Common Plant Triggers Asthma

Different types of airborne pollens can trigger asthma problems. A new study finds two common European plant pollens trigger more emergency hospital admissions than average.
The research was conducted from 1995 to 1998 in Madrid. During this time, researchers tracked all hospital admissions for respiratory illnesses. They also collected data on pollen levels from trees and plants from 10 monitoring stations and information on air pollutants, temperature and humidity levels. They compared this data with the hospital admissions.

The study reports there were close to 5,000 emergency admissions and half involved children. They found, at times, the emergency admissions rose but did not reach epidemic levels. They also found heavy rains tended to lessen the amount of circulating pollen. Researchers note in the last two weeks of May 1996 and the first two weeks of June 1998, there were dramatic surges in emergency admissions. They found these two times coincided with the release of high levels of pollen from the two plants, Plantago and Poeceae. Both of these plants are found throughout Europe.

The study found for the Poeceae plant, the emergency admission happened about three days after the high levels were recorded and two days later than high levels of the Plantago plant were recorded. Study authors say this type of time lag is consistent with the biology of allergens. They also say this surge of respiratory problems was not associated with the amount of air pollutants.

Study authors conclude there is a marked relationship with two popular plant pollens and their implication in the high levels of asthma emergencies during their release into the environment.