Non specific environmental factors and asthma development.

Environmental pollutants seem to be responsible for dramatical increase of allergic disorders that have been observed lately. The best documented environmental factors facilitating allergy development are: ozone, diesel-exhaust particulate matter and tobacco smoke. Formaldehyde and SO2 seem to be also very important but still are not sufficiently documented. Mechanisms involved in allergy promotion include: better penetration of allergens across respiratory mucosa or direct modulation of immunological response.