Monitoring lead in hair of children and adolescents of Alcalá de Henares, Spain. A study by gender and residential areas

In recent years there has been an increased interest from the European Union (EU) in the development of large Human Bio-monitoring (HBM) studies across Europe, especially biomonitoring toxic metals. In Spain, most studies using hair as a biomarker have been conducted to determine occupational or industrial exposures, and have involved adult populations. Few studies have involved adolescents and children, despite these groups being sensitive to environmental contamination and pollutants. Therefore, the objective of the present study was to determine the degree of lead exposure in children and adolescents residing in Alcalá de Henares, Spain. Lead poisoning is the number one toxicological threat in the environment. So, lead (Pb) was selected as it is a persistent environmental contaminant, is measureable and is also a neurotoxin that can affect brain development. The city of Alcalá de Henares was divided into four zones to determine the influence of residence area on Pb levels. A range of other variables including age and gender were also considered within the study. The study comprised 115 children (6–9 years old) and 96 adolescents (13–16 years old). There was a significant difference between the levels of Pb in the hair of adolescents, for different gender and area of residence (p < 0.001 and p < 0.01 respectively). There was no significant difference in the Pb levels in hair of children, for different gender or area of the city. The levels of Pb were significantly (p < 0.001) elevated in children compared to adolescents (1.48 vs. 0.70 μg/g), and there was a significant difference in Pb levels in male and female adolescent hair (0.53 vs. 0.77 μg/g) (p < 0.001). The association observed between areas of residence and the Pb level in hair of the adolescent group could be mainly attributed to dietary habits and/or socioeconomic status.