Particulate matter, fungal spores linked with poor airway responses in schoolchildren

Chen B. Pediatrics. 2011;127:e690-e698.

Schoolchildren who are exposed to particulate matter and fungal spores are at higher risk of having airway dysfunction, according to a study published online.

Bing-Yu Chen, MS, and colleagues of the National Taiwan University recruited 100 elementary- and middle-school students in Taipei County, Taiwan, and asked them to complete a respiratory health questionnaire, followed by monthly spirometry. The researchers monitored air pollutants and measured fungal spores from each week that lung-function measurements were taken.

On the days after air pollutant readings registered particulate matter with an aerodynamic diameter of 2.5 mcm or less, lung function measurements were typically worse. The researchers said the “fungal spore level was negatively associated with both forced expiratory vital capacity and forced expiratory volume in 1 second (FEV₁). O₃ level was negatively associated with forced expiratory flow at 25%, 50% and 75% of forced vital capacity, and average expiratory flow over the middle half of forced vital capacity.”

The researchers said in other studies, particulate matter has been linked with tissue inflammation and cell death.

“It is believed that the smaller the size of particulate matter, the higher the toxicity through mechanisms of oxidative stress and inflammation,” they wrote.

The researchers said there were some study limitations, specifically that they did not document time-activity for each child relative to how much they spent indoors or out, particularly on high air pollution days. However, this would likely “cause a bias toward observing less pollutant effects if the children chose to stay indoors when the air pollution levels were higher. In any case, it was unlikely that the observed effects were overestimated.”

Pollen levels were not measured, so “the potential confounding effects of pollen on the observed lung function effects caused by air pollutants and fungal spores could not be totally ruled out,” they said. However, the “main effects of pollen would have been obstructive ventilator defects of the lung and not the restrictive pattern we observed to be associated with air pollutants and fungal spores.”

Disclosure: The researchers report no relevant financial disclosures.

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