Cigarette smoke is a major source of indoor pollution. Active and secondary smoke increases the risk of developing asthma. Children of mothers who smoke have a higher incidence of wheezing illnesses. This effect worsens with more years of exposure.
   
Perfume is an indoor pollutant that can irritate already inflamed airways in patients with allergies or asthma and should be avoided whenever possible.

Formaldehyde is a surprisingly common chemical used in plywood and carpet adhesives, paints and even some purfumes.  The allergenic chemicals are released through offgassing.