended nutrient intake available based on Iranian diet. All statistical analyses were done with the Statistical Package for the Social Sciences (SPSS), version 16.0. Data were utilized by descriptive statistics like mean and percentage. The mean and standard deviation were used to summarize some variables.
3. Result and Discussion
The most abundant chemical elements found (Table 2) were Br and Ti (Ti > Br), with concentrations average Br = 1.42 µg/g and Ti = 4.65 µg/g. Other elements with concentrations greater than 1 µg/g were, in order of abundance, V > La > Sb > Co > U > Hf > Th > Au (= Sc) > Sm. Also observed was the great variability of many elements, as shown by the coefficients of variation (CV) ranging from 31.9% (Sc) to 184.1% (Au). The calculated CVs reflect the intrinsic biological variability within the group of street children, together with variations due to lifestyle, and small-scale environmental factors [15]. Regression analysis did not reveal any highly significant relationship between variables. For example, just two elements Co-Sc and La-Sc have R-squared values greater than 0.6. Because Br is an essential element in our body, high concentration of Br in the hair samples is not related to the environmental effects [27]. The second abundance among trace elements is Ti. Hair is extremely susceptible to contamination with titanium from hair treatment products. However, titanium concentrations of individual human foods have not been reported.
The high concentration of As in street children compared to control group (in Figure 1) may be related to the use of contaminated water [28,29] or the smoking status during their lifestyle [30]. However, the average concen-
Table 2. Raw data for street children group with individual concentration in ng/g for detected trace elements.
Figure 1. Comparison of mean concentration of trace elements between street children and control group.
tration of As in the hair of street children in Isfahan is less than those in China, Gambodia, India, Italy, Nigeria and Malaysia [31-33] and is same compared to Japan and is greater than those in Canada, USA and Poland [32].
Vanadium content between control groups is greater compared to street children. Vanadium is commonly found in vegetables and seafood. Although for non-occupationally exposed individuals, the primary sources of these metals are food, drinking water and breathed air, according to their usual concentration sin ambient air, the most probable exposure pathways remain foodstuffs and water [20]. The content of cobalt in the street children is greater than control groups. Cobalt hair levels occasionally reflect external contamination from hair preparation products. Occupational or environmental exposures to cobalt dusts or chemicals may cause exogenous contamination. The mean concentration of La in street children was 120.3 ± 90.0 ng/g greater than that reported in the literature (11.0 ± 1.00 ng/g) [34].
Lanthanum is dumped in many different ways to the environment, mainly by petrol-producing industries. It may enter the environment when household equipment is thrown away. Then it accumulates in soils and water soils and eventually leads to increasing concentrations in humans, animals and soil particles. The concentrations of uranium in both street children and control groups are compared with those in the literatures [35,36]. The results show the concern of uranium for individual child is less than that maximum reported (180.0 ng/g and 170.0 ng/g respectively).
The summary of anthropometric data was shown in Table 3. The mean of anthropometric parameters for male subjects were 27 ± 6.9 kg (weight), 14.9 ± 1.3 kg/m2 (BMI), and 133.8 ± 13.3 cm (height). Female subjects had higher mean of weight (38.2 ± 13.7 kg), BMI (18.5 ± 4.9 kg/m2), height (142.7 ± 11.1 cm). Distribution of weight-for-height among subjects showed that 17.6% of all subjects were wasted (<3rd percentile) and 10.0% of all subjects were stunted (<3rd percentile). Obesity was seen only among 5.9% of subjects. According to weight-for-age relative to the WHO reference standard, 11.8% were underweight (<3rd percentile). Mean energy and macronutrients intake according to one-day food recall of male and female subjects were showed in Table 3. The mean intakes of energy and protein of male and female subjects were 1682 ± 129 kcal/day and 65.9 ± 8.4 g/day and 1484 ± 398 kcal/day and 38.7 ± 12.3 g/day, respectively. Comparison of the mean percentage intake of energy and protein of subjects with recommended of energy and protein according to reference values was done. Percentage achievements of energy for male and female subjects were 99.4% and 99.8%, meaning that subjects almost achieved their energy needs based on estimated energy requirement (EER). Protein intake of subjects achieved 100% of their protein needs based on DRI recommendation in both males (188.2%) and females (117.2%).
In this study, protein and energy intakes in both gender all most achieved reference value. The results were compared to the nutritional status and dietary adequacy of single homeless women and their children in Shelters [37] and the results were consistent. Moreover, our results were compared to the obtained results in Pakistan and Indonesia. The obtained results showed that 17.6% of street children were wasted and 10% were stunted while in Pakistan 12% were wasted and 20% were stunted, in Indonesia, 7% were wasted and 52% were stunted [4,38].
4. Conclusion
This study determined trace element concentrations in the hair of street children for the first time. Thirteen trace elements (As, Au, Br, Co, Hf, La, Sb, Sc, Sm, Th, Ti, U and V) in the hair of 17 healthy street children living in Isfahan, Iran were determined by neutron activation analysis method. The average values of these trace elements together with their respective ranges and coefficient variation values were presented and relevant comments
Table 3. The mean of anthropometric and food intake of street children.
on them were made. Bearing in mind that the street children spend most of their time in the street, they are influenced mostly by environmental situation. We hypothesized that these baseline data obtained from the healthy street children could be reliably used as monitors leading to better assessment of the health status in this social group.
5. Acknowledgements
The Authors thank the research fellows of the Laboratory of Activation Analysis, Isfahan Research and, Fuel Production Center, for their technical advice and State Welfare Organization in Isfahan city. We are also deeply grateful to engineer Farshad Majidi who actively took part in all stages of this work.
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