Pollen

Trigger Description and What you can do

Pollen may also be a trigger for respiratory conditions.

What you can do:

Stay inside with the windows closed on high pollen days, if possible.

Use your air conditioner to help filter the air coming into the home. Central air systems are the best.

Remove indoor plants if they irritate or produce symptoms for you or your family.

Pollen
http://www.epa.gov/asthma/pollen.html