HITEA: "Health Effects of Indoor Pollutants: Integrating microbial, toxicological and epidemiological approaches"

Indoor air pollution in public buildings is an emerging issue. Respiratory
health of children may be affected by exposure to chemical and biological
agents in the indoor environment. Studies in other European countries have
shown that allergy and asthma at school age may be associated with exposure to
microbial agents, allergens and irritants from swimming pools. These factors
have not been studied in Dutch school age children extensively and insight in
school air quality from larger scale studies is completely lacking. Some
smaller scale studies have indicated that school air quality by measurement of
CO2 levels also is an issue in Dutch schools because of modern building
technologies and choice of building sites near busy traffic areas. However,
information about levels on respiratory hazards including microbial exposure,
allergens and irritants is lacking.

The overall aim of the study is to identify the role of indoor biological and
chemical agents that lead to respiratory, inflammatory and allergic health
impacts in school aged 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. As some
important aspects are difficult to study among children (e.g., nasal lavage,
breath condensate sampling), adults with similar exposures are also included.
The four essential issues are: the extent of the dampness problem in schools,
detailed characterization of the exposure to indoor school and pool
environment, measurement of the health effects during and without the exposure
(after summer holidays), and clarification of the mechanisms of the health
effects.

Six schools in the region of Utrecht will be selected, representing moisture
damaged (n=4) and control schools (n=2). Lung function measurements and blood
will be taken from all pupils aged between 6 and 12 (baseline survey; t=0). The
goal is to include 1500 students for health measurements. Parents-administered
questionnaires will be distributed among the pupils.
Pupils with symptoms highly suggestive of asthma (based on history of asthma,
recent symptoms treatment and lung function) will be identified. A randomly
selected sub-sample of these children (n=180; 6 schools x 30 pupils) will be
considered for the longitudinal part of the HITEA study. In these children,
lung function and exhaled NO will be determined an additional 3 times (at the
end of term [t=1], after summer holidays [t=2], and at the end of the following
fall term [t=3]).
The teachers* health will also be assessed in the longitudinal study. At three
moments in time ([t=1], [t=2], [t=3]) respiratory health will determined in 60
teachers (6 schools x 10 teachers) by spirometry tests, a symptom
questionnaire, measuring exhaled NO, assessment of inflammatory markers in
nasal lavage fluid and exhaled breath condensate, and measurements of specific
sensitization in peripheral blood (serum) samples (only at t=1).

This is an observational study and participants will not be experimentally
exposed to agent concentrations. Only current exposure to concentrations in
indoor air of the daily environments will be registered, so no health risks due
to exposure will be present. Increased insight in the air quality can help to
improve the understanding of possible measures that are needed to improve the
air quality.
The health risks of lung function testing, blood sampling, measuring exhaled NO
and measuring exhaled condensed breath and nasal lavage are negligible.
Therefore, additional insurance for subjects participating in the study is not
needed. Each health measurement session wil take about 5-10 minutes in
children, and a maximum of 30 minutes in teachers. So the tests will take 5-10
minutes time from 1320 children, 20-40 minutes time (4x 5-10 minutes repeated
measurements) from 180 children, and 3x 30 minutes=1.5 hour time from the
teachers. Completing the questionnaire will take about 10 to 15 minutes.