Hair lead levels to evaluate the subclinical impact of lead on growth in Sardinian children (Italy)

Objectives: The aim of this study was to determine if there are significant relationships between lead concentrations in children’s hair and height, sitting height, and estimated leg length. Methods: We analyzed three samples collected at different times: 1998, 2002, 2007. The total sample consisted of 825 children between 11 and 14 years of age living in different municipalities of Sardinia (Italy). Inductively coupled plasma atomic emission spectrometry (1998), inductively coupled plasma atomic absorption spectrometry (2002), and inductively coupled mass spectrometry (2007) were used to measure the lead concentration in hair (PbH). Some AAS measurements were also performed on the 1998 and 2007 samples to check the reliability of the data. Results: The mean PbH is much higher in 1998 (5.84 lg/g) than in 2002 (1.49 lg/g) and 2007 (0.78 lg/g). Multivariate regression analysis of the three samples, controlling for age and sex, indicates a subclinical impact of lead on growth that differs according to the mean lead concentration in the hair. In fact, for 1998, the relationships between all three anthropometric variables and logPbH are significantly negative. For 2002, there are significant negative associations between height and estimated leg length and logPbH but not between sitting height and logPbH. For 2007, there are not significant associations between logPbH and anthropometric variables. Conclusions: Our results support the use of hair lead levels as a biomarker to assess the impact of subclinical lead on the physical growth of children, especially when the study area presents medium and/or high levels of lead pollution.