In 1992 a study was launched in Southern California, to measure the impact of poor air quality on the long term health of children living in areas with chronically high pollution levels. The Children’s Health Study assessed 550 children in twelve different areas, with over two-thirds of the children being enrolled in 4th grade at school. Children are more susceptible to exposure to air pollution because they spend considerable periods of time outdoors and they are likely to be more active, resulting in them breathing in polluted air in greater quantities.

In addition, because children’s bodies and especially the sensitive respiratory organs are still developing, exposure to polluted air carries even greater health risks than it does for adults.

For more than ten years, the health of the study group was monitored, together withluchtkwaliteit meten in huis measurements and monitoring of the air quality and pollution levels in the twelve regions were they resided. It represents the most detailed and comprehensive longitudinal child study to date, of the impact of air quality and pollution levels on the development and function of lung development in children. It also highlighted the connection between pollution and the development of bronchitis, asthma and acute respiratory conditions.

The twelve regions were specially selected because they presented differing pollution and air quality profiles. In particular, they provided a range of pollution patterns and levels in respect of four main pollutants: Ozone; NO2 (Nitrogen Dioxide); Acid Vapor (Acid Rain); and Particulate Pollution which is breathed deeply.

The study took detailed measurements of these four pollutant groups within each region throughout the entire period of the medical study. In addition, there were shorter, selected periods of pollution monitoring conducted in individual homes and schools throughout the study sample.

On the child health monitoring side, the children were assessed for lung function each spring. Parents received an annual questionnaire dealing with the respiratory condition of their children, including collecting information on symptoms and conditions, including excessive coughing, asthma and other respiratory conditions. In addition, parents were asked to assess factors such as the level of physical activity their children engaged in and environmental factors in the home, such as whether smoking in the home was permitted, the incidence of mold or pets within the home.