Lead and Cadmium Exposure Assessment Using Biomarkers Collected from Children Living in an Industrial Complex Area in Korea

Children are particularly vulnerable to adverse health effects associated with heavy metal exposure. The goal of this study was to investigate the relationship between proximity to an industry complex and blood lead and urinary cadmium levels for children aged 7-13 who lived in Ulsan where a big petrochemical complex is located. We conducted a questionnaire survey to collect data including sociodemographics, daily habits, residential environment, etc. We also analyzed blood lead and urinary cadmium levels using Atomic Absorption Spectrometry (AAS). Data were analyzed using regression analysis. All statistical analyses were conducted with SAS software version 9.2. We calculated distance by using a Geographic Information System (ArcGIS version 10.0). The geometric mean blood lead level was 1.55 μg/dL (boys: 1.59 μg/dL, girls: 1.51 μg/dL), and the geometric mean urinary cadmium level was 0.51 μg/g creatinine (boys: 0.45 μg/g creatinine, girls: 0.58 μg/g creatinine). In the results of regression analyses, we found that urinary cadmium levels significantly decreased as distance between residence and industrial complex increased after adjusting for age, gender, income, passive smoking and the length of residence. This result was opposite to that for lead levels. Our observations support the hypothesis that urinary cadmium levels in children are related to their proximity to an industrial complex.