Elevated hair levels of cadmium and lead in school children exposed to smoking and in highways near schools Tülin Ayşe Özden a, ⁎ , Gülbin Gökçay a , Hayriye Vehid Ertem a , Özlem Durmaz Süoğlu a , AyşeKılıç a , Semra Sökücü b , Günay Saner a a Institute of Child Health, Istanbul University, Çapa 34093, Istanbul, Turkey b Department of Child Health, Istanbul University, Istanbul Medical Faculty, Çapa 34093, Turkey Received 9 June 2006; received in revised form 25 July 2006; accepted 27 July 2006 Available online 12 August 2006 Abstract Objectives: Heavy metal pollution has become a serious health concern in recent years. Cadmium (Cd) and Lead (Pb) are toxic heavy metals. This study was aimed to determine the risk factors for high cadmium and lead levels in school children. Design and methods: The scalp hair samples were obtained from 760 children at 13 schools in Istanbul. A questionnaire was prepared to gather information about demographic and socioeconomic characteristics of the children. Hair cadmium and lead concentrations were determined by atomic absorption spectrophotometer. Results: Household exposure to smoking and attending a school near to Main Streets were found to be the most important risk factors for the high hair cadmium and lead levels in our study. Conclusion: These findings support the public health recommendations that children should not have household exposure to smoking, schools should not be near to the main streets and unleaded gasoline use should be promoted. © 2006 The Canadian Society of Clinical Chemists. All rights reserved. Keywords: Toxic metals; Cadmium; Lead; Environmental exposure; School children; Hair analysis; Smoking Introduction Heavy metal pollution has become a serious health concern in recent years. Cadmium (Cd) and lead (Pb) are toxic heavy metals. Continuous exposure to low levels of these toxic heavy metals may result in bioaccumulation and can cause a wide variety of biological effects on human beings depending upon the level and the duration of exposure [1,2]. Long-term, low- level exposure to cadmium will result in accumulation in liver and kidneys, the main storage organ to cadmium [3]. Several studies have suggested that even low levels of lead exposure may cause adverse impacts on cognitive functioning [4,5]. These metals can be found in the work place, drinking water, in food, consumer products, enamel utensils and traditional medicines [6,7]. These metals enter the human body mainly after inhalation and also via gastrointestinal absorption. Inhalation is the second major means of cadmium and lead absorption for children [6– 9]. The strength of the problem depends on the body dimensions of the child. In addition, children absorb greater percentage of ingested lead than adults [9]. Many authors have reported that human hair is a good indicator of environmental pollution. Therefore using scalp hair as an indicator of the environmental exposure to several trace elements has become a common method [10–12]. However, there is no definite result about the significance of Cd in hair as an index of exposure [13]. With the increasing importance of these metals in clinical medicine, reference ranges of these metals in biological samples are needed as tools for diagnosis. However, trace element concentrations in biological samples are affected by environ- mental and geographical factors. Therefore, considerable variations can occur between specific subgroups of the populations [2]. Clinical Biochemistry 40 (2007) 52 – 56 ⁎ Corresponding author. Fax: +90 212 631 39 97. E-mail address: tulozden@istanbul.edu.tr (T.A. Özden). 0009-9120/$ - see front matter © 2006 The Canadian Society of Clinical Chemists. All rights reserved. doi:10.1016/j.clinbiochem.2006.07.006