Concentrations of lead in blood, hair and saliva of German children living in three different areas of traffic density

Lead contents in hair, whole blood and saliva were determined for 245 healthy children (121 male, 124 female, age: 8–10 years) from three residential areas of Düsseldorf (North-Rhine-Westphalia, Germany) with different traffic densities. The geometric mean for the lead content in hair was found to be 0.87 μg/g (range: 0.2–9.9 μg/g) for the entire test group. While the levels of lead in hair in the suburban population were significantly lower than in the two city centre populations, no significant difference concerning the lead content in hair could be detected in the latter. The geometric mean for lead concentration in whole blood amounted to 25.0 μg/l (range: 8.0–154 μg/l). There was no significant difference between the sub-groups. The lead concentrations found in saliva were rather low (range: <1.5–47.0 μg/l). Of the values, 89% were below the detection limit of 1.5 μg/l. Due to reduced levels of lead in fuel, the present study exposes that the amount of lead in the children examined has further decreased compared to preceding surveys. The correlation between the lead content in hair and the road traffic density was not corroborated by the findings with regard to amounts of lead found in blood, indicating that residual lead from fuel does not result in a substantial burden of lead found in the whole body. In contrast to levels of lead found in blood, levels of lead found in hair may be influenced more by environmental conditions. Saliva is not a suitable material for biological monitoring with respect to lead exposure in children.