Longitudinal analyses of blood-lead levels and risk factors for lead poisoning in healthy children under two years of age

This study aimed to determine the risk factors for lead poisoning of infants living in Istanbul. It was a longitudinal study conducted between March 1998 and September 2000 at the "Well-Child Unit" based at the Istanbul Medical School. During the study period, a total of 242 newborns were registered and 220 of them met the eligibility criteria. The families of 199 infants gave consent for this study. At the end of two years, 131 infants had completed the study. Blood samples were collected when the infants were aged 1, 6, 12, and 24 months. All samples were assessed using atomic absorption spectrophotometry. Blood-lead levels (BLL) increased with age. The maximum BLL was observed at 24 months. There was no infant with a BILL above 10 mug dL(-1) at one-month of age but this figure was exceeded for 0.5% of the cohort at 6 months, 1.1% at 12 months and 11.5% at 24 months. Children who were given herbal tea and exposed to tobacco smoke, lived in centrally heated homes, and whose fathers were manual workers had significantly higher BLL. The study identified herbal tea, exposure to dust, soil, paint and metal construction debris containing lead and living in an environment where people smoked as factors that put children under two years of age at increased risk of "elevated" BLL.