SchoolNurse.com:Air Pollution Affect on Students’ Immune Systems

The effect of air pollutants, especially indoor air pollutants, on children’s respiratory health has been demonstrated in many studies. Poor pulmonary function and increased respiratory symptoms are the results of such poor air. What is not well understood is the mechanism by which this occurs.

Looking at “immune system biomarkers” is a relatively new field of study. The human immune system reacts fairly quickly to environmental changes. Some researchers have begun to look at changes in the immune system to environmental problems as a predictor of those who are at greatest risk of exposure to the pollutants.

In six Hungarian cities, all students attending third-grade in 16 schools were studied with standardized parent questionnaires. Children whose home environment made them susceptible to indoor air pollutants (e.g., smoker at home, gas heating/cooking, recent home renovations, and asthma histories) were included in the study. Passive air monitors were placed in 33 homes in each of the six cities and measured the following pollutants: nitrogen dioxide, formaldehyde, benzene, xylene, and toluene. Blood samples were taken from children. Children with symptoms in these environments were compared to normal children in theses environments.

Numerous immune biomarkers were significantly elevated in sensitive children, as compared to children without symptoms. Several of the biomarkers that were high in the symptomatic children could be correlated to high concentrations of air pollutants in their home. The strongest and most significant associations were seen between high indoor nitrogen dioxide concentrations and increased white blood cell counts, monocytes, red blood cells and IgG and lower IgM levels. These findings suggest that the immune system plays a large role in how indoor air pollution at home causes respiratory symptoms in school age children.

Comment: This is interesting because it demonstrates that it is not simply the “irritation” of air pollution that is causing coughing and other respiratory problems. We may actually be changing children’s immune response by exposing them to these pollutants. To me this suggests that removing the pollution does not necessarily mean you have brought the child back to their original state. Perhaps exposure to pollution could have adverse effects that outlast the period of exposure. -- H.T.