The overall aim of the HITEA study is to identify the role of indoor biological agents in development of long term respiratory, inflammatory and allergic health impacts among children. The focus is on microbial exposures due to dampness problems of buildings; in addition, the role of allergens, chemicals, cleaning agents, traffic exhaust and poor ventilation will be studied. The study includes a cross-sectional and a longitudinal study in school buildings in three European countries as well as new analyses of already existing birth cohorts. Since some important aspects are difficult to study among children (e.g., invasive sampling), an adult cohort with similar exposures is also included.

Microbiological, toxicological, analytical and immunological techniques will be used to study the exposures and their short term and long term impacts on health and the mechanisms behind. Data on determinants of the variation of indoor microbial agents across Europe will be provided. Emphasis is on respiratory health and on cytotoxicity, inflammatory and oxidative stress related mechanisms of the health effects.