Abstracts: ISEE 21st Annual Conference, Dublin, Ireland, August 25–29, 2009: Symposium Abstracts: Symposia Presentations
In 2007 Ministry of Environment established a contract with the Institute of Health Carlos III to start the first National Human Biomonitoring program with focus on persistent organic pollutants (POPs) and Heavy Metals. The study started in 2009 and was established in collaboration to medical examination centers across the spanish peninsula Study participants were selected through a stratified cluster sampling. Strata were defined according to 11 geographical areas: Northwest 1 (Galicia), Northwest 2 (Asturias, Cantabria), Northeast 1 (Basque Country), Northeast 2 (Navarre, La Rioja, Aragon), Central 1 (Castile and Leon), Central 2 (Madrid), Central 3 (Castile-La Mancha, Extremadura), East 1 (Catalonia), East 2 (Valencian Community), South 1 (Andalusia), and South 2 (Murcia). A total of 36 physical examination centers were selected across these strata following a compromise allocation: a minimum of 2 examination centers within each geographical area, with the remaining 14 centers being distributed proportionally to the working population in each area according to the Spanish Active Population Survey 2007. Also, to ensure a proper seasonal distribution the 36 selected centers were assigned to 4 recruitment periods: January–March, April–June, July–September, and October–December 2009.
Firstly, the corresponding centers within each geographical area were randomly selected with probability proportional to its size (annual number of physical examinations).
At a second stage, 25 workers of service sector (10 men and 15 women) and 25 workers of other economic sectors - agriculture, industry, or construction - (15 men and 10 women) were sampled within each selected examination center. Participants were consecutively selected within the recruitment period randomly assigned to each center.
The overall sample comprised 1800 participants. Small geographical areas, non-service economic sectors, and women were over-sampled in order to improve precision in these subgroups. The presentation will give an overview of the aims, plans and advances achieved under this program.